//===-- SelectionDAGBuilder.cpp - Selection-DAG building ------------------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This implements routines for translating from LLVM IR into SelectionDAG IR. // //===----------------------------------------------------------------------===// #include "SelectionDAGBuilder.h" #include "SDNodeDbgValue.h" #include "llvm/ADT/BitVector.h" #include "llvm/ADT/Optional.h" #include "llvm/ADT/SmallSet.h" #include "llvm/ADT/Statistic.h" #include "llvm/Analysis/AliasAnalysis.h" #include "llvm/Analysis/BranchProbabilityInfo.h" #include "llvm/Analysis/ConstantFolding.h" #include "llvm/Analysis/Loads.h" #include "llvm/Analysis/TargetLibraryInfo.h" #include "llvm/Analysis/ValueTracking.h" #include "llvm/Analysis/VectorUtils.h" #include "llvm/CodeGen/Analysis.h" #include "llvm/CodeGen/FastISel.h" #include "llvm/CodeGen/FunctionLoweringInfo.h" #include "llvm/CodeGen/GCMetadata.h" #include "llvm/CodeGen/GCStrategy.h" #include "llvm/CodeGen/MachineFrameInfo.h" #include "llvm/CodeGen/MachineFunction.h" #include "llvm/CodeGen/MachineInstrBuilder.h" #include "llvm/CodeGen/MachineJumpTableInfo.h" #include "llvm/CodeGen/MachineModuleInfo.h" #include "llvm/CodeGen/MachineRegisterInfo.h" #include "llvm/CodeGen/SelectionDAG.h" #include "llvm/CodeGen/SelectionDAGTargetInfo.h" #include "llvm/CodeGen/StackMaps.h" #include "llvm/CodeGen/WinEHFuncInfo.h" #include "llvm/IR/CallingConv.h" #include "llvm/IR/Constants.h" #include "llvm/IR/DataLayout.h" #include "llvm/IR/DebugInfo.h" #include "llvm/IR/DerivedTypes.h" #include "llvm/IR/Function.h" #include "llvm/IR/GetElementPtrTypeIterator.h" #include "llvm/IR/GlobalVariable.h" #include "llvm/IR/InlineAsm.h" #include "llvm/IR/Instructions.h" #include "llvm/IR/IntrinsicInst.h" #include "llvm/IR/Intrinsics.h" #include "llvm/IR/LLVMContext.h" #include "llvm/IR/Module.h" #include "llvm/IR/Statepoint.h" #include "llvm/MC/MCSymbol.h" #include "llvm/Support/CommandLine.h" #include "llvm/Support/Debug.h" #include "llvm/Support/ErrorHandling.h" #include "llvm/Support/MathExtras.h" #include "llvm/Support/raw_ostream.h" #include "llvm/Target/TargetFrameLowering.h" #include "llvm/Target/TargetInstrInfo.h" #include "llvm/Target/TargetIntrinsicInfo.h" #include "llvm/Target/TargetLowering.h" #include "llvm/Target/TargetOptions.h" #include "llvm/Target/TargetSubtargetInfo.h" #include <algorithm> #include <utility> using namespace llvm; #define DEBUG_TYPE "isel" /// LimitFloatPrecision - Generate low-precision inline sequences for /// some float libcalls (6, 8 or 12 bits). static unsigned LimitFloatPrecision; static cl::opt<unsigned, true> LimitFPPrecision("limit-float-precision", cl::desc("Generate low-precision inline sequences " "for some float libcalls"), cl::location(LimitFloatPrecision), cl::init(0)); static cl::opt<bool> EnableFMFInDAG("enable-fmf-dag", cl::init(true), cl::Hidden, cl::desc("Enable fast-math-flags for DAG nodes")); /// Minimum jump table density for normal functions. static cl::opt<unsigned> JumpTableDensity("jump-table-density", cl::init(10), cl::Hidden, cl::desc("Minimum density for building a jump table in " "a normal function")); /// Minimum jump table density for -Os or -Oz functions. static cl::opt<unsigned> OptsizeJumpTableDensity("optsize-jump-table-density", cl::init(40), cl::Hidden, cl::desc("Minimum density for building a jump table in " "an optsize function")); // Limit the width of DAG chains. This is important in general to prevent // DAG-based analysis from blowing up. For example, alias analysis and // load clustering may not complete in reasonable time. It is difficult to // recognize and avoid this situation within each individual analysis, and // future analyses are likely to have the same behavior. Limiting DAG width is // the safe approach and will be especially important with global DAGs. // // MaxParallelChains default is arbitrarily high to avoid affecting // optimization, but could be lowered to improve compile time. Any ld-ld-st-st // sequence over this should have been converted to llvm.memcpy by the // frontend. It is easy to induce this behavior with .ll code such as: // %buffer = alloca [4096 x i8] // %data = load [4096 x i8]* %argPtr // store [4096 x i8] %data, [4096 x i8]* %buffer static const unsigned MaxParallelChains = 64; static SDValue getCopyFromPartsVector(SelectionDAG &DAG, const SDLoc &DL, const SDValue *Parts, unsigned NumParts, MVT PartVT, EVT ValueVT, const Value *V); /// getCopyFromParts - Create a value that contains the specified legal parts /// combined into the value they represent. If the parts combine to a type /// larger than ValueVT then AssertOp can be used to specify whether the extra /// bits are known to be zero (ISD::AssertZext) or sign extended from ValueVT /// (ISD::AssertSext). static SDValue getCopyFromParts(SelectionDAG &DAG, const SDLoc &DL, const SDValue *Parts, unsigned NumParts, MVT PartVT, EVT ValueVT, const Value *V, Optional<ISD::NodeType> AssertOp = None) { if (ValueVT.isVector()) return getCopyFromPartsVector(DAG, DL, Parts, NumParts, PartVT, ValueVT, V); assert(NumParts > 0 && "No parts to assemble!"); const TargetLowering &TLI = DAG.getTargetLoweringInfo(); SDValue Val = Parts[0]; if (NumParts > 1) { // Assemble the value from multiple parts. if (ValueVT.isInteger()) { unsigned PartBits = PartVT.getSizeInBits(); unsigned ValueBits = ValueVT.getSizeInBits(); // Assemble the power of 2 part. unsigned RoundParts = NumParts & (NumParts - 1) ? 1 << Log2_32(NumParts) : NumParts; unsigned RoundBits = PartBits * RoundParts; EVT RoundVT = RoundBits == ValueBits ? ValueVT : EVT::getIntegerVT(*DAG.getContext(), RoundBits); SDValue Lo, Hi; EVT HalfVT = EVT::getIntegerVT(*DAG.getContext(), RoundBits/2); if (RoundParts > 2) { Lo = getCopyFromParts(DAG, DL, Parts, RoundParts / 2, PartVT, HalfVT, V); Hi = getCopyFromParts(DAG, DL, Parts + RoundParts / 2, RoundParts / 2, PartVT, HalfVT, V); } else { Lo = DAG.getNode(ISD::BITCAST, DL, HalfVT, Parts[0]); Hi = DAG.getNode(ISD::BITCAST, DL, HalfVT, Parts[1]); } if (DAG.getDataLayout().isBigEndian()) std::swap(Lo, Hi); Val = DAG.getNode(ISD::BUILD_PAIR, DL, RoundVT, Lo, Hi); if (RoundParts < NumParts) { // Assemble the trailing non-power-of-2 part. unsigned OddParts = NumParts - RoundParts; EVT OddVT = EVT::getIntegerVT(*DAG.getContext(), OddParts * PartBits); Hi = getCopyFromParts(DAG, DL, Parts + RoundParts, OddParts, PartVT, OddVT, V); // Combine the round and odd parts. Lo = Val; if (DAG.getDataLayout().isBigEndian()) std::swap(Lo, Hi); EVT TotalVT = EVT::getIntegerVT(*DAG.getContext(), NumParts * PartBits); Hi = DAG.getNode(ISD::ANY_EXTEND, DL, TotalVT, Hi); Hi = DAG.getNode(ISD::SHL, DL, TotalVT, Hi, DAG.getConstant(Lo.getValueType().getSizeInBits(), DL, TLI.getPointerTy(DAG.getDataLayout()))); Lo = DAG.getNode(ISD::ZERO_EXTEND, DL, TotalVT, Lo); Val = DAG.getNode(ISD::OR, DL, TotalVT, Lo, Hi); } } else if (PartVT.isFloatingPoint()) { // FP split into multiple FP parts (for ppcf128) assert(ValueVT == EVT(MVT::ppcf128) && PartVT == MVT::f64 && "Unexpected split"); SDValue Lo, Hi; Lo = DAG.getNode(ISD::BITCAST, DL, EVT(MVT::f64), Parts[0]); Hi = DAG.getNode(ISD::BITCAST, DL, EVT(MVT::f64), Parts[1]); if (TLI.hasBigEndianPartOrdering(ValueVT, DAG.getDataLayout())) std::swap(Lo, Hi); Val = DAG.getNode(ISD::BUILD_PAIR, DL, ValueVT, Lo, Hi); } else { // FP split into integer parts (soft fp) assert(ValueVT.isFloatingPoint() && PartVT.isInteger() && !PartVT.isVector() && "Unexpected split"); EVT IntVT = EVT::getIntegerVT(*DAG.getContext(), ValueVT.getSizeInBits()); Val = getCopyFromParts(DAG, DL, Parts, NumParts, PartVT, IntVT, V); } } // There is now one part, held in Val. Correct it to match ValueVT. // PartEVT is the type of the register class that holds the value. // ValueVT is the type of the inline asm operation. EVT PartEVT = Val.getValueType(); if (PartEVT == ValueVT) return Val; if (PartEVT.isInteger() && ValueVT.isFloatingPoint() && ValueVT.bitsLT(PartEVT)) { // For an FP value in an integer part, we need to truncate to the right // width first. PartEVT = EVT::getIntegerVT(*DAG.getContext(), ValueVT.getSizeInBits()); Val = DAG.getNode(ISD::TRUNCATE, DL, PartEVT, Val); } // Handle types that have the same size. if (PartEVT.getSizeInBits() == ValueVT.getSizeInBits()) return DAG.getNode(ISD::BITCAST, DL, ValueVT, Val); // Handle types with different sizes. if (PartEVT.isInteger() && ValueVT.isInteger()) { if (ValueVT.bitsLT(PartEVT)) { // For a truncate, see if we have any information to // indicate whether the truncated bits will always be // zero or sign-extension. if (AssertOp.hasValue()) Val = DAG.getNode(*AssertOp, DL, PartEVT, Val, DAG.getValueType(ValueVT)); return DAG.getNode(ISD::TRUNCATE, DL, ValueVT, Val); } return DAG.getNode(ISD::ANY_EXTEND, DL, ValueVT, Val); } if (PartEVT.isFloatingPoint() && ValueVT.isFloatingPoint()) { // FP_ROUND's are always exact here. if (ValueVT.bitsLT(Val.getValueType())) return DAG.getNode( ISD::FP_ROUND, DL, ValueVT, Val, DAG.getTargetConstant(1, DL, TLI.getPointerTy(DAG.getDataLayout()))); return DAG.getNode(ISD::FP_EXTEND, DL, ValueVT, Val); } llvm_unreachable("Unknown mismatch!"); } static void diagnosePossiblyInvalidConstraint(LLVMContext &Ctx, const Value *V, const Twine &ErrMsg) { const Instruction *I = dyn_cast_or_null<Instruction>(V); if (!V) return Ctx.emitError(ErrMsg); const char *AsmError = ", possible invalid constraint for vector type"; if (const CallInst *CI = dyn_cast<CallInst>(I)) if (isa<InlineAsm>(CI->getCalledValue())) return Ctx.emitError(I, ErrMsg + AsmError); return Ctx.emitError(I, ErrMsg); } /// getCopyFromPartsVector - Create a value that contains the specified legal /// parts combined into the value they represent. If the parts combine to a /// type larger than ValueVT then AssertOp can be used to specify whether the /// extra bits are known to be zero (ISD::AssertZext) or sign extended from /// ValueVT (ISD::AssertSext). static SDValue getCopyFromPartsVector(SelectionDAG &DAG, const SDLoc &DL, const SDValue *Parts, unsigned NumParts, MVT PartVT, EVT ValueVT, const Value *V) { assert(ValueVT.isVector() && "Not a vector value"); assert(NumParts > 0 && "No parts to assemble!"); const TargetLowering &TLI = DAG.getTargetLoweringInfo(); SDValue Val = Parts[0]; // Handle a multi-element vector. if (NumParts > 1) { EVT IntermediateVT; MVT RegisterVT; unsigned NumIntermediates; unsigned NumRegs = TLI.getVectorTypeBreakdown(*DAG.getContext(), ValueVT, IntermediateVT, NumIntermediates, RegisterVT); assert(NumRegs == NumParts && "Part count doesn't match vector breakdown!"); NumParts = NumRegs; // Silence a compiler warning. assert(RegisterVT == PartVT && "Part type doesn't match vector breakdown!"); assert(RegisterVT.getSizeInBits() == Parts[0].getSimpleValueType().getSizeInBits() && "Part type sizes don't match!"); // Assemble the parts into intermediate operands. SmallVector<SDValue, 8> Ops(NumIntermediates); if (NumIntermediates == NumParts) { // If the register was not expanded, truncate or copy the value, // as appropriate. for (unsigned i = 0; i != NumParts; ++i) Ops[i] = getCopyFromParts(DAG, DL, &Parts[i], 1, PartVT, IntermediateVT, V); } else if (NumParts > 0) { // If the intermediate type was expanded, build the intermediate // operands from the parts. assert(NumParts % NumIntermediates == 0 && "Must expand into a divisible number of parts!"); unsigned Factor = NumParts / NumIntermediates; for (unsigned i = 0; i != NumIntermediates; ++i) Ops[i] = getCopyFromParts(DAG, DL, &Parts[i * Factor], Factor, PartVT, IntermediateVT, V); } // Build a vector with BUILD_VECTOR or CONCAT_VECTORS from the // intermediate operands. Val = DAG.getNode(IntermediateVT.isVector() ? ISD::CONCAT_VECTORS : ISD::BUILD_VECTOR, DL, ValueVT, Ops); } // There is now one part, held in Val. Correct it to match ValueVT. EVT PartEVT = Val.getValueType(); if (PartEVT == ValueVT) return Val; if (PartEVT.isVector()) { // If the element type of the source/dest vectors are the same, but the // parts vector has more elements than the value vector, then we have a // vector widening case (e.g. <2 x float> -> <4 x float>). Extract the // elements we want. if (PartEVT.getVectorElementType() == ValueVT.getVectorElementType()) { assert(PartEVT.getVectorNumElements() > ValueVT.getVectorNumElements() && "Cannot narrow, it would be a lossy transformation"); return DAG.getNode( ISD::EXTRACT_SUBVECTOR, DL, ValueVT, Val, DAG.getConstant(0, DL, TLI.getVectorIdxTy(DAG.getDataLayout()))); } // Vector/Vector bitcast. if (ValueVT.getSizeInBits() == PartEVT.getSizeInBits()) return DAG.getNode(ISD::BITCAST, DL, ValueVT, Val); assert(PartEVT.getVectorNumElements() == ValueVT.getVectorNumElements() && "Cannot handle this kind of promotion"); // Promoted vector extract return DAG.getAnyExtOrTrunc(Val, DL, ValueVT); } // Trivial bitcast if the types are the same size and the destination // vector type is legal. if (PartEVT.getSizeInBits() == ValueVT.getSizeInBits() && TLI.isTypeLegal(ValueVT)) return DAG.getNode(ISD::BITCAST, DL, ValueVT, Val); // Handle cases such as i8 -> <1 x i1> if (ValueVT.getVectorNumElements() != 1) { diagnosePossiblyInvalidConstraint(*DAG.getContext(), V, "non-trivial scalar-to-vector conversion"); return DAG.getUNDEF(ValueVT); } if (ValueVT.getVectorNumElements() == 1 && ValueVT.getVectorElementType() != PartEVT) Val = DAG.getAnyExtOrTrunc(Val, DL, ValueVT.getScalarType()); return DAG.getNode(ISD::BUILD_VECTOR, DL, ValueVT, Val); } static void getCopyToPartsVector(SelectionDAG &DAG, const SDLoc &dl, SDValue Val, SDValue *Parts, unsigned NumParts, MVT PartVT, const Value *V); /// getCopyToParts - Create a series of nodes that contain the specified value /// split into legal parts. If the parts contain more bits than Val, then, for /// integers, ExtendKind can be used to specify how to generate the extra bits. static void getCopyToParts(SelectionDAG &DAG, const SDLoc &DL, SDValue Val, SDValue *Parts, unsigned NumParts, MVT PartVT, const Value *V, ISD::NodeType ExtendKind = ISD::ANY_EXTEND) { EVT ValueVT = Val.getValueType(); // Handle the vector case separately. if (ValueVT.isVector()) return getCopyToPartsVector(DAG, DL, Val, Parts, NumParts, PartVT, V); unsigned PartBits = PartVT.getSizeInBits(); unsigned OrigNumParts = NumParts; assert(DAG.getTargetLoweringInfo().isTypeLegal(PartVT) && "Copying to an illegal type!"); if (NumParts == 0) return; assert(!ValueVT.isVector() && "Vector case handled elsewhere"); EVT PartEVT = PartVT; if (PartEVT == ValueVT) { assert(NumParts == 1 && "No-op copy with multiple parts!"); Parts[0] = Val; return; } if (NumParts * PartBits > ValueVT.getSizeInBits()) { // If the parts cover more bits than the value has, promote the value. if (PartVT.isFloatingPoint() && ValueVT.isFloatingPoint()) { assert(NumParts == 1 && "Do not know what to promote to!"); Val = DAG.getNode(ISD::FP_EXTEND, DL, PartVT, Val); } else { if (ValueVT.isFloatingPoint()) { // FP values need to be bitcast, then extended if they are being put // into a larger container. ValueVT = EVT::getIntegerVT(*DAG.getContext(), ValueVT.getSizeInBits()); Val = DAG.getNode(ISD::BITCAST, DL, ValueVT, Val); } assert((PartVT.isInteger() || PartVT == MVT::x86mmx) && ValueVT.isInteger() && "Unknown mismatch!"); ValueVT = EVT::getIntegerVT(*DAG.getContext(), NumParts * PartBits); Val = DAG.getNode(ExtendKind, DL, ValueVT, Val); if (PartVT == MVT::x86mmx) Val = DAG.getNode(ISD::BITCAST, DL, PartVT, Val); } } else if (PartBits == ValueVT.getSizeInBits()) { // Different types of the same size. assert(NumParts == 1 && PartEVT != ValueVT); Val = DAG.getNode(ISD::BITCAST, DL, PartVT, Val); } else if (NumParts * PartBits < ValueVT.getSizeInBits()) { // If the parts cover less bits than value has, truncate the value. assert((PartVT.isInteger() || PartVT == MVT::x86mmx) && ValueVT.isInteger() && "Unknown mismatch!"); ValueVT = EVT::getIntegerVT(*DAG.getContext(), NumParts * PartBits); Val = DAG.getNode(ISD::TRUNCATE, DL, ValueVT, Val); if (PartVT == MVT::x86mmx) Val = DAG.getNode(ISD::BITCAST, DL, PartVT, Val); } // The value may have changed - recompute ValueVT. ValueVT = Val.getValueType(); assert(NumParts * PartBits == ValueVT.getSizeInBits() && "Failed to tile the value with PartVT!"); if (NumParts == 1) { if (PartEVT != ValueVT) { diagnosePossiblyInvalidConstraint(*DAG.getContext(), V, "scalar-to-vector conversion failed"); Val = DAG.getNode(ISD::BITCAST, DL, PartVT, Val); } Parts[0] = Val; return; } // Expand the value into multiple parts. if (NumParts & (NumParts - 1)) { // The number of parts is not a power of 2. Split off and copy the tail. assert(PartVT.isInteger() && ValueVT.isInteger() && "Do not know what to expand to!"); unsigned RoundParts = 1 << Log2_32(NumParts); unsigned RoundBits = RoundParts * PartBits; unsigned OddParts = NumParts - RoundParts; SDValue OddVal = DAG.getNode(ISD::SRL, DL, ValueVT, Val, DAG.getIntPtrConstant(RoundBits, DL)); getCopyToParts(DAG, DL, OddVal, Parts + RoundParts, OddParts, PartVT, V); if (DAG.getDataLayout().isBigEndian()) // The odd parts were reversed by getCopyToParts - unreverse them. std::reverse(Parts + RoundParts, Parts + NumParts); NumParts = RoundParts; ValueVT = EVT::getIntegerVT(*DAG.getContext(), NumParts * PartBits); Val = DAG.getNode(ISD::TRUNCATE, DL, ValueVT, Val); } // The number of parts is a power of 2. Repeatedly bisect the value using // EXTRACT_ELEMENT. Parts[0] = DAG.getNode(ISD::BITCAST, DL, EVT::getIntegerVT(*DAG.getContext(), ValueVT.getSizeInBits()), Val); for (unsigned StepSize = NumParts; StepSize > 1; StepSize /= 2) { for (unsigned i = 0; i < NumParts; i += StepSize) { unsigned ThisBits = StepSize * PartBits / 2; EVT ThisVT = EVT::getIntegerVT(*DAG.getContext(), ThisBits); SDValue &Part0 = Parts[i]; SDValue &Part1 = Parts[i+StepSize/2]; Part1 = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, ThisVT, Part0, DAG.getIntPtrConstant(1, DL)); Part0 = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, ThisVT, Part0, DAG.getIntPtrConstant(0, DL)); if (ThisBits == PartBits && ThisVT != PartVT) { Part0 = DAG.getNode(ISD::BITCAST, DL, PartVT, Part0); Part1 = DAG.getNode(ISD::BITCAST, DL, PartVT, Part1); } } } if (DAG.getDataLayout().isBigEndian()) std::reverse(Parts, Parts + OrigNumParts); } /// getCopyToPartsVector - Create a series of nodes that contain the specified /// value split into legal parts. static void getCopyToPartsVector(SelectionDAG &DAG, const SDLoc &DL, SDValue Val, SDValue *Parts, unsigned NumParts, MVT PartVT, const Value *V) { EVT ValueVT = Val.getValueType(); assert(ValueVT.isVector() && "Not a vector"); const TargetLowering &TLI = DAG.getTargetLoweringInfo(); if (NumParts == 1) { EVT PartEVT = PartVT; if (PartEVT == ValueVT) { // Nothing to do. } else if (PartVT.getSizeInBits() == ValueVT.getSizeInBits()) { // Bitconvert vector->vector case. Val = DAG.getNode(ISD::BITCAST, DL, PartVT, Val); } else if (PartVT.isVector() && PartEVT.getVectorElementType() == ValueVT.getVectorElementType() && PartEVT.getVectorNumElements() > ValueVT.getVectorNumElements()) { EVT ElementVT = PartVT.getVectorElementType(); // Vector widening case, e.g. <2 x float> -> <4 x float>. Shuffle in // undef elements. SmallVector<SDValue, 16> Ops; for (unsigned i = 0, e = ValueVT.getVectorNumElements(); i != e; ++i) Ops.push_back(DAG.getNode( ISD::EXTRACT_VECTOR_ELT, DL, ElementVT, Val, DAG.getConstant(i, DL, TLI.getVectorIdxTy(DAG.getDataLayout())))); for (unsigned i = ValueVT.getVectorNumElements(), e = PartVT.getVectorNumElements(); i != e; ++i) Ops.push_back(DAG.getUNDEF(ElementVT)); Val = DAG.getNode(ISD::BUILD_VECTOR, DL, PartVT, Ops); // FIXME: Use CONCAT for 2x -> 4x. //SDValue UndefElts = DAG.getUNDEF(VectorTy); //Val = DAG.getNode(ISD::CONCAT_VECTORS, DL, PartVT, Val, UndefElts); } else if (PartVT.isVector() && PartEVT.getVectorElementType().bitsGE( ValueVT.getVectorElementType()) && PartEVT.getVectorNumElements() == ValueVT.getVectorNumElements()) { // Promoted vector extract Val = DAG.getAnyExtOrTrunc(Val, DL, PartVT); } else{ // Vector -> scalar conversion. assert(ValueVT.getVectorNumElements() == 1 && "Only trivial vector-to-scalar conversions should get here!"); Val = DAG.getNode( ISD::EXTRACT_VECTOR_ELT, DL, PartVT, Val, DAG.getConstant(0, DL, TLI.getVectorIdxTy(DAG.getDataLayout()))); Val = DAG.getAnyExtOrTrunc(Val, DL, PartVT); } Parts[0] = Val; return; } // Handle a multi-element vector. EVT IntermediateVT; MVT RegisterVT; unsigned NumIntermediates; unsigned NumRegs = TLI.getVectorTypeBreakdown(*DAG.getContext(), ValueVT, IntermediateVT, NumIntermediates, RegisterVT); unsigned NumElements = ValueVT.getVectorNumElements(); assert(NumRegs == NumParts && "Part count doesn't match vector breakdown!"); NumParts = NumRegs; // Silence a compiler warning. assert(RegisterVT == PartVT && "Part type doesn't match vector breakdown!"); // Split the vector into intermediate operands. SmallVector<SDValue, 8> Ops(NumIntermediates); for (unsigned i = 0; i != NumIntermediates; ++i) { if (IntermediateVT.isVector()) Ops[i] = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, IntermediateVT, Val, DAG.getConstant(i * (NumElements / NumIntermediates), DL, TLI.getVectorIdxTy(DAG.getDataLayout()))); else Ops[i] = DAG.getNode( ISD::EXTRACT_VECTOR_ELT, DL, IntermediateVT, Val, DAG.getConstant(i, DL, TLI.getVectorIdxTy(DAG.getDataLayout()))); } // Split the intermediate operands into legal parts. if (NumParts == NumIntermediates) { // If the register was not expanded, promote or copy the value, // as appropriate. for (unsigned i = 0; i != NumParts; ++i) getCopyToParts(DAG, DL, Ops[i], &Parts[i], 1, PartVT, V); } else if (NumParts > 0) { // If the intermediate type was expanded, split each the value into // legal parts. assert(NumIntermediates != 0 && "division by zero"); assert(NumParts % NumIntermediates == 0 && "Must expand into a divisible number of parts!"); unsigned Factor = NumParts / NumIntermediates; for (unsigned i = 0; i != NumIntermediates; ++i) getCopyToParts(DAG, DL, Ops[i], &Parts[i*Factor], Factor, PartVT, V); } } RegsForValue::RegsForValue() {} RegsForValue::RegsForValue(const SmallVector<unsigned, 4> ®s, MVT regvt, EVT valuevt) : ValueVTs(1, valuevt), RegVTs(1, regvt), Regs(regs) {} RegsForValue::RegsForValue(LLVMContext &Context, const TargetLowering &TLI, const DataLayout &DL, unsigned Reg, Type *Ty) { ComputeValueVTs(TLI, DL, Ty, ValueVTs); for (EVT ValueVT : ValueVTs) { unsigned NumRegs = TLI.getNumRegisters(Context, ValueVT); MVT RegisterVT = TLI.getRegisterType(Context, ValueVT); for (unsigned i = 0; i != NumRegs; ++i) Regs.push_back(Reg + i); RegVTs.push_back(RegisterVT); Reg += NumRegs; } } /// getCopyFromRegs - Emit a series of CopyFromReg nodes that copies from /// this value and returns the result as a ValueVT value. This uses /// Chain/Flag as the input and updates them for the output Chain/Flag. /// If the Flag pointer is NULL, no flag is used. SDValue RegsForValue::getCopyFromRegs(SelectionDAG &DAG, FunctionLoweringInfo &FuncInfo, const SDLoc &dl, SDValue &Chain, SDValue *Flag, const Value *V) const { // A Value with type {} or [0 x %t] needs no registers. if (ValueVTs.empty()) return SDValue(); const TargetLowering &TLI = DAG.getTargetLoweringInfo(); // Assemble the legal parts into the final values. SmallVector<SDValue, 4> Values(ValueVTs.size()); SmallVector<SDValue, 8> Parts; for (unsigned Value = 0, Part = 0, e = ValueVTs.size(); Value != e; ++Value) { // Copy the legal parts from the registers. EVT ValueVT = ValueVTs[Value]; unsigned NumRegs = TLI.getNumRegisters(*DAG.getContext(), ValueVT); MVT RegisterVT = RegVTs[Value]; Parts.resize(NumRegs); for (unsigned i = 0; i != NumRegs; ++i) { SDValue P; if (!Flag) { P = DAG.getCopyFromReg(Chain, dl, Regs[Part+i], RegisterVT); } else { P = DAG.getCopyFromReg(Chain, dl, Regs[Part+i], RegisterVT, *Flag); *Flag = P.getValue(2); } Chain = P.getValue(1); Parts[i] = P; // If the source register was virtual and if we know something about it, // add an assert node. if (!TargetRegisterInfo::isVirtualRegister(Regs[Part+i]) || !RegisterVT.isInteger() || RegisterVT.isVector()) continue; const FunctionLoweringInfo::LiveOutInfo *LOI = FuncInfo.GetLiveOutRegInfo(Regs[Part+i]); if (!LOI) continue; unsigned RegSize = RegisterVT.getSizeInBits(); unsigned NumSignBits = LOI->NumSignBits; unsigned NumZeroBits = LOI->KnownZero.countLeadingOnes(); if (NumZeroBits == RegSize) { // The current value is a zero. // Explicitly express that as it would be easier for // optimizations to kick in. Parts[i] = DAG.getConstant(0, dl, RegisterVT); continue; } // FIXME: We capture more information than the dag can represent. For // now, just use the tightest assertzext/assertsext possible. bool isSExt = true; EVT FromVT(MVT::Other); if (NumSignBits == RegSize) { isSExt = true; // ASSERT SEXT 1 FromVT = MVT::i1; } else if (NumZeroBits >= RegSize - 1) { isSExt = false; // ASSERT ZEXT 1 FromVT = MVT::i1; } else if (NumSignBits > RegSize - 8) { isSExt = true; // ASSERT SEXT 8 FromVT = MVT::i8; } else if (NumZeroBits >= RegSize - 8) { isSExt = false; // ASSERT ZEXT 8 FromVT = MVT::i8; } else if (NumSignBits > RegSize - 16) { isSExt = true; // ASSERT SEXT 16 FromVT = MVT::i16; } else if (NumZeroBits >= RegSize - 16) { isSExt = false; // ASSERT ZEXT 16 FromVT = MVT::i16; } else if (NumSignBits > RegSize - 32) { isSExt = true; // ASSERT SEXT 32 FromVT = MVT::i32; } else if (NumZeroBits >= RegSize - 32) { isSExt = false; // ASSERT ZEXT 32 FromVT = MVT::i32; } else { continue; } // Add an assertion node. assert(FromVT != MVT::Other); Parts[i] = DAG.getNode(isSExt ? ISD::AssertSext : ISD::AssertZext, dl, RegisterVT, P, DAG.getValueType(FromVT)); } Values[Value] = getCopyFromParts(DAG, dl, Parts.begin(), NumRegs, RegisterVT, ValueVT, V); Part += NumRegs; Parts.clear(); } return DAG.getNode(ISD::MERGE_VALUES, dl, DAG.getVTList(ValueVTs), Values); } /// getCopyToRegs - Emit a series of CopyToReg nodes that copies the /// specified value into the registers specified by this object. This uses /// Chain/Flag as the input and updates them for the output Chain/Flag. /// If the Flag pointer is NULL, no flag is used. void RegsForValue::getCopyToRegs(SDValue Val, SelectionDAG &DAG, const SDLoc &dl, SDValue &Chain, SDValue *Flag, const Value *V, ISD::NodeType PreferredExtendType) const { const TargetLowering &TLI = DAG.getTargetLoweringInfo(); ISD::NodeType ExtendKind = PreferredExtendType; // Get the list of the values's legal parts. unsigned NumRegs = Regs.size(); SmallVector<SDValue, 8> Parts(NumRegs); for (unsigned Value = 0, Part = 0, e = ValueVTs.size(); Value != e; ++Value) { EVT ValueVT = ValueVTs[Value]; unsigned NumParts = TLI.getNumRegisters(*DAG.getContext(), ValueVT); MVT RegisterVT = RegVTs[Value]; if (ExtendKind == ISD::ANY_EXTEND && TLI.isZExtFree(Val, RegisterVT)) ExtendKind = ISD::ZERO_EXTEND; getCopyToParts(DAG, dl, Val.getValue(Val.getResNo() + Value), &Parts[Part], NumParts, RegisterVT, V, ExtendKind); Part += NumParts; } // Copy the parts into the registers. SmallVector<SDValue, 8> Chains(NumRegs); for (unsigned i = 0; i != NumRegs; ++i) { SDValue Part; if (!Flag) { Part = DAG.getCopyToReg(Chain, dl, Regs[i], Parts[i]); } else { Part = DAG.getCopyToReg(Chain, dl, Regs[i], Parts[i], *Flag); *Flag = Part.getValue(1); } Chains[i] = Part.getValue(0); } if (NumRegs == 1 || Flag) // If NumRegs > 1 && Flag is used then the use of the last CopyToReg is // flagged to it. That is the CopyToReg nodes and the user are considered // a single scheduling unit. If we create a TokenFactor and return it as // chain, then the TokenFactor is both a predecessor (operand) of the // user as well as a successor (the TF operands are flagged to the user). // c1, f1 = CopyToReg // c2, f2 = CopyToReg // c3 = TokenFactor c1, c2 // ... // = op c3, ..., f2 Chain = Chains[NumRegs-1]; else Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Chains); } /// AddInlineAsmOperands - Add this value to the specified inlineasm node /// operand list. This adds the code marker and includes the number of /// values added into it. void RegsForValue::AddInlineAsmOperands(unsigned Code, bool HasMatching, unsigned MatchingIdx, const SDLoc &dl, SelectionDAG &DAG, std::vector<SDValue> &Ops) const { const TargetLowering &TLI = DAG.getTargetLoweringInfo(); unsigned Flag = InlineAsm::getFlagWord(Code, Regs.size()); if (HasMatching) Flag = InlineAsm::getFlagWordForMatchingOp(Flag, MatchingIdx); else if (!Regs.empty() && TargetRegisterInfo::isVirtualRegister(Regs.front())) { // Put the register class of the virtual registers in the flag word. That // way, later passes can recompute register class constraints for inline // assembly as well as normal instructions. // Don't do this for tied operands that can use the regclass information // from the def. const MachineRegisterInfo &MRI = DAG.getMachineFunction().getRegInfo(); const TargetRegisterClass *RC = MRI.getRegClass(Regs.front()); Flag = InlineAsm::getFlagWordForRegClass(Flag, RC->getID()); } SDValue Res = DAG.getTargetConstant(Flag, dl, MVT::i32); Ops.push_back(Res); unsigned SP = TLI.getStackPointerRegisterToSaveRestore(); for (unsigned Value = 0, Reg = 0, e = ValueVTs.size(); Value != e; ++Value) { unsigned NumRegs = TLI.getNumRegisters(*DAG.getContext(), ValueVTs[Value]); MVT RegisterVT = RegVTs[Value]; for (unsigned i = 0; i != NumRegs; ++i) { assert(Reg < Regs.size() && "Mismatch in # registers expected"); unsigned TheReg = Regs[Reg++]; Ops.push_back(DAG.getRegister(TheReg, RegisterVT)); if (TheReg == SP && Code == InlineAsm::Kind_Clobber) { // If we clobbered the stack pointer, MFI should know about it. assert(DAG.getMachineFunction().getFrameInfo()-> hasOpaqueSPAdjustment()); } } } } void SelectionDAGBuilder::init(GCFunctionInfo *gfi, AliasAnalysis &aa, const TargetLibraryInfo *li) { AA = &aa; GFI = gfi; LibInfo = li; DL = &DAG.getDataLayout(); Context = DAG.getContext(); LPadToCallSiteMap.clear(); } /// clear - Clear out the current SelectionDAG and the associated /// state and prepare this SelectionDAGBuilder object to be used /// for a new block. This doesn't clear out information about /// additional blocks that are needed to complete switch lowering /// or PHI node updating; that information is cleared out as it is /// consumed. void SelectionDAGBuilder::clear() { NodeMap.clear(); UnusedArgNodeMap.clear(); PendingLoads.clear(); PendingExports.clear(); CurInst = nullptr; HasTailCall = false; SDNodeOrder = LowestSDNodeOrder; StatepointLowering.clear(); } /// clearDanglingDebugInfo - Clear the dangling debug information /// map. This function is separated from the clear so that debug /// information that is dangling in a basic block can be properly /// resolved in a different basic block. This allows the /// SelectionDAG to resolve dangling debug information attached /// to PHI nodes. void SelectionDAGBuilder::clearDanglingDebugInfo() { DanglingDebugInfoMap.clear(); } /// getRoot - Return the current virtual root of the Selection DAG, /// flushing any PendingLoad items. This must be done before emitting /// a store or any other node that may need to be ordered after any /// prior load instructions. /// SDValue SelectionDAGBuilder::getRoot() { if (PendingLoads.empty()) return DAG.getRoot(); if (PendingLoads.size() == 1) { SDValue Root = PendingLoads[0]; DAG.setRoot(Root); PendingLoads.clear(); return Root; } // Otherwise, we have to make a token factor node. SDValue Root = DAG.getNode(ISD::TokenFactor, getCurSDLoc(), MVT::Other, PendingLoads); PendingLoads.clear(); DAG.setRoot(Root); return Root; } /// getControlRoot - Similar to getRoot, but instead of flushing all the /// PendingLoad items, flush all the PendingExports items. It is necessary /// to do this before emitting a terminator instruction. /// SDValue SelectionDAGBuilder::getControlRoot() { SDValue Root = DAG.getRoot(); if (PendingExports.empty()) return Root; // Turn all of the CopyToReg chains into one factored node. if (Root.getOpcode() != ISD::EntryToken) { unsigned i = 0, e = PendingExports.size(); for (; i != e; ++i) { assert(PendingExports[i].getNode()->getNumOperands() > 1); if (PendingExports[i].getNode()->getOperand(0) == Root) break; // Don't add the root if we already indirectly depend on it. } if (i == e) PendingExports.push_back(Root); } Root = DAG.getNode(ISD::TokenFactor, getCurSDLoc(), MVT::Other, PendingExports); PendingExports.clear(); DAG.setRoot(Root); return Root; } /// Copy swift error to the final virtual register at end of a basic block, as /// specified by SwiftErrorWorklist, if necessary. static void copySwiftErrorsToFinalVRegs(SelectionDAGBuilder &SDB) { const TargetLowering &TLI = SDB.DAG.getTargetLoweringInfo(); if (!TLI.supportSwiftError()) return; if (!SDB.FuncInfo.SwiftErrorWorklist.count(SDB.FuncInfo.MBB)) return; // Go through entries in SwiftErrorWorklist, and create copy as necessary. FunctionLoweringInfo::SwiftErrorVRegs &WorklistEntry = SDB.FuncInfo.SwiftErrorWorklist[SDB.FuncInfo.MBB]; FunctionLoweringInfo::SwiftErrorVRegs &MapEntry = SDB.FuncInfo.SwiftErrorMap[SDB.FuncInfo.MBB]; for (unsigned I = 0, E = WorklistEntry.size(); I < E; I++) { unsigned WorkReg = WorklistEntry[I]; // Find the swifterror virtual register for the value in SwiftErrorMap. unsigned MapReg = MapEntry[I]; assert(TargetRegisterInfo::isVirtualRegister(MapReg) && "Entries in SwiftErrorMap should be virtual registers"); if (WorkReg == MapReg) continue; // Create copy from SwiftErrorMap to SwiftWorklist. auto &DL = SDB.DAG.getDataLayout(); SDValue CopyNode = SDB.DAG.getCopyToReg( SDB.getRoot(), SDB.getCurSDLoc(), WorkReg, SDB.DAG.getRegister(MapReg, EVT(TLI.getPointerTy(DL)))); MapEntry[I] = WorkReg; SDB.DAG.setRoot(CopyNode); } } void SelectionDAGBuilder::visit(const Instruction &I) { // Set up outgoing PHI node register values before emitting the terminator. if (isa<TerminatorInst>(&I)) { copySwiftErrorsToFinalVRegs(*this); HandlePHINodesInSuccessorBlocks(I.getParent()); } ++SDNodeOrder; CurInst = &I; visit(I.getOpcode(), I); if (!isa<TerminatorInst>(&I) && !HasTailCall && !isStatepoint(&I)) // statepoints handle their exports internally CopyToExportRegsIfNeeded(&I); CurInst = nullptr; } void SelectionDAGBuilder::visitPHI(const PHINode &) { llvm_unreachable("SelectionDAGBuilder shouldn't visit PHI nodes!"); } void SelectionDAGBuilder::visit(unsigned Opcode, const User &I) { // Note: this doesn't use InstVisitor, because it has to work with // ConstantExpr's in addition to instructions. switch (Opcode) { default: llvm_unreachable("Unknown instruction type encountered!"); // Build the switch statement using the Instruction.def file. #define HANDLE_INST(NUM, OPCODE, CLASS) \ case Instruction::OPCODE: visit##OPCODE((const CLASS&)I); break; #include "llvm/IR/Instruction.def" } } // resolveDanglingDebugInfo - if we saw an earlier dbg_value referring to V, // generate the debug data structures now that we've seen its definition. void SelectionDAGBuilder::resolveDanglingDebugInfo(const Value *V, SDValue Val) { DanglingDebugInfo &DDI = DanglingDebugInfoMap[V]; if (DDI.getDI()) { const DbgValueInst *DI = DDI.getDI(); DebugLoc dl = DDI.getdl(); unsigned DbgSDNodeOrder = DDI.getSDNodeOrder(); DILocalVariable *Variable = DI->getVariable(); DIExpression *Expr = DI->getExpression(); assert(Variable->isValidLocationForIntrinsic(dl) && "Expected inlined-at fields to agree"); uint64_t Offset = DI->getOffset(); SDDbgValue *SDV; if (Val.getNode()) { if (!EmitFuncArgumentDbgValue(V, Variable, Expr, dl, Offset, false, Val)) { SDV = DAG.getDbgValue(Variable, Expr, Val.getNode(), Val.getResNo(), false, Offset, dl, DbgSDNodeOrder); DAG.AddDbgValue(SDV, Val.getNode(), false); } } else DEBUG(dbgs() << "Dropping debug info for " << *DI << "\n"); DanglingDebugInfoMap[V] = DanglingDebugInfo(); } } /// getCopyFromRegs - If there was virtual register allocated for the value V /// emit CopyFromReg of the specified type Ty. Return empty SDValue() otherwise. SDValue SelectionDAGBuilder::getCopyFromRegs(const Value *V, Type *Ty) { DenseMap<const Value *, unsigned>::iterator It = FuncInfo.ValueMap.find(V); SDValue Result; if (It != FuncInfo.ValueMap.end()) { unsigned InReg = It->second; RegsForValue RFV(*DAG.getContext(), DAG.getTargetLoweringInfo(), DAG.getDataLayout(), InReg, Ty); SDValue Chain = DAG.getEntryNode(); Result = RFV.getCopyFromRegs(DAG, FuncInfo, getCurSDLoc(), Chain, nullptr, V); resolveDanglingDebugInfo(V, Result); } return Result; } /// getValue - Return an SDValue for the given Value. SDValue SelectionDAGBuilder::getValue(const Value *V) { // If we already have an SDValue for this value, use it. It's important // to do this first, so that we don't create a CopyFromReg if we already // have a regular SDValue. SDValue &N = NodeMap[V]; if (N.getNode()) return N; // If there's a virtual register allocated and initialized for this // value, use it. if (SDValue copyFromReg = getCopyFromRegs(V, V->getType())) return copyFromReg; // Otherwise create a new SDValue and remember it. SDValue Val = getValueImpl(V); NodeMap[V] = Val; resolveDanglingDebugInfo(V, Val); return Val; } // Return true if SDValue exists for the given Value bool SelectionDAGBuilder::findValue(const Value *V) const { return (NodeMap.find(V) != NodeMap.end()) || (FuncInfo.ValueMap.find(V) != FuncInfo.ValueMap.end()); } /// getNonRegisterValue - Return an SDValue for the given Value, but /// don't look in FuncInfo.ValueMap for a virtual register. SDValue SelectionDAGBuilder::getNonRegisterValue(const Value *V) { // If we already have an SDValue for this value, use it. SDValue &N = NodeMap[V]; if (N.getNode()) { if (isa<ConstantSDNode>(N) || isa<ConstantFPSDNode>(N)) { // Remove the debug location from the node as the node is about to be used // in a location which may differ from the original debug location. This // is relevant to Constant and ConstantFP nodes because they can appear // as constant expressions inside PHI nodes. N->setDebugLoc(DebugLoc()); } return N; } // Otherwise create a new SDValue and remember it. SDValue Val = getValueImpl(V); NodeMap[V] = Val; resolveDanglingDebugInfo(V, Val); return Val; } /// getValueImpl - Helper function for getValue and getNonRegisterValue. /// Create an SDValue for the given value. SDValue SelectionDAGBuilder::getValueImpl(const Value *V) { const TargetLowering &TLI = DAG.getTargetLoweringInfo(); if (const Constant *C = dyn_cast<Constant>(V)) { EVT VT = TLI.getValueType(DAG.getDataLayout(), V->getType(), true); if (const ConstantInt *CI = dyn_cast<ConstantInt>(C)) return DAG.getConstant(*CI, getCurSDLoc(), VT); if (const GlobalValue *GV = dyn_cast<GlobalValue>(C)) return DAG.getGlobalAddress(GV, getCurSDLoc(), VT); if (isa<ConstantPointerNull>(C)) { unsigned AS = V->getType()->getPointerAddressSpace(); return DAG.getConstant(0, getCurSDLoc(), TLI.getPointerTy(DAG.getDataLayout(), AS)); } if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) return DAG.getConstantFP(*CFP, getCurSDLoc(), VT); if (isa<UndefValue>(C) && !V->getType()->isAggregateType()) return DAG.getUNDEF(VT); if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) { visit(CE->getOpcode(), *CE); SDValue N1 = NodeMap[V]; assert(N1.getNode() && "visit didn't populate the NodeMap!"); return N1; } if (isa<ConstantStruct>(C) || isa<ConstantArray>(C)) { SmallVector<SDValue, 4> Constants; for (User::const_op_iterator OI = C->op_begin(), OE = C->op_end(); OI != OE; ++OI) { SDNode *Val = getValue(*OI).getNode(); // If the operand is an empty aggregate, there are no values. if (!Val) continue; // Add each leaf value from the operand to the Constants list // to form a flattened list of all the values. for (unsigned i = 0, e = Val->getNumValues(); i != e; ++i) Constants.push_back(SDValue(Val, i)); } return DAG.getMergeValues(Constants, getCurSDLoc()); } if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(C)) { SmallVector<SDValue, 4> Ops; for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) { SDNode *Val = getValue(CDS->getElementAsConstant(i)).getNode(); // Add each leaf value from the operand to the Constants list // to form a flattened list of all the values. for (unsigned i = 0, e = Val->getNumValues(); i != e; ++i) Ops.push_back(SDValue(Val, i)); } if (isa<ArrayType>(CDS->getType())) return DAG.getMergeValues(Ops, getCurSDLoc()); return NodeMap[V] = DAG.getNode(ISD::BUILD_VECTOR, getCurSDLoc(), VT, Ops); } if (C->getType()->isStructTy() || C->getType()->isArrayTy()) { assert((isa<ConstantAggregateZero>(C) || isa<UndefValue>(C)) && "Unknown struct or array constant!"); SmallVector<EVT, 4> ValueVTs; ComputeValueVTs(TLI, DAG.getDataLayout(), C->getType(), ValueVTs); unsigned NumElts = ValueVTs.size(); if (NumElts == 0) return SDValue(); // empty struct SmallVector<SDValue, 4> Constants(NumElts); for (unsigned i = 0; i != NumElts; ++i) { EVT EltVT = ValueVTs[i]; if (isa<UndefValue>(C)) Constants[i] = DAG.getUNDEF(EltVT); else if (EltVT.isFloatingPoint()) Constants[i] = DAG.getConstantFP(0, getCurSDLoc(), EltVT); else Constants[i] = DAG.getConstant(0, getCurSDLoc(), EltVT); } return DAG.getMergeValues(Constants, getCurSDLoc()); } if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) return DAG.getBlockAddress(BA, VT); VectorType *VecTy = cast<VectorType>(V->getType()); unsigned NumElements = VecTy->getNumElements(); // Now that we know the number and type of the elements, get that number of // elements into the Ops array based on what kind of constant it is. SmallVector<SDValue, 16> Ops; if (const ConstantVector *CV = dyn_cast<ConstantVector>(C)) { for (unsigned i = 0; i != NumElements; ++i) Ops.push_back(getValue(CV->getOperand(i))); } else { assert(isa<ConstantAggregateZero>(C) && "Unknown vector constant!"); EVT EltVT = TLI.getValueType(DAG.getDataLayout(), VecTy->getElementType()); SDValue Op; if (EltVT.isFloatingPoint()) Op = DAG.getConstantFP(0, getCurSDLoc(), EltVT); else Op = DAG.getConstant(0, getCurSDLoc(), EltVT); Ops.assign(NumElements, Op); } // Create a BUILD_VECTOR node. return NodeMap[V] = DAG.getNode(ISD::BUILD_VECTOR, getCurSDLoc(), VT, Ops); } // If this is a static alloca, generate it as the frameindex instead of // computation. if (const AllocaInst *AI = dyn_cast<AllocaInst>(V)) { DenseMap<const AllocaInst*, int>::iterator SI = FuncInfo.StaticAllocaMap.find(AI); if (SI != FuncInfo.StaticAllocaMap.end()) return DAG.getFrameIndex(SI->second, TLI.getPointerTy(DAG.getDataLayout())); } // If this is an instruction which fast-isel has deferred, select it now. if (const Instruction *Inst = dyn_cast<Instruction>(V)) { unsigned InReg = FuncInfo.InitializeRegForValue(Inst); RegsForValue RFV(*DAG.getContext(), TLI, DAG.getDataLayout(), InReg, Inst->getType()); SDValue Chain = DAG.getEntryNode(); return RFV.getCopyFromRegs(DAG, FuncInfo, getCurSDLoc(), Chain, nullptr, V); } llvm_unreachable("Can't get register for value!"); } void SelectionDAGBuilder::visitCatchPad(const CatchPadInst &I) { auto Pers = classifyEHPersonality(FuncInfo.Fn->getPersonalityFn()); bool IsMSVCCXX = Pers == EHPersonality::MSVC_CXX; bool IsCoreCLR = Pers == EHPersonality::CoreCLR; MachineBasicBlock *CatchPadMBB = FuncInfo.MBB; // In MSVC C++ and CoreCLR, catchblocks are funclets and need prologues. if (IsMSVCCXX || IsCoreCLR) CatchPadMBB->setIsEHFuncletEntry(); DAG.setRoot(DAG.getNode(ISD::CATCHPAD, getCurSDLoc(), MVT::Other, getControlRoot())); } void SelectionDAGBuilder::visitCatchRet(const CatchReturnInst &I) { // Update machine-CFG edge. MachineBasicBlock *TargetMBB = FuncInfo.MBBMap[I.getSuccessor()]; FuncInfo.MBB->addSuccessor(TargetMBB); auto Pers = classifyEHPersonality(FuncInfo.Fn->getPersonalityFn()); bool IsSEH = isAsynchronousEHPersonality(Pers); if (IsSEH) { // If this is not a fall-through branch or optimizations are switched off, // emit the branch. if (TargetMBB != NextBlock(FuncInfo.MBB) || TM.getOptLevel() == CodeGenOpt::None) DAG.setRoot(DAG.getNode(ISD::BR, getCurSDLoc(), MVT::Other, getControlRoot(), DAG.getBasicBlock(TargetMBB))); return; } // Figure out the funclet membership for the catchret's successor. // This will be used by the FuncletLayout pass to determine how to order the // BB's. // A 'catchret' returns to the outer scope's color. Value *ParentPad = I.getCatchSwitchParentPad(); const BasicBlock *SuccessorColor; if (isa<ConstantTokenNone>(ParentPad)) SuccessorColor = &FuncInfo.Fn->getEntryBlock(); else SuccessorColor = cast<Instruction>(ParentPad)->getParent(); assert(SuccessorColor && "No parent funclet for catchret!"); MachineBasicBlock *SuccessorColorMBB = FuncInfo.MBBMap[SuccessorColor]; assert(SuccessorColorMBB && "No MBB for SuccessorColor!"); // Create the terminator node. SDValue Ret = DAG.getNode(ISD::CATCHRET, getCurSDLoc(), MVT::Other, getControlRoot(), DAG.getBasicBlock(TargetMBB), DAG.getBasicBlock(SuccessorColorMBB)); DAG.setRoot(Ret); } void SelectionDAGBuilder::visitCleanupPad(const CleanupPadInst &CPI) { // Don't emit any special code for the cleanuppad instruction. It just marks // the start of a funclet. FuncInfo.MBB->setIsEHFuncletEntry(); FuncInfo.MBB->setIsCleanupFuncletEntry(); } /// When an invoke or a cleanupret unwinds to the next EH pad, there are /// many places it could ultimately go. In the IR, we have a single unwind /// destination, but in the machine CFG, we enumerate all the possible blocks. /// This function skips over imaginary basic blocks that hold catchswitch /// instructions, and finds all the "real" machine /// basic block destinations. As those destinations may not be successors of /// EHPadBB, here we also calculate the edge probability to those destinations. /// The passed-in Prob is the edge probability to EHPadBB. static void findUnwindDestinations( FunctionLoweringInfo &FuncInfo, const BasicBlock *EHPadBB, BranchProbability Prob, SmallVectorImpl<std::pair<MachineBasicBlock *, BranchProbability>> &UnwindDests) { EHPersonality Personality = classifyEHPersonality(FuncInfo.Fn->getPersonalityFn()); bool IsMSVCCXX = Personality == EHPersonality::MSVC_CXX; bool IsCoreCLR = Personality == EHPersonality::CoreCLR; while (EHPadBB) { const Instruction *Pad = EHPadBB->getFirstNonPHI(); BasicBlock *NewEHPadBB = nullptr; if (isa<LandingPadInst>(Pad)) { // Stop on landingpads. They are not funclets. UnwindDests.emplace_back(FuncInfo.MBBMap[EHPadBB], Prob); break; } else if (isa<CleanupPadInst>(Pad)) { // Stop on cleanup pads. Cleanups are always funclet entries for all known // personalities. UnwindDests.emplace_back(FuncInfo.MBBMap[EHPadBB], Prob); UnwindDests.back().first->setIsEHFuncletEntry(); break; } else if (auto *CatchSwitch = dyn_cast<CatchSwitchInst>(Pad)) { // Add the catchpad handlers to the possible destinations. for (const BasicBlock *CatchPadBB : CatchSwitch->handlers()) { UnwindDests.emplace_back(FuncInfo.MBBMap[CatchPadBB], Prob); // For MSVC++ and the CLR, catchblocks are funclets and need prologues. if (IsMSVCCXX || IsCoreCLR) UnwindDests.back().first->setIsEHFuncletEntry(); } NewEHPadBB = CatchSwitch->getUnwindDest(); } else { continue; } BranchProbabilityInfo *BPI = FuncInfo.BPI; if (BPI && NewEHPadBB) Prob *= BPI->getEdgeProbability(EHPadBB, NewEHPadBB); EHPadBB = NewEHPadBB; } } void SelectionDAGBuilder::visitCleanupRet(const CleanupReturnInst &I) { // Update successor info. SmallVector<std::pair<MachineBasicBlock *, BranchProbability>, 1> UnwindDests; auto UnwindDest = I.getUnwindDest(); BranchProbabilityInfo *BPI = FuncInfo.BPI; BranchProbability UnwindDestProb = (BPI && UnwindDest) ? BPI->getEdgeProbability(FuncInfo.MBB->getBasicBlock(), UnwindDest) : BranchProbability::getZero(); findUnwindDestinations(FuncInfo, UnwindDest, UnwindDestProb, UnwindDests); for (auto &UnwindDest : UnwindDests) { UnwindDest.first->setIsEHPad(); addSuccessorWithProb(FuncInfo.MBB, UnwindDest.first, UnwindDest.second); } FuncInfo.MBB->normalizeSuccProbs(); // Create the terminator node. SDValue Ret = DAG.getNode(ISD::CLEANUPRET, getCurSDLoc(), MVT::Other, getControlRoot()); DAG.setRoot(Ret); } void SelectionDAGBuilder::visitCatchSwitch(const CatchSwitchInst &CSI) { report_fatal_error("visitCatchSwitch not yet implemented!"); } void SelectionDAGBuilder::visitRet(const ReturnInst &I) { const TargetLowering &TLI = DAG.getTargetLoweringInfo(); auto &DL = DAG.getDataLayout(); SDValue Chain = getControlRoot(); SmallVector<ISD::OutputArg, 8> Outs; SmallVector<SDValue, 8> OutVals; // Calls to @llvm.experimental.deoptimize don't generate a return value, so // lower // // %val = call <ty> @llvm.experimental.deoptimize() // ret <ty> %val // // differently. if (I.getParent()->getTerminatingDeoptimizeCall()) { LowerDeoptimizingReturn(); return; } if (!FuncInfo.CanLowerReturn) { unsigned DemoteReg = FuncInfo.DemoteRegister; const Function *F = I.getParent()->getParent(); // Emit a store of the return value through the virtual register. // Leave Outs empty so that LowerReturn won't try to load return // registers the usual way. SmallVector<EVT, 1> PtrValueVTs; ComputeValueVTs(TLI, DL, PointerType::getUnqual(F->getReturnType()), PtrValueVTs); SDValue RetPtr = DAG.getCopyFromReg(DAG.getEntryNode(), getCurSDLoc(), DemoteReg, PtrValueVTs[0]); SDValue RetOp = getValue(I.getOperand(0)); SmallVector<EVT, 4> ValueVTs; SmallVector<uint64_t, 4> Offsets; ComputeValueVTs(TLI, DL, I.getOperand(0)->getType(), ValueVTs, &Offsets); unsigned NumValues = ValueVTs.size(); // An aggregate return value cannot wrap around the address space, so // offsets to its parts don't wrap either. SDNodeFlags Flags; Flags.setNoUnsignedWrap(true); SmallVector<SDValue, 4> Chains(NumValues); for (unsigned i = 0; i != NumValues; ++i) { SDValue Add = DAG.getNode(ISD::ADD, getCurSDLoc(), RetPtr.getValueType(), RetPtr, DAG.getIntPtrConstant(Offsets[i], getCurSDLoc()), &Flags); Chains[i] = DAG.getStore(Chain, getCurSDLoc(), SDValue(RetOp.getNode(), RetOp.getResNo() + i), // FIXME: better loc info would be nice. Add, MachinePointerInfo(), false, false, 0); } Chain = DAG.getNode(ISD::TokenFactor, getCurSDLoc(), MVT::Other, Chains); } else if (I.getNumOperands() != 0) { SmallVector<EVT, 4> ValueVTs; ComputeValueVTs(TLI, DL, I.getOperand(0)->getType(), ValueVTs); unsigned NumValues = ValueVTs.size(); if (NumValues) { SDValue RetOp = getValue(I.getOperand(0)); const Function *F = I.getParent()->getParent(); ISD::NodeType ExtendKind = ISD::ANY_EXTEND; if (F->getAttributes().hasAttribute(AttributeSet::ReturnIndex, Attribute::SExt)) ExtendKind = ISD::SIGN_EXTEND; else if (F->getAttributes().hasAttribute(AttributeSet::ReturnIndex, Attribute::ZExt)) ExtendKind = ISD::ZERO_EXTEND; LLVMContext &Context = F->getContext(); bool RetInReg = F->getAttributes().hasAttribute(AttributeSet::ReturnIndex, Attribute::InReg); for (unsigned j = 0; j != NumValues; ++j) { EVT VT = ValueVTs[j]; if (ExtendKind != ISD::ANY_EXTEND && VT.isInteger()) VT = TLI.getTypeForExtReturn(Context, VT, ExtendKind); unsigned NumParts = TLI.getNumRegisters(Context, VT); MVT PartVT = TLI.getRegisterType(Context, VT); SmallVector<SDValue, 4> Parts(NumParts); getCopyToParts(DAG, getCurSDLoc(), SDValue(RetOp.getNode(), RetOp.getResNo() + j), &Parts[0], NumParts, PartVT, &I, ExtendKind); // 'inreg' on function refers to return value ISD::ArgFlagsTy Flags = ISD::ArgFlagsTy(); if (RetInReg) Flags.setInReg(); // Propagate extension type if any if (ExtendKind == ISD::SIGN_EXTEND) Flags.setSExt(); else if (ExtendKind == ISD::ZERO_EXTEND) Flags.setZExt(); for (unsigned i = 0; i < NumParts; ++i) { Outs.push_back(ISD::OutputArg(Flags, Parts[i].getValueType(), VT, /*isfixed=*/true, 0, 0)); OutVals.push_back(Parts[i]); } } } } // Push in swifterror virtual register as the last element of Outs. This makes // sure swifterror virtual register will be returned in the swifterror // physical register. const Function *F = I.getParent()->getParent(); if (TLI.supportSwiftError() && F->getAttributes().hasAttrSomewhere(Attribute::SwiftError)) { ISD::ArgFlagsTy Flags = ISD::ArgFlagsTy(); Flags.setSwiftError(); Outs.push_back(ISD::OutputArg(Flags, EVT(TLI.getPointerTy(DL)) /*vt*/, EVT(TLI.getPointerTy(DL)) /*argvt*/, true /*isfixed*/, 1 /*origidx*/, 0 /*partOffs*/)); // Create SDNode for the swifterror virtual register. OutVals.push_back(DAG.getRegister(FuncInfo.SwiftErrorMap[FuncInfo.MBB][0], EVT(TLI.getPointerTy(DL)))); } bool isVarArg = DAG.getMachineFunction().getFunction()->isVarArg(); CallingConv::ID CallConv = DAG.getMachineFunction().getFunction()->getCallingConv(); Chain = DAG.getTargetLoweringInfo().LowerReturn( Chain, CallConv, isVarArg, Outs, OutVals, getCurSDLoc(), DAG); // Verify that the target's LowerReturn behaved as expected. assert(Chain.getNode() && Chain.getValueType() == MVT::Other && "LowerReturn didn't return a valid chain!"); // Update the DAG with the new chain value resulting from return lowering. DAG.setRoot(Chain); } /// CopyToExportRegsIfNeeded - If the given value has virtual registers /// created for it, emit nodes to copy the value into the virtual /// registers. void SelectionDAGBuilder::CopyToExportRegsIfNeeded(const Value *V) { // Skip empty types if (V->getType()->isEmptyTy()) return; DenseMap<const Value *, unsigned>::iterator VMI = FuncInfo.ValueMap.find(V); if (VMI != FuncInfo.ValueMap.end()) { assert(!V->use_empty() && "Unused value assigned virtual registers!"); CopyValueToVirtualRegister(V, VMI->second); } } /// ExportFromCurrentBlock - If this condition isn't known to be exported from /// the current basic block, add it to ValueMap now so that we'll get a /// CopyTo/FromReg. void SelectionDAGBuilder::ExportFromCurrentBlock(const Value *V) { // No need to export constants. if (!isa<Instruction>(V) && !isa<Argument>(V)) return; // Already exported? if (FuncInfo.isExportedInst(V)) return; unsigned Reg = FuncInfo.InitializeRegForValue(V); CopyValueToVirtualRegister(V, Reg); } bool SelectionDAGBuilder::isExportableFromCurrentBlock(const Value *V, const BasicBlock *FromBB) { // The operands of the setcc have to be in this block. We don't know // how to export them from some other block. if (const Instruction *VI = dyn_cast<Instruction>(V)) { // Can export from current BB. if (VI->getParent() == FromBB) return true; // Is already exported, noop. return FuncInfo.isExportedInst(V); } // If this is an argument, we can export it if the BB is the entry block or // if it is already exported. if (isa<Argument>(V)) { if (FromBB == &FromBB->getParent()->getEntryBlock()) return true; // Otherwise, can only export this if it is already exported. return FuncInfo.isExportedInst(V); } // Otherwise, constants can always be exported. return true; } /// Return branch probability calculated by BranchProbabilityInfo for IR blocks. BranchProbability SelectionDAGBuilder::getEdgeProbability(const MachineBasicBlock *Src, const MachineBasicBlock *Dst) const { BranchProbabilityInfo *BPI = FuncInfo.BPI; const BasicBlock *SrcBB = Src->getBasicBlock(); const BasicBlock *DstBB = Dst->getBasicBlock(); if (!BPI) { // If BPI is not available, set the default probability as 1 / N, where N is // the number of successors. auto SuccSize = std::max<uint32_t>( std::distance(succ_begin(SrcBB), succ_end(SrcBB)), 1); return BranchProbability(1, SuccSize); } return BPI->getEdgeProbability(SrcBB, DstBB); } void SelectionDAGBuilder::addSuccessorWithProb(MachineBasicBlock *Src, MachineBasicBlock *Dst, BranchProbability Prob) { if (!FuncInfo.BPI) Src->addSuccessorWithoutProb(Dst); else { if (Prob.isUnknown()) Prob = getEdgeProbability(Src, Dst); Src->addSuccessor(Dst, Prob); } } static bool InBlock(const Value *V, const BasicBlock *BB) { if (const Instruction *I = dyn_cast<Instruction>(V)) return I->getParent() == BB; return true; } /// EmitBranchForMergedCondition - Helper method for FindMergedConditions. /// This function emits a branch and is used at the leaves of an OR or an /// AND operator tree. /// void SelectionDAGBuilder::EmitBranchForMergedCondition(const Value *Cond, MachineBasicBlock *TBB, MachineBasicBlock *FBB, MachineBasicBlock *CurBB, MachineBasicBlock *SwitchBB, BranchProbability TProb, BranchProbability FProb) { const BasicBlock *BB = CurBB->getBasicBlock(); // If the leaf of the tree is a comparison, merge the condition into // the caseblock. if (const CmpInst *BOp = dyn_cast<CmpInst>(Cond)) { // The operands of the cmp have to be in this block. We don't know // how to export them from some other block. If this is the first block // of the sequence, no exporting is needed. if (CurBB == SwitchBB || (isExportableFromCurrentBlock(BOp->getOperand(0), BB) && isExportableFromCurrentBlock(BOp->getOperand(1), BB))) { ISD::CondCode Condition; if (const ICmpInst *IC = dyn_cast<ICmpInst>(Cond)) { Condition = getICmpCondCode(IC->getPredicate()); } else { const FCmpInst *FC = cast<FCmpInst>(Cond); Condition = getFCmpCondCode(FC->getPredicate()); if (TM.Options.NoNaNsFPMath) Condition = getFCmpCodeWithoutNaN(Condition); } CaseBlock CB(Condition, BOp->getOperand(0), BOp->getOperand(1), nullptr, TBB, FBB, CurBB, TProb, FProb); SwitchCases.push_back(CB); return; } } // Create a CaseBlock record representing this branch. CaseBlock CB(ISD::SETEQ, Cond, ConstantInt::getTrue(*DAG.getContext()), nullptr, TBB, FBB, CurBB, TProb, FProb); SwitchCases.push_back(CB); } /// FindMergedConditions - If Cond is an expression like void SelectionDAGBuilder::FindMergedConditions(const Value *Cond, MachineBasicBlock *TBB, MachineBasicBlock *FBB, MachineBasicBlock *CurBB, MachineBasicBlock *SwitchBB, Instruction::BinaryOps Opc, BranchProbability TProb, BranchProbability FProb) { // If this node is not part of the or/and tree, emit it as a branch. const Instruction *BOp = dyn_cast<Instruction>(Cond); if (!BOp || !(isa<BinaryOperator>(BOp) || isa<CmpInst>(BOp)) || (unsigned)BOp->getOpcode() != Opc || !BOp->hasOneUse() || BOp->getParent() != CurBB->getBasicBlock() || !InBlock(BOp->getOperand(0), CurBB->getBasicBlock()) || !InBlock(BOp->getOperand(1), CurBB->getBasicBlock())) { EmitBranchForMergedCondition(Cond, TBB, FBB, CurBB, SwitchBB, TProb, FProb); return; } // Create TmpBB after CurBB. MachineFunction::iterator BBI(CurBB); MachineFunction &MF = DAG.getMachineFunction(); MachineBasicBlock *TmpBB = MF.CreateMachineBasicBlock(CurBB->getBasicBlock()); CurBB->getParent()->insert(++BBI, TmpBB); if (Opc == Instruction::Or) { // Codegen X | Y as: // BB1: // jmp_if_X TBB // jmp TmpBB // TmpBB: // jmp_if_Y TBB // jmp FBB // // We have flexibility in setting Prob for BB1 and Prob for TmpBB. // The requirement is that // TrueProb for BB1 + (FalseProb for BB1 * TrueProb for TmpBB) // = TrueProb for original BB. // Assuming the original probabilities are A and B, one choice is to set // BB1's probabilities to A/2 and A/2+B, and set TmpBB's probabilities to // A/(1+B) and 2B/(1+B). This choice assumes that // TrueProb for BB1 == FalseProb for BB1 * TrueProb for TmpBB. // Another choice is to assume TrueProb for BB1 equals to TrueProb for // TmpBB, but the math is more complicated. auto NewTrueProb = TProb / 2; auto NewFalseProb = TProb / 2 + FProb; // Emit the LHS condition. FindMergedConditions(BOp->getOperand(0), TBB, TmpBB, CurBB, SwitchBB, Opc, NewTrueProb, NewFalseProb); // Normalize A/2 and B to get A/(1+B) and 2B/(1+B). SmallVector<BranchProbability, 2> Probs{TProb / 2, FProb}; BranchProbability::normalizeProbabilities(Probs.begin(), Probs.end()); // Emit the RHS condition into TmpBB. FindMergedConditions(BOp->getOperand(1), TBB, FBB, TmpBB, SwitchBB, Opc, Probs[0], Probs[1]); } else { assert(Opc == Instruction::And && "Unknown merge op!"); // Codegen X & Y as: // BB1: // jmp_if_X TmpBB // jmp FBB // TmpBB: // jmp_if_Y TBB // jmp FBB // // This requires creation of TmpBB after CurBB. // We have flexibility in setting Prob for BB1 and Prob for TmpBB. // The requirement is that // FalseProb for BB1 + (TrueProb for BB1 * FalseProb for TmpBB) // = FalseProb for original BB. // Assuming the original probabilities are A and B, one choice is to set // BB1's probabilities to A+B/2 and B/2, and set TmpBB's probabilities to // 2A/(1+A) and B/(1+A). This choice assumes that FalseProb for BB1 == // TrueProb for BB1 * FalseProb for TmpBB. auto NewTrueProb = TProb + FProb / 2; auto NewFalseProb = FProb / 2; // Emit the LHS condition. FindMergedConditions(BOp->getOperand(0), TmpBB, FBB, CurBB, SwitchBB, Opc, NewTrueProb, NewFalseProb); // Normalize A and B/2 to get 2A/(1+A) and B/(1+A). SmallVector<BranchProbability, 2> Probs{TProb, FProb / 2}; BranchProbability::normalizeProbabilities(Probs.begin(), Probs.end()); // Emit the RHS condition into TmpBB. FindMergedConditions(BOp->getOperand(1), TBB, FBB, TmpBB, SwitchBB, Opc, Probs[0], Probs[1]); } } /// If the set of cases should be emitted as a series of branches, return true. /// If we should emit this as a bunch of and/or'd together conditions, return /// false. bool SelectionDAGBuilder::ShouldEmitAsBranches(const std::vector<CaseBlock> &Cases) { if (Cases.size() != 2) return true; // If this is two comparisons of the same values or'd or and'd together, they // will get folded into a single comparison, so don't emit two blocks. if ((Cases[0].CmpLHS == Cases[1].CmpLHS && Cases[0].CmpRHS == Cases[1].CmpRHS) || (Cases[0].CmpRHS == Cases[1].CmpLHS && Cases[0].CmpLHS == Cases[1].CmpRHS)) { return false; } // Handle: (X != null) | (Y != null) --> (X|Y) != 0 // Handle: (X == null) & (Y == null) --> (X|Y) == 0 if (Cases[0].CmpRHS == Cases[1].CmpRHS && Cases[0].CC == Cases[1].CC && isa<Constant>(Cases[0].CmpRHS) && cast<Constant>(Cases[0].CmpRHS)->isNullValue()) { if (Cases[0].CC == ISD::SETEQ && Cases[0].TrueBB == Cases[1].ThisBB) return false; if (Cases[0].CC == ISD::SETNE && Cases[0].FalseBB == Cases[1].ThisBB) return false; } return true; } void SelectionDAGBuilder::visitBr(const BranchInst &I) { MachineBasicBlock *BrMBB = FuncInfo.MBB; // Update machine-CFG edges. MachineBasicBlock *Succ0MBB = FuncInfo.MBBMap[I.getSuccessor(0)]; if (I.isUnconditional()) { // Update machine-CFG edges. BrMBB->addSuccessor(Succ0MBB); // If this is not a fall-through branch or optimizations are switched off, // emit the branch. if (Succ0MBB != NextBlock(BrMBB) || TM.getOptLevel() == CodeGenOpt::None) DAG.setRoot(DAG.getNode(ISD::BR, getCurSDLoc(), MVT::Other, getControlRoot(), DAG.getBasicBlock(Succ0MBB))); return; } // If this condition is one of the special cases we handle, do special stuff // now. const Value *CondVal = I.getCondition(); MachineBasicBlock *Succ1MBB = FuncInfo.MBBMap[I.getSuccessor(1)]; // If this is a series of conditions that are or'd or and'd together, emit // this as a sequence of branches instead of setcc's with and/or operations. // As long as jumps are not expensive, this should improve performance. // For example, instead of something like: // cmp A, B // C = seteq // cmp D, E // F = setle // or C, F // jnz foo // Emit: // cmp A, B // je foo // cmp D, E // jle foo // if (const BinaryOperator *BOp = dyn_cast<BinaryOperator>(CondVal)) { Instruction::BinaryOps Opcode = BOp->getOpcode(); if (!DAG.getTargetLoweringInfo().isJumpExpensive() && BOp->hasOneUse() && !I.getMetadata(LLVMContext::MD_unpredictable) && (Opcode == Instruction::And || Opcode == Instruction::Or)) { FindMergedConditions(BOp, Succ0MBB, Succ1MBB, BrMBB, BrMBB, Opcode, getEdgeProbability(BrMBB, Succ0MBB), getEdgeProbability(BrMBB, Succ1MBB)); // If the compares in later blocks need to use values not currently // exported from this block, export them now. This block should always // be the first entry. assert(SwitchCases[0].ThisBB == BrMBB && "Unexpected lowering!"); // Allow some cases to be rejected. if (ShouldEmitAsBranches(SwitchCases)) { for (unsigned i = 1, e = SwitchCases.size(); i != e; ++i) { ExportFromCurrentBlock(SwitchCases[i].CmpLHS); ExportFromCurrentBlock(SwitchCases[i].CmpRHS); } // Emit the branch for this block. visitSwitchCase(SwitchCases[0], BrMBB); SwitchCases.erase(SwitchCases.begin()); return; } // Okay, we decided not to do this, remove any inserted MBB's and clear // SwitchCases. for (unsigned i = 1, e = SwitchCases.size(); i != e; ++i) FuncInfo.MF->erase(SwitchCases[i].ThisBB); SwitchCases.clear(); } } // Create a CaseBlock record representing this branch. CaseBlock CB(ISD::SETEQ, CondVal, ConstantInt::getTrue(*DAG.getContext()), nullptr, Succ0MBB, Succ1MBB, BrMBB); // Use visitSwitchCase to actually insert the fast branch sequence for this // cond branch. visitSwitchCase(CB, BrMBB); } /// visitSwitchCase - Emits the necessary code to represent a single node in /// the binary search tree resulting from lowering a switch instruction. void SelectionDAGBuilder::visitSwitchCase(CaseBlock &CB, MachineBasicBlock *SwitchBB) { SDValue Cond; SDValue CondLHS = getValue(CB.CmpLHS); SDLoc dl = getCurSDLoc(); // Build the setcc now. if (!CB.CmpMHS) { // Fold "(X == true)" to X and "(X == false)" to !X to // handle common cases produced by branch lowering. if (CB.CmpRHS == ConstantInt::getTrue(*DAG.getContext()) && CB.CC == ISD::SETEQ) Cond = CondLHS; else if (CB.CmpRHS == ConstantInt::getFalse(*DAG.getContext()) && CB.CC == ISD::SETEQ) { SDValue True = DAG.getConstant(1, dl, CondLHS.getValueType()); Cond = DAG.getNode(ISD::XOR, dl, CondLHS.getValueType(), CondLHS, True); } else Cond = DAG.getSetCC(dl, MVT::i1, CondLHS, getValue(CB.CmpRHS), CB.CC); } else { assert(CB.CC == ISD::SETLE && "Can handle only LE ranges now"); const APInt& Low = cast<ConstantInt>(CB.CmpLHS)->getValue(); const APInt& High = cast<ConstantInt>(CB.CmpRHS)->getValue(); SDValue CmpOp = getValue(CB.CmpMHS); EVT VT = CmpOp.getValueType(); if (cast<ConstantInt>(CB.CmpLHS)->isMinValue(true)) { Cond = DAG.getSetCC(dl, MVT::i1, CmpOp, DAG.getConstant(High, dl, VT), ISD::SETLE); } else { SDValue SUB = DAG.getNode(ISD::SUB, dl, VT, CmpOp, DAG.getConstant(Low, dl, VT)); Cond = DAG.getSetCC(dl, MVT::i1, SUB, DAG.getConstant(High-Low, dl, VT), ISD::SETULE); } } // Update successor info addSuccessorWithProb(SwitchBB, CB.TrueBB, CB.TrueProb); // TrueBB and FalseBB are always different unless the incoming IR is // degenerate. This only happens when running llc on weird IR. if (CB.TrueBB != CB.FalseBB) addSuccessorWithProb(SwitchBB, CB.FalseBB, CB.FalseProb); SwitchBB->normalizeSuccProbs(); // If the lhs block is the next block, invert the condition so that we can // fall through to the lhs instead of the rhs block. if (CB.TrueBB == NextBlock(SwitchBB)) { std::swap(CB.TrueBB, CB.FalseBB); SDValue True = DAG.getConstant(1, dl, Cond.getValueType()); Cond = DAG.getNode(ISD::XOR, dl, Cond.getValueType(), Cond, True); } SDValue BrCond = DAG.getNode(ISD::BRCOND, dl, MVT::Other, getControlRoot(), Cond, DAG.getBasicBlock(CB.TrueBB)); // Insert the false branch. Do this even if it's a fall through branch, // this makes it easier to do DAG optimizations which require inverting // the branch condition. BrCond = DAG.getNode(ISD::BR, dl, MVT::Other, BrCond, DAG.getBasicBlock(CB.FalseBB)); DAG.setRoot(BrCond); } /// visitJumpTable - Emit JumpTable node in the current MBB void SelectionDAGBuilder::visitJumpTable(JumpTable &JT) { // Emit the code for the jump table assert(JT.Reg != -1U && "Should lower JT Header first!"); EVT PTy = DAG.getTargetLoweringInfo().getPointerTy(DAG.getDataLayout()); SDValue Index = DAG.getCopyFromReg(getControlRoot(), getCurSDLoc(), JT.Reg, PTy); SDValue Table = DAG.getJumpTable(JT.JTI, PTy); SDValue BrJumpTable = DAG.getNode(ISD::BR_JT, getCurSDLoc(), MVT::Other, Index.getValue(1), Table, Index); DAG.setRoot(BrJumpTable); } /// visitJumpTableHeader - This function emits necessary code to produce index /// in the JumpTable from switch case. void SelectionDAGBuilder::visitJumpTableHeader(JumpTable &JT, JumpTableHeader &JTH, MachineBasicBlock *SwitchBB) { SDLoc dl = getCurSDLoc(); // Subtract the lowest switch case value from the value being switched on and // conditional branch to default mbb if the result is greater than the // difference between smallest and largest cases. SDValue SwitchOp = getValue(JTH.SValue); EVT VT = SwitchOp.getValueType(); SDValue Sub = DAG.getNode(ISD::SUB, dl, VT, SwitchOp, DAG.getConstant(JTH.First, dl, VT)); // The SDNode we just created, which holds the value being switched on minus // the smallest case value, needs to be copied to a virtual register so it // can be used as an index into the jump table in a subsequent basic block. // This value may be smaller or larger than the target's pointer type, and // therefore require extension or truncating. const TargetLowering &TLI = DAG.getTargetLoweringInfo(); SwitchOp = DAG.getZExtOrTrunc(Sub, dl, TLI.getPointerTy(DAG.getDataLayout())); unsigned JumpTableReg = FuncInfo.CreateReg(TLI.getPointerTy(DAG.getDataLayout())); SDValue CopyTo = DAG.getCopyToReg(getControlRoot(), dl, JumpTableReg, SwitchOp); JT.Reg = JumpTableReg; // Emit the range check for the jump table, and branch to the default block // for the switch statement if the value being switched on exceeds the largest // case in the switch. SDValue CMP = DAG.getSetCC( dl, TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), Sub.getValueType()), Sub, DAG.getConstant(JTH.Last - JTH.First, dl, VT), ISD::SETUGT); SDValue BrCond = DAG.getNode(ISD::BRCOND, dl, MVT::Other, CopyTo, CMP, DAG.getBasicBlock(JT.Default)); // Avoid emitting unnecessary branches to the next block. if (JT.MBB != NextBlock(SwitchBB)) BrCond = DAG.getNode(ISD::BR, dl, MVT::Other, BrCond, DAG.getBasicBlock(JT.MBB)); DAG.setRoot(BrCond); } /// Create a LOAD_STACK_GUARD node, and let it carry the target specific global /// variable if there exists one. static SDValue getLoadStackGuard(SelectionDAG &DAG, const SDLoc &DL, SDValue &Chain) { const TargetLowering &TLI = DAG.getTargetLoweringInfo(); EVT PtrTy = TLI.getPointerTy(DAG.getDataLayout()); MachineFunction &MF = DAG.getMachineFunction(); Value *Global = TLI.getSDagStackGuard(*MF.getFunction()->getParent()); MachineSDNode *Node = DAG.getMachineNode(TargetOpcode::LOAD_STACK_GUARD, DL, PtrTy, Chain); if (Global) { MachinePointerInfo MPInfo(Global); MachineInstr::mmo_iterator MemRefs = MF.allocateMemRefsArray(1); unsigned Flags = MachineMemOperand::MOLoad | MachineMemOperand::MOInvariant; *MemRefs = MF.getMachineMemOperand(MPInfo, Flags, PtrTy.getSizeInBits() / 8, DAG.getEVTAlignment(PtrTy)); Node->setMemRefs(MemRefs, MemRefs + 1); } return SDValue(Node, 0); } /// Codegen a new tail for a stack protector check ParentMBB which has had its /// tail spliced into a stack protector check success bb. /// /// For a high level explanation of how this fits into the stack protector /// generation see the comment on the declaration of class /// StackProtectorDescriptor. void SelectionDAGBuilder::visitSPDescriptorParent(StackProtectorDescriptor &SPD, MachineBasicBlock *ParentBB) { // First create the loads to the guard/stack slot for the comparison. const TargetLowering &TLI = DAG.getTargetLoweringInfo(); EVT PtrTy = TLI.getPointerTy(DAG.getDataLayout()); MachineFrameInfo *MFI = ParentBB->getParent()->getFrameInfo(); int FI = MFI->getStackProtectorIndex(); SDValue Guard; SDLoc dl = getCurSDLoc(); SDValue StackSlotPtr = DAG.getFrameIndex(FI, PtrTy); const Module &M = *ParentBB->getParent()->getFunction()->getParent(); unsigned Align = DL->getPrefTypeAlignment(Type::getInt8PtrTy(M.getContext())); // Generate code to load the content of the guard slot. SDValue StackSlot = DAG.getLoad( PtrTy, dl, DAG.getEntryNode(), StackSlotPtr, MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI), true, false, false, Align); // Retrieve guard check function, nullptr if instrumentation is inlined. if (const Value *GuardCheck = TLI.getSSPStackGuardCheck(M)) { // The target provides a guard check function to validate the guard value. // Generate a call to that function with the content of the guard slot as // argument. auto *Fn = cast<Function>(GuardCheck); FunctionType *FnTy = Fn->getFunctionType(); assert(FnTy->getNumParams() == 1 && "Invalid function signature"); TargetLowering::ArgListTy Args; TargetLowering::ArgListEntry Entry; Entry.Node = StackSlot; Entry.Ty = FnTy->getParamType(0); if (Fn->hasAttribute(1, Attribute::AttrKind::InReg)) Entry.isInReg = true; Args.push_back(Entry); TargetLowering::CallLoweringInfo CLI(DAG); CLI.setDebugLoc(getCurSDLoc()) .setChain(DAG.getEntryNode()) .setCallee(Fn->getCallingConv(), FnTy->getReturnType(), getValue(GuardCheck), std::move(Args)); std::pair<SDValue, SDValue> Result = TLI.LowerCallTo(CLI); DAG.setRoot(Result.second); return; } // If useLoadStackGuardNode returns true, generate LOAD_STACK_GUARD. // Otherwise, emit a volatile load to retrieve the stack guard value. SDValue Chain = DAG.getEntryNode(); if (TLI.useLoadStackGuardNode()) { Guard = getLoadStackGuard(DAG, dl, Chain); } else { const Value *IRGuard = TLI.getSDagStackGuard(M); SDValue GuardPtr = getValue(IRGuard); Guard = DAG.getLoad(PtrTy, dl, Chain, GuardPtr, MachinePointerInfo(IRGuard, 0), true, false, false, Align); } // Perform the comparison via a subtract/getsetcc. EVT VT = Guard.getValueType(); SDValue Sub = DAG.getNode(ISD::SUB, dl, VT, Guard, StackSlot); SDValue Cmp = DAG.getSetCC(dl, TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), Sub.getValueType()), Sub, DAG.getConstant(0, dl, VT), ISD::SETNE); // If the sub is not 0, then we know the guard/stackslot do not equal, so // branch to failure MBB. SDValue BrCond = DAG.getNode(ISD::BRCOND, dl, MVT::Other, StackSlot.getOperand(0), Cmp, DAG.getBasicBlock(SPD.getFailureMBB())); // Otherwise branch to success MBB. SDValue Br = DAG.getNode(ISD::BR, dl, MVT::Other, BrCond, DAG.getBasicBlock(SPD.getSuccessMBB())); DAG.setRoot(Br); } /// Codegen the failure basic block for a stack protector check. /// /// A failure stack protector machine basic block consists simply of a call to /// __stack_chk_fail(). /// /// For a high level explanation of how this fits into the stack protector /// generation see the comment on the declaration of class /// StackProtectorDescriptor. void SelectionDAGBuilder::visitSPDescriptorFailure(StackProtectorDescriptor &SPD) { const TargetLowering &TLI = DAG.getTargetLoweringInfo(); SDValue Chain = TLI.makeLibCall(DAG, RTLIB::STACKPROTECTOR_CHECK_FAIL, MVT::isVoid, None, false, getCurSDLoc(), false, false).second; DAG.setRoot(Chain); } /// visitBitTestHeader - This function emits necessary code to produce value /// suitable for "bit tests" void SelectionDAGBuilder::visitBitTestHeader(BitTestBlock &B, MachineBasicBlock *SwitchBB) { SDLoc dl = getCurSDLoc(); // Subtract the minimum value SDValue SwitchOp = getValue(B.SValue); EVT VT = SwitchOp.getValueType(); SDValue Sub = DAG.getNode(ISD::SUB, dl, VT, SwitchOp, DAG.getConstant(B.First, dl, VT)); // Check range const TargetLowering &TLI = DAG.getTargetLoweringInfo(); SDValue RangeCmp = DAG.getSetCC( dl, TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), Sub.getValueType()), Sub, DAG.getConstant(B.Range, dl, VT), ISD::SETUGT); // Determine the type of the test operands. bool UsePtrType = false; if (!TLI.isTypeLegal(VT)) UsePtrType = true; else { for (unsigned i = 0, e = B.Cases.size(); i != e; ++i) if (!isUIntN(VT.getSizeInBits(), B.Cases[i].Mask)) { // Switch table case range are encoded into series of masks. // Just use pointer type, it's guaranteed to fit. UsePtrType = true; break; } } if (UsePtrType) { VT = TLI.getPointerTy(DAG.getDataLayout()); Sub = DAG.getZExtOrTrunc(Sub, dl, VT); } B.RegVT = VT.getSimpleVT(); B.Reg = FuncInfo.CreateReg(B.RegVT); SDValue CopyTo = DAG.getCopyToReg(getControlRoot(), dl, B.Reg, Sub); MachineBasicBlock* MBB = B.Cases[0].ThisBB; addSuccessorWithProb(SwitchBB, B.Default, B.DefaultProb); addSuccessorWithProb(SwitchBB, MBB, B.Prob); SwitchBB->normalizeSuccProbs(); SDValue BrRange = DAG.getNode(ISD::BRCOND, dl, MVT::Other, CopyTo, RangeCmp, DAG.getBasicBlock(B.Default)); // Avoid emitting unnecessary branches to the next block. if (MBB != NextBlock(SwitchBB)) BrRange = DAG.getNode(ISD::BR, dl, MVT::Other, BrRange, DAG.getBasicBlock(MBB)); DAG.setRoot(BrRange); } /// visitBitTestCase - this function produces one "bit test" void SelectionDAGBuilder::visitBitTestCase(BitTestBlock &BB, MachineBasicBlock* NextMBB, BranchProbability BranchProbToNext, unsigned Reg, BitTestCase &B, MachineBasicBlock *SwitchBB) { SDLoc dl = getCurSDLoc(); MVT VT = BB.RegVT; SDValue ShiftOp = DAG.getCopyFromReg(getControlRoot(), dl, Reg, VT); SDValue Cmp; unsigned PopCount = countPopulation(B.Mask); const TargetLowering &TLI = DAG.getTargetLoweringInfo(); if (PopCount == 1) { // Testing for a single bit; just compare the shift count with what it // would need to be to shift a 1 bit in that position. Cmp = DAG.getSetCC( dl, TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT), ShiftOp, DAG.getConstant(countTrailingZeros(B.Mask), dl, VT), ISD::SETEQ); } else if (PopCount == BB.Range) { // There is only one zero bit in the range, test for it directly. Cmp = DAG.getSetCC( dl, TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT), ShiftOp, DAG.getConstant(countTrailingOnes(B.Mask), dl, VT), ISD::SETNE); } else { // Make desired shift SDValue SwitchVal = DAG.getNode(ISD::SHL, dl, VT, DAG.getConstant(1, dl, VT), ShiftOp); // Emit bit tests and jumps SDValue AndOp = DAG.getNode(ISD::AND, dl, VT, SwitchVal, DAG.getConstant(B.Mask, dl, VT)); Cmp = DAG.getSetCC( dl, TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT), AndOp, DAG.getConstant(0, dl, VT), ISD::SETNE); } // The branch probability from SwitchBB to B.TargetBB is B.ExtraProb. addSuccessorWithProb(SwitchBB, B.TargetBB, B.ExtraProb); // The branch probability from SwitchBB to NextMBB is BranchProbToNext. addSuccessorWithProb(SwitchBB, NextMBB, BranchProbToNext); // It is not guaranteed that the sum of B.ExtraProb and BranchProbToNext is // one as they are relative probabilities (and thus work more like weights), // and hence we need to normalize them to let the sum of them become one. SwitchBB->normalizeSuccProbs(); SDValue BrAnd = DAG.getNode(ISD::BRCOND, dl, MVT::Other, getControlRoot(), Cmp, DAG.getBasicBlock(B.TargetBB)); // Avoid emitting unnecessary branches to the next block. if (NextMBB != NextBlock(SwitchBB)) BrAnd = DAG.getNode(ISD::BR, dl, MVT::Other, BrAnd, DAG.getBasicBlock(NextMBB)); DAG.setRoot(BrAnd); } void SelectionDAGBuilder::visitInvoke(const InvokeInst &I) { MachineBasicBlock *InvokeMBB = FuncInfo.MBB; // Retrieve successors. Look through artificial IR level blocks like // catchswitch for successors. MachineBasicBlock *Return = FuncInfo.MBBMap[I.getSuccessor(0)]; const BasicBlock *EHPadBB = I.getSuccessor(1); // Deopt bundles are lowered in LowerCallSiteWithDeoptBundle, and we don't // have to do anything here to lower funclet bundles. assert(!I.hasOperandBundlesOtherThan( {LLVMContext::OB_deopt, LLVMContext::OB_funclet}) && "Cannot lower invokes with arbitrary operand bundles yet!"); const Value *Callee(I.getCalledValue()); const Function *Fn = dyn_cast<Function>(Callee); if (isa<InlineAsm>(Callee)) visitInlineAsm(&I); else if (Fn && Fn->isIntrinsic()) { switch (Fn->getIntrinsicID()) { default: llvm_unreachable("Cannot invoke this intrinsic"); case Intrinsic::donothing: // Ignore invokes to @llvm.donothing: jump directly to the next BB. break; case Intrinsic::experimental_patchpoint_void: case Intrinsic::experimental_patchpoint_i64: visitPatchpoint(&I, EHPadBB); break; case Intrinsic::experimental_gc_statepoint: LowerStatepoint(ImmutableStatepoint(&I), EHPadBB); break; } } else if (I.countOperandBundlesOfType(LLVMContext::OB_deopt)) { // Currently we do not lower any intrinsic calls with deopt operand bundles. // Eventually we will support lowering the @llvm.experimental.deoptimize // intrinsic, and right now there are no plans to support other intrinsics // with deopt state. LowerCallSiteWithDeoptBundle(&I, getValue(Callee), EHPadBB); } else { LowerCallTo(&I, getValue(Callee), false, EHPadBB); } // If the value of the invoke is used outside of its defining block, make it // available as a virtual register. // We already took care of the exported value for the statepoint instruction // during call to the LowerStatepoint. if (!isStatepoint(I)) { CopyToExportRegsIfNeeded(&I); } SmallVector<std::pair<MachineBasicBlock *, BranchProbability>, 1> UnwindDests; BranchProbabilityInfo *BPI = FuncInfo.BPI; BranchProbability EHPadBBProb = BPI ? BPI->getEdgeProbability(InvokeMBB->getBasicBlock(), EHPadBB) : BranchProbability::getZero(); findUnwindDestinations(FuncInfo, EHPadBB, EHPadBBProb, UnwindDests); // Update successor info. addSuccessorWithProb(InvokeMBB, Return); for (auto &UnwindDest : UnwindDests) { UnwindDest.first->setIsEHPad(); addSuccessorWithProb(InvokeMBB, UnwindDest.first, UnwindDest.second); } InvokeMBB->normalizeSuccProbs(); // Drop into normal successor. DAG.setRoot(DAG.getNode(ISD::BR, getCurSDLoc(), MVT::Other, getControlRoot(), DAG.getBasicBlock(Return))); } void SelectionDAGBuilder::visitResume(const ResumeInst &RI) { llvm_unreachable("SelectionDAGBuilder shouldn't visit resume instructions!"); } void SelectionDAGBuilder::visitLandingPad(const LandingPadInst &LP) { assert(FuncInfo.MBB->isEHPad() && "Call to landingpad not in landing pad!"); MachineBasicBlock *MBB = FuncInfo.MBB; MachineModuleInfo &MMI = DAG.getMachineFunction().getMMI(); AddLandingPadInfo(LP, MMI, MBB); // If there aren't registers to copy the values into (e.g., during SjLj // exceptions), then don't bother to create these DAG nodes. const TargetLowering &TLI = DAG.getTargetLoweringInfo(); const Constant *PersonalityFn = FuncInfo.Fn->getPersonalityFn(); if (TLI.getExceptionPointerRegister(PersonalityFn) == 0 && TLI.getExceptionSelectorRegister(PersonalityFn) == 0) return; // If landingpad's return type is token type, we don't create DAG nodes // for its exception pointer and selector value. The extraction of exception // pointer or selector value from token type landingpads is not currently // supported. if (LP.getType()->isTokenTy()) return; SmallVector<EVT, 2> ValueVTs; SDLoc dl = getCurSDLoc(); ComputeValueVTs(TLI, DAG.getDataLayout(), LP.getType(), ValueVTs); assert(ValueVTs.size() == 2 && "Only two-valued landingpads are supported"); // Get the two live-in registers as SDValues. The physregs have already been // copied into virtual registers. SDValue Ops[2]; if (FuncInfo.ExceptionPointerVirtReg) { Ops[0] = DAG.getZExtOrTrunc( DAG.getCopyFromReg(DAG.getEntryNode(), dl, FuncInfo.ExceptionPointerVirtReg, TLI.getPointerTy(DAG.getDataLayout())), dl, ValueVTs[0]); } else { Ops[0] = DAG.getConstant(0, dl, TLI.getPointerTy(DAG.getDataLayout())); } Ops[1] = DAG.getZExtOrTrunc( DAG.getCopyFromReg(DAG.getEntryNode(), dl, FuncInfo.ExceptionSelectorVirtReg, TLI.getPointerTy(DAG.getDataLayout())), dl, ValueVTs[1]); // Merge into one. SDValue Res = DAG.getNode(ISD::MERGE_VALUES, dl, DAG.getVTList(ValueVTs), Ops); setValue(&LP, Res); } void SelectionDAGBuilder::sortAndRangeify(CaseClusterVector &Clusters) { #ifndef NDEBUG for (const CaseCluster &CC : Clusters) assert(CC.Low == CC.High && "Input clusters must be single-case"); #endif std::sort(Clusters.begin(), Clusters.end(), [](const CaseCluster &a, const CaseCluster &b) { return a.Low->getValue().slt(b.Low->getValue()); }); // Merge adjacent clusters with the same destination. const unsigned N = Clusters.size(); unsigned DstIndex = 0; for (unsigned SrcIndex = 0; SrcIndex < N; ++SrcIndex) { CaseCluster &CC = Clusters[SrcIndex]; const ConstantInt *CaseVal = CC.Low; MachineBasicBlock *Succ = CC.MBB; if (DstIndex != 0 && Clusters[DstIndex - 1].MBB == Succ && (CaseVal->getValue() - Clusters[DstIndex - 1].High->getValue()) == 1) { // If this case has the same successor and is a neighbour, merge it into // the previous cluster. Clusters[DstIndex - 1].High = CaseVal; Clusters[DstIndex - 1].Prob += CC.Prob; } else { std::memmove(&Clusters[DstIndex++], &Clusters[SrcIndex], sizeof(Clusters[SrcIndex])); } } Clusters.resize(DstIndex); } void SelectionDAGBuilder::UpdateSplitBlock(MachineBasicBlock *First, MachineBasicBlock *Last) { // Update JTCases. for (unsigned i = 0, e = JTCases.size(); i != e; ++i) if (JTCases[i].first.HeaderBB == First) JTCases[i].first.HeaderBB = Last; // Update BitTestCases. for (unsigned i = 0, e = BitTestCases.size(); i != e; ++i) if (BitTestCases[i].Parent == First) BitTestCases[i].Parent = Last; } void SelectionDAGBuilder::visitIndirectBr(const IndirectBrInst &I) { MachineBasicBlock *IndirectBrMBB = FuncInfo.MBB; // Update machine-CFG edges with unique successors. SmallSet<BasicBlock*, 32> Done; for (unsigned i = 0, e = I.getNumSuccessors(); i != e; ++i) { BasicBlock *BB = I.getSuccessor(i); bool Inserted = Done.insert(BB).second; if (!Inserted) continue; MachineBasicBlock *Succ = FuncInfo.MBBMap[BB]; addSuccessorWithProb(IndirectBrMBB, Succ); } IndirectBrMBB->normalizeSuccProbs(); DAG.setRoot(DAG.getNode(ISD::BRIND, getCurSDLoc(), MVT::Other, getControlRoot(), getValue(I.getAddress()))); } void SelectionDAGBuilder::visitUnreachable(const UnreachableInst &I) { if (DAG.getTarget().Options.TrapUnreachable) DAG.setRoot( DAG.getNode(ISD::TRAP, getCurSDLoc(), MVT::Other, DAG.getRoot())); } void SelectionDAGBuilder::visitFSub(const User &I) { // -0.0 - X --> fneg Type *Ty = I.getType(); if (isa<Constant>(I.getOperand(0)) && I.getOperand(0) == ConstantFP::getZeroValueForNegation(Ty)) { SDValue Op2 = getValue(I.getOperand(1)); setValue(&I, DAG.getNode(ISD::FNEG, getCurSDLoc(), Op2.getValueType(), Op2)); return; } visitBinary(I, ISD::FSUB); } /// Checks if the given instruction performs a vector reduction, in which case /// we have the freedom to alter the elements in the result as long as the /// reduction of them stays unchanged. static bool isVectorReductionOp(const User *I) { const Instruction *Inst = dyn_cast<Instruction>(I); if (!Inst || !Inst->getType()->isVectorTy()) return false; auto OpCode = Inst->getOpcode(); switch (OpCode) { case Instruction::Add: case Instruction::Mul: case Instruction::And: case Instruction::Or: case Instruction::Xor: break; case Instruction::FAdd: case Instruction::FMul: if (const FPMathOperator *FPOp = dyn_cast<const FPMathOperator>(Inst)) if (FPOp->getFastMathFlags().unsafeAlgebra()) break; // Fall through. default: return false; } unsigned ElemNum = Inst->getType()->getVectorNumElements(); unsigned ElemNumToReduce = ElemNum; // Do DFS search on the def-use chain from the given instruction. We only // allow four kinds of operations during the search until we reach the // instruction that extracts the first element from the vector: // // 1. The reduction operation of the same opcode as the given instruction. // // 2. PHI node. // // 3. ShuffleVector instruction together with a reduction operation that // does a partial reduction. // // 4. ExtractElement that extracts the first element from the vector, and we // stop searching the def-use chain here. // // 3 & 4 above perform a reduction on all elements of the vector. We push defs // from 1-3 to the stack to continue the DFS. The given instruction is not // a reduction operation if we meet any other instructions other than those // listed above. SmallVector<const User *, 16> UsersToVisit{Inst}; SmallPtrSet<const User *, 16> Visited; bool ReduxExtracted = false; while (!UsersToVisit.empty()) { auto User = UsersToVisit.back(); UsersToVisit.pop_back(); if (!Visited.insert(User).second) continue; for (const auto &U : User->users()) { auto Inst = dyn_cast<Instruction>(U); if (!Inst) return false; if (Inst->getOpcode() == OpCode || isa<PHINode>(U)) { if (const FPMathOperator *FPOp = dyn_cast<const FPMathOperator>(Inst)) if (!isa<PHINode>(FPOp) && !FPOp->getFastMathFlags().unsafeAlgebra()) return false; UsersToVisit.push_back(U); } else if (const ShuffleVectorInst *ShufInst = dyn_cast<ShuffleVectorInst>(U)) { // Detect the following pattern: A ShuffleVector instruction together // with a reduction that do partial reduction on the first and second // ElemNumToReduce / 2 elements, and store the result in // ElemNumToReduce / 2 elements in another vector. unsigned ResultElements = ShufInst->getType()->getVectorNumElements(); if (ResultElements < ElemNum) return false; if (ElemNumToReduce == 1) return false; if (!isa<UndefValue>(U->getOperand(1))) return false; for (unsigned i = 0; i < ElemNumToReduce / 2; ++i) if (ShufInst->getMaskValue(i) != int(i + ElemNumToReduce / 2)) return false; for (unsigned i = ElemNumToReduce / 2; i < ElemNum; ++i) if (ShufInst->getMaskValue(i) != -1) return false; // There is only one user of this ShuffleVector instruction, which // must be a reduction operation. if (!U->hasOneUse()) return false; auto U2 = dyn_cast<Instruction>(*U->user_begin()); if (!U2 || U2->getOpcode() != OpCode) return false; // Check operands of the reduction operation. if ((U2->getOperand(0) == U->getOperand(0) && U2->getOperand(1) == U) || (U2->getOperand(1) == U->getOperand(0) && U2->getOperand(0) == U)) { UsersToVisit.push_back(U2); ElemNumToReduce /= 2; } else return false; } else if (isa<ExtractElementInst>(U)) { // At this moment we should have reduced all elements in the vector. if (ElemNumToReduce != 1) return false; const ConstantInt *Val = dyn_cast<ConstantInt>(U->getOperand(1)); if (!Val || Val->getZExtValue() != 0) return false; ReduxExtracted = true; } else return false; } } return ReduxExtracted; } void SelectionDAGBuilder::visitBinary(const User &I, unsigned OpCode) { SDValue Op1 = getValue(I.getOperand(0)); SDValue Op2 = getValue(I.getOperand(1)); bool nuw = false; bool nsw = false; bool exact = false; bool vec_redux = false; FastMathFlags FMF; if (const OverflowingBinaryOperator *OFBinOp = dyn_cast<const OverflowingBinaryOperator>(&I)) { nuw = OFBinOp->hasNoUnsignedWrap(); nsw = OFBinOp->hasNoSignedWrap(); } if (const PossiblyExactOperator *ExactOp = dyn_cast<const PossiblyExactOperator>(&I)) exact = ExactOp->isExact(); if (const FPMathOperator *FPOp = dyn_cast<const FPMathOperator>(&I)) FMF = FPOp->getFastMathFlags(); if (isVectorReductionOp(&I)) { vec_redux = true; DEBUG(dbgs() << "Detected a reduction operation:" << I << "\n"); } SDNodeFlags Flags; Flags.setExact(exact); Flags.setNoSignedWrap(nsw); Flags.setNoUnsignedWrap(nuw); Flags.setVectorReduction(vec_redux); if (EnableFMFInDAG) { Flags.setAllowReciprocal(FMF.allowReciprocal()); Flags.setNoInfs(FMF.noInfs()); Flags.setNoNaNs(FMF.noNaNs()); Flags.setNoSignedZeros(FMF.noSignedZeros()); Flags.setUnsafeAlgebra(FMF.unsafeAlgebra()); } SDValue BinNodeValue = DAG.getNode(OpCode, getCurSDLoc(), Op1.getValueType(), Op1, Op2, &Flags); setValue(&I, BinNodeValue); } void SelectionDAGBuilder::visitShift(const User &I, unsigned Opcode) { SDValue Op1 = getValue(I.getOperand(0)); SDValue Op2 = getValue(I.getOperand(1)); EVT ShiftTy = DAG.getTargetLoweringInfo().getShiftAmountTy( Op2.getValueType(), DAG.getDataLayout()); // Coerce the shift amount to the right type if we can. if (!I.getType()->isVectorTy() && Op2.getValueType() != ShiftTy) { unsigned ShiftSize = ShiftTy.getSizeInBits(); unsigned Op2Size = Op2.getValueType().getSizeInBits(); SDLoc DL = getCurSDLoc(); // If the operand is smaller than the shift count type, promote it. if (ShiftSize > Op2Size) Op2 = DAG.getNode(ISD::ZERO_EXTEND, DL, ShiftTy, Op2); // If the operand is larger than the shift count type but the shift // count type has enough bits to represent any shift value, truncate // it now. This is a common case and it exposes the truncate to // optimization early. else if (ShiftSize >= Log2_32_Ceil(Op2.getValueType().getSizeInBits())) Op2 = DAG.getNode(ISD::TRUNCATE, DL, ShiftTy, Op2); // Otherwise we'll need to temporarily settle for some other convenient // type. Type legalization will make adjustments once the shiftee is split. else Op2 = DAG.getZExtOrTrunc(Op2, DL, MVT::i32); } bool nuw = false; bool nsw = false; bool exact = false; if (Opcode == ISD::SRL || Opcode == ISD::SRA || Opcode == ISD::SHL) { if (const OverflowingBinaryOperator *OFBinOp = dyn_cast<const OverflowingBinaryOperator>(&I)) { nuw = OFBinOp->hasNoUnsignedWrap(); nsw = OFBinOp->hasNoSignedWrap(); } if (const PossiblyExactOperator *ExactOp = dyn_cast<const PossiblyExactOperator>(&I)) exact = ExactOp->isExact(); } SDNodeFlags Flags; Flags.setExact(exact); Flags.setNoSignedWrap(nsw); Flags.setNoUnsignedWrap(nuw); SDValue Res = DAG.getNode(Opcode, getCurSDLoc(), Op1.getValueType(), Op1, Op2, &Flags); setValue(&I, Res); } void SelectionDAGBuilder::visitSDiv(const User &I) { SDValue Op1 = getValue(I.getOperand(0)); SDValue Op2 = getValue(I.getOperand(1)); SDNodeFlags Flags; Flags.setExact(isa<PossiblyExactOperator>(&I) && cast<PossiblyExactOperator>(&I)->isExact()); setValue(&I, DAG.getNode(ISD::SDIV, getCurSDLoc(), Op1.getValueType(), Op1, Op2, &Flags)); } void SelectionDAGBuilder::visitICmp(const User &I) { ICmpInst::Predicate predicate = ICmpInst::BAD_ICMP_PREDICATE; if (const ICmpInst *IC = dyn_cast<ICmpInst>(&I)) predicate = IC->getPredicate(); else if (const ConstantExpr *IC = dyn_cast<ConstantExpr>(&I)) predicate = ICmpInst::Predicate(IC->getPredicate()); SDValue Op1 = getValue(I.getOperand(0)); SDValue Op2 = getValue(I.getOperand(1)); ISD::CondCode Opcode = getICmpCondCode(predicate); EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), I.getType()); setValue(&I, DAG.getSetCC(getCurSDLoc(), DestVT, Op1, Op2, Opcode)); } void SelectionDAGBuilder::visitFCmp(const User &I) { FCmpInst::Predicate predicate = FCmpInst::BAD_FCMP_PREDICATE; if (const FCmpInst *FC = dyn_cast<FCmpInst>(&I)) predicate = FC->getPredicate(); else if (const ConstantExpr *FC = dyn_cast<ConstantExpr>(&I)) predicate = FCmpInst::Predicate(FC->getPredicate()); SDValue Op1 = getValue(I.getOperand(0)); SDValue Op2 = getValue(I.getOperand(1)); ISD::CondCode Condition = getFCmpCondCode(predicate); // FIXME: Fcmp instructions have fast-math-flags in IR, so we should use them. // FIXME: We should propagate the fast-math-flags to the DAG node itself for // further optimization, but currently FMF is only applicable to binary nodes. if (TM.Options.NoNaNsFPMath) Condition = getFCmpCodeWithoutNaN(Condition); EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), I.getType()); setValue(&I, DAG.getSetCC(getCurSDLoc(), DestVT, Op1, Op2, Condition)); } // Check if the condition of the select has one use or two users that are both // selects with the same condition. static bool hasOnlySelectUsers(const Value *Cond) { return std::all_of(Cond->user_begin(), Cond->user_end(), [](const Value *V) { return isa<SelectInst>(V); }); } void SelectionDAGBuilder::visitSelect(const User &I) { SmallVector<EVT, 4> ValueVTs; ComputeValueVTs(DAG.getTargetLoweringInfo(), DAG.getDataLayout(), I.getType(), ValueVTs); unsigned NumValues = ValueVTs.size(); if (NumValues == 0) return; SmallVector<SDValue, 4> Values(NumValues); SDValue Cond = getValue(I.getOperand(0)); SDValue LHSVal = getValue(I.getOperand(1)); SDValue RHSVal = getValue(I.getOperand(2)); auto BaseOps = {Cond}; ISD::NodeType OpCode = Cond.getValueType().isVector() ? ISD::VSELECT : ISD::SELECT; // Min/max matching is only viable if all output VTs are the same. if (std::equal(ValueVTs.begin(), ValueVTs.end(), ValueVTs.begin())) { EVT VT = ValueVTs[0]; LLVMContext &Ctx = *DAG.getContext(); auto &TLI = DAG.getTargetLoweringInfo(); // We care about the legality of the operation after it has been type // legalized. while (TLI.getTypeAction(Ctx, VT) != TargetLoweringBase::TypeLegal && VT != TLI.getTypeToTransformTo(Ctx, VT)) VT = TLI.getTypeToTransformTo(Ctx, VT); // If the vselect is legal, assume we want to leave this as a vector setcc + // vselect. Otherwise, if this is going to be scalarized, we want to see if // min/max is legal on the scalar type. bool UseScalarMinMax = VT.isVector() && !TLI.isOperationLegalOrCustom(ISD::VSELECT, VT); Value *LHS, *RHS; auto SPR = matchSelectPattern(const_cast<User*>(&I), LHS, RHS); ISD::NodeType Opc = ISD::DELETED_NODE; switch (SPR.Flavor) { case SPF_UMAX: Opc = ISD::UMAX; break; case SPF_UMIN: Opc = ISD::UMIN; break; case SPF_SMAX: Opc = ISD::SMAX; break; case SPF_SMIN: Opc = ISD::SMIN; break; case SPF_FMINNUM: switch (SPR.NaNBehavior) { case SPNB_NA: llvm_unreachable("No NaN behavior for FP op?"); case SPNB_RETURNS_NAN: Opc = ISD::FMINNAN; break; case SPNB_RETURNS_OTHER: Opc = ISD::FMINNUM; break; case SPNB_RETURNS_ANY: { if (TLI.isOperationLegalOrCustom(ISD::FMINNUM, VT)) Opc = ISD::FMINNUM; else if (TLI.isOperationLegalOrCustom(ISD::FMINNAN, VT)) Opc = ISD::FMINNAN; else if (UseScalarMinMax) Opc = TLI.isOperationLegalOrCustom(ISD::FMINNUM, VT.getScalarType()) ? ISD::FMINNUM : ISD::FMINNAN; break; } } break; case SPF_FMAXNUM: switch (SPR.NaNBehavior) { case SPNB_NA: llvm_unreachable("No NaN behavior for FP op?"); case SPNB_RETURNS_NAN: Opc = ISD::FMAXNAN; break; case SPNB_RETURNS_OTHER: Opc = ISD::FMAXNUM; break; case SPNB_RETURNS_ANY: if (TLI.isOperationLegalOrCustom(ISD::FMAXNUM, VT)) Opc = ISD::FMAXNUM; else if (TLI.isOperationLegalOrCustom(ISD::FMAXNAN, VT)) Opc = ISD::FMAXNAN; else if (UseScalarMinMax) Opc = TLI.isOperationLegalOrCustom(ISD::FMAXNUM, VT.getScalarType()) ? ISD::FMAXNUM : ISD::FMAXNAN; break; } break; default: break; } if (Opc != ISD::DELETED_NODE && (TLI.isOperationLegalOrCustom(Opc, VT) || (UseScalarMinMax && TLI.isOperationLegalOrCustom(Opc, VT.getScalarType()))) && // If the underlying comparison instruction is used by any other // instruction, the consumed instructions won't be destroyed, so it is // not profitable to convert to a min/max. hasOnlySelectUsers(cast<SelectInst>(I).getCondition())) { OpCode = Opc; LHSVal = getValue(LHS); RHSVal = getValue(RHS); BaseOps = {}; } } for (unsigned i = 0; i != NumValues; ++i) { SmallVector<SDValue, 3> Ops(BaseOps.begin(), BaseOps.end()); Ops.push_back(SDValue(LHSVal.getNode(), LHSVal.getResNo() + i)); Ops.push_back(SDValue(RHSVal.getNode(), RHSVal.getResNo() + i)); Values[i] = DAG.getNode(OpCode, getCurSDLoc(), LHSVal.getNode()->getValueType(LHSVal.getResNo()+i), Ops); } setValue(&I, DAG.getNode(ISD::MERGE_VALUES, getCurSDLoc(), DAG.getVTList(ValueVTs), Values)); } void SelectionDAGBuilder::visitTrunc(const User &I) { // TruncInst cannot be a no-op cast because sizeof(src) > sizeof(dest). SDValue N = getValue(I.getOperand(0)); EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), I.getType()); setValue(&I, DAG.getNode(ISD::TRUNCATE, getCurSDLoc(), DestVT, N)); } void SelectionDAGBuilder::visitZExt(const User &I) { // ZExt cannot be a no-op cast because sizeof(src) < sizeof(dest). // ZExt also can't be a cast to bool for same reason. So, nothing much to do SDValue N = getValue(I.getOperand(0)); EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), I.getType()); setValue(&I, DAG.getNode(ISD::ZERO_EXTEND, getCurSDLoc(), DestVT, N)); } void SelectionDAGBuilder::visitSExt(const User &I) { // SExt cannot be a no-op cast because sizeof(src) < sizeof(dest). // SExt also can't be a cast to bool for same reason. So, nothing much to do SDValue N = getValue(I.getOperand(0)); EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), I.getType()); setValue(&I, DAG.getNode(ISD::SIGN_EXTEND, getCurSDLoc(), DestVT, N)); } void SelectionDAGBuilder::visitFPTrunc(const User &I) { // FPTrunc is never a no-op cast, no need to check SDValue N = getValue(I.getOperand(0)); SDLoc dl = getCurSDLoc(); const TargetLowering &TLI = DAG.getTargetLoweringInfo(); EVT DestVT = TLI.getValueType(DAG.getDataLayout(), I.getType()); setValue(&I, DAG.getNode(ISD::FP_ROUND, dl, DestVT, N, DAG.getTargetConstant( 0, dl, TLI.getPointerTy(DAG.getDataLayout())))); } void SelectionDAGBuilder::visitFPExt(const User &I) { // FPExt is never a no-op cast, no need to check SDValue N = getValue(I.getOperand(0)); EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), I.getType()); setValue(&I, DAG.getNode(ISD::FP_EXTEND, getCurSDLoc(), DestVT, N)); } void SelectionDAGBuilder::visitFPToUI(const User &I) { // FPToUI is never a no-op cast, no need to check SDValue N = getValue(I.getOperand(0)); EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), I.getType()); setValue(&I, DAG.getNode(ISD::FP_TO_UINT, getCurSDLoc(), DestVT, N)); } void SelectionDAGBuilder::visitFPToSI(const User &I) { // FPToSI is never a no-op cast, no need to check SDValue N = getValue(I.getOperand(0)); EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), I.getType()); setValue(&I, DAG.getNode(ISD::FP_TO_SINT, getCurSDLoc(), DestVT, N)); } void SelectionDAGBuilder::visitUIToFP(const User &I) { // UIToFP is never a no-op cast, no need to check SDValue N = getValue(I.getOperand(0)); EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), I.getType()); setValue(&I, DAG.getNode(ISD::UINT_TO_FP, getCurSDLoc(), DestVT, N)); } void SelectionDAGBuilder::visitSIToFP(const User &I) { // SIToFP is never a no-op cast, no need to check SDValue N = getValue(I.getOperand(0)); EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), I.getType()); setValue(&I, DAG.getNode(ISD::SINT_TO_FP, getCurSDLoc(), DestVT, N)); } void SelectionDAGBuilder::visitPtrToInt(const User &I) { // What to do depends on the size of the integer and the size of the pointer. // We can either truncate, zero extend, or no-op, accordingly. SDValue N = getValue(I.getOperand(0)); EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), I.getType()); setValue(&I, DAG.getZExtOrTrunc(N, getCurSDLoc(), DestVT)); } void SelectionDAGBuilder::visitIntToPtr(const User &I) { // What to do depends on the size of the integer and the size of the pointer. // We can either truncate, zero extend, or no-op, accordingly. SDValue N = getValue(I.getOperand(0)); EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), I.getType()); setValue(&I, DAG.getZExtOrTrunc(N, getCurSDLoc(), DestVT)); } void SelectionDAGBuilder::visitBitCast(const User &I) { SDValue N = getValue(I.getOperand(0)); SDLoc dl = getCurSDLoc(); EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), I.getType()); // BitCast assures us that source and destination are the same size so this is // either a BITCAST or a no-op. if (DestVT != N.getValueType()) setValue(&I, DAG.getNode(ISD::BITCAST, dl, DestVT, N)); // convert types. // Check if the original LLVM IR Operand was a ConstantInt, because getValue() // might fold any kind of constant expression to an integer constant and that // is not what we are looking for. Only regcognize a bitcast of a genuine // constant integer as an opaque constant. else if(ConstantInt *C = dyn_cast<ConstantInt>(I.getOperand(0))) setValue(&I, DAG.getConstant(C->getValue(), dl, DestVT, /*isTarget=*/false, /*isOpaque*/true)); else setValue(&I, N); // noop cast. } void SelectionDAGBuilder::visitAddrSpaceCast(const User &I) { const TargetLowering &TLI = DAG.getTargetLoweringInfo(); const Value *SV = I.getOperand(0); SDValue N = getValue(SV); EVT DestVT = TLI.getValueType(DAG.getDataLayout(), I.getType()); unsigned SrcAS = SV->getType()->getPointerAddressSpace(); unsigned DestAS = I.getType()->getPointerAddressSpace(); if (!TLI.isNoopAddrSpaceCast(SrcAS, DestAS)) N = DAG.getAddrSpaceCast(getCurSDLoc(), DestVT, N, SrcAS, DestAS); setValue(&I, N); } void SelectionDAGBuilder::visitInsertElement(const User &I) { const TargetLowering &TLI = DAG.getTargetLoweringInfo(); SDValue InVec = getValue(I.getOperand(0)); SDValue InVal = getValue(I.getOperand(1)); SDValue InIdx = DAG.getSExtOrTrunc(getValue(I.getOperand(2)), getCurSDLoc(), TLI.getVectorIdxTy(DAG.getDataLayout())); setValue(&I, DAG.getNode(ISD::INSERT_VECTOR_ELT, getCurSDLoc(), TLI.getValueType(DAG.getDataLayout(), I.getType()), InVec, InVal, InIdx)); } void SelectionDAGBuilder::visitExtractElement(const User &I) { const TargetLowering &TLI = DAG.getTargetLoweringInfo(); SDValue InVec = getValue(I.getOperand(0)); SDValue InIdx = DAG.getSExtOrTrunc(getValue(I.getOperand(1)), getCurSDLoc(), TLI.getVectorIdxTy(DAG.getDataLayout())); setValue(&I, DAG.getNode(ISD::EXTRACT_VECTOR_ELT, getCurSDLoc(), TLI.getValueType(DAG.getDataLayout(), I.getType()), InVec, InIdx)); } void SelectionDAGBuilder::visitShuffleVector(const User &I) { SDValue Src1 = getValue(I.getOperand(0)); SDValue Src2 = getValue(I.getOperand(1)); SmallVector<int, 8> Mask; ShuffleVectorInst::getShuffleMask(cast<Constant>(I.getOperand(2)), Mask); unsigned MaskNumElts = Mask.size(); const TargetLowering &TLI = DAG.getTargetLoweringInfo(); EVT VT = TLI.getValueType(DAG.getDataLayout(), I.getType()); EVT SrcVT = Src1.getValueType(); unsigned SrcNumElts = SrcVT.getVectorNumElements(); if (SrcNumElts == MaskNumElts) { setValue(&I, DAG.getVectorShuffle(VT, getCurSDLoc(), Src1, Src2, Mask)); return; } // Normalize the shuffle vector since mask and vector length don't match. if (SrcNumElts < MaskNumElts && MaskNumElts % SrcNumElts == 0) { // Mask is longer than the source vectors and is a multiple of the source // vectors. We can use concatenate vector to make the mask and vectors // lengths match. unsigned NumConcat = MaskNumElts / SrcNumElts; // Check if the shuffle is some kind of concatenation of the input vectors. bool IsConcat = true; SmallVector<int, 8> ConcatSrcs(NumConcat, -1); for (unsigned i = 0; i != MaskNumElts; ++i) { int Idx = Mask[i]; if (Idx < 0) continue; // Ensure the indices in each SrcVT sized piece are sequential and that // the same source is used for the whole piece. if ((Idx % SrcNumElts != (i % SrcNumElts)) || (ConcatSrcs[i / SrcNumElts] >= 0 && ConcatSrcs[i / SrcNumElts] != (int)(Idx / SrcNumElts))) { IsConcat = false; break; } // Remember which source this index came from. ConcatSrcs[i / SrcNumElts] = Idx / SrcNumElts; } // The shuffle is concatenating multiple vectors together. Just emit // a CONCAT_VECTORS operation. if (IsConcat) { SmallVector<SDValue, 8> ConcatOps; for (auto Src : ConcatSrcs) { if (Src < 0) ConcatOps.push_back(DAG.getUNDEF(SrcVT)); else if (Src == 0) ConcatOps.push_back(Src1); else ConcatOps.push_back(Src2); } setValue(&I, DAG.getNode(ISD::CONCAT_VECTORS, getCurSDLoc(), VT, ConcatOps)); return; } // Pad both vectors with undefs to make them the same length as the mask. SDValue UndefVal = DAG.getUNDEF(SrcVT); SmallVector<SDValue, 8> MOps1(NumConcat, UndefVal); SmallVector<SDValue, 8> MOps2(NumConcat, UndefVal); MOps1[0] = Src1; MOps2[0] = Src2; Src1 = Src1.isUndef() ? DAG.getUNDEF(VT) : DAG.getNode(ISD::CONCAT_VECTORS, getCurSDLoc(), VT, MOps1); Src2 = Src2.isUndef() ? DAG.getUNDEF(VT) : DAG.getNode(ISD::CONCAT_VECTORS, getCurSDLoc(), VT, MOps2); // Readjust mask for new input vector length. SmallVector<int, 8> MappedOps; for (unsigned i = 0; i != MaskNumElts; ++i) { int Idx = Mask[i]; if (Idx >= (int)SrcNumElts) Idx -= SrcNumElts - MaskNumElts; MappedOps.push_back(Idx); } setValue(&I, DAG.getVectorShuffle(VT, getCurSDLoc(), Src1, Src2, MappedOps)); return; } if (SrcNumElts > MaskNumElts) { // Analyze the access pattern of the vector to see if we can extract // two subvectors and do the shuffle. The analysis is done by calculating // the range of elements the mask access on both vectors. int MinRange[2] = { static_cast<int>(SrcNumElts), static_cast<int>(SrcNumElts)}; int MaxRange[2] = {-1, -1}; for (unsigned i = 0; i != MaskNumElts; ++i) { int Idx = Mask[i]; unsigned Input = 0; if (Idx < 0) continue; if (Idx >= (int)SrcNumElts) { Input = 1; Idx -= SrcNumElts; } if (Idx > MaxRange[Input]) MaxRange[Input] = Idx; if (Idx < MinRange[Input]) MinRange[Input] = Idx; } // Check if the access is smaller than the vector size and can we find // a reasonable extract index. int RangeUse[2] = { -1, -1 }; // 0 = Unused, 1 = Extract, -1 = Can not // Extract. int StartIdx[2]; // StartIdx to extract from for (unsigned Input = 0; Input < 2; ++Input) { if (MinRange[Input] >= (int)SrcNumElts && MaxRange[Input] < 0) { RangeUse[Input] = 0; // Unused StartIdx[Input] = 0; continue; } // Find a good start index that is a multiple of the mask length. Then // see if the rest of the elements are in range. StartIdx[Input] = (MinRange[Input]/MaskNumElts)*MaskNumElts; if (MaxRange[Input] - StartIdx[Input] < (int)MaskNumElts && StartIdx[Input] + MaskNumElts <= SrcNumElts) RangeUse[Input] = 1; // Extract from a multiple of the mask length. } if (RangeUse[0] == 0 && RangeUse[1] == 0) { setValue(&I, DAG.getUNDEF(VT)); // Vectors are not used. return; } if (RangeUse[0] >= 0 && RangeUse[1] >= 0) { // Extract appropriate subvector and generate a vector shuffle for (unsigned Input = 0; Input < 2; ++Input) { SDValue &Src = Input == 0 ? Src1 : Src2; if (RangeUse[Input] == 0) Src = DAG.getUNDEF(VT); else { SDLoc dl = getCurSDLoc(); Src = DAG.getNode( ISD::EXTRACT_SUBVECTOR, dl, VT, Src, DAG.getConstant(StartIdx[Input], dl, TLI.getVectorIdxTy(DAG.getDataLayout()))); } } // Calculate new mask. SmallVector<int, 8> MappedOps; for (unsigned i = 0; i != MaskNumElts; ++i) { int Idx = Mask[i]; if (Idx >= 0) { if (Idx < (int)SrcNumElts) Idx -= StartIdx[0]; else Idx -= SrcNumElts + StartIdx[1] - MaskNumElts; } MappedOps.push_back(Idx); } setValue(&I, DAG.getVectorShuffle(VT, getCurSDLoc(), Src1, Src2, MappedOps)); return; } } // We can't use either concat vectors or extract subvectors so fall back to // replacing the shuffle with extract and build vector. // to insert and build vector. EVT EltVT = VT.getVectorElementType(); EVT IdxVT = TLI.getVectorIdxTy(DAG.getDataLayout()); SDLoc dl = getCurSDLoc(); SmallVector<SDValue,8> Ops; for (unsigned i = 0; i != MaskNumElts; ++i) { int Idx = Mask[i]; SDValue Res; if (Idx < 0) { Res = DAG.getUNDEF(EltVT); } else { SDValue &Src = Idx < (int)SrcNumElts ? Src1 : Src2; if (Idx >= (int)SrcNumElts) Idx -= SrcNumElts; Res = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT, Src, DAG.getConstant(Idx, dl, IdxVT)); } Ops.push_back(Res); } setValue(&I, DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Ops)); } void SelectionDAGBuilder::visitInsertValue(const InsertValueInst &I) { const Value *Op0 = I.getOperand(0); const Value *Op1 = I.getOperand(1); Type *AggTy = I.getType(); Type *ValTy = Op1->getType(); bool IntoUndef = isa<UndefValue>(Op0); bool FromUndef = isa<UndefValue>(Op1); unsigned LinearIndex = ComputeLinearIndex(AggTy, I.getIndices()); const TargetLowering &TLI = DAG.getTargetLoweringInfo(); SmallVector<EVT, 4> AggValueVTs; ComputeValueVTs(TLI, DAG.getDataLayout(), AggTy, AggValueVTs); SmallVector<EVT, 4> ValValueVTs; ComputeValueVTs(TLI, DAG.getDataLayout(), ValTy, ValValueVTs); unsigned NumAggValues = AggValueVTs.size(); unsigned NumValValues = ValValueVTs.size(); SmallVector<SDValue, 4> Values(NumAggValues); // Ignore an insertvalue that produces an empty object if (!NumAggValues) { setValue(&I, DAG.getUNDEF(MVT(MVT::Other))); return; } SDValue Agg = getValue(Op0); unsigned i = 0; // Copy the beginning value(s) from the original aggregate. for (; i != LinearIndex; ++i) Values[i] = IntoUndef ? DAG.getUNDEF(AggValueVTs[i]) : SDValue(Agg.getNode(), Agg.getResNo() + i); // Copy values from the inserted value(s). if (NumValValues) { SDValue Val = getValue(Op1); for (; i != LinearIndex + NumValValues; ++i) Values[i] = FromUndef ? DAG.getUNDEF(AggValueVTs[i]) : SDValue(Val.getNode(), Val.getResNo() + i - LinearIndex); } // Copy remaining value(s) from the original aggregate. for (; i != NumAggValues; ++i) Values[i] = IntoUndef ? DAG.getUNDEF(AggValueVTs[i]) : SDValue(Agg.getNode(), Agg.getResNo() + i); setValue(&I, DAG.getNode(ISD::MERGE_VALUES, getCurSDLoc(), DAG.getVTList(AggValueVTs), Values)); } void SelectionDAGBuilder::visitExtractValue(const ExtractValueInst &I) { const Value *Op0 = I.getOperand(0); Type *AggTy = Op0->getType(); Type *ValTy = I.getType(); bool OutOfUndef = isa<UndefValue>(Op0); unsigned LinearIndex = ComputeLinearIndex(AggTy, I.getIndices()); const TargetLowering &TLI = DAG.getTargetLoweringInfo(); SmallVector<EVT, 4> ValValueVTs; ComputeValueVTs(TLI, DAG.getDataLayout(), ValTy, ValValueVTs); unsigned NumValValues = ValValueVTs.size(); // Ignore a extractvalue that produces an empty object if (!NumValValues) { setValue(&I, DAG.getUNDEF(MVT(MVT::Other))); return; } SmallVector<SDValue, 4> Values(NumValValues); SDValue Agg = getValue(Op0); // Copy out the selected value(s). for (unsigned i = LinearIndex; i != LinearIndex + NumValValues; ++i) Values[i - LinearIndex] = OutOfUndef ? DAG.getUNDEF(Agg.getNode()->getValueType(Agg.getResNo() + i)) : SDValue(Agg.getNode(), Agg.getResNo() + i); setValue(&I, DAG.getNode(ISD::MERGE_VALUES, getCurSDLoc(), DAG.getVTList(ValValueVTs), Values)); } void SelectionDAGBuilder::visitGetElementPtr(const User &I) { Value *Op0 = I.getOperand(0); // Note that the pointer operand may be a vector of pointers. Take the scalar // element which holds a pointer. unsigned AS = Op0->getType()->getScalarType()->getPointerAddressSpace(); SDValue N = getValue(Op0); SDLoc dl = getCurSDLoc(); // Normalize Vector GEP - all scalar operands should be converted to the // splat vector. unsigned VectorWidth = I.getType()->isVectorTy() ? cast<VectorType>(I.getType())->getVectorNumElements() : 0; if (VectorWidth && !N.getValueType().isVector()) { LLVMContext &Context = *DAG.getContext(); EVT VT = EVT::getVectorVT(Context, N.getValueType(), VectorWidth); SmallVector<SDValue, 16> Ops(VectorWidth, N); N = DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Ops); } for (gep_type_iterator GTI = gep_type_begin(&I), E = gep_type_end(&I); GTI != E; ++GTI) { const Value *Idx = GTI.getOperand(); if (StructType *StTy = dyn_cast<StructType>(*GTI)) { unsigned Field = cast<Constant>(Idx)->getUniqueInteger().getZExtValue(); if (Field) { // N = N + Offset uint64_t Offset = DL->getStructLayout(StTy)->getElementOffset(Field); // In an inbouds GEP with an offset that is nonnegative even when // interpreted as signed, assume there is no unsigned overflow. SDNodeFlags Flags; if (int64_t(Offset) >= 0 && cast<GEPOperator>(I).isInBounds()) Flags.setNoUnsignedWrap(true); N = DAG.getNode(ISD::ADD, dl, N.getValueType(), N, DAG.getConstant(Offset, dl, N.getValueType()), &Flags); } } else { MVT PtrTy = DAG.getTargetLoweringInfo().getPointerTy(DAG.getDataLayout(), AS); unsigned PtrSize = PtrTy.getSizeInBits(); APInt ElementSize(PtrSize, DL->getTypeAllocSize(GTI.getIndexedType())); // If this is a scalar constant or a splat vector of constants, // handle it quickly. const auto *CI = dyn_cast<ConstantInt>(Idx); if (!CI && isa<ConstantDataVector>(Idx) && cast<ConstantDataVector>(Idx)->getSplatValue()) CI = cast<ConstantInt>(cast<ConstantDataVector>(Idx)->getSplatValue()); if (CI) { if (CI->isZero()) continue; APInt Offs = ElementSize * CI->getValue().sextOrTrunc(PtrSize); SDValue OffsVal = VectorWidth ? DAG.getConstant(Offs, dl, MVT::getVectorVT(PtrTy, VectorWidth)) : DAG.getConstant(Offs, dl, PtrTy); // In an inbouds GEP with an offset that is nonnegative even when // interpreted as signed, assume there is no unsigned overflow. SDNodeFlags Flags; if (Offs.isNonNegative() && cast<GEPOperator>(I).isInBounds()) Flags.setNoUnsignedWrap(true); N = DAG.getNode(ISD::ADD, dl, N.getValueType(), N, OffsVal, &Flags); continue; } // N = N + Idx * ElementSize; SDValue IdxN = getValue(Idx); if (!IdxN.getValueType().isVector() && VectorWidth) { MVT VT = MVT::getVectorVT(IdxN.getValueType().getSimpleVT(), VectorWidth); SmallVector<SDValue, 16> Ops(VectorWidth, IdxN); IdxN = DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Ops); } // If the index is smaller or larger than intptr_t, truncate or extend // it. IdxN = DAG.getSExtOrTrunc(IdxN, dl, N.getValueType()); // If this is a multiply by a power of two, turn it into a shl // immediately. This is a very common case. if (ElementSize != 1) { if (ElementSize.isPowerOf2()) { unsigned Amt = ElementSize.logBase2(); IdxN = DAG.getNode(ISD::SHL, dl, N.getValueType(), IdxN, DAG.getConstant(Amt, dl, IdxN.getValueType())); } else { SDValue Scale = DAG.getConstant(ElementSize, dl, IdxN.getValueType()); IdxN = DAG.getNode(ISD::MUL, dl, N.getValueType(), IdxN, Scale); } } N = DAG.getNode(ISD::ADD, dl, N.getValueType(), N, IdxN); } } setValue(&I, N); } void SelectionDAGBuilder::visitAlloca(const AllocaInst &I) { // If this is a fixed sized alloca in the entry block of the function, // allocate it statically on the stack. if (FuncInfo.StaticAllocaMap.count(&I)) return; // getValue will auto-populate this. SDLoc dl = getCurSDLoc(); Type *Ty = I.getAllocatedType(); const TargetLowering &TLI = DAG.getTargetLoweringInfo(); auto &DL = DAG.getDataLayout(); uint64_t TySize = DL.getTypeAllocSize(Ty); unsigned Align = std::max((unsigned)DL.getPrefTypeAlignment(Ty), I.getAlignment()); SDValue AllocSize = getValue(I.getArraySize()); EVT IntPtr = TLI.getPointerTy(DAG.getDataLayout()); if (AllocSize.getValueType() != IntPtr) AllocSize = DAG.getZExtOrTrunc(AllocSize, dl, IntPtr); AllocSize = DAG.getNode(ISD::MUL, dl, IntPtr, AllocSize, DAG.getConstant(TySize, dl, IntPtr)); // Handle alignment. If the requested alignment is less than or equal to // the stack alignment, ignore it. If the size is greater than or equal to // the stack alignment, we note this in the DYNAMIC_STACKALLOC node. unsigned StackAlign = DAG.getSubtarget().getFrameLowering()->getStackAlignment(); if (Align <= StackAlign) Align = 0; // Round the size of the allocation up to the stack alignment size // by add SA-1 to the size. This doesn't overflow because we're computing // an address inside an alloca. SDNodeFlags Flags; Flags.setNoUnsignedWrap(true); AllocSize = DAG.getNode(ISD::ADD, dl, AllocSize.getValueType(), AllocSize, DAG.getIntPtrConstant(StackAlign - 1, dl), &Flags); // Mask out the low bits for alignment purposes. AllocSize = DAG.getNode(ISD::AND, dl, AllocSize.getValueType(), AllocSize, DAG.getIntPtrConstant(~(uint64_t)(StackAlign - 1), dl)); SDValue Ops[] = { getRoot(), AllocSize, DAG.getIntPtrConstant(Align, dl) }; SDVTList VTs = DAG.getVTList(AllocSize.getValueType(), MVT::Other); SDValue DSA = DAG.getNode(ISD::DYNAMIC_STACKALLOC, dl, VTs, Ops); setValue(&I, DSA); DAG.setRoot(DSA.getValue(1)); assert(FuncInfo.MF->getFrameInfo()->hasVarSizedObjects()); } void SelectionDAGBuilder::visitLoad(const LoadInst &I) { if (I.isAtomic()) return visitAtomicLoad(I); const TargetLowering &TLI = DAG.getTargetLoweringInfo(); const Value *SV = I.getOperand(0); if (TLI.supportSwiftError()) { // Swifterror values can come from either a function parameter with // swifterror attribute or an alloca with swifterror attribute. if (const Argument *Arg = dyn_cast<Argument>(SV)) { if (Arg->hasSwiftErrorAttr()) return visitLoadFromSwiftError(I); } if (const AllocaInst *Alloca = dyn_cast<AllocaInst>(SV)) { if (Alloca->isSwiftError()) return visitLoadFromSwiftError(I); } } SDValue Ptr = getValue(SV); Type *Ty = I.getType(); bool isVolatile = I.isVolatile(); bool isNonTemporal = I.getMetadata(LLVMContext::MD_nontemporal) != nullptr; // The IR notion of invariant_load only guarantees that all *non-faulting* // invariant loads result in the same value. The MI notion of invariant load // guarantees that the load can be legally moved to any location within its // containing function. The MI notion of invariant_load is stronger than the // IR notion of invariant_load -- an MI invariant_load is an IR invariant_load // with a guarantee that the location being loaded from is dereferenceable // throughout the function's lifetime. bool isInvariant = I.getMetadata(LLVMContext::MD_invariant_load) != nullptr && isDereferenceablePointer(SV, DAG.getDataLayout()); unsigned Alignment = I.getAlignment(); AAMDNodes AAInfo; I.getAAMetadata(AAInfo); const MDNode *Ranges = I.getMetadata(LLVMContext::MD_range); SmallVector<EVT, 4> ValueVTs; SmallVector<uint64_t, 4> Offsets; ComputeValueVTs(TLI, DAG.getDataLayout(), Ty, ValueVTs, &Offsets); unsigned NumValues = ValueVTs.size(); if (NumValues == 0) return; SDValue Root; bool ConstantMemory = false; if (isVolatile || NumValues > MaxParallelChains) // Serialize volatile loads with other side effects. Root = getRoot(); else if (AA->pointsToConstantMemory(MemoryLocation( SV, DAG.getDataLayout().getTypeStoreSize(Ty), AAInfo))) { // Do not serialize (non-volatile) loads of constant memory with anything. Root = DAG.getEntryNode(); ConstantMemory = true; } else { // Do not serialize non-volatile loads against each other. Root = DAG.getRoot(); } SDLoc dl = getCurSDLoc(); if (isVolatile) Root = TLI.prepareVolatileOrAtomicLoad(Root, dl, DAG); // An aggregate load cannot wrap around the address space, so offsets to its // parts don't wrap either. SDNodeFlags Flags; Flags.setNoUnsignedWrap(true); SmallVector<SDValue, 4> Values(NumValues); SmallVector<SDValue, 4> Chains(std::min(MaxParallelChains, NumValues)); EVT PtrVT = Ptr.getValueType(); unsigned ChainI = 0; for (unsigned i = 0; i != NumValues; ++i, ++ChainI) { // Serializing loads here may result in excessive register pressure, and // TokenFactor places arbitrary choke points on the scheduler. SD scheduling // could recover a bit by hoisting nodes upward in the chain by recognizing // they are side-effect free or do not alias. The optimizer should really // avoid this case by converting large object/array copies to llvm.memcpy // (MaxParallelChains should always remain as failsafe). if (ChainI == MaxParallelChains) { assert(PendingLoads.empty() && "PendingLoads must be serialized first"); SDValue Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, makeArrayRef(Chains.data(), ChainI)); Root = Chain; ChainI = 0; } SDValue A = DAG.getNode(ISD::ADD, dl, PtrVT, Ptr, DAG.getConstant(Offsets[i], dl, PtrVT), &Flags); SDValue L = DAG.getLoad(ValueVTs[i], dl, Root, A, MachinePointerInfo(SV, Offsets[i]), isVolatile, isNonTemporal, isInvariant, Alignment, AAInfo, Ranges); Values[i] = L; Chains[ChainI] = L.getValue(1); } if (!ConstantMemory) { SDValue Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, makeArrayRef(Chains.data(), ChainI)); if (isVolatile) DAG.setRoot(Chain); else PendingLoads.push_back(Chain); } setValue(&I, DAG.getNode(ISD::MERGE_VALUES, dl, DAG.getVTList(ValueVTs), Values)); } void SelectionDAGBuilder::visitStoreToSwiftError(const StoreInst &I) { const TargetLowering &TLI = DAG.getTargetLoweringInfo(); assert(TLI.supportSwiftError() && "call visitStoreToSwiftError when backend supports swifterror"); SmallVector<EVT, 4> ValueVTs; SmallVector<uint64_t, 4> Offsets; const Value *SrcV = I.getOperand(0); ComputeValueVTs(DAG.getTargetLoweringInfo(), DAG.getDataLayout(), SrcV->getType(), ValueVTs, &Offsets); assert(ValueVTs.size() == 1 && Offsets[0] == 0 && "expect a single EVT for swifterror"); SDValue Src = getValue(SrcV); // Create a virtual register, then update the virtual register. auto &DL = DAG.getDataLayout(); const TargetRegisterClass *RC = TLI.getRegClassFor(TLI.getPointerTy(DL)); unsigned VReg = FuncInfo.MF->getRegInfo().createVirtualRegister(RC); // Chain, DL, Reg, N or Chain, DL, Reg, N, Glue // Chain can be getRoot or getControlRoot. SDValue CopyNode = DAG.getCopyToReg(getRoot(), getCurSDLoc(), VReg, SDValue(Src.getNode(), Src.getResNo())); DAG.setRoot(CopyNode); FuncInfo.setSwiftErrorVReg(FuncInfo.MBB, I.getOperand(1), VReg); } void SelectionDAGBuilder::visitLoadFromSwiftError(const LoadInst &I) { assert(DAG.getTargetLoweringInfo().supportSwiftError() && "call visitLoadFromSwiftError when backend supports swifterror"); assert(!I.isVolatile() && I.getMetadata(LLVMContext::MD_nontemporal) == nullptr && I.getMetadata(LLVMContext::MD_invariant_load) == nullptr && "Support volatile, non temporal, invariant for load_from_swift_error"); const Value *SV = I.getOperand(0); Type *Ty = I.getType(); AAMDNodes AAInfo; I.getAAMetadata(AAInfo); assert(!AA->pointsToConstantMemory(MemoryLocation( SV, DAG.getDataLayout().getTypeStoreSize(Ty), AAInfo)) && "load_from_swift_error should not be constant memory"); SmallVector<EVT, 4> ValueVTs; SmallVector<uint64_t, 4> Offsets; ComputeValueVTs(DAG.getTargetLoweringInfo(), DAG.getDataLayout(), Ty, ValueVTs, &Offsets); assert(ValueVTs.size() == 1 && Offsets[0] == 0 && "expect a single EVT for swifterror"); // Chain, DL, Reg, VT, Glue or Chain, DL, Reg, VT SDValue L = DAG.getCopyFromReg(getRoot(), getCurSDLoc(), FuncInfo.findSwiftErrorVReg(FuncInfo.MBB, SV), ValueVTs[0]); setValue(&I, L); } void SelectionDAGBuilder::visitStore(const StoreInst &I) { if (I.isAtomic()) return visitAtomicStore(I); const Value *SrcV = I.getOperand(0); const Value *PtrV = I.getOperand(1); const TargetLowering &TLI = DAG.getTargetLoweringInfo(); if (TLI.supportSwiftError()) { // Swifterror values can come from either a function parameter with // swifterror attribute or an alloca with swifterror attribute. if (const Argument *Arg = dyn_cast<Argument>(PtrV)) { if (Arg->hasSwiftErrorAttr()) return visitStoreToSwiftError(I); } if (const AllocaInst *Alloca = dyn_cast<AllocaInst>(PtrV)) { if (Alloca->isSwiftError()) return visitStoreToSwiftError(I); } } SmallVector<EVT, 4> ValueVTs; SmallVector<uint64_t, 4> Offsets; ComputeValueVTs(DAG.getTargetLoweringInfo(), DAG.getDataLayout(), SrcV->getType(), ValueVTs, &Offsets); unsigned NumValues = ValueVTs.size(); if (NumValues == 0) return; // Get the lowered operands. Note that we do this after // checking if NumResults is zero, because with zero results // the operands won't have values in the map. SDValue Src = getValue(SrcV); SDValue Ptr = getValue(PtrV); SDValue Root = getRoot(); SmallVector<SDValue, 4> Chains(std::min(MaxParallelChains, NumValues)); EVT PtrVT = Ptr.getValueType(); bool isVolatile = I.isVolatile(); bool isNonTemporal = I.getMetadata(LLVMContext::MD_nontemporal) != nullptr; unsigned Alignment = I.getAlignment(); SDLoc dl = getCurSDLoc(); AAMDNodes AAInfo; I.getAAMetadata(AAInfo); // An aggregate load cannot wrap around the address space, so offsets to its // parts don't wrap either. SDNodeFlags Flags; Flags.setNoUnsignedWrap(true); unsigned ChainI = 0; for (unsigned i = 0; i != NumValues; ++i, ++ChainI) { // See visitLoad comments. if (ChainI == MaxParallelChains) { SDValue Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, makeArrayRef(Chains.data(), ChainI)); Root = Chain; ChainI = 0; } SDValue Add = DAG.getNode(ISD::ADD, dl, PtrVT, Ptr, DAG.getConstant(Offsets[i], dl, PtrVT), &Flags); SDValue St = DAG.getStore(Root, dl, SDValue(Src.getNode(), Src.getResNo() + i), Add, MachinePointerInfo(PtrV, Offsets[i]), isVolatile, isNonTemporal, Alignment, AAInfo); Chains[ChainI] = St; } SDValue StoreNode = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, makeArrayRef(Chains.data(), ChainI)); DAG.setRoot(StoreNode); } void SelectionDAGBuilder::visitMaskedStore(const CallInst &I) { SDLoc sdl = getCurSDLoc(); // llvm.masked.store.*(Src0, Ptr, alignment, Mask) Value *PtrOperand = I.getArgOperand(1); SDValue Ptr = getValue(PtrOperand); SDValue Src0 = getValue(I.getArgOperand(0)); SDValue Mask = getValue(I.getArgOperand(3)); EVT VT = Src0.getValueType(); unsigned Alignment = (cast<ConstantInt>(I.getArgOperand(2)))->getZExtValue(); if (!Alignment) Alignment = DAG.getEVTAlignment(VT); AAMDNodes AAInfo; I.getAAMetadata(AAInfo); MachineMemOperand *MMO = DAG.getMachineFunction(). getMachineMemOperand(MachinePointerInfo(PtrOperand), MachineMemOperand::MOStore, VT.getStoreSize(), Alignment, AAInfo); SDValue StoreNode = DAG.getMaskedStore(getRoot(), sdl, Src0, Ptr, Mask, VT, MMO, false); DAG.setRoot(StoreNode); setValue(&I, StoreNode); } // Get a uniform base for the Gather/Scatter intrinsic. // The first argument of the Gather/Scatter intrinsic is a vector of pointers. // We try to represent it as a base pointer + vector of indices. // Usually, the vector of pointers comes from a 'getelementptr' instruction. // The first operand of the GEP may be a single pointer or a vector of pointers // Example: // %gep.ptr = getelementptr i32, <8 x i32*> %vptr, <8 x i32> %ind // or // %gep.ptr = getelementptr i32, i32* %ptr, <8 x i32> %ind // %res = call <8 x i32> @llvm.masked.gather.v8i32(<8 x i32*> %gep.ptr, .. // // When the first GEP operand is a single pointer - it is the uniform base we // are looking for. If first operand of the GEP is a splat vector - we // extract the spalt value and use it as a uniform base. // In all other cases the function returns 'false'. // static bool getUniformBase(const Value *& Ptr, SDValue& Base, SDValue& Index, SelectionDAGBuilder* SDB) { SelectionDAG& DAG = SDB->DAG; LLVMContext &Context = *DAG.getContext(); assert(Ptr->getType()->isVectorTy() && "Uexpected pointer type"); const GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Ptr); if (!GEP || GEP->getNumOperands() > 2) return false; const Value *GEPPtr = GEP->getPointerOperand(); if (!GEPPtr->getType()->isVectorTy()) Ptr = GEPPtr; else if (!(Ptr = getSplatValue(GEPPtr))) return false; Value *IndexVal = GEP->getOperand(1); // The operands of the GEP may be defined in another basic block. // In this case we'll not find nodes for the operands. if (!SDB->findValue(Ptr) || !SDB->findValue(IndexVal)) return false; Base = SDB->getValue(Ptr); Index = SDB->getValue(IndexVal); // Suppress sign extension. if (SExtInst* Sext = dyn_cast<SExtInst>(IndexVal)) { if (SDB->findValue(Sext->getOperand(0))) { IndexVal = Sext->getOperand(0); Index = SDB->getValue(IndexVal); } } if (!Index.getValueType().isVector()) { unsigned GEPWidth = GEP->getType()->getVectorNumElements(); EVT VT = EVT::getVectorVT(Context, Index.getValueType(), GEPWidth); SmallVector<SDValue, 16> Ops(GEPWidth, Index); Index = DAG.getNode(ISD::BUILD_VECTOR, SDLoc(Index), VT, Ops); } return true; } void SelectionDAGBuilder::visitMaskedScatter(const CallInst &I) { SDLoc sdl = getCurSDLoc(); // llvm.masked.scatter.*(Src0, Ptrs, alignemt, Mask) const Value *Ptr = I.getArgOperand(1); SDValue Src0 = getValue(I.getArgOperand(0)); SDValue Mask = getValue(I.getArgOperand(3)); EVT VT = Src0.getValueType(); unsigned Alignment = (cast<ConstantInt>(I.getArgOperand(2)))->getZExtValue(); if (!Alignment) Alignment = DAG.getEVTAlignment(VT); const TargetLowering &TLI = DAG.getTargetLoweringInfo(); AAMDNodes AAInfo; I.getAAMetadata(AAInfo); SDValue Base; SDValue Index; const Value *BasePtr = Ptr; bool UniformBase = getUniformBase(BasePtr, Base, Index, this); const Value *MemOpBasePtr = UniformBase ? BasePtr : nullptr; MachineMemOperand *MMO = DAG.getMachineFunction(). getMachineMemOperand(MachinePointerInfo(MemOpBasePtr), MachineMemOperand::MOStore, VT.getStoreSize(), Alignment, AAInfo); if (!UniformBase) { Base = DAG.getTargetConstant(0, sdl, TLI.getPointerTy(DAG.getDataLayout())); Index = getValue(Ptr); } SDValue Ops[] = { getRoot(), Src0, Mask, Base, Index }; SDValue Scatter = DAG.getMaskedScatter(DAG.getVTList(MVT::Other), VT, sdl, Ops, MMO); DAG.setRoot(Scatter); setValue(&I, Scatter); } void SelectionDAGBuilder::visitMaskedLoad(const CallInst &I) { SDLoc sdl = getCurSDLoc(); // @llvm.masked.load.*(Ptr, alignment, Mask, Src0) Value *PtrOperand = I.getArgOperand(0); SDValue Ptr = getValue(PtrOperand); SDValue Src0 = getValue(I.getArgOperand(3)); SDValue Mask = getValue(I.getArgOperand(2)); const TargetLowering &TLI = DAG.getTargetLoweringInfo(); EVT VT = TLI.getValueType(DAG.getDataLayout(), I.getType()); unsigned Alignment = (cast<ConstantInt>(I.getArgOperand(1)))->getZExtValue(); if (!Alignment) Alignment = DAG.getEVTAlignment(VT); AAMDNodes AAInfo; I.getAAMetadata(AAInfo); const MDNode *Ranges = I.getMetadata(LLVMContext::MD_range); // Do not serialize masked loads of constant memory with anything. bool AddToChain = !AA->pointsToConstantMemory(MemoryLocation( PtrOperand, DAG.getDataLayout().getTypeStoreSize(I.getType()), AAInfo)); SDValue InChain = AddToChain ? DAG.getRoot() : DAG.getEntryNode(); MachineMemOperand *MMO = DAG.getMachineFunction(). getMachineMemOperand(MachinePointerInfo(PtrOperand), MachineMemOperand::MOLoad, VT.getStoreSize(), Alignment, AAInfo, Ranges); SDValue Load = DAG.getMaskedLoad(VT, sdl, InChain, Ptr, Mask, Src0, VT, MMO, ISD::NON_EXTLOAD); if (AddToChain) { SDValue OutChain = Load.getValue(1); DAG.setRoot(OutChain); } setValue(&I, Load); } void SelectionDAGBuilder::visitMaskedGather(const CallInst &I) { SDLoc sdl = getCurSDLoc(); // @llvm.masked.gather.*(Ptrs, alignment, Mask, Src0) const Value *Ptr = I.getArgOperand(0); SDValue Src0 = getValue(I.getArgOperand(3)); SDValue Mask = getValue(I.getArgOperand(2)); const TargetLowering &TLI = DAG.getTargetLoweringInfo(); EVT VT = TLI.getValueType(DAG.getDataLayout(), I.getType()); unsigned Alignment = (cast<ConstantInt>(I.getArgOperand(1)))->getZExtValue(); if (!Alignment) Alignment = DAG.getEVTAlignment(VT); AAMDNodes AAInfo; I.getAAMetadata(AAInfo); const MDNode *Ranges = I.getMetadata(LLVMContext::MD_range); SDValue Root = DAG.getRoot(); SDValue Base; SDValue Index; const Value *BasePtr = Ptr; bool UniformBase = getUniformBase(BasePtr, Base, Index, this); bool ConstantMemory = false; if (UniformBase && AA->pointsToConstantMemory(MemoryLocation( BasePtr, DAG.getDataLayout().getTypeStoreSize(I.getType()), AAInfo))) { // Do not serialize (non-volatile) loads of constant memory with anything. Root = DAG.getEntryNode(); ConstantMemory = true; } MachineMemOperand *MMO = DAG.getMachineFunction(). getMachineMemOperand(MachinePointerInfo(UniformBase ? BasePtr : nullptr), MachineMemOperand::MOLoad, VT.getStoreSize(), Alignment, AAInfo, Ranges); if (!UniformBase) { Base = DAG.getTargetConstant(0, sdl, TLI.getPointerTy(DAG.getDataLayout())); Index = getValue(Ptr); } SDValue Ops[] = { Root, Src0, Mask, Base, Index }; SDValue Gather = DAG.getMaskedGather(DAG.getVTList(VT, MVT::Other), VT, sdl, Ops, MMO); SDValue OutChain = Gather.getValue(1); if (!ConstantMemory) PendingLoads.push_back(OutChain); setValue(&I, Gather); } void SelectionDAGBuilder::visitAtomicCmpXchg(const AtomicCmpXchgInst &I) { SDLoc dl = getCurSDLoc(); AtomicOrdering SuccessOrder = I.getSuccessOrdering(); AtomicOrdering FailureOrder = I.getFailureOrdering(); SynchronizationScope Scope = I.getSynchScope(); SDValue InChain = getRoot(); MVT MemVT = getValue(I.getCompareOperand()).getSimpleValueType(); SDVTList VTs = DAG.getVTList(MemVT, MVT::i1, MVT::Other); SDValue L = DAG.getAtomicCmpSwap( ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS, dl, MemVT, VTs, InChain, getValue(I.getPointerOperand()), getValue(I.getCompareOperand()), getValue(I.getNewValOperand()), MachinePointerInfo(I.getPointerOperand()), /*Alignment=*/ 0, SuccessOrder, FailureOrder, Scope); SDValue OutChain = L.getValue(2); setValue(&I, L); DAG.setRoot(OutChain); } void SelectionDAGBuilder::visitAtomicRMW(const AtomicRMWInst &I) { SDLoc dl = getCurSDLoc(); ISD::NodeType NT; switch (I.getOperation()) { default: llvm_unreachable("Unknown atomicrmw operation"); case AtomicRMWInst::Xchg: NT = ISD::ATOMIC_SWAP; break; case AtomicRMWInst::Add: NT = ISD::ATOMIC_LOAD_ADD; break; case AtomicRMWInst::Sub: NT = ISD::ATOMIC_LOAD_SUB; break; case AtomicRMWInst::And: NT = ISD::ATOMIC_LOAD_AND; break; case AtomicRMWInst::Nand: NT = ISD::ATOMIC_LOAD_NAND; break; case AtomicRMWInst::Or: NT = ISD::ATOMIC_LOAD_OR; break; case AtomicRMWInst::Xor: NT = ISD::ATOMIC_LOAD_XOR; break; case AtomicRMWInst::Max: NT = ISD::ATOMIC_LOAD_MAX; break; case AtomicRMWInst::Min: NT = ISD::ATOMIC_LOAD_MIN; break; case AtomicRMWInst::UMax: NT = ISD::ATOMIC_LOAD_UMAX; break; case AtomicRMWInst::UMin: NT = ISD::ATOMIC_LOAD_UMIN; break; } AtomicOrdering Order = I.getOrdering(); SynchronizationScope Scope = I.getSynchScope(); SDValue InChain = getRoot(); SDValue L = DAG.getAtomic(NT, dl, getValue(I.getValOperand()).getSimpleValueType(), InChain, getValue(I.getPointerOperand()), getValue(I.getValOperand()), I.getPointerOperand(), /* Alignment=*/ 0, Order, Scope); SDValue OutChain = L.getValue(1); setValue(&I, L); DAG.setRoot(OutChain); } void SelectionDAGBuilder::visitFence(const FenceInst &I) { SDLoc dl = getCurSDLoc(); const TargetLowering &TLI = DAG.getTargetLoweringInfo(); SDValue Ops[3]; Ops[0] = getRoot(); Ops[1] = DAG.getConstant((unsigned)I.getOrdering(), dl, TLI.getPointerTy(DAG.getDataLayout())); Ops[2] = DAG.getConstant(I.getSynchScope(), dl, TLI.getPointerTy(DAG.getDataLayout())); DAG.setRoot(DAG.getNode(ISD::ATOMIC_FENCE, dl, MVT::Other, Ops)); } void SelectionDAGBuilder::visitAtomicLoad(const LoadInst &I) { SDLoc dl = getCurSDLoc(); AtomicOrdering Order = I.getOrdering(); SynchronizationScope Scope = I.getSynchScope(); SDValue InChain = getRoot(); const TargetLowering &TLI = DAG.getTargetLoweringInfo(); EVT VT = TLI.getValueType(DAG.getDataLayout(), I.getType()); if (I.getAlignment() < VT.getSizeInBits() / 8) report_fatal_error("Cannot generate unaligned atomic load"); MachineMemOperand *MMO = DAG.getMachineFunction(). getMachineMemOperand(MachinePointerInfo(I.getPointerOperand()), MachineMemOperand::MOVolatile | MachineMemOperand::MOLoad, VT.getStoreSize(), I.getAlignment() ? I.getAlignment() : DAG.getEVTAlignment(VT)); InChain = TLI.prepareVolatileOrAtomicLoad(InChain, dl, DAG); SDValue L = DAG.getAtomic(ISD::ATOMIC_LOAD, dl, VT, VT, InChain, getValue(I.getPointerOperand()), MMO, Order, Scope); SDValue OutChain = L.getValue(1); setValue(&I, L); DAG.setRoot(OutChain); } void SelectionDAGBuilder::visitAtomicStore(const StoreInst &I) { SDLoc dl = getCurSDLoc(); AtomicOrdering Order = I.getOrdering(); SynchronizationScope Scope = I.getSynchScope(); SDValue InChain = getRoot(); const TargetLowering &TLI = DAG.getTargetLoweringInfo(); EVT VT = TLI.getValueType(DAG.getDataLayout(), I.getValueOperand()->getType()); if (I.getAlignment() < VT.getSizeInBits() / 8) report_fatal_error("Cannot generate unaligned atomic store"); SDValue OutChain = DAG.getAtomic(ISD::ATOMIC_STORE, dl, VT, InChain, getValue(I.getPointerOperand()), getValue(I.getValueOperand()), I.getPointerOperand(), I.getAlignment(), Order, Scope); DAG.setRoot(OutChain); } /// visitTargetIntrinsic - Lower a call of a target intrinsic to an INTRINSIC /// node. void SelectionDAGBuilder::visitTargetIntrinsic(const CallInst &I, unsigned Intrinsic) { bool HasChain = !I.doesNotAccessMemory(); bool OnlyLoad = HasChain && I.onlyReadsMemory(); // Build the operand list. SmallVector<SDValue, 8> Ops; if (HasChain) { // If this intrinsic has side-effects, chainify it. if (OnlyLoad) { // We don't need to serialize loads against other loads. Ops.push_back(DAG.getRoot()); } else { Ops.push_back(getRoot()); } } // Info is set by getTgtMemInstrinsic TargetLowering::IntrinsicInfo Info; const TargetLowering &TLI = DAG.getTargetLoweringInfo(); bool IsTgtIntrinsic = TLI.getTgtMemIntrinsic(Info, I, Intrinsic); // Add the intrinsic ID as an integer operand if it's not a target intrinsic. if (!IsTgtIntrinsic || Info.opc == ISD::INTRINSIC_VOID || Info.opc == ISD::INTRINSIC_W_CHAIN) Ops.push_back(DAG.getTargetConstant(Intrinsic, getCurSDLoc(), TLI.getPointerTy(DAG.getDataLayout()))); // Add all operands of the call to the operand list. for (unsigned i = 0, e = I.getNumArgOperands(); i != e; ++i) { SDValue Op = getValue(I.getArgOperand(i)); Ops.push_back(Op); } SmallVector<EVT, 4> ValueVTs; ComputeValueVTs(TLI, DAG.getDataLayout(), I.getType(), ValueVTs); if (HasChain) ValueVTs.push_back(MVT::Other); SDVTList VTs = DAG.getVTList(ValueVTs); // Create the node. SDValue Result; if (IsTgtIntrinsic) { // This is target intrinsic that touches memory Result = DAG.getMemIntrinsicNode(Info.opc, getCurSDLoc(), VTs, Ops, Info.memVT, MachinePointerInfo(Info.ptrVal, Info.offset), Info.align, Info.vol, Info.readMem, Info.writeMem, Info.size); } else if (!HasChain) { Result = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, getCurSDLoc(), VTs, Ops); } else if (!I.getType()->isVoidTy()) { Result = DAG.getNode(ISD::INTRINSIC_W_CHAIN, getCurSDLoc(), VTs, Ops); } else { Result = DAG.getNode(ISD::INTRINSIC_VOID, getCurSDLoc(), VTs, Ops); } if (HasChain) { SDValue Chain = Result.getValue(Result.getNode()->getNumValues()-1); if (OnlyLoad) PendingLoads.push_back(Chain); else DAG.setRoot(Chain); } if (!I.getType()->isVoidTy()) { if (VectorType *PTy = dyn_cast<VectorType>(I.getType())) { EVT VT = TLI.getValueType(DAG.getDataLayout(), PTy); Result = DAG.getNode(ISD::BITCAST, getCurSDLoc(), VT, Result); } else Result = lowerRangeToAssertZExt(DAG, I, Result); setValue(&I, Result); } } /// GetSignificand - Get the significand and build it into a floating-point /// number with exponent of 1: /// /// Op = (Op & 0x007fffff) | 0x3f800000; /// /// where Op is the hexadecimal representation of floating point value. static SDValue GetSignificand(SelectionDAG &DAG, SDValue Op, const SDLoc &dl) { SDValue t1 = DAG.getNode(ISD::AND, dl, MVT::i32, Op, DAG.getConstant(0x007fffff, dl, MVT::i32)); SDValue t2 = DAG.getNode(ISD::OR, dl, MVT::i32, t1, DAG.getConstant(0x3f800000, dl, MVT::i32)); return DAG.getNode(ISD::BITCAST, dl, MVT::f32, t2); } /// GetExponent - Get the exponent: /// /// (float)(int)(((Op & 0x7f800000) >> 23) - 127); /// /// where Op is the hexadecimal representation of floating point value. static SDValue GetExponent(SelectionDAG &DAG, SDValue Op, const TargetLowering &TLI, const SDLoc &dl) { SDValue t0 = DAG.getNode(ISD::AND, dl, MVT::i32, Op, DAG.getConstant(0x7f800000, dl, MVT::i32)); SDValue t1 = DAG.getNode( ISD::SRL, dl, MVT::i32, t0, DAG.getConstant(23, dl, TLI.getPointerTy(DAG.getDataLayout()))); SDValue t2 = DAG.getNode(ISD::SUB, dl, MVT::i32, t1, DAG.getConstant(127, dl, MVT::i32)); return DAG.getNode(ISD::SINT_TO_FP, dl, MVT::f32, t2); } /// getF32Constant - Get 32-bit floating point constant. static SDValue getF32Constant(SelectionDAG &DAG, unsigned Flt, const SDLoc &dl) { return DAG.getConstantFP(APFloat(APFloat::IEEEsingle, APInt(32, Flt)), dl, MVT::f32); } static SDValue getLimitedPrecisionExp2(SDValue t0, const SDLoc &dl, SelectionDAG &DAG) { // TODO: What fast-math-flags should be set on the floating-point nodes? // IntegerPartOfX = ((int32_t)(t0); SDValue IntegerPartOfX = DAG.getNode(ISD::FP_TO_SINT, dl, MVT::i32, t0); // FractionalPartOfX = t0 - (float)IntegerPartOfX; SDValue t1 = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::f32, IntegerPartOfX); SDValue X = DAG.getNode(ISD::FSUB, dl, MVT::f32, t0, t1); // IntegerPartOfX <<= 23; IntegerPartOfX = DAG.getNode( ISD::SHL, dl, MVT::i32, IntegerPartOfX, DAG.getConstant(23, dl, DAG.getTargetLoweringInfo().getPointerTy( DAG.getDataLayout()))); SDValue TwoToFractionalPartOfX; if (LimitFloatPrecision <= 6) { // For floating-point precision of 6: // // TwoToFractionalPartOfX = // 0.997535578f + // (0.735607626f + 0.252464424f * x) * x; // // error 0.0144103317, which is 6 bits SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X, getF32Constant(DAG, 0x3e814304, dl)); SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2, getF32Constant(DAG, 0x3f3c50c8, dl)); SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X); TwoToFractionalPartOfX = DAG.getNode(ISD::FADD, dl, MVT::f32, t4, getF32Constant(DAG, 0x3f7f5e7e, dl)); } else if (LimitFloatPrecision <= 12) { // For floating-point precision of 12: // // TwoToFractionalPartOfX = // 0.999892986f + // (0.696457318f + // (0.224338339f + 0.792043434e-1f * x) * x) * x; // // error 0.000107046256, which is 13 to 14 bits SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X, getF32Constant(DAG, 0x3da235e3, dl)); SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2, getF32Constant(DAG, 0x3e65b8f3, dl)); SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X); SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4, getF32Constant(DAG, 0x3f324b07, dl)); SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X); TwoToFractionalPartOfX = DAG.getNode(ISD::FADD, dl, MVT::f32, t6, getF32Constant(DAG, 0x3f7ff8fd, dl)); } else { // LimitFloatPrecision <= 18 // For floating-point precision of 18: // // TwoToFractionalPartOfX = // 0.999999982f + // (0.693148872f + // (0.240227044f + // (0.554906021e-1f + // (0.961591928e-2f + // (0.136028312e-2f + 0.157059148e-3f *x)*x)*x)*x)*x)*x; // error 2.47208000*10^(-7), which is better than 18 bits SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X, getF32Constant(DAG, 0x3924b03e, dl)); SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2, getF32Constant(DAG, 0x3ab24b87, dl)); SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X); SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4, getF32Constant(DAG, 0x3c1d8c17, dl)); SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X); SDValue t7 = DAG.getNode(ISD::FADD, dl, MVT::f32, t6, getF32Constant(DAG, 0x3d634a1d, dl)); SDValue t8 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t7, X); SDValue t9 = DAG.getNode(ISD::FADD, dl, MVT::f32, t8, getF32Constant(DAG, 0x3e75fe14, dl)); SDValue t10 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t9, X); SDValue t11 = DAG.getNode(ISD::FADD, dl, MVT::f32, t10, getF32Constant(DAG, 0x3f317234, dl)); SDValue t12 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t11, X); TwoToFractionalPartOfX = DAG.getNode(ISD::FADD, dl, MVT::f32, t12, getF32Constant(DAG, 0x3f800000, dl)); } // Add the exponent into the result in integer domain. SDValue t13 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, TwoToFractionalPartOfX); return DAG.getNode(ISD::BITCAST, dl, MVT::f32, DAG.getNode(ISD::ADD, dl, MVT::i32, t13, IntegerPartOfX)); } /// expandExp - Lower an exp intrinsic. Handles the special sequences for /// limited-precision mode. static SDValue expandExp(const SDLoc &dl, SDValue Op, SelectionDAG &DAG, const TargetLowering &TLI) { if (Op.getValueType() == MVT::f32 && LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) { // Put the exponent in the right bit position for later addition to the // final result: // // #define LOG2OFe 1.4426950f // t0 = Op * LOG2OFe // TODO: What fast-math-flags should be set here? SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, Op, getF32Constant(DAG, 0x3fb8aa3b, dl)); return getLimitedPrecisionExp2(t0, dl, DAG); } // No special expansion. return DAG.getNode(ISD::FEXP, dl, Op.getValueType(), Op); } /// expandLog - Lower a log intrinsic. Handles the special sequences for /// limited-precision mode. static SDValue expandLog(const SDLoc &dl, SDValue Op, SelectionDAG &DAG, const TargetLowering &TLI) { // TODO: What fast-math-flags should be set on the floating-point nodes? if (Op.getValueType() == MVT::f32 && LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) { SDValue Op1 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Op); // Scale the exponent by log(2) [0.69314718f]. SDValue Exp = GetExponent(DAG, Op1, TLI, dl); SDValue LogOfExponent = DAG.getNode(ISD::FMUL, dl, MVT::f32, Exp, getF32Constant(DAG, 0x3f317218, dl)); // Get the significand and build it into a floating-point number with // exponent of 1. SDValue X = GetSignificand(DAG, Op1, dl); SDValue LogOfMantissa; if (LimitFloatPrecision <= 6) { // For floating-point precision of 6: // // LogofMantissa = // -1.1609546f + // (1.4034025f - 0.23903021f * x) * x; // // error 0.0034276066, which is better than 8 bits SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X, getF32Constant(DAG, 0xbe74c456, dl)); SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0, getF32Constant(DAG, 0x3fb3a2b1, dl)); SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X); LogOfMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2, getF32Constant(DAG, 0x3f949a29, dl)); } else if (LimitFloatPrecision <= 12) { // For floating-point precision of 12: // // LogOfMantissa = // -1.7417939f + // (2.8212026f + // (-1.4699568f + // (0.44717955f - 0.56570851e-1f * x) * x) * x) * x; // // error 0.000061011436, which is 14 bits SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X, getF32Constant(DAG, 0xbd67b6d6, dl)); SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0, getF32Constant(DAG, 0x3ee4f4b8, dl)); SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X); SDValue t3 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2, getF32Constant(DAG, 0x3fbc278b, dl)); SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X); SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4, getF32Constant(DAG, 0x40348e95, dl)); SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X); LogOfMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t6, getF32Constant(DAG, 0x3fdef31a, dl)); } else { // LimitFloatPrecision <= 18 // For floating-point precision of 18: // // LogOfMantissa = // -2.1072184f + // (4.2372794f + // (-3.7029485f + // (2.2781945f + // (-0.87823314f + // (0.19073739f - 0.17809712e-1f * x) * x) * x) * x) * x)*x; // // error 0.0000023660568, which is better than 18 bits SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X, getF32Constant(DAG, 0xbc91e5ac, dl)); SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0, getF32Constant(DAG, 0x3e4350aa, dl)); SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X); SDValue t3 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2, getF32Constant(DAG, 0x3f60d3e3, dl)); SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X); SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4, getF32Constant(DAG, 0x4011cdf0, dl)); SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X); SDValue t7 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t6, getF32Constant(DAG, 0x406cfd1c, dl)); SDValue t8 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t7, X); SDValue t9 = DAG.getNode(ISD::FADD, dl, MVT::f32, t8, getF32Constant(DAG, 0x408797cb, dl)); SDValue t10 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t9, X); LogOfMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t10, getF32Constant(DAG, 0x4006dcab, dl)); } return DAG.getNode(ISD::FADD, dl, MVT::f32, LogOfExponent, LogOfMantissa); } // No special expansion. return DAG.getNode(ISD::FLOG, dl, Op.getValueType(), Op); } /// expandLog2 - Lower a log2 intrinsic. Handles the special sequences for /// limited-precision mode. static SDValue expandLog2(const SDLoc &dl, SDValue Op, SelectionDAG &DAG, const TargetLowering &TLI) { // TODO: What fast-math-flags should be set on the floating-point nodes? if (Op.getValueType() == MVT::f32 && LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) { SDValue Op1 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Op); // Get the exponent. SDValue LogOfExponent = GetExponent(DAG, Op1, TLI, dl); // Get the significand and build it into a floating-point number with // exponent of 1. SDValue X = GetSignificand(DAG, Op1, dl); // Different possible minimax approximations of significand in // floating-point for various degrees of accuracy over [1,2]. SDValue Log2ofMantissa; if (LimitFloatPrecision <= 6) { // For floating-point precision of 6: // // Log2ofMantissa = -1.6749035f + (2.0246817f - .34484768f * x) * x; // // error 0.0049451742, which is more than 7 bits SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X, getF32Constant(DAG, 0xbeb08fe0, dl)); SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0, getF32Constant(DAG, 0x40019463, dl)); SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X); Log2ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2, getF32Constant(DAG, 0x3fd6633d, dl)); } else if (LimitFloatPrecision <= 12) { // For floating-point precision of 12: // // Log2ofMantissa = // -2.51285454f + // (4.07009056f + // (-2.12067489f + // (.645142248f - 0.816157886e-1f * x) * x) * x) * x; // // error 0.0000876136000, which is better than 13 bits SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X, getF32Constant(DAG, 0xbda7262e, dl)); SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0, getF32Constant(DAG, 0x3f25280b, dl)); SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X); SDValue t3 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2, getF32Constant(DAG, 0x4007b923, dl)); SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X); SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4, getF32Constant(DAG, 0x40823e2f, dl)); SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X); Log2ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t6, getF32Constant(DAG, 0x4020d29c, dl)); } else { // LimitFloatPrecision <= 18 // For floating-point precision of 18: // // Log2ofMantissa = // -3.0400495f + // (6.1129976f + // (-5.3420409f + // (3.2865683f + // (-1.2669343f + // (0.27515199f - // 0.25691327e-1f * x) * x) * x) * x) * x) * x; // // error 0.0000018516, which is better than 18 bits SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X, getF32Constant(DAG, 0xbcd2769e, dl)); SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0, getF32Constant(DAG, 0x3e8ce0b9, dl)); SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X); SDValue t3 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2, getF32Constant(DAG, 0x3fa22ae7, dl)); SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X); SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4, getF32Constant(DAG, 0x40525723, dl)); SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X); SDValue t7 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t6, getF32Constant(DAG, 0x40aaf200, dl)); SDValue t8 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t7, X); SDValue t9 = DAG.getNode(ISD::FADD, dl, MVT::f32, t8, getF32Constant(DAG, 0x40c39dad, dl)); SDValue t10 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t9, X); Log2ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t10, getF32Constant(DAG, 0x4042902c, dl)); } return DAG.getNode(ISD::FADD, dl, MVT::f32, LogOfExponent, Log2ofMantissa); } // No special expansion. return DAG.getNode(ISD::FLOG2, dl, Op.getValueType(), Op); } /// expandLog10 - Lower a log10 intrinsic. Handles the special sequences for /// limited-precision mode. static SDValue expandLog10(const SDLoc &dl, SDValue Op, SelectionDAG &DAG, const TargetLowering &TLI) { // TODO: What fast-math-flags should be set on the floating-point nodes? if (Op.getValueType() == MVT::f32 && LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) { SDValue Op1 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Op); // Scale the exponent by log10(2) [0.30102999f]. SDValue Exp = GetExponent(DAG, Op1, TLI, dl); SDValue LogOfExponent = DAG.getNode(ISD::FMUL, dl, MVT::f32, Exp, getF32Constant(DAG, 0x3e9a209a, dl)); // Get the significand and build it into a floating-point number with // exponent of 1. SDValue X = GetSignificand(DAG, Op1, dl); SDValue Log10ofMantissa; if (LimitFloatPrecision <= 6) { // For floating-point precision of 6: // // Log10ofMantissa = // -0.50419619f + // (0.60948995f - 0.10380950f * x) * x; // // error 0.0014886165, which is 6 bits SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X, getF32Constant(DAG, 0xbdd49a13, dl)); SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0, getF32Constant(DAG, 0x3f1c0789, dl)); SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X); Log10ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2, getF32Constant(DAG, 0x3f011300, dl)); } else if (LimitFloatPrecision <= 12) { // For floating-point precision of 12: // // Log10ofMantissa = // -0.64831180f + // (0.91751397f + // (-0.31664806f + 0.47637168e-1f * x) * x) * x; // // error 0.00019228036, which is better than 12 bits SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X, getF32Constant(DAG, 0x3d431f31, dl)); SDValue t1 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t0, getF32Constant(DAG, 0x3ea21fb2, dl)); SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X); SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2, getF32Constant(DAG, 0x3f6ae232, dl)); SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X); Log10ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t4, getF32Constant(DAG, 0x3f25f7c3, dl)); } else { // LimitFloatPrecision <= 18 // For floating-point precision of 18: // // Log10ofMantissa = // -0.84299375f + // (1.5327582f + // (-1.0688956f + // (0.49102474f + // (-0.12539807f + 0.13508273e-1f * x) * x) * x) * x) * x; // // error 0.0000037995730, which is better than 18 bits SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X, getF32Constant(DAG, 0x3c5d51ce, dl)); SDValue t1 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t0, getF32Constant(DAG, 0x3e00685a, dl)); SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X); SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2, getF32Constant(DAG, 0x3efb6798, dl)); SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X); SDValue t5 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t4, getF32Constant(DAG, 0x3f88d192, dl)); SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X); SDValue t7 = DAG.getNode(ISD::FADD, dl, MVT::f32, t6, getF32Constant(DAG, 0x3fc4316c, dl)); SDValue t8 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t7, X); Log10ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t8, getF32Constant(DAG, 0x3f57ce70, dl)); } return DAG.getNode(ISD::FADD, dl, MVT::f32, LogOfExponent, Log10ofMantissa); } // No special expansion. return DAG.getNode(ISD::FLOG10, dl, Op.getValueType(), Op); } /// expandExp2 - Lower an exp2 intrinsic. Handles the special sequences for /// limited-precision mode. static SDValue expandExp2(const SDLoc &dl, SDValue Op, SelectionDAG &DAG, const TargetLowering &TLI) { if (Op.getValueType() == MVT::f32 && LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) return getLimitedPrecisionExp2(Op, dl, DAG); // No special expansion. return DAG.getNode(ISD::FEXP2, dl, Op.getValueType(), Op); } /// visitPow - Lower a pow intrinsic. Handles the special sequences for /// limited-precision mode with x == 10.0f. static SDValue expandPow(const SDLoc &dl, SDValue LHS, SDValue RHS, SelectionDAG &DAG, const TargetLowering &TLI) { bool IsExp10 = false; if (LHS.getValueType() == MVT::f32 && RHS.getValueType() == MVT::f32 && LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) { if (ConstantFPSDNode *LHSC = dyn_cast<ConstantFPSDNode>(LHS)) { APFloat Ten(10.0f); IsExp10 = LHSC->isExactlyValue(Ten); } } // TODO: What fast-math-flags should be set on the FMUL node? if (IsExp10) { // Put the exponent in the right bit position for later addition to the // final result: // // #define LOG2OF10 3.3219281f // t0 = Op * LOG2OF10; SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, RHS, getF32Constant(DAG, 0x40549a78, dl)); return getLimitedPrecisionExp2(t0, dl, DAG); } // No special expansion. return DAG.getNode(ISD::FPOW, dl, LHS.getValueType(), LHS, RHS); } /// ExpandPowI - Expand a llvm.powi intrinsic. static SDValue ExpandPowI(const SDLoc &DL, SDValue LHS, SDValue RHS, SelectionDAG &DAG) { // If RHS is a constant, we can expand this out to a multiplication tree, // otherwise we end up lowering to a call to __powidf2 (for example). When // optimizing for size, we only want to do this if the expansion would produce // a small number of multiplies, otherwise we do the full expansion. if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(RHS)) { // Get the exponent as a positive value. unsigned Val = RHSC->getSExtValue(); if ((int)Val < 0) Val = -Val; // powi(x, 0) -> 1.0 if (Val == 0) return DAG.getConstantFP(1.0, DL, LHS.getValueType()); const Function *F = DAG.getMachineFunction().getFunction(); if (!F->optForSize() || // If optimizing for size, don't insert too many multiplies. // This inserts up to 5 multiplies. countPopulation(Val) + Log2_32(Val) < 7) { // We use the simple binary decomposition method to generate the multiply // sequence. There are more optimal ways to do this (for example, // powi(x,15) generates one more multiply than it should), but this has // the benefit of being both really simple and much better than a libcall. SDValue Res; // Logically starts equal to 1.0 SDValue CurSquare = LHS; // TODO: Intrinsics should have fast-math-flags that propagate to these // nodes. while (Val) { if (Val & 1) { if (Res.getNode()) Res = DAG.getNode(ISD::FMUL, DL,Res.getValueType(), Res, CurSquare); else Res = CurSquare; // 1.0*CurSquare. } CurSquare = DAG.getNode(ISD::FMUL, DL, CurSquare.getValueType(), CurSquare, CurSquare); Val >>= 1; } // If the original was negative, invert the result, producing 1/(x*x*x). if (RHSC->getSExtValue() < 0) Res = DAG.getNode(ISD::FDIV, DL, LHS.getValueType(), DAG.getConstantFP(1.0, DL, LHS.getValueType()), Res); return Res; } } // Otherwise, expand to a libcall. return DAG.getNode(ISD::FPOWI, DL, LHS.getValueType(), LHS, RHS); } // getUnderlyingArgReg - Find underlying register used for a truncated or // bitcasted argument. static unsigned getUnderlyingArgReg(const SDValue &N) { switch (N.getOpcode()) { case ISD::CopyFromReg: return cast<RegisterSDNode>(N.getOperand(1))->getReg(); case ISD::BITCAST: case ISD::AssertZext: case ISD::AssertSext: case ISD::TRUNCATE: return getUnderlyingArgReg(N.getOperand(0)); default: return 0; } } /// EmitFuncArgumentDbgValue - If the DbgValueInst is a dbg_value of a function /// argument, create the corresponding DBG_VALUE machine instruction for it now. /// At the end of instruction selection, they will be inserted to the entry BB. bool SelectionDAGBuilder::EmitFuncArgumentDbgValue( const Value *V, DILocalVariable *Variable, DIExpression *Expr, DILocation *DL, int64_t Offset, bool IsIndirect, const SDValue &N) { const Argument *Arg = dyn_cast<Argument>(V); if (!Arg) return false; MachineFunction &MF = DAG.getMachineFunction(); const TargetInstrInfo *TII = DAG.getSubtarget().getInstrInfo(); // Ignore inlined function arguments here. // // FIXME: Should we be checking DL->inlinedAt() to determine this? if (!Variable->getScope()->getSubprogram()->describes(MF.getFunction())) return false; Optional<MachineOperand> Op; // Some arguments' frame index is recorded during argument lowering. if (int FI = FuncInfo.getArgumentFrameIndex(Arg)) Op = MachineOperand::CreateFI(FI); if (!Op && N.getNode()) { unsigned Reg = getUnderlyingArgReg(N); if (Reg && TargetRegisterInfo::isVirtualRegister(Reg)) { MachineRegisterInfo &RegInfo = MF.getRegInfo(); unsigned PR = RegInfo.getLiveInPhysReg(Reg); if (PR) Reg = PR; } if (Reg) Op = MachineOperand::CreateReg(Reg, false); } if (!Op) { // Check if ValueMap has reg number. DenseMap<const Value *, unsigned>::iterator VMI = FuncInfo.ValueMap.find(V); if (VMI != FuncInfo.ValueMap.end()) Op = MachineOperand::CreateReg(VMI->second, false); } if (!Op && N.getNode()) // Check if frame index is available. if (LoadSDNode *LNode = dyn_cast<LoadSDNode>(N.getNode())) if (FrameIndexSDNode *FINode = dyn_cast<FrameIndexSDNode>(LNode->getBasePtr().getNode())) Op = MachineOperand::CreateFI(FINode->getIndex()); if (!Op) return false; assert(Variable->isValidLocationForIntrinsic(DL) && "Expected inlined-at fields to agree"); if (Op->isReg()) FuncInfo.ArgDbgValues.push_back( BuildMI(MF, DL, TII->get(TargetOpcode::DBG_VALUE), IsIndirect, Op->getReg(), Offset, Variable, Expr)); else FuncInfo.ArgDbgValues.push_back( BuildMI(MF, DL, TII->get(TargetOpcode::DBG_VALUE)) .addOperand(*Op) .addImm(Offset) .addMetadata(Variable) .addMetadata(Expr)); return true; } // VisualStudio defines setjmp as _setjmp #if defined(_MSC_VER) && defined(setjmp) && \ !defined(setjmp_undefined_for_msvc) # pragma push_macro("setjmp") # undef setjmp # define setjmp_undefined_for_msvc #endif /// visitIntrinsicCall - Lower the call to the specified intrinsic function. If /// we want to emit this as a call to a named external function, return the name /// otherwise lower it and return null. const char * SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I, unsigned Intrinsic) { const TargetLowering &TLI = DAG.getTargetLoweringInfo(); SDLoc sdl = getCurSDLoc(); DebugLoc dl = getCurDebugLoc(); SDValue Res; switch (Intrinsic) { default: // By default, turn this into a target intrinsic node. visitTargetIntrinsic(I, Intrinsic); return nullptr; case Intrinsic::vastart: visitVAStart(I); return nullptr; case Intrinsic::vaend: visitVAEnd(I); return nullptr; case Intrinsic::vacopy: visitVACopy(I); return nullptr; case Intrinsic::returnaddress: setValue(&I, DAG.getNode(ISD::RETURNADDR, sdl, TLI.getPointerTy(DAG.getDataLayout()), getValue(I.getArgOperand(0)))); return nullptr; case Intrinsic::frameaddress: setValue(&I, DAG.getNode(ISD::FRAMEADDR, sdl, TLI.getPointerTy(DAG.getDataLayout()), getValue(I.getArgOperand(0)))); return nullptr; case Intrinsic::read_register: { Value *Reg = I.getArgOperand(0); SDValue Chain = getRoot(); SDValue RegName = DAG.getMDNode(cast<MDNode>(cast<MetadataAsValue>(Reg)->getMetadata())); EVT VT = TLI.getValueType(DAG.getDataLayout(), I.getType()); Res = DAG.getNode(ISD::READ_REGISTER, sdl, DAG.getVTList(VT, MVT::Other), Chain, RegName); setValue(&I, Res); DAG.setRoot(Res.getValue(1)); return nullptr; } case Intrinsic::write_register: { Value *Reg = I.getArgOperand(0); Value *RegValue = I.getArgOperand(1); SDValue Chain = getRoot(); SDValue RegName = DAG.getMDNode(cast<MDNode>(cast<MetadataAsValue>(Reg)->getMetadata())); DAG.setRoot(DAG.getNode(ISD::WRITE_REGISTER, sdl, MVT::Other, Chain, RegName, getValue(RegValue))); return nullptr; } case Intrinsic::setjmp: return &"_setjmp"[!TLI.usesUnderscoreSetJmp()]; case Intrinsic::longjmp: return &"_longjmp"[!TLI.usesUnderscoreLongJmp()]; case Intrinsic::memcpy: { SDValue Op1 = getValue(I.getArgOperand(0)); SDValue Op2 = getValue(I.getArgOperand(1)); SDValue Op3 = getValue(I.getArgOperand(2)); unsigned Align = cast<ConstantInt>(I.getArgOperand(3))->getZExtValue(); if (!Align) Align = 1; // @llvm.memcpy defines 0 and 1 to both mean no alignment. bool isVol = cast<ConstantInt>(I.getArgOperand(4))->getZExtValue(); bool isTC = I.isTailCall() && isInTailCallPosition(&I, DAG.getTarget()); SDValue MC = DAG.getMemcpy(getRoot(), sdl, Op1, Op2, Op3, Align, isVol, false, isTC, MachinePointerInfo(I.getArgOperand(0)), MachinePointerInfo(I.getArgOperand(1))); updateDAGForMaybeTailCall(MC); return nullptr; } case Intrinsic::memset: { SDValue Op1 = getValue(I.getArgOperand(0)); SDValue Op2 = getValue(I.getArgOperand(1)); SDValue Op3 = getValue(I.getArgOperand(2)); unsigned Align = cast<ConstantInt>(I.getArgOperand(3))->getZExtValue(); if (!Align) Align = 1; // @llvm.memset defines 0 and 1 to both mean no alignment. bool isVol = cast<ConstantInt>(I.getArgOperand(4))->getZExtValue(); bool isTC = I.isTailCall() && isInTailCallPosition(&I, DAG.getTarget()); SDValue MS = DAG.getMemset(getRoot(), sdl, Op1, Op2, Op3, Align, isVol, isTC, MachinePointerInfo(I.getArgOperand(0))); updateDAGForMaybeTailCall(MS); return nullptr; } case Intrinsic::memmove: { SDValue Op1 = getValue(I.getArgOperand(0)); SDValue Op2 = getValue(I.getArgOperand(1)); SDValue Op3 = getValue(I.getArgOperand(2)); unsigned Align = cast<ConstantInt>(I.getArgOperand(3))->getZExtValue(); if (!Align) Align = 1; // @llvm.memmove defines 0 and 1 to both mean no alignment. bool isVol = cast<ConstantInt>(I.getArgOperand(4))->getZExtValue(); bool isTC = I.isTailCall() && isInTailCallPosition(&I, DAG.getTarget()); SDValue MM = DAG.getMemmove(getRoot(), sdl, Op1, Op2, Op3, Align, isVol, isTC, MachinePointerInfo(I.getArgOperand(0)), MachinePointerInfo(I.getArgOperand(1))); updateDAGForMaybeTailCall(MM); return nullptr; } case Intrinsic::dbg_declare: { const DbgDeclareInst &DI = cast<DbgDeclareInst>(I); DILocalVariable *Variable = DI.getVariable(); DIExpression *Expression = DI.getExpression(); const Value *Address = DI.getAddress(); assert(Variable && "Missing variable"); if (!Address) { DEBUG(dbgs() << "Dropping debug info for " << DI << "\n"); return nullptr; } // Check if address has undef value. if (isa<UndefValue>(Address) || (Address->use_empty() && !isa<Argument>(Address))) { DEBUG(dbgs() << "Dropping debug info for " << DI << "\n"); return nullptr; } SDValue &N = NodeMap[Address]; if (!N.getNode() && isa<Argument>(Address)) // Check unused arguments map. N = UnusedArgNodeMap[Address]; SDDbgValue *SDV; if (N.getNode()) { if (const BitCastInst *BCI = dyn_cast<BitCastInst>(Address)) Address = BCI->getOperand(0); // Parameters are handled specially. bool isParameter = Variable->isParameter() || isa<Argument>(Address); auto FINode = dyn_cast<FrameIndexSDNode>(N.getNode()); if (isParameter && FINode) { // Byval parameter. We have a frame index at this point. SDV = DAG.getFrameIndexDbgValue(Variable, Expression, FINode->getIndex(), 0, dl, SDNodeOrder); } else if (isa<Argument>(Address)) { // Address is an argument, so try to emit its dbg value using // virtual register info from the FuncInfo.ValueMap. EmitFuncArgumentDbgValue(Address, Variable, Expression, dl, 0, false, N); return nullptr; } else { SDV = DAG.getDbgValue(Variable, Expression, N.getNode(), N.getResNo(), true, 0, dl, SDNodeOrder); } DAG.AddDbgValue(SDV, N.getNode(), isParameter); } else { // If Address is an argument then try to emit its dbg value using // virtual register info from the FuncInfo.ValueMap. if (!EmitFuncArgumentDbgValue(Address, Variable, Expression, dl, 0, false, N)) { // If variable is pinned by a alloca in dominating bb then // use StaticAllocaMap. if (const AllocaInst *AI = dyn_cast<AllocaInst>(Address)) { if (AI->getParent() != DI.getParent()) { DenseMap<const AllocaInst*, int>::iterator SI = FuncInfo.StaticAllocaMap.find(AI); if (SI != FuncInfo.StaticAllocaMap.end()) { SDV = DAG.getFrameIndexDbgValue(Variable, Expression, SI->second, 0, dl, SDNodeOrder); DAG.AddDbgValue(SDV, nullptr, false); return nullptr; } } } DEBUG(dbgs() << "Dropping debug info for " << DI << "\n"); } } return nullptr; } case Intrinsic::dbg_value: { const DbgValueInst &DI = cast<DbgValueInst>(I); assert(DI.getVariable() && "Missing variable"); DILocalVariable *Variable = DI.getVariable(); DIExpression *Expression = DI.getExpression(); uint64_t Offset = DI.getOffset(); const Value *V = DI.getValue(); if (!V) return nullptr; SDDbgValue *SDV; if (isa<ConstantInt>(V) || isa<ConstantFP>(V) || isa<UndefValue>(V)) { SDV = DAG.getConstantDbgValue(Variable, Expression, V, Offset, dl, SDNodeOrder); DAG.AddDbgValue(SDV, nullptr, false); } else { // Do not use getValue() in here; we don't want to generate code at // this point if it hasn't been done yet. SDValue N = NodeMap[V]; if (!N.getNode() && isa<Argument>(V)) // Check unused arguments map. N = UnusedArgNodeMap[V]; if (N.getNode()) { if (!EmitFuncArgumentDbgValue(V, Variable, Expression, dl, Offset, false, N)) { SDV = DAG.getDbgValue(Variable, Expression, N.getNode(), N.getResNo(), false, Offset, dl, SDNodeOrder); DAG.AddDbgValue(SDV, N.getNode(), false); } } else if (!V->use_empty() ) { // Do not call getValue(V) yet, as we don't want to generate code. // Remember it for later. DanglingDebugInfo DDI(&DI, dl, SDNodeOrder); DanglingDebugInfoMap[V] = DDI; } else { // We may expand this to cover more cases. One case where we have no // data available is an unreferenced parameter. DEBUG(dbgs() << "Dropping debug info for " << DI << "\n"); } } // Build a debug info table entry. if (const BitCastInst *BCI = dyn_cast<BitCastInst>(V)) V = BCI->getOperand(0); const AllocaInst *AI = dyn_cast<AllocaInst>(V); // Don't handle byval struct arguments or VLAs, for example. if (!AI) { DEBUG(dbgs() << "Dropping debug location info for:\n " << DI << "\n"); DEBUG(dbgs() << " Last seen at:\n " << *V << "\n"); return nullptr; } DenseMap<const AllocaInst*, int>::iterator SI = FuncInfo.StaticAllocaMap.find(AI); if (SI == FuncInfo.StaticAllocaMap.end()) return nullptr; // VLAs. return nullptr; } case Intrinsic::eh_typeid_for: { // Find the type id for the given typeinfo. GlobalValue *GV = ExtractTypeInfo(I.getArgOperand(0)); unsigned TypeID = DAG.getMachineFunction().getMMI().getTypeIDFor(GV); Res = DAG.getConstant(TypeID, sdl, MVT::i32); setValue(&I, Res); return nullptr; } case Intrinsic::eh_return_i32: case Intrinsic::eh_return_i64: DAG.getMachineFunction().getMMI().setCallsEHReturn(true); DAG.setRoot(DAG.getNode(ISD::EH_RETURN, sdl, MVT::Other, getControlRoot(), getValue(I.getArgOperand(0)), getValue(I.getArgOperand(1)))); return nullptr; case Intrinsic::eh_unwind_init: DAG.getMachineFunction().getMMI().setCallsUnwindInit(true); return nullptr; case Intrinsic::eh_dwarf_cfa: { SDValue CfaArg = DAG.getSExtOrTrunc(getValue(I.getArgOperand(0)), sdl, TLI.getPointerTy(DAG.getDataLayout())); SDValue Offset = DAG.getNode(ISD::ADD, sdl, CfaArg.getValueType(), DAG.getNode(ISD::FRAME_TO_ARGS_OFFSET, sdl, CfaArg.getValueType()), CfaArg); SDValue FA = DAG.getNode( ISD::FRAMEADDR, sdl, TLI.getPointerTy(DAG.getDataLayout()), DAG.getConstant(0, sdl, TLI.getPointerTy(DAG.getDataLayout()))); setValue(&I, DAG.getNode(ISD::ADD, sdl, FA.getValueType(), FA, Offset)); return nullptr; } case Intrinsic::eh_sjlj_callsite: { MachineModuleInfo &MMI = DAG.getMachineFunction().getMMI(); ConstantInt *CI = dyn_cast<ConstantInt>(I.getArgOperand(0)); assert(CI && "Non-constant call site value in eh.sjlj.callsite!"); assert(MMI.getCurrentCallSite() == 0 && "Overlapping call sites!"); MMI.setCurrentCallSite(CI->getZExtValue()); return nullptr; } case Intrinsic::eh_sjlj_functioncontext: { // Get and store the index of the function context. MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo(); AllocaInst *FnCtx = cast<AllocaInst>(I.getArgOperand(0)->stripPointerCasts()); int FI = FuncInfo.StaticAllocaMap[FnCtx]; MFI->setFunctionContextIndex(FI); return nullptr; } case Intrinsic::eh_sjlj_setjmp: { SDValue Ops[2]; Ops[0] = getRoot(); Ops[1] = getValue(I.getArgOperand(0)); SDValue Op = DAG.getNode(ISD::EH_SJLJ_SETJMP, sdl, DAG.getVTList(MVT::i32, MVT::Other), Ops); setValue(&I, Op.getValue(0)); DAG.setRoot(Op.getValue(1)); return nullptr; } case Intrinsic::eh_sjlj_longjmp: { DAG.setRoot(DAG.getNode(ISD::EH_SJLJ_LONGJMP, sdl, MVT::Other, getRoot(), getValue(I.getArgOperand(0)))); return nullptr; } case Intrinsic::eh_sjlj_setup_dispatch: { DAG.setRoot(DAG.getNode(ISD::EH_SJLJ_SETUP_DISPATCH, sdl, MVT::Other, getRoot())); return nullptr; } case Intrinsic::masked_gather: visitMaskedGather(I); return nullptr; case Intrinsic::masked_load: visitMaskedLoad(I); return nullptr; case Intrinsic::masked_scatter: visitMaskedScatter(I); return nullptr; case Intrinsic::masked_store: visitMaskedStore(I); return nullptr; case Intrinsic::x86_mmx_pslli_w: case Intrinsic::x86_mmx_pslli_d: case Intrinsic::x86_mmx_pslli_q: case Intrinsic::x86_mmx_psrli_w: case Intrinsic::x86_mmx_psrli_d: case Intrinsic::x86_mmx_psrli_q: case Intrinsic::x86_mmx_psrai_w: case Intrinsic::x86_mmx_psrai_d: { SDValue ShAmt = getValue(I.getArgOperand(1)); if (isa<ConstantSDNode>(ShAmt)) { visitTargetIntrinsic(I, Intrinsic); return nullptr; } unsigned NewIntrinsic = 0; EVT ShAmtVT = MVT::v2i32; switch (Intrinsic) { case Intrinsic::x86_mmx_pslli_w: NewIntrinsic = Intrinsic::x86_mmx_psll_w; break; case Intrinsic::x86_mmx_pslli_d: NewIntrinsic = Intrinsic::x86_mmx_psll_d; break; case Intrinsic::x86_mmx_pslli_q: NewIntrinsic = Intrinsic::x86_mmx_psll_q; break; case Intrinsic::x86_mmx_psrli_w: NewIntrinsic = Intrinsic::x86_mmx_psrl_w; break; case Intrinsic::x86_mmx_psrli_d: NewIntrinsic = Intrinsic::x86_mmx_psrl_d; break; case Intrinsic::x86_mmx_psrli_q: NewIntrinsic = Intrinsic::x86_mmx_psrl_q; break; case Intrinsic::x86_mmx_psrai_w: NewIntrinsic = Intrinsic::x86_mmx_psra_w; break; case Intrinsic::x86_mmx_psrai_d: NewIntrinsic = Intrinsic::x86_mmx_psra_d; break; default: llvm_unreachable("Impossible intrinsic"); // Can't reach here. } // The vector shift intrinsics with scalars uses 32b shift amounts but // the sse2/mmx shift instructions reads 64 bits. Set the upper 32 bits // to be zero. // We must do this early because v2i32 is not a legal type. SDValue ShOps[2]; ShOps[0] = ShAmt; ShOps[1] = DAG.getConstant(0, sdl, MVT::i32); ShAmt = DAG.getNode(ISD::BUILD_VECTOR, sdl, ShAmtVT, ShOps); EVT DestVT = TLI.getValueType(DAG.getDataLayout(), I.getType()); ShAmt = DAG.getNode(ISD::BITCAST, sdl, DestVT, ShAmt); Res = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, sdl, DestVT, DAG.getConstant(NewIntrinsic, sdl, MVT::i32), getValue(I.getArgOperand(0)), ShAmt); setValue(&I, Res); return nullptr; } case Intrinsic::convertff: case Intrinsic::convertfsi: case Intrinsic::convertfui: case Intrinsic::convertsif: case Intrinsic::convertuif: case Intrinsic::convertss: case Intrinsic::convertsu: case Intrinsic::convertus: case Intrinsic::convertuu: { ISD::CvtCode Code = ISD::CVT_INVALID; switch (Intrinsic) { default: llvm_unreachable("Impossible intrinsic"); // Can't reach here. case Intrinsic::convertff: Code = ISD::CVT_FF; break; case Intrinsic::convertfsi: Code = ISD::CVT_FS; break; case Intrinsic::convertfui: Code = ISD::CVT_FU; break; case Intrinsic::convertsif: Code = ISD::CVT_SF; break; case Intrinsic::convertuif: Code = ISD::CVT_UF; break; case Intrinsic::convertss: Code = ISD::CVT_SS; break; case Intrinsic::convertsu: Code = ISD::CVT_SU; break; case Intrinsic::convertus: Code = ISD::CVT_US; break; case Intrinsic::convertuu: Code = ISD::CVT_UU; break; } EVT DestVT = TLI.getValueType(DAG.getDataLayout(), I.getType()); const Value *Op1 = I.getArgOperand(0); Res = DAG.getConvertRndSat(DestVT, sdl, getValue(Op1), DAG.getValueType(DestVT), DAG.getValueType(getValue(Op1).getValueType()), getValue(I.getArgOperand(1)), getValue(I.getArgOperand(2)), Code); setValue(&I, Res); return nullptr; } case Intrinsic::powi: setValue(&I, ExpandPowI(sdl, getValue(I.getArgOperand(0)), getValue(I.getArgOperand(1)), DAG)); return nullptr; case Intrinsic::log: setValue(&I, expandLog(sdl, getValue(I.getArgOperand(0)), DAG, TLI)); return nullptr; case Intrinsic::log2: setValue(&I, expandLog2(sdl, getValue(I.getArgOperand(0)), DAG, TLI)); return nullptr; case Intrinsic::log10: setValue(&I, expandLog10(sdl, getValue(I.getArgOperand(0)), DAG, TLI)); return nullptr; case Intrinsic::exp: setValue(&I, expandExp(sdl, getValue(I.getArgOperand(0)), DAG, TLI)); return nullptr; case Intrinsic::exp2: setValue(&I, expandExp2(sdl, getValue(I.getArgOperand(0)), DAG, TLI)); return nullptr; case Intrinsic::pow: setValue(&I, expandPow(sdl, getValue(I.getArgOperand(0)), getValue(I.getArgOperand(1)), DAG, TLI)); return nullptr; case Intrinsic::sqrt: case Intrinsic::fabs: case Intrinsic::sin: case Intrinsic::cos: case Intrinsic::floor: case Intrinsic::ceil: case Intrinsic::trunc: case Intrinsic::rint: case Intrinsic::nearbyint: case Intrinsic::round: case Intrinsic::canonicalize: { unsigned Opcode; switch (Intrinsic) { default: llvm_unreachable("Impossible intrinsic"); // Can't reach here. case Intrinsic::sqrt: Opcode = ISD::FSQRT; break; case Intrinsic::fabs: Opcode = ISD::FABS; break; case Intrinsic::sin: Opcode = ISD::FSIN; break; case Intrinsic::cos: Opcode = ISD::FCOS; break; case Intrinsic::floor: Opcode = ISD::FFLOOR; break; case Intrinsic::ceil: Opcode = ISD::FCEIL; break; case Intrinsic::trunc: Opcode = ISD::FTRUNC; break; case Intrinsic::rint: Opcode = ISD::FRINT; break; case Intrinsic::nearbyint: Opcode = ISD::FNEARBYINT; break; case Intrinsic::round: Opcode = ISD::FROUND; break; case Intrinsic::canonicalize: Opcode = ISD::FCANONICALIZE; break; } setValue(&I, DAG.getNode(Opcode, sdl, getValue(I.getArgOperand(0)).getValueType(), getValue(I.getArgOperand(0)))); return nullptr; } case Intrinsic::minnum: { auto VT = getValue(I.getArgOperand(0)).getValueType(); unsigned Opc = I.hasNoNaNs() && TLI.isOperationLegalOrCustom(ISD::FMINNAN, VT) ? ISD::FMINNAN : ISD::FMINNUM; setValue(&I, DAG.getNode(Opc, sdl, VT, getValue(I.getArgOperand(0)), getValue(I.getArgOperand(1)))); return nullptr; } case Intrinsic::maxnum: { auto VT = getValue(I.getArgOperand(0)).getValueType(); unsigned Opc = I.hasNoNaNs() && TLI.isOperationLegalOrCustom(ISD::FMAXNAN, VT) ? ISD::FMAXNAN : ISD::FMAXNUM; setValue(&I, DAG.getNode(Opc, sdl, VT, getValue(I.getArgOperand(0)), getValue(I.getArgOperand(1)))); return nullptr; } case Intrinsic::copysign: setValue(&I, DAG.getNode(ISD::FCOPYSIGN, sdl, getValue(I.getArgOperand(0)).getValueType(), getValue(I.getArgOperand(0)), getValue(I.getArgOperand(1)))); return nullptr; case Intrinsic::fma: setValue(&I, DAG.getNode(ISD::FMA, sdl, getValue(I.getArgOperand(0)).getValueType(), getValue(I.getArgOperand(0)), getValue(I.getArgOperand(1)), getValue(I.getArgOperand(2)))); return nullptr; case Intrinsic::fmuladd: { EVT VT = TLI.getValueType(DAG.getDataLayout(), I.getType()); if (TM.Options.AllowFPOpFusion != FPOpFusion::Strict && TLI.isFMAFasterThanFMulAndFAdd(VT)) { setValue(&I, DAG.getNode(ISD::FMA, sdl, getValue(I.getArgOperand(0)).getValueType(), getValue(I.getArgOperand(0)), getValue(I.getArgOperand(1)), getValue(I.getArgOperand(2)))); } else { // TODO: Intrinsic calls should have fast-math-flags. SDValue Mul = DAG.getNode(ISD::FMUL, sdl, getValue(I.getArgOperand(0)).getValueType(), getValue(I.getArgOperand(0)), getValue(I.getArgOperand(1))); SDValue Add = DAG.getNode(ISD::FADD, sdl, getValue(I.getArgOperand(0)).getValueType(), Mul, getValue(I.getArgOperand(2))); setValue(&I, Add); } return nullptr; } case Intrinsic::convert_to_fp16: setValue(&I, DAG.getNode(ISD::BITCAST, sdl, MVT::i16, DAG.getNode(ISD::FP_ROUND, sdl, MVT::f16, getValue(I.getArgOperand(0)), DAG.getTargetConstant(0, sdl, MVT::i32)))); return nullptr; case Intrinsic::convert_from_fp16: setValue(&I, DAG.getNode(ISD::FP_EXTEND, sdl, TLI.getValueType(DAG.getDataLayout(), I.getType()), DAG.getNode(ISD::BITCAST, sdl, MVT::f16, getValue(I.getArgOperand(0))))); return nullptr; case Intrinsic::pcmarker: { SDValue Tmp = getValue(I.getArgOperand(0)); DAG.setRoot(DAG.getNode(ISD::PCMARKER, sdl, MVT::Other, getRoot(), Tmp)); return nullptr; } case Intrinsic::readcyclecounter: { SDValue Op = getRoot(); Res = DAG.getNode(ISD::READCYCLECOUNTER, sdl, DAG.getVTList(MVT::i64, MVT::Other), Op); setValue(&I, Res); DAG.setRoot(Res.getValue(1)); return nullptr; } case Intrinsic::bitreverse: setValue(&I, DAG.getNode(ISD::BITREVERSE, sdl, getValue(I.getArgOperand(0)).getValueType(), getValue(I.getArgOperand(0)))); return nullptr; case Intrinsic::bswap: setValue(&I, DAG.getNode(ISD::BSWAP, sdl, getValue(I.getArgOperand(0)).getValueType(), getValue(I.getArgOperand(0)))); return nullptr; case Intrinsic::cttz: { SDValue Arg = getValue(I.getArgOperand(0)); ConstantInt *CI = cast<ConstantInt>(I.getArgOperand(1)); EVT Ty = Arg.getValueType(); setValue(&I, DAG.getNode(CI->isZero() ? ISD::CTTZ : ISD::CTTZ_ZERO_UNDEF, sdl, Ty, Arg)); return nullptr; } case Intrinsic::ctlz: { SDValue Arg = getValue(I.getArgOperand(0)); ConstantInt *CI = cast<ConstantInt>(I.getArgOperand(1)); EVT Ty = Arg.getValueType(); setValue(&I, DAG.getNode(CI->isZero() ? ISD::CTLZ : ISD::CTLZ_ZERO_UNDEF, sdl, Ty, Arg)); return nullptr; } case Intrinsic::ctpop: { SDValue Arg = getValue(I.getArgOperand(0)); EVT Ty = Arg.getValueType(); setValue(&I, DAG.getNode(ISD::CTPOP, sdl, Ty, Arg)); return nullptr; } case Intrinsic::stacksave: { SDValue Op = getRoot(); Res = DAG.getNode( ISD::STACKSAVE, sdl, DAG.getVTList(TLI.getPointerTy(DAG.getDataLayout()), MVT::Other), Op); setValue(&I, Res); DAG.setRoot(Res.getValue(1)); return nullptr; } case Intrinsic::stackrestore: { Res = getValue(I.getArgOperand(0)); DAG.setRoot(DAG.getNode(ISD::STACKRESTORE, sdl, MVT::Other, getRoot(), Res)); return nullptr; } case Intrinsic::get_dynamic_area_offset: { SDValue Op = getRoot(); EVT PtrTy = TLI.getPointerTy(DAG.getDataLayout()); EVT ResTy = TLI.getValueType(DAG.getDataLayout(), I.getType()); // Result type for @llvm.get.dynamic.area.offset should match PtrTy for // target. if (PtrTy != ResTy) report_fatal_error("Wrong result type for @llvm.get.dynamic.area.offset" " intrinsic!"); Res = DAG.getNode(ISD::GET_DYNAMIC_AREA_OFFSET, sdl, DAG.getVTList(ResTy), Op); DAG.setRoot(Op); setValue(&I, Res); return nullptr; } case Intrinsic::stackguard: { EVT PtrTy = TLI.getPointerTy(DAG.getDataLayout()); MachineFunction &MF = DAG.getMachineFunction(); const Module &M = *MF.getFunction()->getParent(); SDValue Chain = getRoot(); if (TLI.useLoadStackGuardNode()) { Res = getLoadStackGuard(DAG, sdl, Chain); } else { const Value *Global = TLI.getSDagStackGuard(M); unsigned Align = DL->getPrefTypeAlignment(Global->getType()); Res = DAG.getLoad(PtrTy, sdl, Chain, getValue(Global), MachinePointerInfo(Global, 0), true, false, false, Align); } DAG.setRoot(Chain); setValue(&I, Res); return nullptr; } case Intrinsic::stackprotector: { // Emit code into the DAG to store the stack guard onto the stack. MachineFunction &MF = DAG.getMachineFunction(); MachineFrameInfo *MFI = MF.getFrameInfo(); EVT PtrTy = TLI.getPointerTy(DAG.getDataLayout()); SDValue Src, Chain = getRoot(); if (TLI.useLoadStackGuardNode()) Src = getLoadStackGuard(DAG, sdl, Chain); else Src = getValue(I.getArgOperand(0)); // The guard's value. AllocaInst *Slot = cast<AllocaInst>(I.getArgOperand(1)); int FI = FuncInfo.StaticAllocaMap[Slot]; MFI->setStackProtectorIndex(FI); SDValue FIN = DAG.getFrameIndex(FI, PtrTy); // Store the stack protector onto the stack. Res = DAG.getStore(Chain, sdl, Src, FIN, MachinePointerInfo::getFixedStack( DAG.getMachineFunction(), FI), true, false, 0); setValue(&I, Res); DAG.setRoot(Res); return nullptr; } case Intrinsic::objectsize: { // If we don't know by now, we're never going to know. ConstantInt *CI = dyn_cast<ConstantInt>(I.getArgOperand(1)); assert(CI && "Non-constant type in __builtin_object_size?"); SDValue Arg = getValue(I.getCalledValue()); EVT Ty = Arg.getValueType(); if (CI->isZero()) Res = DAG.getConstant(-1ULL, sdl, Ty); else Res = DAG.getConstant(0, sdl, Ty); setValue(&I, Res); return nullptr; } case Intrinsic::annotation: case Intrinsic::ptr_annotation: // Drop the intrinsic, but forward the value setValue(&I, getValue(I.getOperand(0))); return nullptr; case Intrinsic::assume: case Intrinsic::var_annotation: // Discard annotate attributes and assumptions return nullptr; case Intrinsic::init_trampoline: { const Function *F = cast<Function>(I.getArgOperand(1)->stripPointerCasts()); SDValue Ops[6]; Ops[0] = getRoot(); Ops[1] = getValue(I.getArgOperand(0)); Ops[2] = getValue(I.getArgOperand(1)); Ops[3] = getValue(I.getArgOperand(2)); Ops[4] = DAG.getSrcValue(I.getArgOperand(0)); Ops[5] = DAG.getSrcValue(F); Res = DAG.getNode(ISD::INIT_TRAMPOLINE, sdl, MVT::Other, Ops); DAG.setRoot(Res); return nullptr; } case Intrinsic::adjust_trampoline: { setValue(&I, DAG.getNode(ISD::ADJUST_TRAMPOLINE, sdl, TLI.getPointerTy(DAG.getDataLayout()), getValue(I.getArgOperand(0)))); return nullptr; } case Intrinsic::gcroot: { MachineFunction &MF = DAG.getMachineFunction(); const Function *F = MF.getFunction(); (void)F; assert(F->hasGC() && "only valid in functions with gc specified, enforced by Verifier"); assert(GFI && "implied by previous"); const Value *Alloca = I.getArgOperand(0)->stripPointerCasts(); const Constant *TypeMap = cast<Constant>(I.getArgOperand(1)); FrameIndexSDNode *FI = cast<FrameIndexSDNode>(getValue(Alloca).getNode()); GFI->addStackRoot(FI->getIndex(), TypeMap); return nullptr; } case Intrinsic::gcread: case Intrinsic::gcwrite: llvm_unreachable("GC failed to lower gcread/gcwrite intrinsics!"); case Intrinsic::flt_rounds: setValue(&I, DAG.getNode(ISD::FLT_ROUNDS_, sdl, MVT::i32)); return nullptr; case Intrinsic::expect: { // Just replace __builtin_expect(exp, c) with EXP. setValue(&I, getValue(I.getArgOperand(0))); return nullptr; } case Intrinsic::debugtrap: case Intrinsic::trap: { StringRef TrapFuncName = I.getAttributes() .getAttribute(AttributeSet::FunctionIndex, "trap-func-name") .getValueAsString(); if (TrapFuncName.empty()) { ISD::NodeType Op = (Intrinsic == Intrinsic::trap) ? ISD::TRAP : ISD::DEBUGTRAP; DAG.setRoot(DAG.getNode(Op, sdl,MVT::Other, getRoot())); return nullptr; } TargetLowering::ArgListTy Args; TargetLowering::CallLoweringInfo CLI(DAG); CLI.setDebugLoc(sdl).setChain(getRoot()).setCallee( CallingConv::C, I.getType(), DAG.getExternalSymbol(TrapFuncName.data(), TLI.getPointerTy(DAG.getDataLayout())), std::move(Args)); std::pair<SDValue, SDValue> Result = TLI.LowerCallTo(CLI); DAG.setRoot(Result.second); return nullptr; } case Intrinsic::uadd_with_overflow: case Intrinsic::sadd_with_overflow: case Intrinsic::usub_with_overflow: case Intrinsic::ssub_with_overflow: case Intrinsic::umul_with_overflow: case Intrinsic::smul_with_overflow: { ISD::NodeType Op; switch (Intrinsic) { default: llvm_unreachable("Impossible intrinsic"); // Can't reach here. case Intrinsic::uadd_with_overflow: Op = ISD::UADDO; break; case Intrinsic::sadd_with_overflow: Op = ISD::SADDO; break; case Intrinsic::usub_with_overflow: Op = ISD::USUBO; break; case Intrinsic::ssub_with_overflow: Op = ISD::SSUBO; break; case Intrinsic::umul_with_overflow: Op = ISD::UMULO; break; case Intrinsic::smul_with_overflow: Op = ISD::SMULO; break; } SDValue Op1 = getValue(I.getArgOperand(0)); SDValue Op2 = getValue(I.getArgOperand(1)); SDVTList VTs = DAG.getVTList(Op1.getValueType(), MVT::i1); setValue(&I, DAG.getNode(Op, sdl, VTs, Op1, Op2)); return nullptr; } case Intrinsic::prefetch: { SDValue Ops[5]; unsigned rw = cast<ConstantInt>(I.getArgOperand(1))->getZExtValue(); Ops[0] = getRoot(); Ops[1] = getValue(I.getArgOperand(0)); Ops[2] = getValue(I.getArgOperand(1)); Ops[3] = getValue(I.getArgOperand(2)); Ops[4] = getValue(I.getArgOperand(3)); DAG.setRoot(DAG.getMemIntrinsicNode(ISD::PREFETCH, sdl, DAG.getVTList(MVT::Other), Ops, EVT::getIntegerVT(*Context, 8), MachinePointerInfo(I.getArgOperand(0)), 0, /* align */ false, /* volatile */ rw==0, /* read */ rw==1)); /* write */ return nullptr; } case Intrinsic::lifetime_start: case Intrinsic::lifetime_end: { bool IsStart = (Intrinsic == Intrinsic::lifetime_start); // Stack coloring is not enabled in O0, discard region information. if (TM.getOptLevel() == CodeGenOpt::None) return nullptr; SmallVector<Value *, 4> Allocas; GetUnderlyingObjects(I.getArgOperand(1), Allocas, *DL); for (SmallVectorImpl<Value*>::iterator Object = Allocas.begin(), E = Allocas.end(); Object != E; ++Object) { AllocaInst *LifetimeObject = dyn_cast_or_null<AllocaInst>(*Object); // Could not find an Alloca. if (!LifetimeObject) continue; // First check that the Alloca is static, otherwise it won't have a // valid frame index. auto SI = FuncInfo.StaticAllocaMap.find(LifetimeObject); if (SI == FuncInfo.StaticAllocaMap.end()) return nullptr; int FI = SI->second; SDValue Ops[2]; Ops[0] = getRoot(); Ops[1] = DAG.getFrameIndex(FI, TLI.getPointerTy(DAG.getDataLayout()), true); unsigned Opcode = (IsStart ? ISD::LIFETIME_START : ISD::LIFETIME_END); Res = DAG.getNode(Opcode, sdl, MVT::Other, Ops); DAG.setRoot(Res); } return nullptr; } case Intrinsic::invariant_start: // Discard region information. setValue(&I, DAG.getUNDEF(TLI.getPointerTy(DAG.getDataLayout()))); return nullptr; case Intrinsic::invariant_end: // Discard region information. return nullptr; case Intrinsic::clear_cache: return TLI.getClearCacheBuiltinName(); case Intrinsic::donothing: // ignore return nullptr; case Intrinsic::experimental_stackmap: { visitStackmap(I); return nullptr; } case Intrinsic::experimental_patchpoint_void: case Intrinsic::experimental_patchpoint_i64: { visitPatchpoint(&I); return nullptr; } case Intrinsic::experimental_gc_statepoint: { LowerStatepoint(ImmutableStatepoint(&I)); return nullptr; } case Intrinsic::experimental_gc_result: { visitGCResult(cast<GCResultInst>(I)); return nullptr; } case Intrinsic::experimental_gc_relocate: { visitGCRelocate(cast<GCRelocateInst>(I)); return nullptr; } case Intrinsic::instrprof_increment: llvm_unreachable("instrprof failed to lower an increment"); case Intrinsic::instrprof_value_profile: llvm_unreachable("instrprof failed to lower a value profiling call"); case Intrinsic::localescape: { MachineFunction &MF = DAG.getMachineFunction(); const TargetInstrInfo *TII = DAG.getSubtarget().getInstrInfo(); // Directly emit some LOCAL_ESCAPE machine instrs. Label assignment emission // is the same on all targets. for (unsigned Idx = 0, E = I.getNumArgOperands(); Idx < E; ++Idx) { Value *Arg = I.getArgOperand(Idx)->stripPointerCasts(); if (isa<ConstantPointerNull>(Arg)) continue; // Skip null pointers. They represent a hole in index space. AllocaInst *Slot = cast<AllocaInst>(Arg); assert(FuncInfo.StaticAllocaMap.count(Slot) && "can only escape static allocas"); int FI = FuncInfo.StaticAllocaMap[Slot]; MCSymbol *FrameAllocSym = MF.getMMI().getContext().getOrCreateFrameAllocSymbol( GlobalValue::getRealLinkageName(MF.getName()), Idx); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, dl, TII->get(TargetOpcode::LOCAL_ESCAPE)) .addSym(FrameAllocSym) .addFrameIndex(FI); } return nullptr; } case Intrinsic::localrecover: { // i8* @llvm.localrecover(i8* %fn, i8* %fp, i32 %idx) MachineFunction &MF = DAG.getMachineFunction(); MVT PtrVT = TLI.getPointerTy(DAG.getDataLayout(), 0); // Get the symbol that defines the frame offset. auto *Fn = cast<Function>(I.getArgOperand(0)->stripPointerCasts()); auto *Idx = cast<ConstantInt>(I.getArgOperand(2)); unsigned IdxVal = unsigned(Idx->getLimitedValue(INT_MAX)); MCSymbol *FrameAllocSym = MF.getMMI().getContext().getOrCreateFrameAllocSymbol( GlobalValue::getRealLinkageName(Fn->getName()), IdxVal); // Create a MCSymbol for the label to avoid any target lowering // that would make this PC relative. SDValue OffsetSym = DAG.getMCSymbol(FrameAllocSym, PtrVT); SDValue OffsetVal = DAG.getNode(ISD::LOCAL_RECOVER, sdl, PtrVT, OffsetSym); // Add the offset to the FP. Value *FP = I.getArgOperand(1); SDValue FPVal = getValue(FP); SDValue Add = DAG.getNode(ISD::ADD, sdl, PtrVT, FPVal, OffsetVal); setValue(&I, Add); return nullptr; } case Intrinsic::eh_exceptionpointer: case Intrinsic::eh_exceptioncode: { // Get the exception pointer vreg, copy from it, and resize it to fit. const auto *CPI = cast<CatchPadInst>(I.getArgOperand(0)); MVT PtrVT = TLI.getPointerTy(DAG.getDataLayout()); const TargetRegisterClass *PtrRC = TLI.getRegClassFor(PtrVT); unsigned VReg = FuncInfo.getCatchPadExceptionPointerVReg(CPI, PtrRC); SDValue N = DAG.getCopyFromReg(DAG.getEntryNode(), getCurSDLoc(), VReg, PtrVT); if (Intrinsic == Intrinsic::eh_exceptioncode) N = DAG.getZExtOrTrunc(N, getCurSDLoc(), MVT::i32); setValue(&I, N); return nullptr; } case Intrinsic::experimental_deoptimize: LowerDeoptimizeCall(&I); return nullptr; } } std::pair<SDValue, SDValue> SelectionDAGBuilder::lowerInvokable(TargetLowering::CallLoweringInfo &CLI, const BasicBlock *EHPadBB) { MachineModuleInfo &MMI = DAG.getMachineFunction().getMMI(); MCSymbol *BeginLabel = nullptr; if (EHPadBB) { // Insert a label before the invoke call to mark the try range. This can be // used to detect deletion of the invoke via the MachineModuleInfo. BeginLabel = MMI.getContext().createTempSymbol(); // For SjLj, keep track of which landing pads go with which invokes // so as to maintain the ordering of pads in the LSDA. unsigned CallSiteIndex = MMI.getCurrentCallSite(); if (CallSiteIndex) { MMI.setCallSiteBeginLabel(BeginLabel, CallSiteIndex); LPadToCallSiteMap[FuncInfo.MBBMap[EHPadBB]].push_back(CallSiteIndex); // Now that the call site is handled, stop tracking it. MMI.setCurrentCallSite(0); } // Both PendingLoads and PendingExports must be flushed here; // this call might not return. (void)getRoot(); DAG.setRoot(DAG.getEHLabel(getCurSDLoc(), getControlRoot(), BeginLabel)); CLI.setChain(getRoot()); } const TargetLowering &TLI = DAG.getTargetLoweringInfo(); std::pair<SDValue, SDValue> Result = TLI.LowerCallTo(CLI); assert((CLI.IsTailCall || Result.second.getNode()) && "Non-null chain expected with non-tail call!"); assert((Result.second.getNode() || !Result.first.getNode()) && "Null value expected with tail call!"); if (!Result.second.getNode()) { // As a special case, a null chain means that a tail call has been emitted // and the DAG root is already updated. HasTailCall = true; // Since there's no actual continuation from this block, nothing can be // relying on us setting vregs for them. PendingExports.clear(); } else { DAG.setRoot(Result.second); } if (EHPadBB) { // Insert a label at the end of the invoke call to mark the try range. This // can be used to detect deletion of the invoke via the MachineModuleInfo. MCSymbol *EndLabel = MMI.getContext().createTempSymbol(); DAG.setRoot(DAG.getEHLabel(getCurSDLoc(), getRoot(), EndLabel)); // Inform MachineModuleInfo of range. if (MMI.hasEHFunclets()) { assert(CLI.CS); WinEHFuncInfo *EHInfo = DAG.getMachineFunction().getWinEHFuncInfo(); EHInfo->addIPToStateRange(cast<InvokeInst>(CLI.CS->getInstruction()), BeginLabel, EndLabel); } else { MMI.addInvoke(FuncInfo.MBBMap[EHPadBB], BeginLabel, EndLabel); } } return Result; } void SelectionDAGBuilder::LowerCallTo(ImmutableCallSite CS, SDValue Callee, bool isTailCall, const BasicBlock *EHPadBB) { auto &DL = DAG.getDataLayout(); FunctionType *FTy = CS.getFunctionType(); Type *RetTy = CS.getType(); TargetLowering::ArgListTy Args; TargetLowering::ArgListEntry Entry; Args.reserve(CS.arg_size()); const Value *SwiftErrorVal = nullptr; const TargetLowering &TLI = DAG.getTargetLoweringInfo(); for (ImmutableCallSite::arg_iterator i = CS.arg_begin(), e = CS.arg_end(); i != e; ++i) { const Value *V = *i; // Skip empty types if (V->getType()->isEmptyTy()) continue; SDValue ArgNode = getValue(V); Entry.Node = ArgNode; Entry.Ty = V->getType(); // Skip the first return-type Attribute to get to params. Entry.setAttributes(&CS, i - CS.arg_begin() + 1); // Use swifterror virtual register as input to the call. if (Entry.isSwiftError && TLI.supportSwiftError()) { SwiftErrorVal = V; // We find the virtual register for the actual swifterror argument. // Instead of using the Value, we use the virtual register instead. Entry.Node = DAG.getRegister( FuncInfo.findSwiftErrorVReg(FuncInfo.MBB, V), EVT(TLI.getPointerTy(DL))); } Args.push_back(Entry); // If we have an explicit sret argument that is an Instruction, (i.e., it // might point to function-local memory), we can't meaningfully tail-call. if (Entry.isSRet && isa<Instruction>(V)) isTailCall = false; } // Check if target-independent constraints permit a tail call here. // Target-dependent constraints are checked within TLI->LowerCallTo. if (isTailCall && !isInTailCallPosition(CS, DAG.getTarget())) isTailCall = false; TargetLowering::CallLoweringInfo CLI(DAG); CLI.setDebugLoc(getCurSDLoc()) .setChain(getRoot()) .setCallee(RetTy, FTy, Callee, std::move(Args), CS) .setTailCall(isTailCall) .setConvergent(CS.isConvergent()); std::pair<SDValue, SDValue> Result = lowerInvokable(CLI, EHPadBB); if (Result.first.getNode()) { const Instruction *Inst = CS.getInstruction(); Result.first = lowerRangeToAssertZExt(DAG, *Inst, Result.first); setValue(Inst, Result.first); } // The last element of CLI.InVals has the SDValue for swifterror return. // Here we copy it to a virtual register and update SwiftErrorMap for // book-keeping. if (SwiftErrorVal && TLI.supportSwiftError()) { // Get the last element of InVals. SDValue Src = CLI.InVals.back(); const TargetRegisterClass *RC = TLI.getRegClassFor(TLI.getPointerTy(DL)); unsigned VReg = FuncInfo.MF->getRegInfo().createVirtualRegister(RC); SDValue CopyNode = CLI.DAG.getCopyToReg(Result.second, CLI.DL, VReg, Src); // We update the virtual register for the actual swifterror argument. FuncInfo.setSwiftErrorVReg(FuncInfo.MBB, SwiftErrorVal, VReg); DAG.setRoot(CopyNode); } } /// IsOnlyUsedInZeroEqualityComparison - Return true if it only matters that the /// value is equal or not-equal to zero. static bool IsOnlyUsedInZeroEqualityComparison(const Value *V) { for (const User *U : V->users()) { if (const ICmpInst *IC = dyn_cast<ICmpInst>(U)) if (IC->isEquality()) if (const Constant *C = dyn_cast<Constant>(IC->getOperand(1))) if (C->isNullValue()) continue; // Unknown instruction. return false; } return true; } static SDValue getMemCmpLoad(const Value *PtrVal, MVT LoadVT, Type *LoadTy, SelectionDAGBuilder &Builder) { // Check to see if this load can be trivially constant folded, e.g. if the // input is from a string literal. if (const Constant *LoadInput = dyn_cast<Constant>(PtrVal)) { // Cast pointer to the type we really want to load. LoadInput = ConstantExpr::getBitCast(const_cast<Constant *>(LoadInput), PointerType::getUnqual(LoadTy)); if (const Constant *LoadCst = ConstantFoldLoadFromConstPtr( const_cast<Constant *>(LoadInput), LoadTy, *Builder.DL)) return Builder.getValue(LoadCst); } // Otherwise, we have to emit the load. If the pointer is to unfoldable but // still constant memory, the input chain can be the entry node. SDValue Root; bool ConstantMemory = false; // Do not serialize (non-volatile) loads of constant memory with anything. if (Builder.AA->pointsToConstantMemory(PtrVal)) { Root = Builder.DAG.getEntryNode(); ConstantMemory = true; } else { // Do not serialize non-volatile loads against each other. Root = Builder.DAG.getRoot(); } SDValue Ptr = Builder.getValue(PtrVal); SDValue LoadVal = Builder.DAG.getLoad(LoadVT, Builder.getCurSDLoc(), Root, Ptr, MachinePointerInfo(PtrVal), false /*volatile*/, false /*nontemporal*/, false /*isinvariant*/, 1 /* align=1 */); if (!ConstantMemory) Builder.PendingLoads.push_back(LoadVal.getValue(1)); return LoadVal; } /// processIntegerCallValue - Record the value for an instruction that /// produces an integer result, converting the type where necessary. void SelectionDAGBuilder::processIntegerCallValue(const Instruction &I, SDValue Value, bool IsSigned) { EVT VT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), I.getType(), true); if (IsSigned) Value = DAG.getSExtOrTrunc(Value, getCurSDLoc(), VT); else Value = DAG.getZExtOrTrunc(Value, getCurSDLoc(), VT); setValue(&I, Value); } /// visitMemCmpCall - See if we can lower a call to memcmp in an optimized form. /// If so, return true and lower it, otherwise return false and it will be /// lowered like a normal call. bool SelectionDAGBuilder::visitMemCmpCall(const CallInst &I) { // Verify that the prototype makes sense. int memcmp(void*,void*,size_t) if (I.getNumArgOperands() != 3) return false; const Value *LHS = I.getArgOperand(0), *RHS = I.getArgOperand(1); if (!LHS->getType()->isPointerTy() || !RHS->getType()->isPointerTy() || !I.getArgOperand(2)->getType()->isIntegerTy() || !I.getType()->isIntegerTy()) return false; const Value *Size = I.getArgOperand(2); const ConstantInt *CSize = dyn_cast<ConstantInt>(Size); if (CSize && CSize->getZExtValue() == 0) { EVT CallVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), I.getType(), true); setValue(&I, DAG.getConstant(0, getCurSDLoc(), CallVT)); return true; } const SelectionDAGTargetInfo &TSI = DAG.getSelectionDAGInfo(); std::pair<SDValue, SDValue> Res = TSI.EmitTargetCodeForMemcmp(DAG, getCurSDLoc(), DAG.getRoot(), getValue(LHS), getValue(RHS), getValue(Size), MachinePointerInfo(LHS), MachinePointerInfo(RHS)); if (Res.first.getNode()) { processIntegerCallValue(I, Res.first, true); PendingLoads.push_back(Res.second); return true; } // memcmp(S1,S2,2) != 0 -> (*(short*)LHS != *(short*)RHS) != 0 // memcmp(S1,S2,4) != 0 -> (*(int*)LHS != *(int*)RHS) != 0 if (CSize && IsOnlyUsedInZeroEqualityComparison(&I)) { bool ActuallyDoIt = true; MVT LoadVT; Type *LoadTy; switch (CSize->getZExtValue()) { default: LoadVT = MVT::Other; LoadTy = nullptr; ActuallyDoIt = false; break; case 2: LoadVT = MVT::i16; LoadTy = Type::getInt16Ty(CSize->getContext()); break; case 4: LoadVT = MVT::i32; LoadTy = Type::getInt32Ty(CSize->getContext()); break; case 8: LoadVT = MVT::i64; LoadTy = Type::getInt64Ty(CSize->getContext()); break; /* case 16: LoadVT = MVT::v4i32; LoadTy = Type::getInt32Ty(CSize->getContext()); LoadTy = VectorType::get(LoadTy, 4); break; */ } // This turns into unaligned loads. We only do this if the target natively // supports the MVT we'll be loading or if it is small enough (<= 4) that // we'll only produce a small number of byte loads. // Require that we can find a legal MVT, and only do this if the target // supports unaligned loads of that type. Expanding into byte loads would // bloat the code. const TargetLowering &TLI = DAG.getTargetLoweringInfo(); if (ActuallyDoIt && CSize->getZExtValue() > 4) { unsigned DstAS = LHS->getType()->getPointerAddressSpace(); unsigned SrcAS = RHS->getType()->getPointerAddressSpace(); // TODO: Handle 5 byte compare as 4-byte + 1 byte. // TODO: Handle 8 byte compare on x86-32 as two 32-bit loads. // TODO: Check alignment of src and dest ptrs. if (!TLI.isTypeLegal(LoadVT) || !TLI.allowsMisalignedMemoryAccesses(LoadVT, SrcAS) || !TLI.allowsMisalignedMemoryAccesses(LoadVT, DstAS)) ActuallyDoIt = false; } if (ActuallyDoIt) { SDValue LHSVal = getMemCmpLoad(LHS, LoadVT, LoadTy, *this); SDValue RHSVal = getMemCmpLoad(RHS, LoadVT, LoadTy, *this); SDValue Res = DAG.getSetCC(getCurSDLoc(), MVT::i1, LHSVal, RHSVal, ISD::SETNE); processIntegerCallValue(I, Res, false); return true; } } return false; } /// visitMemChrCall -- See if we can lower a memchr call into an optimized /// form. If so, return true and lower it, otherwise return false and it /// will be lowered like a normal call. bool SelectionDAGBuilder::visitMemChrCall(const CallInst &I) { // Verify that the prototype makes sense. void *memchr(void *, int, size_t) if (I.getNumArgOperands() != 3) return false; const Value *Src = I.getArgOperand(0); const Value *Char = I.getArgOperand(1); const Value *Length = I.getArgOperand(2); if (!Src->getType()->isPointerTy() || !Char->getType()->isIntegerTy() || !Length->getType()->isIntegerTy() || !I.getType()->isPointerTy()) return false; const SelectionDAGTargetInfo &TSI = DAG.getSelectionDAGInfo(); std::pair<SDValue, SDValue> Res = TSI.EmitTargetCodeForMemchr(DAG, getCurSDLoc(), DAG.getRoot(), getValue(Src), getValue(Char), getValue(Length), MachinePointerInfo(Src)); if (Res.first.getNode()) { setValue(&I, Res.first); PendingLoads.push_back(Res.second); return true; } return false; } /// visitStrCpyCall -- See if we can lower a strcpy or stpcpy call into an /// optimized form. If so, return true and lower it, otherwise return false /// and it will be lowered like a normal call. bool SelectionDAGBuilder::visitStrCpyCall(const CallInst &I, bool isStpcpy) { // Verify that the prototype makes sense. char *strcpy(char *, char *) if (I.getNumArgOperands() != 2) return false; const Value *Arg0 = I.getArgOperand(0), *Arg1 = I.getArgOperand(1); if (!Arg0->getType()->isPointerTy() || !Arg1->getType()->isPointerTy() || !I.getType()->isPointerTy()) return false; const SelectionDAGTargetInfo &TSI = DAG.getSelectionDAGInfo(); std::pair<SDValue, SDValue> Res = TSI.EmitTargetCodeForStrcpy(DAG, getCurSDLoc(), getRoot(), getValue(Arg0), getValue(Arg1), MachinePointerInfo(Arg0), MachinePointerInfo(Arg1), isStpcpy); if (Res.first.getNode()) { setValue(&I, Res.first); DAG.setRoot(Res.second); return true; } return false; } /// visitStrCmpCall - See if we can lower a call to strcmp in an optimized form. /// If so, return true and lower it, otherwise return false and it will be /// lowered like a normal call. bool SelectionDAGBuilder::visitStrCmpCall(const CallInst &I) { // Verify that the prototype makes sense. int strcmp(void*,void*) if (I.getNumArgOperands() != 2) return false; const Value *Arg0 = I.getArgOperand(0), *Arg1 = I.getArgOperand(1); if (!Arg0->getType()->isPointerTy() || !Arg1->getType()->isPointerTy() || !I.getType()->isIntegerTy()) return false; const SelectionDAGTargetInfo &TSI = DAG.getSelectionDAGInfo(); std::pair<SDValue, SDValue> Res = TSI.EmitTargetCodeForStrcmp(DAG, getCurSDLoc(), DAG.getRoot(), getValue(Arg0), getValue(Arg1), MachinePointerInfo(Arg0), MachinePointerInfo(Arg1)); if (Res.first.getNode()) { processIntegerCallValue(I, Res.first, true); PendingLoads.push_back(Res.second); return true; } return false; } /// visitStrLenCall -- See if we can lower a strlen call into an optimized /// form. If so, return true and lower it, otherwise return false and it /// will be lowered like a normal call. bool SelectionDAGBuilder::visitStrLenCall(const CallInst &I) { // Verify that the prototype makes sense. size_t strlen(char *) if (I.getNumArgOperands() != 1) return false; const Value *Arg0 = I.getArgOperand(0); if (!Arg0->getType()->isPointerTy() || !I.getType()->isIntegerTy()) return false; const SelectionDAGTargetInfo &TSI = DAG.getSelectionDAGInfo(); std::pair<SDValue, SDValue> Res = TSI.EmitTargetCodeForStrlen(DAG, getCurSDLoc(), DAG.getRoot(), getValue(Arg0), MachinePointerInfo(Arg0)); if (Res.first.getNode()) { processIntegerCallValue(I, Res.first, false); PendingLoads.push_back(Res.second); return true; } return false; } /// visitStrNLenCall -- See if we can lower a strnlen call into an optimized /// form. If so, return true and lower it, otherwise return false and it /// will be lowered like a normal call. bool SelectionDAGBuilder::visitStrNLenCall(const CallInst &I) { // Verify that the prototype makes sense. size_t strnlen(char *, size_t) if (I.getNumArgOperands() != 2) return false; const Value *Arg0 = I.getArgOperand(0), *Arg1 = I.getArgOperand(1); if (!Arg0->getType()->isPointerTy() || !Arg1->getType()->isIntegerTy() || !I.getType()->isIntegerTy()) return false; const SelectionDAGTargetInfo &TSI = DAG.getSelectionDAGInfo(); std::pair<SDValue, SDValue> Res = TSI.EmitTargetCodeForStrnlen(DAG, getCurSDLoc(), DAG.getRoot(), getValue(Arg0), getValue(Arg1), MachinePointerInfo(Arg0)); if (Res.first.getNode()) { processIntegerCallValue(I, Res.first, false); PendingLoads.push_back(Res.second); return true; } return false; } /// visitUnaryFloatCall - If a call instruction is a unary floating-point /// operation (as expected), translate it to an SDNode with the specified opcode /// and return true. bool SelectionDAGBuilder::visitUnaryFloatCall(const CallInst &I, unsigned Opcode) { // Sanity check that it really is a unary floating-point call. if (I.getNumArgOperands() != 1 || !I.getArgOperand(0)->getType()->isFloatingPointTy() || I.getType() != I.getArgOperand(0)->getType() || !I.onlyReadsMemory()) return false; SDValue Tmp = getValue(I.getArgOperand(0)); setValue(&I, DAG.getNode(Opcode, getCurSDLoc(), Tmp.getValueType(), Tmp)); return true; } /// visitBinaryFloatCall - If a call instruction is a binary floating-point /// operation (as expected), translate it to an SDNode with the specified opcode /// and return true. bool SelectionDAGBuilder::visitBinaryFloatCall(const CallInst &I, unsigned Opcode) { // Sanity check that it really is a binary floating-point call. if (I.getNumArgOperands() != 2 || !I.getArgOperand(0)->getType()->isFloatingPointTy() || I.getType() != I.getArgOperand(0)->getType() || I.getType() != I.getArgOperand(1)->getType() || !I.onlyReadsMemory()) return false; SDValue Tmp0 = getValue(I.getArgOperand(0)); SDValue Tmp1 = getValue(I.getArgOperand(1)); EVT VT = Tmp0.getValueType(); setValue(&I, DAG.getNode(Opcode, getCurSDLoc(), VT, Tmp0, Tmp1)); return true; } void SelectionDAGBuilder::visitCall(const CallInst &I) { // Handle inline assembly differently. if (isa<InlineAsm>(I.getCalledValue())) { visitInlineAsm(&I); return; } MachineModuleInfo &MMI = DAG.getMachineFunction().getMMI(); ComputeUsesVAFloatArgument(I, &MMI); const char *RenameFn = nullptr; if (Function *F = I.getCalledFunction()) { if (F->isDeclaration()) { if (const TargetIntrinsicInfo *II = TM.getIntrinsicInfo()) { if (unsigned IID = II->getIntrinsicID(F)) { RenameFn = visitIntrinsicCall(I, IID); if (!RenameFn) return; } } if (Intrinsic::ID IID = F->getIntrinsicID()) { RenameFn = visitIntrinsicCall(I, IID); if (!RenameFn) return; } } // Check for well-known libc/libm calls. If the function is internal, it // can't be a library call. Don't do the check if marked as nobuiltin for // some reason. LibFunc::Func Func; if (!I.isNoBuiltin() && !F->hasLocalLinkage() && F->hasName() && LibInfo->getLibFunc(F->getName(), Func) && LibInfo->hasOptimizedCodeGen(Func)) { switch (Func) { default: break; case LibFunc::copysign: case LibFunc::copysignf: case LibFunc::copysignl: if (I.getNumArgOperands() == 2 && // Basic sanity checks. I.getArgOperand(0)->getType()->isFloatingPointTy() && I.getType() == I.getArgOperand(0)->getType() && I.getType() == I.getArgOperand(1)->getType() && I.onlyReadsMemory()) { SDValue LHS = getValue(I.getArgOperand(0)); SDValue RHS = getValue(I.getArgOperand(1)); setValue(&I, DAG.getNode(ISD::FCOPYSIGN, getCurSDLoc(), LHS.getValueType(), LHS, RHS)); return; } break; case LibFunc::fabs: case LibFunc::fabsf: case LibFunc::fabsl: if (visitUnaryFloatCall(I, ISD::FABS)) return; break; case LibFunc::fmin: case LibFunc::fminf: case LibFunc::fminl: if (visitBinaryFloatCall(I, ISD::FMINNUM)) return; break; case LibFunc::fmax: case LibFunc::fmaxf: case LibFunc::fmaxl: if (visitBinaryFloatCall(I, ISD::FMAXNUM)) return; break; case LibFunc::sin: case LibFunc::sinf: case LibFunc::sinl: if (visitUnaryFloatCall(I, ISD::FSIN)) return; break; case LibFunc::cos: case LibFunc::cosf: case LibFunc::cosl: if (visitUnaryFloatCall(I, ISD::FCOS)) return; break; case LibFunc::sqrt: case LibFunc::sqrtf: case LibFunc::sqrtl: case LibFunc::sqrt_finite: case LibFunc::sqrtf_finite: case LibFunc::sqrtl_finite: if (visitUnaryFloatCall(I, ISD::FSQRT)) return; break; case LibFunc::floor: case LibFunc::floorf: case LibFunc::floorl: if (visitUnaryFloatCall(I, ISD::FFLOOR)) return; break; case LibFunc::nearbyint: case LibFunc::nearbyintf: case LibFunc::nearbyintl: if (visitUnaryFloatCall(I, ISD::FNEARBYINT)) return; break; case LibFunc::ceil: case LibFunc::ceilf: case LibFunc::ceill: if (visitUnaryFloatCall(I, ISD::FCEIL)) return; break; case LibFunc::rint: case LibFunc::rintf: case LibFunc::rintl: if (visitUnaryFloatCall(I, ISD::FRINT)) return; break; case LibFunc::round: case LibFunc::roundf: case LibFunc::roundl: if (visitUnaryFloatCall(I, ISD::FROUND)) return; break; case LibFunc::trunc: case LibFunc::truncf: case LibFunc::truncl: if (visitUnaryFloatCall(I, ISD::FTRUNC)) return; break; case LibFunc::log2: case LibFunc::log2f: case LibFunc::log2l: if (visitUnaryFloatCall(I, ISD::FLOG2)) return; break; case LibFunc::exp2: case LibFunc::exp2f: case LibFunc::exp2l: if (visitUnaryFloatCall(I, ISD::FEXP2)) return; break; case LibFunc::memcmp: if (visitMemCmpCall(I)) return; break; case LibFunc::memchr: if (visitMemChrCall(I)) return; break; case LibFunc::strcpy: if (visitStrCpyCall(I, false)) return; break; case LibFunc::stpcpy: if (visitStrCpyCall(I, true)) return; break; case LibFunc::strcmp: if (visitStrCmpCall(I)) return; break; case LibFunc::strlen: if (visitStrLenCall(I)) return; break; case LibFunc::strnlen: if (visitStrNLenCall(I)) return; break; } } } SDValue Callee; if (!RenameFn) Callee = getValue(I.getCalledValue()); else Callee = DAG.getExternalSymbol( RenameFn, DAG.getTargetLoweringInfo().getPointerTy(DAG.getDataLayout())); // Deopt bundles are lowered in LowerCallSiteWithDeoptBundle, and we don't // have to do anything here to lower funclet bundles. assert(!I.hasOperandBundlesOtherThan( {LLVMContext::OB_deopt, LLVMContext::OB_funclet}) && "Cannot lower calls with arbitrary operand bundles!"); if (I.countOperandBundlesOfType(LLVMContext::OB_deopt)) LowerCallSiteWithDeoptBundle(&I, Callee, nullptr); else // Check if we can potentially perform a tail call. More detailed checking // is be done within LowerCallTo, after more information about the call is // known. LowerCallTo(&I, Callee, I.isTailCall()); } namespace { /// AsmOperandInfo - This contains information for each constraint that we are /// lowering. class SDISelAsmOperandInfo : public TargetLowering::AsmOperandInfo { public: /// CallOperand - If this is the result output operand or a clobber /// this is null, otherwise it is the incoming operand to the CallInst. /// This gets modified as the asm is processed. SDValue CallOperand; /// AssignedRegs - If this is a register or register class operand, this /// contains the set of register corresponding to the operand. RegsForValue AssignedRegs; explicit SDISelAsmOperandInfo(const TargetLowering::AsmOperandInfo &info) : TargetLowering::AsmOperandInfo(info), CallOperand(nullptr,0) { } /// getCallOperandValEVT - Return the EVT of the Value* that this operand /// corresponds to. If there is no Value* for this operand, it returns /// MVT::Other. EVT getCallOperandValEVT(LLVMContext &Context, const TargetLowering &TLI, const DataLayout &DL) const { if (!CallOperandVal) return MVT::Other; if (isa<BasicBlock>(CallOperandVal)) return TLI.getPointerTy(DL); llvm::Type *OpTy = CallOperandVal->getType(); // FIXME: code duplicated from TargetLowering::ParseConstraints(). // If this is an indirect operand, the operand is a pointer to the // accessed type. if (isIndirect) { llvm::PointerType *PtrTy = dyn_cast<PointerType>(OpTy); if (!PtrTy) report_fatal_error("Indirect operand for inline asm not a pointer!"); OpTy = PtrTy->getElementType(); } // Look for vector wrapped in a struct. e.g. { <16 x i8> }. if (StructType *STy = dyn_cast<StructType>(OpTy)) if (STy->getNumElements() == 1) OpTy = STy->getElementType(0); // If OpTy is not a single value, it may be a struct/union that we // can tile with integers. if (!OpTy->isSingleValueType() && OpTy->isSized()) { unsigned BitSize = DL.getTypeSizeInBits(OpTy); switch (BitSize) { default: break; case 1: case 8: case 16: case 32: case 64: case 128: OpTy = IntegerType::get(Context, BitSize); break; } } return TLI.getValueType(DL, OpTy, true); } }; typedef SmallVector<SDISelAsmOperandInfo,16> SDISelAsmOperandInfoVector; } // end anonymous namespace /// GetRegistersForValue - Assign registers (virtual or physical) for the /// specified operand. We prefer to assign virtual registers, to allow the /// register allocator to handle the assignment process. However, if the asm /// uses features that we can't model on machineinstrs, we have SDISel do the /// allocation. This produces generally horrible, but correct, code. /// /// OpInfo describes the operand. /// static void GetRegistersForValue(SelectionDAG &DAG, const TargetLowering &TLI, const SDLoc &DL, SDISelAsmOperandInfo &OpInfo) { LLVMContext &Context = *DAG.getContext(); MachineFunction &MF = DAG.getMachineFunction(); SmallVector<unsigned, 4> Regs; // If this is a constraint for a single physreg, or a constraint for a // register class, find it. std::pair<unsigned, const TargetRegisterClass *> PhysReg = TLI.getRegForInlineAsmConstraint(MF.getSubtarget().getRegisterInfo(), OpInfo.ConstraintCode, OpInfo.ConstraintVT); unsigned NumRegs = 1; if (OpInfo.ConstraintVT != MVT::Other) { // If this is a FP input in an integer register (or visa versa) insert a bit // cast of the input value. More generally, handle any case where the input // value disagrees with the register class we plan to stick this in. if (OpInfo.Type == InlineAsm::isInput && PhysReg.second && !PhysReg.second->hasType(OpInfo.ConstraintVT)) { // Try to convert to the first EVT that the reg class contains. If the // types are identical size, use a bitcast to convert (e.g. two differing // vector types). MVT RegVT = *PhysReg.second->vt_begin(); if (RegVT.getSizeInBits() == OpInfo.CallOperand.getValueSizeInBits()) { OpInfo.CallOperand = DAG.getNode(ISD::BITCAST, DL, RegVT, OpInfo.CallOperand); OpInfo.ConstraintVT = RegVT; } else if (RegVT.isInteger() && OpInfo.ConstraintVT.isFloatingPoint()) { // If the input is a FP value and we want it in FP registers, do a // bitcast to the corresponding integer type. This turns an f64 value // into i64, which can be passed with two i32 values on a 32-bit // machine. RegVT = MVT::getIntegerVT(OpInfo.ConstraintVT.getSizeInBits()); OpInfo.CallOperand = DAG.getNode(ISD::BITCAST, DL, RegVT, OpInfo.CallOperand); OpInfo.ConstraintVT = RegVT; } } NumRegs = TLI.getNumRegisters(Context, OpInfo.ConstraintVT); } MVT RegVT; EVT ValueVT = OpInfo.ConstraintVT; // If this is a constraint for a specific physical register, like {r17}, // assign it now. if (unsigned AssignedReg = PhysReg.first) { const TargetRegisterClass *RC = PhysReg.second; if (OpInfo.ConstraintVT == MVT::Other) ValueVT = *RC->vt_begin(); // Get the actual register value type. This is important, because the user // may have asked for (e.g.) the AX register in i32 type. We need to // remember that AX is actually i16 to get the right extension. RegVT = *RC->vt_begin(); // This is a explicit reference to a physical register. Regs.push_back(AssignedReg); // If this is an expanded reference, add the rest of the regs to Regs. if (NumRegs != 1) { TargetRegisterClass::iterator I = RC->begin(); for (; *I != AssignedReg; ++I) assert(I != RC->end() && "Didn't find reg!"); // Already added the first reg. --NumRegs; ++I; for (; NumRegs; --NumRegs, ++I) { assert(I != RC->end() && "Ran out of registers to allocate!"); Regs.push_back(*I); } } OpInfo.AssignedRegs = RegsForValue(Regs, RegVT, ValueVT); return; } // Otherwise, if this was a reference to an LLVM register class, create vregs // for this reference. if (const TargetRegisterClass *RC = PhysReg.second) { RegVT = *RC->vt_begin(); if (OpInfo.ConstraintVT == MVT::Other) ValueVT = RegVT; // Create the appropriate number of virtual registers. MachineRegisterInfo &RegInfo = MF.getRegInfo(); for (; NumRegs; --NumRegs) Regs.push_back(RegInfo.createVirtualRegister(RC)); OpInfo.AssignedRegs = RegsForValue(Regs, RegVT, ValueVT); return; } // Otherwise, we couldn't allocate enough registers for this. } /// visitInlineAsm - Handle a call to an InlineAsm object. /// void SelectionDAGBuilder::visitInlineAsm(ImmutableCallSite CS) { const InlineAsm *IA = cast<InlineAsm>(CS.getCalledValue()); /// ConstraintOperands - Information about all of the constraints. SDISelAsmOperandInfoVector ConstraintOperands; const TargetLowering &TLI = DAG.getTargetLoweringInfo(); TargetLowering::AsmOperandInfoVector TargetConstraints = TLI.ParseConstraints( DAG.getDataLayout(), DAG.getSubtarget().getRegisterInfo(), CS); bool hasMemory = false; unsigned ArgNo = 0; // ArgNo - The argument of the CallInst. unsigned ResNo = 0; // ResNo - The result number of the next output. for (unsigned i = 0, e = TargetConstraints.size(); i != e; ++i) { ConstraintOperands.push_back(SDISelAsmOperandInfo(TargetConstraints[i])); SDISelAsmOperandInfo &OpInfo = ConstraintOperands.back(); MVT OpVT = MVT::Other; // Compute the value type for each operand. switch (OpInfo.Type) { case InlineAsm::isOutput: // Indirect outputs just consume an argument. if (OpInfo.isIndirect) { OpInfo.CallOperandVal = const_cast<Value *>(CS.getArgument(ArgNo++)); break; } // The return value of the call is this value. As such, there is no // corresponding argument. assert(!CS.getType()->isVoidTy() && "Bad inline asm!"); if (StructType *STy = dyn_cast<StructType>(CS.getType())) { OpVT = TLI.getSimpleValueType(DAG.getDataLayout(), STy->getElementType(ResNo)); } else { assert(ResNo == 0 && "Asm only has one result!"); OpVT = TLI.getSimpleValueType(DAG.getDataLayout(), CS.getType()); } ++ResNo; break; case InlineAsm::isInput: OpInfo.CallOperandVal = const_cast<Value *>(CS.getArgument(ArgNo++)); break; case InlineAsm::isClobber: // Nothing to do. break; } // If this is an input or an indirect output, process the call argument. // BasicBlocks are labels, currently appearing only in asm's. if (OpInfo.CallOperandVal) { if (const BasicBlock *BB = dyn_cast<BasicBlock>(OpInfo.CallOperandVal)) { OpInfo.CallOperand = DAG.getBasicBlock(FuncInfo.MBBMap[BB]); } else { OpInfo.CallOperand = getValue(OpInfo.CallOperandVal); } OpVT = OpInfo.getCallOperandValEVT(*DAG.getContext(), TLI, DAG.getDataLayout()).getSimpleVT(); } OpInfo.ConstraintVT = OpVT; // Indirect operand accesses access memory. if (OpInfo.isIndirect) hasMemory = true; else { for (unsigned j = 0, ee = OpInfo.Codes.size(); j != ee; ++j) { TargetLowering::ConstraintType CType = TLI.getConstraintType(OpInfo.Codes[j]); if (CType == TargetLowering::C_Memory) { hasMemory = true; break; } } } } SDValue Chain, Flag; // We won't need to flush pending loads if this asm doesn't touch // memory and is nonvolatile. if (hasMemory || IA->hasSideEffects()) Chain = getRoot(); else Chain = DAG.getRoot(); // Second pass over the constraints: compute which constraint option to use // and assign registers to constraints that want a specific physreg. for (unsigned i = 0, e = ConstraintOperands.size(); i != e; ++i) { SDISelAsmOperandInfo &OpInfo = ConstraintOperands[i]; // If this is an output operand with a matching input operand, look up the // matching input. If their types mismatch, e.g. one is an integer, the // other is floating point, or their sizes are different, flag it as an // error. if (OpInfo.hasMatchingInput()) { SDISelAsmOperandInfo &Input = ConstraintOperands[OpInfo.MatchingInput]; if (OpInfo.ConstraintVT != Input.ConstraintVT) { const TargetRegisterInfo *TRI = DAG.getSubtarget().getRegisterInfo(); std::pair<unsigned, const TargetRegisterClass *> MatchRC = TLI.getRegForInlineAsmConstraint(TRI, OpInfo.ConstraintCode, OpInfo.ConstraintVT); std::pair<unsigned, const TargetRegisterClass *> InputRC = TLI.getRegForInlineAsmConstraint(TRI, Input.ConstraintCode, Input.ConstraintVT); if ((OpInfo.ConstraintVT.isInteger() != Input.ConstraintVT.isInteger()) || (MatchRC.second != InputRC.second)) { report_fatal_error("Unsupported asm: input constraint" " with a matching output constraint of" " incompatible type!"); } Input.ConstraintVT = OpInfo.ConstraintVT; } } // Compute the constraint code and ConstraintType to use. TLI.ComputeConstraintToUse(OpInfo, OpInfo.CallOperand, &DAG); if (OpInfo.ConstraintType == TargetLowering::C_Memory && OpInfo.Type == InlineAsm::isClobber) continue; // If this is a memory input, and if the operand is not indirect, do what we // need to to provide an address for the memory input. if (OpInfo.ConstraintType == TargetLowering::C_Memory && !OpInfo.isIndirect) { assert((OpInfo.isMultipleAlternative || (OpInfo.Type == InlineAsm::isInput)) && "Can only indirectify direct input operands!"); // Memory operands really want the address of the value. If we don't have // an indirect input, put it in the constpool if we can, otherwise spill // it to a stack slot. // TODO: This isn't quite right. We need to handle these according to // the addressing mode that the constraint wants. Also, this may take // an additional register for the computation and we don't want that // either. // If the operand is a float, integer, or vector constant, spill to a // constant pool entry to get its address. const Value *OpVal = OpInfo.CallOperandVal; if (isa<ConstantFP>(OpVal) || isa<ConstantInt>(OpVal) || isa<ConstantVector>(OpVal) || isa<ConstantDataVector>(OpVal)) { OpInfo.CallOperand = DAG.getConstantPool( cast<Constant>(OpVal), TLI.getPointerTy(DAG.getDataLayout())); } else { // Otherwise, create a stack slot and emit a store to it before the // asm. Type *Ty = OpVal->getType(); auto &DL = DAG.getDataLayout(); uint64_t TySize = DL.getTypeAllocSize(Ty); unsigned Align = DL.getPrefTypeAlignment(Ty); MachineFunction &MF = DAG.getMachineFunction(); int SSFI = MF.getFrameInfo()->CreateStackObject(TySize, Align, false); SDValue StackSlot = DAG.getFrameIndex(SSFI, TLI.getPointerTy(DAG.getDataLayout())); Chain = DAG.getStore( Chain, getCurSDLoc(), OpInfo.CallOperand, StackSlot, MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SSFI), false, false, 0); OpInfo.CallOperand = StackSlot; } // There is no longer a Value* corresponding to this operand. OpInfo.CallOperandVal = nullptr; // It is now an indirect operand. OpInfo.isIndirect = true; } // If this constraint is for a specific register, allocate it before // anything else. if (OpInfo.ConstraintType == TargetLowering::C_Register) GetRegistersForValue(DAG, TLI, getCurSDLoc(), OpInfo); } // Second pass - Loop over all of the operands, assigning virtual or physregs // to register class operands. for (unsigned i = 0, e = ConstraintOperands.size(); i != e; ++i) { SDISelAsmOperandInfo &OpInfo = ConstraintOperands[i]; // C_Register operands have already been allocated, Other/Memory don't need // to be. if (OpInfo.ConstraintType == TargetLowering::C_RegisterClass) GetRegistersForValue(DAG, TLI, getCurSDLoc(), OpInfo); } // AsmNodeOperands - The operands for the ISD::INLINEASM node. std::vector<SDValue> AsmNodeOperands; AsmNodeOperands.push_back(SDValue()); // reserve space for input chain AsmNodeOperands.push_back(DAG.getTargetExternalSymbol( IA->getAsmString().c_str(), TLI.getPointerTy(DAG.getDataLayout()))); // If we have a !srcloc metadata node associated with it, we want to attach // this to the ultimately generated inline asm machineinstr. To do this, we // pass in the third operand as this (potentially null) inline asm MDNode. const MDNode *SrcLoc = CS.getInstruction()->getMetadata("srcloc"); AsmNodeOperands.push_back(DAG.getMDNode(SrcLoc)); // Remember the HasSideEffect, AlignStack, AsmDialect, MayLoad and MayStore // bits as operand 3. unsigned ExtraInfo = 0; if (IA->hasSideEffects()) ExtraInfo |= InlineAsm::Extra_HasSideEffects; if (IA->isAlignStack()) ExtraInfo |= InlineAsm::Extra_IsAlignStack; if (CS.isConvergent()) ExtraInfo |= InlineAsm::Extra_IsConvergent; // Set the asm dialect. ExtraInfo |= IA->getDialect() * InlineAsm::Extra_AsmDialect; // Determine if this InlineAsm MayLoad or MayStore based on the constraints. for (unsigned i = 0, e = TargetConstraints.size(); i != e; ++i) { TargetLowering::AsmOperandInfo &OpInfo = TargetConstraints[i]; // Compute the constraint code and ConstraintType to use. TLI.ComputeConstraintToUse(OpInfo, SDValue()); // Ideally, we would only check against memory constraints. However, the // meaning of an other constraint can be target-specific and we can't easily // reason about it. Therefore, be conservative and set MayLoad/MayStore // for other constriants as well. if (OpInfo.ConstraintType == TargetLowering::C_Memory || OpInfo.ConstraintType == TargetLowering::C_Other) { if (OpInfo.Type == InlineAsm::isInput) ExtraInfo |= InlineAsm::Extra_MayLoad; else if (OpInfo.Type == InlineAsm::isOutput) ExtraInfo |= InlineAsm::Extra_MayStore; else if (OpInfo.Type == InlineAsm::isClobber) ExtraInfo |= (InlineAsm::Extra_MayLoad | InlineAsm::Extra_MayStore); } } AsmNodeOperands.push_back(DAG.getTargetConstant( ExtraInfo, getCurSDLoc(), TLI.getPointerTy(DAG.getDataLayout()))); // Loop over all of the inputs, copying the operand values into the // appropriate registers and processing the output regs. RegsForValue RetValRegs; // IndirectStoresToEmit - The set of stores to emit after the inline asm node. std::vector<std::pair<RegsForValue, Value*> > IndirectStoresToEmit; for (unsigned i = 0, e = ConstraintOperands.size(); i != e; ++i) { SDISelAsmOperandInfo &OpInfo = ConstraintOperands[i]; switch (OpInfo.Type) { case InlineAsm::isOutput: { if (OpInfo.ConstraintType != TargetLowering::C_RegisterClass && OpInfo.ConstraintType != TargetLowering::C_Register) { // Memory output, or 'other' output (e.g. 'X' constraint). assert(OpInfo.isIndirect && "Memory output must be indirect operand"); unsigned ConstraintID = TLI.getInlineAsmMemConstraint(OpInfo.ConstraintCode); assert(ConstraintID != InlineAsm::Constraint_Unknown && "Failed to convert memory constraint code to constraint id."); // Add information to the INLINEASM node to know about this output. unsigned OpFlags = InlineAsm::getFlagWord(InlineAsm::Kind_Mem, 1); OpFlags = InlineAsm::getFlagWordForMem(OpFlags, ConstraintID); AsmNodeOperands.push_back(DAG.getTargetConstant(OpFlags, getCurSDLoc(), MVT::i32)); AsmNodeOperands.push_back(OpInfo.CallOperand); break; } // Otherwise, this is a register or register class output. // Copy the output from the appropriate register. Find a register that // we can use. if (OpInfo.AssignedRegs.Regs.empty()) { emitInlineAsmError( CS, "couldn't allocate output register for constraint '" + Twine(OpInfo.ConstraintCode) + "'"); return; } // If this is an indirect operand, store through the pointer after the // asm. if (OpInfo.isIndirect) { IndirectStoresToEmit.push_back(std::make_pair(OpInfo.AssignedRegs, OpInfo.CallOperandVal)); } else { // This is the result value of the call. assert(!CS.getType()->isVoidTy() && "Bad inline asm!"); // Concatenate this output onto the outputs list. RetValRegs.append(OpInfo.AssignedRegs); } // Add information to the INLINEASM node to know that this register is // set. OpInfo.AssignedRegs .AddInlineAsmOperands(OpInfo.isEarlyClobber ? InlineAsm::Kind_RegDefEarlyClobber : InlineAsm::Kind_RegDef, false, 0, getCurSDLoc(), DAG, AsmNodeOperands); break; } case InlineAsm::isInput: { SDValue InOperandVal = OpInfo.CallOperand; if (OpInfo.isMatchingInputConstraint()) { // Matching constraint? // If this is required to match an output register we have already set, // just use its register. unsigned OperandNo = OpInfo.getMatchedOperand(); // Scan until we find the definition we already emitted of this operand. // When we find it, create a RegsForValue operand. unsigned CurOp = InlineAsm::Op_FirstOperand; for (; OperandNo; --OperandNo) { // Advance to the next operand. unsigned OpFlag = cast<ConstantSDNode>(AsmNodeOperands[CurOp])->getZExtValue(); assert((InlineAsm::isRegDefKind(OpFlag) || InlineAsm::isRegDefEarlyClobberKind(OpFlag) || InlineAsm::isMemKind(OpFlag)) && "Skipped past definitions?"); CurOp += InlineAsm::getNumOperandRegisters(OpFlag)+1; } unsigned OpFlag = cast<ConstantSDNode>(AsmNodeOperands[CurOp])->getZExtValue(); if (InlineAsm::isRegDefKind(OpFlag) || InlineAsm::isRegDefEarlyClobberKind(OpFlag)) { // Add (OpFlag&0xffff)>>3 registers to MatchedRegs. if (OpInfo.isIndirect) { // This happens on gcc/testsuite/gcc.dg/pr8788-1.c emitInlineAsmError(CS, "inline asm not supported yet:" " don't know how to handle tied " "indirect register inputs"); return; } RegsForValue MatchedRegs; MatchedRegs.ValueVTs.push_back(InOperandVal.getValueType()); MVT RegVT = AsmNodeOperands[CurOp+1].getSimpleValueType(); MatchedRegs.RegVTs.push_back(RegVT); MachineRegisterInfo &RegInfo = DAG.getMachineFunction().getRegInfo(); for (unsigned i = 0, e = InlineAsm::getNumOperandRegisters(OpFlag); i != e; ++i) { if (const TargetRegisterClass *RC = TLI.getRegClassFor(RegVT)) MatchedRegs.Regs.push_back(RegInfo.createVirtualRegister(RC)); else { emitInlineAsmError( CS, "inline asm error: This value" " type register class is not natively supported!"); return; } } SDLoc dl = getCurSDLoc(); // Use the produced MatchedRegs object to MatchedRegs.getCopyToRegs(InOperandVal, DAG, dl, Chain, &Flag, CS.getInstruction()); MatchedRegs.AddInlineAsmOperands(InlineAsm::Kind_RegUse, true, OpInfo.getMatchedOperand(), dl, DAG, AsmNodeOperands); break; } assert(InlineAsm::isMemKind(OpFlag) && "Unknown matching constraint!"); assert(InlineAsm::getNumOperandRegisters(OpFlag) == 1 && "Unexpected number of operands"); // Add information to the INLINEASM node to know about this input. // See InlineAsm.h isUseOperandTiedToDef. OpFlag = InlineAsm::convertMemFlagWordToMatchingFlagWord(OpFlag); OpFlag = InlineAsm::getFlagWordForMatchingOp(OpFlag, OpInfo.getMatchedOperand()); AsmNodeOperands.push_back(DAG.getTargetConstant( OpFlag, getCurSDLoc(), TLI.getPointerTy(DAG.getDataLayout()))); AsmNodeOperands.push_back(AsmNodeOperands[CurOp+1]); break; } // Treat indirect 'X' constraint as memory. if (OpInfo.ConstraintType == TargetLowering::C_Other && OpInfo.isIndirect) OpInfo.ConstraintType = TargetLowering::C_Memory; if (OpInfo.ConstraintType == TargetLowering::C_Other) { std::vector<SDValue> Ops; TLI.LowerAsmOperandForConstraint(InOperandVal, OpInfo.ConstraintCode, Ops, DAG); if (Ops.empty()) { emitInlineAsmError(CS, "invalid operand for inline asm constraint '" + Twine(OpInfo.ConstraintCode) + "'"); return; } // Add information to the INLINEASM node to know about this input. unsigned ResOpType = InlineAsm::getFlagWord(InlineAsm::Kind_Imm, Ops.size()); AsmNodeOperands.push_back(DAG.getTargetConstant( ResOpType, getCurSDLoc(), TLI.getPointerTy(DAG.getDataLayout()))); AsmNodeOperands.insert(AsmNodeOperands.end(), Ops.begin(), Ops.end()); break; } if (OpInfo.ConstraintType == TargetLowering::C_Memory) { assert(OpInfo.isIndirect && "Operand must be indirect to be a mem!"); assert(InOperandVal.getValueType() == TLI.getPointerTy(DAG.getDataLayout()) && "Memory operands expect pointer values"); unsigned ConstraintID = TLI.getInlineAsmMemConstraint(OpInfo.ConstraintCode); assert(ConstraintID != InlineAsm::Constraint_Unknown && "Failed to convert memory constraint code to constraint id."); // Add information to the INLINEASM node to know about this input. unsigned ResOpType = InlineAsm::getFlagWord(InlineAsm::Kind_Mem, 1); ResOpType = InlineAsm::getFlagWordForMem(ResOpType, ConstraintID); AsmNodeOperands.push_back(DAG.getTargetConstant(ResOpType, getCurSDLoc(), MVT::i32)); AsmNodeOperands.push_back(InOperandVal); break; } assert((OpInfo.ConstraintType == TargetLowering::C_RegisterClass || OpInfo.ConstraintType == TargetLowering::C_Register) && "Unknown constraint type!"); // TODO: Support this. if (OpInfo.isIndirect) { emitInlineAsmError( CS, "Don't know how to handle indirect register inputs yet " "for constraint '" + Twine(OpInfo.ConstraintCode) + "'"); return; } // Copy the input into the appropriate registers. if (OpInfo.AssignedRegs.Regs.empty()) { emitInlineAsmError(CS, "couldn't allocate input reg for constraint '" + Twine(OpInfo.ConstraintCode) + "'"); return; } SDLoc dl = getCurSDLoc(); OpInfo.AssignedRegs.getCopyToRegs(InOperandVal, DAG, dl, Chain, &Flag, CS.getInstruction()); OpInfo.AssignedRegs.AddInlineAsmOperands(InlineAsm::Kind_RegUse, false, 0, dl, DAG, AsmNodeOperands); break; } case InlineAsm::isClobber: { // Add the clobbered value to the operand list, so that the register // allocator is aware that the physreg got clobbered. if (!OpInfo.AssignedRegs.Regs.empty()) OpInfo.AssignedRegs.AddInlineAsmOperands(InlineAsm::Kind_Clobber, false, 0, getCurSDLoc(), DAG, AsmNodeOperands); break; } } } // Finish up input operands. Set the input chain and add the flag last. AsmNodeOperands[InlineAsm::Op_InputChain] = Chain; if (Flag.getNode()) AsmNodeOperands.push_back(Flag); Chain = DAG.getNode(ISD::INLINEASM, getCurSDLoc(), DAG.getVTList(MVT::Other, MVT::Glue), AsmNodeOperands); Flag = Chain.getValue(1); // If this asm returns a register value, copy the result from that register // and set it as the value of the call. if (!RetValRegs.Regs.empty()) { SDValue Val = RetValRegs.getCopyFromRegs(DAG, FuncInfo, getCurSDLoc(), Chain, &Flag, CS.getInstruction()); // FIXME: Why don't we do this for inline asms with MRVs? if (CS.getType()->isSingleValueType() && CS.getType()->isSized()) { EVT ResultType = TLI.getValueType(DAG.getDataLayout(), CS.getType()); // If any of the results of the inline asm is a vector, it may have the // wrong width/num elts. This can happen for register classes that can // contain multiple different value types. The preg or vreg allocated may // not have the same VT as was expected. Convert it to the right type // with bit_convert. if (ResultType != Val.getValueType() && Val.getValueType().isVector()) { Val = DAG.getNode(ISD::BITCAST, getCurSDLoc(), ResultType, Val); } else if (ResultType != Val.getValueType() && ResultType.isInteger() && Val.getValueType().isInteger()) { // If a result value was tied to an input value, the computed result may // have a wider width than the expected result. Extract the relevant // portion. Val = DAG.getNode(ISD::TRUNCATE, getCurSDLoc(), ResultType, Val); } assert(ResultType == Val.getValueType() && "Asm result value mismatch!"); } setValue(CS.getInstruction(), Val); // Don't need to use this as a chain in this case. if (!IA->hasSideEffects() && !hasMemory && IndirectStoresToEmit.empty()) return; } std::vector<std::pair<SDValue, const Value *> > StoresToEmit; // Process indirect outputs, first output all of the flagged copies out of // physregs. for (unsigned i = 0, e = IndirectStoresToEmit.size(); i != e; ++i) { RegsForValue &OutRegs = IndirectStoresToEmit[i].first; const Value *Ptr = IndirectStoresToEmit[i].second; SDValue OutVal = OutRegs.getCopyFromRegs(DAG, FuncInfo, getCurSDLoc(), Chain, &Flag, IA); StoresToEmit.push_back(std::make_pair(OutVal, Ptr)); } // Emit the non-flagged stores from the physregs. SmallVector<SDValue, 8> OutChains; for (unsigned i = 0, e = StoresToEmit.size(); i != e; ++i) { SDValue Val = DAG.getStore(Chain, getCurSDLoc(), StoresToEmit[i].first, getValue(StoresToEmit[i].second), MachinePointerInfo(StoresToEmit[i].second), false, false, 0); OutChains.push_back(Val); } if (!OutChains.empty()) Chain = DAG.getNode(ISD::TokenFactor, getCurSDLoc(), MVT::Other, OutChains); DAG.setRoot(Chain); } void SelectionDAGBuilder::emitInlineAsmError(ImmutableCallSite CS, const Twine &Message) { LLVMContext &Ctx = *DAG.getContext(); Ctx.emitError(CS.getInstruction(), Message); // Make sure we leave the DAG in a valid state const TargetLowering &TLI = DAG.getTargetLoweringInfo(); auto VT = TLI.getValueType(DAG.getDataLayout(), CS.getType()); setValue(CS.getInstruction(), DAG.getUNDEF(VT)); } void SelectionDAGBuilder::visitVAStart(const CallInst &I) { DAG.setRoot(DAG.getNode(ISD::VASTART, getCurSDLoc(), MVT::Other, getRoot(), getValue(I.getArgOperand(0)), DAG.getSrcValue(I.getArgOperand(0)))); } void SelectionDAGBuilder::visitVAArg(const VAArgInst &I) { const TargetLowering &TLI = DAG.getTargetLoweringInfo(); const DataLayout &DL = DAG.getDataLayout(); SDValue V = DAG.getVAArg(TLI.getValueType(DAG.getDataLayout(), I.getType()), getCurSDLoc(), getRoot(), getValue(I.getOperand(0)), DAG.getSrcValue(I.getOperand(0)), DL.getABITypeAlignment(I.getType())); setValue(&I, V); DAG.setRoot(V.getValue(1)); } void SelectionDAGBuilder::visitVAEnd(const CallInst &I) { DAG.setRoot(DAG.getNode(ISD::VAEND, getCurSDLoc(), MVT::Other, getRoot(), getValue(I.getArgOperand(0)), DAG.getSrcValue(I.getArgOperand(0)))); } void SelectionDAGBuilder::visitVACopy(const CallInst &I) { DAG.setRoot(DAG.getNode(ISD::VACOPY, getCurSDLoc(), MVT::Other, getRoot(), getValue(I.getArgOperand(0)), getValue(I.getArgOperand(1)), DAG.getSrcValue(I.getArgOperand(0)), DAG.getSrcValue(I.getArgOperand(1)))); } SDValue SelectionDAGBuilder::lowerRangeToAssertZExt(SelectionDAG &DAG, const Instruction &I, SDValue Op) { const MDNode *Range = I.getMetadata(LLVMContext::MD_range); if (!Range) return Op; Constant *Lo = cast<ConstantAsMetadata>(Range->getOperand(0))->getValue(); if (!Lo->isNullValue()) return Op; Constant *Hi = cast<ConstantAsMetadata>(Range->getOperand(1))->getValue(); unsigned Bits = cast<ConstantInt>(Hi)->getValue().logBase2(); EVT SmallVT = EVT::getIntegerVT(*DAG.getContext(), Bits); SDLoc SL = getCurSDLoc(); SDValue ZExt = DAG.getNode(ISD::AssertZext, SL, Op.getValueType(), Op, DAG.getValueType(SmallVT)); unsigned NumVals = Op.getNode()->getNumValues(); if (NumVals == 1) return ZExt; SmallVector<SDValue, 4> Ops; Ops.push_back(ZExt); for (unsigned I = 1; I != NumVals; ++I) Ops.push_back(Op.getValue(I)); return DAG.getMergeValues(Ops, SL); } /// \brief Populate a CallLowerinInfo (into \p CLI) based on the properties of /// the call being lowered. /// /// This is a helper for lowering intrinsics that follow a target calling /// convention or require stack pointer adjustment. Only a subset of the /// intrinsic's operands need to participate in the calling convention. void SelectionDAGBuilder::populateCallLoweringInfo( TargetLowering::CallLoweringInfo &CLI, ImmutableCallSite CS, unsigned ArgIdx, unsigned NumArgs, SDValue Callee, Type *ReturnTy, bool IsPatchPoint) { TargetLowering::ArgListTy Args; Args.reserve(NumArgs); // Populate the argument list. // Attributes for args start at offset 1, after the return attribute. for (unsigned ArgI = ArgIdx, ArgE = ArgIdx + NumArgs, AttrI = ArgIdx + 1; ArgI != ArgE; ++ArgI) { const Value *V = CS->getOperand(ArgI); assert(!V->getType()->isEmptyTy() && "Empty type passed to intrinsic."); TargetLowering::ArgListEntry Entry; Entry.Node = getValue(V); Entry.Ty = V->getType(); Entry.setAttributes(&CS, AttrI); Args.push_back(Entry); } CLI.setDebugLoc(getCurSDLoc()) .setChain(getRoot()) .setCallee(CS.getCallingConv(), ReturnTy, Callee, std::move(Args)) .setDiscardResult(CS->use_empty()) .setIsPatchPoint(IsPatchPoint); } /// \brief Add a stack map intrinsic call's live variable operands to a stackmap /// or patchpoint target node's operand list. /// /// Constants are converted to TargetConstants purely as an optimization to /// avoid constant materialization and register allocation. /// /// FrameIndex operands are converted to TargetFrameIndex so that ISEL does not /// generate addess computation nodes, and so ExpandISelPseudo can convert the /// TargetFrameIndex into a DirectMemRefOp StackMap location. This avoids /// address materialization and register allocation, but may also be required /// for correctness. If a StackMap (or PatchPoint) intrinsic directly uses an /// alloca in the entry block, then the runtime may assume that the alloca's /// StackMap location can be read immediately after compilation and that the /// location is valid at any point during execution (this is similar to the /// assumption made by the llvm.gcroot intrinsic). If the alloca's location were /// only available in a register, then the runtime would need to trap when /// execution reaches the StackMap in order to read the alloca's location. static void addStackMapLiveVars(ImmutableCallSite CS, unsigned StartIdx, const SDLoc &DL, SmallVectorImpl<SDValue> &Ops, SelectionDAGBuilder &Builder) { for (unsigned i = StartIdx, e = CS.arg_size(); i != e; ++i) { SDValue OpVal = Builder.getValue(CS.getArgument(i)); if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(OpVal)) { Ops.push_back( Builder.DAG.getTargetConstant(StackMaps::ConstantOp, DL, MVT::i64)); Ops.push_back( Builder.DAG.getTargetConstant(C->getSExtValue(), DL, MVT::i64)); } else if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(OpVal)) { const TargetLowering &TLI = Builder.DAG.getTargetLoweringInfo(); Ops.push_back(Builder.DAG.getTargetFrameIndex( FI->getIndex(), TLI.getPointerTy(Builder.DAG.getDataLayout()))); } else Ops.push_back(OpVal); } } /// \brief Lower llvm.experimental.stackmap directly to its target opcode. void SelectionDAGBuilder::visitStackmap(const CallInst &CI) { // void @llvm.experimental.stackmap(i32 <id>, i32 <numShadowBytes>, // [live variables...]) assert(CI.getType()->isVoidTy() && "Stackmap cannot return a value."); SDValue Chain, InFlag, Callee, NullPtr; SmallVector<SDValue, 32> Ops; SDLoc DL = getCurSDLoc(); Callee = getValue(CI.getCalledValue()); NullPtr = DAG.getIntPtrConstant(0, DL, true); // The stackmap intrinsic only records the live variables (the arguemnts // passed to it) and emits NOPS (if requested). Unlike the patchpoint // intrinsic, this won't be lowered to a function call. This means we don't // have to worry about calling conventions and target specific lowering code. // Instead we perform the call lowering right here. // // chain, flag = CALLSEQ_START(chain, 0) // chain, flag = STACKMAP(id, nbytes, ..., chain, flag) // chain, flag = CALLSEQ_END(chain, 0, 0, flag) // Chain = DAG.getCALLSEQ_START(getRoot(), NullPtr, DL); InFlag = Chain.getValue(1); // Add the <id> and <numBytes> constants. SDValue IDVal = getValue(CI.getOperand(PatchPointOpers::IDPos)); Ops.push_back(DAG.getTargetConstant( cast<ConstantSDNode>(IDVal)->getZExtValue(), DL, MVT::i64)); SDValue NBytesVal = getValue(CI.getOperand(PatchPointOpers::NBytesPos)); Ops.push_back(DAG.getTargetConstant( cast<ConstantSDNode>(NBytesVal)->getZExtValue(), DL, MVT::i32)); // Push live variables for the stack map. addStackMapLiveVars(&CI, 2, DL, Ops, *this); // We are not pushing any register mask info here on the operands list, // because the stackmap doesn't clobber anything. // Push the chain and the glue flag. Ops.push_back(Chain); Ops.push_back(InFlag); // Create the STACKMAP node. SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue); SDNode *SM = DAG.getMachineNode(TargetOpcode::STACKMAP, DL, NodeTys, Ops); Chain = SDValue(SM, 0); InFlag = Chain.getValue(1); Chain = DAG.getCALLSEQ_END(Chain, NullPtr, NullPtr, InFlag, DL); // Stackmaps don't generate values, so nothing goes into the NodeMap. // Set the root to the target-lowered call chain. DAG.setRoot(Chain); // Inform the Frame Information that we have a stackmap in this function. FuncInfo.MF->getFrameInfo()->setHasStackMap(); } /// \brief Lower llvm.experimental.patchpoint directly to its target opcode. void SelectionDAGBuilder::visitPatchpoint(ImmutableCallSite CS, const BasicBlock *EHPadBB) { // void|i64 @llvm.experimental.patchpoint.void|i64(i64 <id>, // i32 <numBytes>, // i8* <target>, // i32 <numArgs>, // [Args...], // [live variables...]) CallingConv::ID CC = CS.getCallingConv(); bool IsAnyRegCC = CC == CallingConv::AnyReg; bool HasDef = !CS->getType()->isVoidTy(); SDLoc dl = getCurSDLoc(); SDValue Callee = getValue(CS->getOperand(PatchPointOpers::TargetPos)); // Handle immediate and symbolic callees. if (auto* ConstCallee = dyn_cast<ConstantSDNode>(Callee)) Callee = DAG.getIntPtrConstant(ConstCallee->getZExtValue(), dl, /*isTarget=*/true); else if (auto* SymbolicCallee = dyn_cast<GlobalAddressSDNode>(Callee)) Callee = DAG.getTargetGlobalAddress(SymbolicCallee->getGlobal(), SDLoc(SymbolicCallee), SymbolicCallee->getValueType(0)); // Get the real number of arguments participating in the call <numArgs> SDValue NArgVal = getValue(CS.getArgument(PatchPointOpers::NArgPos)); unsigned NumArgs = cast<ConstantSDNode>(NArgVal)->getZExtValue(); // Skip the four meta args: <id>, <numNopBytes>, <target>, <numArgs> // Intrinsics include all meta-operands up to but not including CC. unsigned NumMetaOpers = PatchPointOpers::CCPos; assert(CS.arg_size() >= NumMetaOpers + NumArgs && "Not enough arguments provided to the patchpoint intrinsic"); // For AnyRegCC the arguments are lowered later on manually. unsigned NumCallArgs = IsAnyRegCC ? 0 : NumArgs; Type *ReturnTy = IsAnyRegCC ? Type::getVoidTy(*DAG.getContext()) : CS->getType(); TargetLowering::CallLoweringInfo CLI(DAG); populateCallLoweringInfo(CLI, CS, NumMetaOpers, NumCallArgs, Callee, ReturnTy, true); std::pair<SDValue, SDValue> Result = lowerInvokable(CLI, EHPadBB); SDNode *CallEnd = Result.second.getNode(); if (HasDef && (CallEnd->getOpcode() == ISD::CopyFromReg)) CallEnd = CallEnd->getOperand(0).getNode(); /// Get a call instruction from the call sequence chain. /// Tail calls are not allowed. assert(CallEnd->getOpcode() == ISD::CALLSEQ_END && "Expected a callseq node."); SDNode *Call = CallEnd->getOperand(0).getNode(); bool HasGlue = Call->getGluedNode(); // Replace the target specific call node with the patchable intrinsic. SmallVector<SDValue, 8> Ops; // Add the <id> and <numBytes> constants. SDValue IDVal = getValue(CS->getOperand(PatchPointOpers::IDPos)); Ops.push_back(DAG.getTargetConstant( cast<ConstantSDNode>(IDVal)->getZExtValue(), dl, MVT::i64)); SDValue NBytesVal = getValue(CS->getOperand(PatchPointOpers::NBytesPos)); Ops.push_back(DAG.getTargetConstant( cast<ConstantSDNode>(NBytesVal)->getZExtValue(), dl, MVT::i32)); // Add the callee. Ops.push_back(Callee); // Adjust <numArgs> to account for any arguments that have been passed on the // stack instead. // Call Node: Chain, Target, {Args}, RegMask, [Glue] unsigned NumCallRegArgs = Call->getNumOperands() - (HasGlue ? 4 : 3); NumCallRegArgs = IsAnyRegCC ? NumArgs : NumCallRegArgs; Ops.push_back(DAG.getTargetConstant(NumCallRegArgs, dl, MVT::i32)); // Add the calling convention Ops.push_back(DAG.getTargetConstant((unsigned)CC, dl, MVT::i32)); // Add the arguments we omitted previously. The register allocator should // place these in any free register. if (IsAnyRegCC) for (unsigned i = NumMetaOpers, e = NumMetaOpers + NumArgs; i != e; ++i) Ops.push_back(getValue(CS.getArgument(i))); // Push the arguments from the call instruction up to the register mask. SDNode::op_iterator e = HasGlue ? Call->op_end()-2 : Call->op_end()-1; Ops.append(Call->op_begin() + 2, e); // Push live variables for the stack map. addStackMapLiveVars(CS, NumMetaOpers + NumArgs, dl, Ops, *this); // Push the register mask info. if (HasGlue) Ops.push_back(*(Call->op_end()-2)); else Ops.push_back(*(Call->op_end()-1)); // Push the chain (this is originally the first operand of the call, but // becomes now the last or second to last operand). Ops.push_back(*(Call->op_begin())); // Push the glue flag (last operand). if (HasGlue) Ops.push_back(*(Call->op_end()-1)); SDVTList NodeTys; if (IsAnyRegCC && HasDef) { // Create the return types based on the intrinsic definition const TargetLowering &TLI = DAG.getTargetLoweringInfo(); SmallVector<EVT, 3> ValueVTs; ComputeValueVTs(TLI, DAG.getDataLayout(), CS->getType(), ValueVTs); assert(ValueVTs.size() == 1 && "Expected only one return value type."); // There is always a chain and a glue type at the end ValueVTs.push_back(MVT::Other); ValueVTs.push_back(MVT::Glue); NodeTys = DAG.getVTList(ValueVTs); } else NodeTys = DAG.getVTList(MVT::Other, MVT::Glue); // Replace the target specific call node with a PATCHPOINT node. MachineSDNode *MN = DAG.getMachineNode(TargetOpcode::PATCHPOINT, dl, NodeTys, Ops); // Update the NodeMap. if (HasDef) { if (IsAnyRegCC) setValue(CS.getInstruction(), SDValue(MN, 0)); else setValue(CS.getInstruction(), Result.first); } // Fixup the consumers of the intrinsic. The chain and glue may be used in the // call sequence. Furthermore the location of the chain and glue can change // when the AnyReg calling convention is used and the intrinsic returns a // value. if (IsAnyRegCC && HasDef) { SDValue From[] = {SDValue(Call, 0), SDValue(Call, 1)}; SDValue To[] = {SDValue(MN, 1), SDValue(MN, 2)}; DAG.ReplaceAllUsesOfValuesWith(From, To, 2); } else DAG.ReplaceAllUsesWith(Call, MN); DAG.DeleteNode(Call); // Inform the Frame Information that we have a patchpoint in this function. FuncInfo.MF->getFrameInfo()->setHasPatchPoint(); } /// Returns an AttributeSet representing the attributes applied to the return /// value of the given call. static AttributeSet getReturnAttrs(TargetLowering::CallLoweringInfo &CLI) { SmallVector<Attribute::AttrKind, 2> Attrs; if (CLI.RetSExt) Attrs.push_back(Attribute::SExt); if (CLI.RetZExt) Attrs.push_back(Attribute::ZExt); if (CLI.IsInReg) Attrs.push_back(Attribute::InReg); return AttributeSet::get(CLI.RetTy->getContext(), AttributeSet::ReturnIndex, Attrs); } /// TargetLowering::LowerCallTo - This is the default LowerCallTo /// implementation, which just calls LowerCall. /// FIXME: When all targets are /// migrated to using LowerCall, this hook should be integrated into SDISel. std::pair<SDValue, SDValue> TargetLowering::LowerCallTo(TargetLowering::CallLoweringInfo &CLI) const { // Handle the incoming return values from the call. CLI.Ins.clear(); Type *OrigRetTy = CLI.RetTy; SmallVector<EVT, 4> RetTys; SmallVector<uint64_t, 4> Offsets; auto &DL = CLI.DAG.getDataLayout(); ComputeValueVTs(*this, DL, CLI.RetTy, RetTys, &Offsets); SmallVector<ISD::OutputArg, 4> Outs; GetReturnInfo(CLI.RetTy, getReturnAttrs(CLI), Outs, *this, DL); bool CanLowerReturn = this->CanLowerReturn(CLI.CallConv, CLI.DAG.getMachineFunction(), CLI.IsVarArg, Outs, CLI.RetTy->getContext()); SDValue DemoteStackSlot; int DemoteStackIdx = -100; if (!CanLowerReturn) { // FIXME: equivalent assert? // assert(!CS.hasInAllocaArgument() && // "sret demotion is incompatible with inalloca"); uint64_t TySize = DL.getTypeAllocSize(CLI.RetTy); unsigned Align = DL.getPrefTypeAlignment(CLI.RetTy); MachineFunction &MF = CLI.DAG.getMachineFunction(); DemoteStackIdx = MF.getFrameInfo()->CreateStackObject(TySize, Align, false); Type *StackSlotPtrType = PointerType::getUnqual(CLI.RetTy); DemoteStackSlot = CLI.DAG.getFrameIndex(DemoteStackIdx, getPointerTy(DL)); ArgListEntry Entry; Entry.Node = DemoteStackSlot; Entry.Ty = StackSlotPtrType; Entry.isSExt = false; Entry.isZExt = false; Entry.isInReg = false; Entry.isSRet = true; Entry.isNest = false; Entry.isByVal = false; Entry.isReturned = false; Entry.isSwiftSelf = false; Entry.isSwiftError = false; Entry.Alignment = Align; CLI.getArgs().insert(CLI.getArgs().begin(), Entry); CLI.RetTy = Type::getVoidTy(CLI.RetTy->getContext()); // sret demotion isn't compatible with tail-calls, since the sret argument // points into the callers stack frame. CLI.IsTailCall = false; } else { for (unsigned I = 0, E = RetTys.size(); I != E; ++I) { EVT VT = RetTys[I]; MVT RegisterVT = getRegisterType(CLI.RetTy->getContext(), VT); unsigned NumRegs = getNumRegisters(CLI.RetTy->getContext(), VT); for (unsigned i = 0; i != NumRegs; ++i) { ISD::InputArg MyFlags; MyFlags.VT = RegisterVT; MyFlags.ArgVT = VT; MyFlags.Used = CLI.IsReturnValueUsed; if (CLI.RetSExt) MyFlags.Flags.setSExt(); if (CLI.RetZExt) MyFlags.Flags.setZExt(); if (CLI.IsInReg) MyFlags.Flags.setInReg(); CLI.Ins.push_back(MyFlags); } } } // We push in swifterror return as the last element of CLI.Ins. ArgListTy &Args = CLI.getArgs(); if (supportSwiftError()) { for (unsigned i = 0, e = Args.size(); i != e; ++i) { if (Args[i].isSwiftError) { ISD::InputArg MyFlags; MyFlags.VT = getPointerTy(DL); MyFlags.ArgVT = EVT(getPointerTy(DL)); MyFlags.Flags.setSwiftError(); CLI.Ins.push_back(MyFlags); } } } // Handle all of the outgoing arguments. CLI.Outs.clear(); CLI.OutVals.clear(); for (unsigned i = 0, e = Args.size(); i != e; ++i) { SmallVector<EVT, 4> ValueVTs; ComputeValueVTs(*this, DL, Args[i].Ty, ValueVTs); Type *FinalType = Args[i].Ty; if (Args[i].isByVal) FinalType = cast<PointerType>(Args[i].Ty)->getElementType(); bool NeedsRegBlock = functionArgumentNeedsConsecutiveRegisters( FinalType, CLI.CallConv, CLI.IsVarArg); for (unsigned Value = 0, NumValues = ValueVTs.size(); Value != NumValues; ++Value) { EVT VT = ValueVTs[Value]; Type *ArgTy = VT.getTypeForEVT(CLI.RetTy->getContext()); SDValue Op = SDValue(Args[i].Node.getNode(), Args[i].Node.getResNo() + Value); ISD::ArgFlagsTy Flags; unsigned OriginalAlignment = DL.getABITypeAlignment(ArgTy); if (Args[i].isZExt) Flags.setZExt(); if (Args[i].isSExt) Flags.setSExt(); if (Args[i].isInReg) Flags.setInReg(); if (Args[i].isSRet) Flags.setSRet(); if (Args[i].isSwiftSelf) Flags.setSwiftSelf(); if (Args[i].isSwiftError) Flags.setSwiftError(); if (Args[i].isByVal) Flags.setByVal(); if (Args[i].isInAlloca) { Flags.setInAlloca(); // Set the byval flag for CCAssignFn callbacks that don't know about // inalloca. This way we can know how many bytes we should've allocated // and how many bytes a callee cleanup function will pop. If we port // inalloca to more targets, we'll have to add custom inalloca handling // in the various CC lowering callbacks. Flags.setByVal(); } if (Args[i].isByVal || Args[i].isInAlloca) { PointerType *Ty = cast<PointerType>(Args[i].Ty); Type *ElementTy = Ty->getElementType(); Flags.setByValSize(DL.getTypeAllocSize(ElementTy)); // For ByVal, alignment should come from FE. BE will guess if this // info is not there but there are cases it cannot get right. unsigned FrameAlign; if (Args[i].Alignment) FrameAlign = Args[i].Alignment; else FrameAlign = getByValTypeAlignment(ElementTy, DL); Flags.setByValAlign(FrameAlign); } if (Args[i].isNest) Flags.setNest(); if (NeedsRegBlock) Flags.setInConsecutiveRegs(); Flags.setOrigAlign(OriginalAlignment); MVT PartVT = getRegisterType(CLI.RetTy->getContext(), VT); unsigned NumParts = getNumRegisters(CLI.RetTy->getContext(), VT); SmallVector<SDValue, 4> Parts(NumParts); ISD::NodeType ExtendKind = ISD::ANY_EXTEND; if (Args[i].isSExt) ExtendKind = ISD::SIGN_EXTEND; else if (Args[i].isZExt) ExtendKind = ISD::ZERO_EXTEND; // Conservatively only handle 'returned' on non-vectors for now if (Args[i].isReturned && !Op.getValueType().isVector()) { assert(CLI.RetTy == Args[i].Ty && RetTys.size() == NumValues && "unexpected use of 'returned'"); // Before passing 'returned' to the target lowering code, ensure that // either the register MVT and the actual EVT are the same size or that // the return value and argument are extended in the same way; in these // cases it's safe to pass the argument register value unchanged as the // return register value (although it's at the target's option whether // to do so) // TODO: allow code generation to take advantage of partially preserved // registers rather than clobbering the entire register when the // parameter extension method is not compatible with the return // extension method if ((NumParts * PartVT.getSizeInBits() == VT.getSizeInBits()) || (ExtendKind != ISD::ANY_EXTEND && CLI.RetSExt == Args[i].isSExt && CLI.RetZExt == Args[i].isZExt)) Flags.setReturned(); } getCopyToParts(CLI.DAG, CLI.DL, Op, &Parts[0], NumParts, PartVT, CLI.CS ? CLI.CS->getInstruction() : nullptr, ExtendKind); for (unsigned j = 0; j != NumParts; ++j) { // if it isn't first piece, alignment must be 1 ISD::OutputArg MyFlags(Flags, Parts[j].getValueType(), VT, i < CLI.NumFixedArgs, i, j*Parts[j].getValueType().getStoreSize()); if (NumParts > 1 && j == 0) MyFlags.Flags.setSplit(); else if (j != 0) { MyFlags.Flags.setOrigAlign(1); if (j == NumParts - 1) MyFlags.Flags.setSplitEnd(); } CLI.Outs.push_back(MyFlags); CLI.OutVals.push_back(Parts[j]); } if (NeedsRegBlock && Value == NumValues - 1) CLI.Outs[CLI.Outs.size() - 1].Flags.setInConsecutiveRegsLast(); } } SmallVector<SDValue, 4> InVals; CLI.Chain = LowerCall(CLI, InVals); // Update CLI.InVals to use outside of this function. CLI.InVals = InVals; // Verify that the target's LowerCall behaved as expected. assert(CLI.Chain.getNode() && CLI.Chain.getValueType() == MVT::Other && "LowerCall didn't return a valid chain!"); assert((!CLI.IsTailCall || InVals.empty()) && "LowerCall emitted a return value for a tail call!"); assert((CLI.IsTailCall || InVals.size() == CLI.Ins.size()) && "LowerCall didn't emit the correct number of values!"); // For a tail call, the return value is merely live-out and there aren't // any nodes in the DAG representing it. Return a special value to // indicate that a tail call has been emitted and no more Instructions // should be processed in the current block. if (CLI.IsTailCall) { CLI.DAG.setRoot(CLI.Chain); return std::make_pair(SDValue(), SDValue()); } #ifndef NDEBUG for (unsigned i = 0, e = CLI.Ins.size(); i != e; ++i) { assert(InVals[i].getNode() && "LowerCall emitted a null value!"); assert(EVT(CLI.Ins[i].VT) == InVals[i].getValueType() && "LowerCall emitted a value with the wrong type!"); } #endif SmallVector<SDValue, 4> ReturnValues; if (!CanLowerReturn) { // The instruction result is the result of loading from the // hidden sret parameter. SmallVector<EVT, 1> PVTs; Type *PtrRetTy = PointerType::getUnqual(OrigRetTy); ComputeValueVTs(*this, DL, PtrRetTy, PVTs); assert(PVTs.size() == 1 && "Pointers should fit in one register"); EVT PtrVT = PVTs[0]; unsigned NumValues = RetTys.size(); ReturnValues.resize(NumValues); SmallVector<SDValue, 4> Chains(NumValues); // An aggregate return value cannot wrap around the address space, so // offsets to its parts don't wrap either. SDNodeFlags Flags; Flags.setNoUnsignedWrap(true); for (unsigned i = 0; i < NumValues; ++i) { SDValue Add = CLI.DAG.getNode(ISD::ADD, CLI.DL, PtrVT, DemoteStackSlot, CLI.DAG.getConstant(Offsets[i], CLI.DL, PtrVT), &Flags); SDValue L = CLI.DAG.getLoad( RetTys[i], CLI.DL, CLI.Chain, Add, MachinePointerInfo::getFixedStack(CLI.DAG.getMachineFunction(), DemoteStackIdx, Offsets[i]), false, false, false, 1); ReturnValues[i] = L; Chains[i] = L.getValue(1); } CLI.Chain = CLI.DAG.getNode(ISD::TokenFactor, CLI.DL, MVT::Other, Chains); } else { // Collect the legal value parts into potentially illegal values // that correspond to the original function's return values. Optional<ISD::NodeType> AssertOp; if (CLI.RetSExt) AssertOp = ISD::AssertSext; else if (CLI.RetZExt) AssertOp = ISD::AssertZext; unsigned CurReg = 0; for (unsigned I = 0, E = RetTys.size(); I != E; ++I) { EVT VT = RetTys[I]; MVT RegisterVT = getRegisterType(CLI.RetTy->getContext(), VT); unsigned NumRegs = getNumRegisters(CLI.RetTy->getContext(), VT); ReturnValues.push_back(getCopyFromParts(CLI.DAG, CLI.DL, &InVals[CurReg], NumRegs, RegisterVT, VT, nullptr, AssertOp)); CurReg += NumRegs; } // For a function returning void, there is no return value. We can't create // such a node, so we just return a null return value in that case. In // that case, nothing will actually look at the value. if (ReturnValues.empty()) return std::make_pair(SDValue(), CLI.Chain); } SDValue Res = CLI.DAG.getNode(ISD::MERGE_VALUES, CLI.DL, CLI.DAG.getVTList(RetTys), ReturnValues); return std::make_pair(Res, CLI.Chain); } void TargetLowering::LowerOperationWrapper(SDNode *N, SmallVectorImpl<SDValue> &Results, SelectionDAG &DAG) const { if (SDValue Res = LowerOperation(SDValue(N, 0), DAG)) Results.push_back(Res); } SDValue TargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const { llvm_unreachable("LowerOperation not implemented for this target!"); } void SelectionDAGBuilder::CopyValueToVirtualRegister(const Value *V, unsigned Reg) { SDValue Op = getNonRegisterValue(V); assert((Op.getOpcode() != ISD::CopyFromReg || cast<RegisterSDNode>(Op.getOperand(1))->getReg() != Reg) && "Copy from a reg to the same reg!"); assert(!TargetRegisterInfo::isPhysicalRegister(Reg) && "Is a physreg"); const TargetLowering &TLI = DAG.getTargetLoweringInfo(); RegsForValue RFV(V->getContext(), TLI, DAG.getDataLayout(), Reg, V->getType()); SDValue Chain = DAG.getEntryNode(); ISD::NodeType ExtendType = (FuncInfo.PreferredExtendType.find(V) == FuncInfo.PreferredExtendType.end()) ? ISD::ANY_EXTEND : FuncInfo.PreferredExtendType[V]; RFV.getCopyToRegs(Op, DAG, getCurSDLoc(), Chain, nullptr, V, ExtendType); PendingExports.push_back(Chain); } #include "llvm/CodeGen/SelectionDAGISel.h" /// isOnlyUsedInEntryBlock - If the specified argument is only used in the /// entry block, return true. This includes arguments used by switches, since /// the switch may expand into multiple basic blocks. static bool isOnlyUsedInEntryBlock(const Argument *A, bool FastISel) { // With FastISel active, we may be splitting blocks, so force creation // of virtual registers for all non-dead arguments. if (FastISel) return A->use_empty(); const BasicBlock &Entry = A->getParent()->front(); for (const User *U : A->users()) if (cast<Instruction>(U)->getParent() != &Entry || isa<SwitchInst>(U)) return false; // Use not in entry block. return true; } void SelectionDAGISel::LowerArguments(const Function &F) { SelectionDAG &DAG = SDB->DAG; SDLoc dl = SDB->getCurSDLoc(); const DataLayout &DL = DAG.getDataLayout(); SmallVector<ISD::InputArg, 16> Ins; if (!FuncInfo->CanLowerReturn) { // Put in an sret pointer parameter before all the other parameters. SmallVector<EVT, 1> ValueVTs; ComputeValueVTs(*TLI, DAG.getDataLayout(), PointerType::getUnqual(F.getReturnType()), ValueVTs); // NOTE: Assuming that a pointer will never break down to more than one VT // or one register. ISD::ArgFlagsTy Flags; Flags.setSRet(); MVT RegisterVT = TLI->getRegisterType(*DAG.getContext(), ValueVTs[0]); ISD::InputArg RetArg(Flags, RegisterVT, ValueVTs[0], true, ISD::InputArg::NoArgIndex, 0); Ins.push_back(RetArg); } // Set up the incoming argument description vector. unsigned Idx = 1; for (Function::const_arg_iterator I = F.arg_begin(), E = F.arg_end(); I != E; ++I, ++Idx) { SmallVector<EVT, 4> ValueVTs; ComputeValueVTs(*TLI, DAG.getDataLayout(), I->getType(), ValueVTs); bool isArgValueUsed = !I->use_empty(); unsigned PartBase = 0; Type *FinalType = I->getType(); if (F.getAttributes().hasAttribute(Idx, Attribute::ByVal)) FinalType = cast<PointerType>(FinalType)->getElementType(); bool NeedsRegBlock = TLI->functionArgumentNeedsConsecutiveRegisters( FinalType, F.getCallingConv(), F.isVarArg()); for (unsigned Value = 0, NumValues = ValueVTs.size(); Value != NumValues; ++Value) { EVT VT = ValueVTs[Value]; Type *ArgTy = VT.getTypeForEVT(*DAG.getContext()); ISD::ArgFlagsTy Flags; unsigned OriginalAlignment = DL.getABITypeAlignment(ArgTy); if (F.getAttributes().hasAttribute(Idx, Attribute::ZExt)) Flags.setZExt(); if (F.getAttributes().hasAttribute(Idx, Attribute::SExt)) Flags.setSExt(); if (F.getAttributes().hasAttribute(Idx, Attribute::InReg)) Flags.setInReg(); if (F.getAttributes().hasAttribute(Idx, Attribute::StructRet)) Flags.setSRet(); if (F.getAttributes().hasAttribute(Idx, Attribute::SwiftSelf)) Flags.setSwiftSelf(); if (F.getAttributes().hasAttribute(Idx, Attribute::SwiftError)) Flags.setSwiftError(); if (F.getAttributes().hasAttribute(Idx, Attribute::ByVal)) Flags.setByVal(); if (F.getAttributes().hasAttribute(Idx, Attribute::InAlloca)) { Flags.setInAlloca(); // Set the byval flag for CCAssignFn callbacks that don't know about // inalloca. This way we can know how many bytes we should've allocated // and how many bytes a callee cleanup function will pop. If we port // inalloca to more targets, we'll have to add custom inalloca handling // in the various CC lowering callbacks. Flags.setByVal(); } if (F.getCallingConv() == CallingConv::X86_INTR) { // IA Interrupt passes frame (1st parameter) by value in the stack. if (Idx == 1) Flags.setByVal(); } if (Flags.isByVal() || Flags.isInAlloca()) { PointerType *Ty = cast<PointerType>(I->getType()); Type *ElementTy = Ty->getElementType(); Flags.setByValSize(DL.getTypeAllocSize(ElementTy)); // For ByVal, alignment should be passed from FE. BE will guess if // this info is not there but there are cases it cannot get right. unsigned FrameAlign; if (F.getParamAlignment(Idx)) FrameAlign = F.getParamAlignment(Idx); else FrameAlign = TLI->getByValTypeAlignment(ElementTy, DL); Flags.setByValAlign(FrameAlign); } if (F.getAttributes().hasAttribute(Idx, Attribute::Nest)) Flags.setNest(); if (NeedsRegBlock) Flags.setInConsecutiveRegs(); Flags.setOrigAlign(OriginalAlignment); MVT RegisterVT = TLI->getRegisterType(*CurDAG->getContext(), VT); unsigned NumRegs = TLI->getNumRegisters(*CurDAG->getContext(), VT); for (unsigned i = 0; i != NumRegs; ++i) { ISD::InputArg MyFlags(Flags, RegisterVT, VT, isArgValueUsed, Idx-1, PartBase+i*RegisterVT.getStoreSize()); if (NumRegs > 1 && i == 0) MyFlags.Flags.setSplit(); // if it isn't first piece, alignment must be 1 else if (i > 0) { MyFlags.Flags.setOrigAlign(1); if (i == NumRegs - 1) MyFlags.Flags.setSplitEnd(); } Ins.push_back(MyFlags); } if (NeedsRegBlock && Value == NumValues - 1) Ins[Ins.size() - 1].Flags.setInConsecutiveRegsLast(); PartBase += VT.getStoreSize(); } } // Call the target to set up the argument values. SmallVector<SDValue, 8> InVals; SDValue NewRoot = TLI->LowerFormalArguments( DAG.getRoot(), F.getCallingConv(), F.isVarArg(), Ins, dl, DAG, InVals); // Verify that the target's LowerFormalArguments behaved as expected. assert(NewRoot.getNode() && NewRoot.getValueType() == MVT::Other && "LowerFormalArguments didn't return a valid chain!"); assert(InVals.size() == Ins.size() && "LowerFormalArguments didn't emit the correct number of values!"); DEBUG({ for (unsigned i = 0, e = Ins.size(); i != e; ++i) { assert(InVals[i].getNode() && "LowerFormalArguments emitted a null value!"); assert(EVT(Ins[i].VT) == InVals[i].getValueType() && "LowerFormalArguments emitted a value with the wrong type!"); } }); // Update the DAG with the new chain value resulting from argument lowering. DAG.setRoot(NewRoot); // Set up the argument values. unsigned i = 0; Idx = 1; if (!FuncInfo->CanLowerReturn) { // Create a virtual register for the sret pointer, and put in a copy // from the sret argument into it. SmallVector<EVT, 1> ValueVTs; ComputeValueVTs(*TLI, DAG.getDataLayout(), PointerType::getUnqual(F.getReturnType()), ValueVTs); MVT VT = ValueVTs[0].getSimpleVT(); MVT RegVT = TLI->getRegisterType(*CurDAG->getContext(), VT); Optional<ISD::NodeType> AssertOp = None; SDValue ArgValue = getCopyFromParts(DAG, dl, &InVals[0], 1, RegVT, VT, nullptr, AssertOp); MachineFunction& MF = SDB->DAG.getMachineFunction(); MachineRegisterInfo& RegInfo = MF.getRegInfo(); unsigned SRetReg = RegInfo.createVirtualRegister(TLI->getRegClassFor(RegVT)); FuncInfo->DemoteRegister = SRetReg; NewRoot = SDB->DAG.getCopyToReg(NewRoot, SDB->getCurSDLoc(), SRetReg, ArgValue); DAG.setRoot(NewRoot); // i indexes lowered arguments. Bump it past the hidden sret argument. // Idx indexes LLVM arguments. Don't touch it. ++i; } for (Function::const_arg_iterator I = F.arg_begin(), E = F.arg_end(); I != E; ++I, ++Idx) { SmallVector<SDValue, 4> ArgValues; SmallVector<EVT, 4> ValueVTs; ComputeValueVTs(*TLI, DAG.getDataLayout(), I->getType(), ValueVTs); unsigned NumValues = ValueVTs.size(); // If this argument is unused then remember its value. It is used to generate // debugging information. if (I->use_empty() && NumValues) { SDB->setUnusedArgValue(&*I, InVals[i]); // Also remember any frame index for use in FastISel. if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(InVals[i].getNode())) FuncInfo->setArgumentFrameIndex(&*I, FI->getIndex()); } for (unsigned Val = 0; Val != NumValues; ++Val) { EVT VT = ValueVTs[Val]; MVT PartVT = TLI->getRegisterType(*CurDAG->getContext(), VT); unsigned NumParts = TLI->getNumRegisters(*CurDAG->getContext(), VT); if (!I->use_empty()) { Optional<ISD::NodeType> AssertOp; if (F.getAttributes().hasAttribute(Idx, Attribute::SExt)) AssertOp = ISD::AssertSext; else if (F.getAttributes().hasAttribute(Idx, Attribute::ZExt)) AssertOp = ISD::AssertZext; ArgValues.push_back(getCopyFromParts(DAG, dl, &InVals[i], NumParts, PartVT, VT, nullptr, AssertOp)); } i += NumParts; } // We don't need to do anything else for unused arguments. if (ArgValues.empty()) continue; // Note down frame index. if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(ArgValues[0].getNode())) FuncInfo->setArgumentFrameIndex(&*I, FI->getIndex()); SDValue Res = DAG.getMergeValues(makeArrayRef(ArgValues.data(), NumValues), SDB->getCurSDLoc()); SDB->setValue(&*I, Res); if (!TM.Options.EnableFastISel && Res.getOpcode() == ISD::BUILD_PAIR) { if (LoadSDNode *LNode = dyn_cast<LoadSDNode>(Res.getOperand(0).getNode())) if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(LNode->getBasePtr().getNode())) FuncInfo->setArgumentFrameIndex(&*I, FI->getIndex()); } // Update SwiftErrorMap. if (Res.getOpcode() == ISD::CopyFromReg && TLI->supportSwiftError() && F.getAttributes().hasAttribute(Idx, Attribute::SwiftError)) { unsigned Reg = cast<RegisterSDNode>(Res.getOperand(1))->getReg(); if (TargetRegisterInfo::isVirtualRegister(Reg)) FuncInfo->SwiftErrorMap[FuncInfo->MBB][0] = Reg; } // If this argument is live outside of the entry block, insert a copy from // wherever we got it to the vreg that other BB's will reference it as. if (!TM.Options.EnableFastISel && Res.getOpcode() == ISD::CopyFromReg) { // If we can, though, try to skip creating an unnecessary vreg. // FIXME: This isn't very clean... it would be nice to make this more // general. It's also subtly incompatible with the hacks FastISel // uses with vregs. unsigned Reg = cast<RegisterSDNode>(Res.getOperand(1))->getReg(); if (TargetRegisterInfo::isVirtualRegister(Reg)) { FuncInfo->ValueMap[&*I] = Reg; continue; } } if (!isOnlyUsedInEntryBlock(&*I, TM.Options.EnableFastISel)) { FuncInfo->InitializeRegForValue(&*I); SDB->CopyToExportRegsIfNeeded(&*I); } } assert(i == InVals.size() && "Argument register count mismatch!"); // Finally, if the target has anything special to do, allow it to do so. EmitFunctionEntryCode(); } /// Handle PHI nodes in successor blocks. Emit code into the SelectionDAG to /// ensure constants are generated when needed. Remember the virtual registers /// that need to be added to the Machine PHI nodes as input. We cannot just /// directly add them, because expansion might result in multiple MBB's for one /// BB. As such, the start of the BB might correspond to a different MBB than /// the end. /// void SelectionDAGBuilder::HandlePHINodesInSuccessorBlocks(const BasicBlock *LLVMBB) { const TerminatorInst *TI = LLVMBB->getTerminator(); SmallPtrSet<MachineBasicBlock *, 4> SuccsHandled; // Check PHI nodes in successors that expect a value to be available from this // block. for (unsigned succ = 0, e = TI->getNumSuccessors(); succ != e; ++succ) { const BasicBlock *SuccBB = TI->getSuccessor(succ); if (!isa<PHINode>(SuccBB->begin())) continue; MachineBasicBlock *SuccMBB = FuncInfo.MBBMap[SuccBB]; // If this terminator has multiple identical successors (common for // switches), only handle each succ once. if (!SuccsHandled.insert(SuccMBB).second) continue; MachineBasicBlock::iterator MBBI = SuccMBB->begin(); // At this point we know that there is a 1-1 correspondence between LLVM PHI // nodes and Machine PHI nodes, but the incoming operands have not been // emitted yet. for (BasicBlock::const_iterator I = SuccBB->begin(); const PHINode *PN = dyn_cast<PHINode>(I); ++I) { // Ignore dead phi's. if (PN->use_empty()) continue; // Skip empty types if (PN->getType()->isEmptyTy()) continue; unsigned Reg; const Value *PHIOp = PN->getIncomingValueForBlock(LLVMBB); if (const Constant *C = dyn_cast<Constant>(PHIOp)) { unsigned &RegOut = ConstantsOut[C]; if (RegOut == 0) { RegOut = FuncInfo.CreateRegs(C->getType()); CopyValueToVirtualRegister(C, RegOut); } Reg = RegOut; } else { DenseMap<const Value *, unsigned>::iterator I = FuncInfo.ValueMap.find(PHIOp); if (I != FuncInfo.ValueMap.end()) Reg = I->second; else { assert(isa<AllocaInst>(PHIOp) && FuncInfo.StaticAllocaMap.count(cast<AllocaInst>(PHIOp)) && "Didn't codegen value into a register!??"); Reg = FuncInfo.CreateRegs(PHIOp->getType()); CopyValueToVirtualRegister(PHIOp, Reg); } } // Remember that this register needs to added to the machine PHI node as // the input for this MBB. SmallVector<EVT, 4> ValueVTs; const TargetLowering &TLI = DAG.getTargetLoweringInfo(); ComputeValueVTs(TLI, DAG.getDataLayout(), PN->getType(), ValueVTs); for (unsigned vti = 0, vte = ValueVTs.size(); vti != vte; ++vti) { EVT VT = ValueVTs[vti]; unsigned NumRegisters = TLI.getNumRegisters(*DAG.getContext(), VT); for (unsigned i = 0, e = NumRegisters; i != e; ++i) FuncInfo.PHINodesToUpdate.push_back( std::make_pair(&*MBBI++, Reg + i)); Reg += NumRegisters; } } } ConstantsOut.clear(); } /// Add a successor MBB to ParentMBB< creating a new MachineBB for BB if SuccMBB /// is 0. MachineBasicBlock * SelectionDAGBuilder::StackProtectorDescriptor:: AddSuccessorMBB(const BasicBlock *BB, MachineBasicBlock *ParentMBB, bool IsLikely, MachineBasicBlock *SuccMBB) { // If SuccBB has not been created yet, create it. if (!SuccMBB) { MachineFunction *MF = ParentMBB->getParent(); MachineFunction::iterator BBI(ParentMBB); SuccMBB = MF->CreateMachineBasicBlock(BB); MF->insert(++BBI, SuccMBB); } // Add it as a successor of ParentMBB. ParentMBB->addSuccessor( SuccMBB, BranchProbabilityInfo::getBranchProbStackProtector(IsLikely)); return SuccMBB; } MachineBasicBlock *SelectionDAGBuilder::NextBlock(MachineBasicBlock *MBB) { MachineFunction::iterator I(MBB); if (++I == FuncInfo.MF->end()) return nullptr; return &*I; } /// During lowering new call nodes can be created (such as memset, etc.). /// Those will become new roots of the current DAG, but complications arise /// when they are tail calls. In such cases, the call lowering will update /// the root, but the builder still needs to know that a tail call has been /// lowered in order to avoid generating an additional return. void SelectionDAGBuilder::updateDAGForMaybeTailCall(SDValue MaybeTC) { // If the node is null, we do have a tail call. if (MaybeTC.getNode() != nullptr) DAG.setRoot(MaybeTC); else HasTailCall = true; } bool SelectionDAGBuilder::isDense(const CaseClusterVector &Clusters, unsigned *TotalCases, unsigned First, unsigned Last, unsigned Density) { assert(Last >= First); assert(TotalCases[Last] >= TotalCases[First]); APInt LowCase = Clusters[First].Low->getValue(); APInt HighCase = Clusters[Last].High->getValue(); assert(LowCase.getBitWidth() == HighCase.getBitWidth()); // FIXME: A range of consecutive cases has 100% density, but only requires one // comparison to lower. We should discriminate against such consecutive ranges // in jump tables. uint64_t Diff = (HighCase - LowCase).getLimitedValue((UINT64_MAX - 1) / 100); uint64_t Range = Diff + 1; uint64_t NumCases = TotalCases[Last] - (First == 0 ? 0 : TotalCases[First - 1]); assert(NumCases < UINT64_MAX / 100); assert(Range >= NumCases); return NumCases * 100 >= Range * Density; } static inline bool areJTsAllowed(const TargetLowering &TLI, const SwitchInst *SI) { const Function *Fn = SI->getParent()->getParent(); if (Fn->getFnAttribute("no-jump-tables").getValueAsString() == "true") return false; return TLI.isOperationLegalOrCustom(ISD::BR_JT, MVT::Other) || TLI.isOperationLegalOrCustom(ISD::BRIND, MVT::Other); } bool SelectionDAGBuilder::buildJumpTable(CaseClusterVector &Clusters, unsigned First, unsigned Last, const SwitchInst *SI, MachineBasicBlock *DefaultMBB, CaseCluster &JTCluster) { assert(First <= Last); auto Prob = BranchProbability::getZero(); unsigned NumCmps = 0; std::vector<MachineBasicBlock*> Table; DenseMap<MachineBasicBlock*, BranchProbability> JTProbs; // Initialize probabilities in JTProbs. for (unsigned I = First; I <= Last; ++I) JTProbs[Clusters[I].MBB] = BranchProbability::getZero(); for (unsigned I = First; I <= Last; ++I) { assert(Clusters[I].Kind == CC_Range); Prob += Clusters[I].Prob; APInt Low = Clusters[I].Low->getValue(); APInt High = Clusters[I].High->getValue(); NumCmps += (Low == High) ? 1 : 2; if (I != First) { // Fill the gap between this and the previous cluster. APInt PreviousHigh = Clusters[I - 1].High->getValue(); assert(PreviousHigh.slt(Low)); uint64_t Gap = (Low - PreviousHigh).getLimitedValue() - 1; for (uint64_t J = 0; J < Gap; J++) Table.push_back(DefaultMBB); } uint64_t ClusterSize = (High - Low).getLimitedValue() + 1; for (uint64_t J = 0; J < ClusterSize; ++J) Table.push_back(Clusters[I].MBB); JTProbs[Clusters[I].MBB] += Clusters[I].Prob; } unsigned NumDests = JTProbs.size(); if (isSuitableForBitTests(NumDests, NumCmps, Clusters[First].Low->getValue(), Clusters[Last].High->getValue())) { // Clusters[First..Last] should be lowered as bit tests instead. return false; } // Create the MBB that will load from and jump through the table. // Note: We create it here, but it's not inserted into the function yet. MachineFunction *CurMF = FuncInfo.MF; MachineBasicBlock *JumpTableMBB = CurMF->CreateMachineBasicBlock(SI->getParent()); // Add successors. Note: use table order for determinism. SmallPtrSet<MachineBasicBlock *, 8> Done; for (MachineBasicBlock *Succ : Table) { if (Done.count(Succ)) continue; addSuccessorWithProb(JumpTableMBB, Succ, JTProbs[Succ]); Done.insert(Succ); } JumpTableMBB->normalizeSuccProbs(); const TargetLowering &TLI = DAG.getTargetLoweringInfo(); unsigned JTI = CurMF->getOrCreateJumpTableInfo(TLI.getJumpTableEncoding()) ->createJumpTableIndex(Table); // Set up the jump table info. JumpTable JT(-1U, JTI, JumpTableMBB, nullptr); JumpTableHeader JTH(Clusters[First].Low->getValue(), Clusters[Last].High->getValue(), SI->getCondition(), nullptr, false); JTCases.emplace_back(std::move(JTH), std::move(JT)); JTCluster = CaseCluster::jumpTable(Clusters[First].Low, Clusters[Last].High, JTCases.size() - 1, Prob); return true; } void SelectionDAGBuilder::findJumpTables(CaseClusterVector &Clusters, const SwitchInst *SI, MachineBasicBlock *DefaultMBB) { #ifndef NDEBUG // Clusters must be non-empty, sorted, and only contain Range clusters. assert(!Clusters.empty()); for (CaseCluster &C : Clusters) assert(C.Kind == CC_Range); for (unsigned i = 1, e = Clusters.size(); i < e; ++i) assert(Clusters[i - 1].High->getValue().slt(Clusters[i].Low->getValue())); #endif const TargetLowering &TLI = DAG.getTargetLoweringInfo(); if (!areJTsAllowed(TLI, SI)) return; const int64_t N = Clusters.size(); const unsigned MinJumpTableSize = TLI.getMinimumJumpTableEntries(); // TotalCases[i]: Total nbr of cases in Clusters[0..i]. SmallVector<unsigned, 8> TotalCases(N); for (unsigned i = 0; i < N; ++i) { APInt Hi = Clusters[i].High->getValue(); APInt Lo = Clusters[i].Low->getValue(); TotalCases[i] = (Hi - Lo).getLimitedValue() + 1; if (i != 0) TotalCases[i] += TotalCases[i - 1]; } unsigned MinDensity = JumpTableDensity; if (DefaultMBB->getParent()->getFunction()->optForSize()) MinDensity = OptsizeJumpTableDensity; if (N >= MinJumpTableSize && isDense(Clusters, &TotalCases[0], 0, N - 1, MinDensity)) { // Cheap case: the whole range might be suitable for jump table. CaseCluster JTCluster; if (buildJumpTable(Clusters, 0, N - 1, SI, DefaultMBB, JTCluster)) { Clusters[0] = JTCluster; Clusters.resize(1); return; } } // The algorithm below is not suitable for -O0. if (TM.getOptLevel() == CodeGenOpt::None) return; // Split Clusters into minimum number of dense partitions. The algorithm uses // the same idea as Kannan & Proebsting "Correction to 'Producing Good Code // for the Case Statement'" (1994), but builds the MinPartitions array in // reverse order to make it easier to reconstruct the partitions in ascending // order. In the choice between two optimal partitionings, it picks the one // which yields more jump tables. // MinPartitions[i] is the minimum nbr of partitions of Clusters[i..N-1]. SmallVector<unsigned, 8> MinPartitions(N); // LastElement[i] is the last element of the partition starting at i. SmallVector<unsigned, 8> LastElement(N); // NumTables[i]: nbr of >= MinJumpTableSize partitions from Clusters[i..N-1]. SmallVector<unsigned, 8> NumTables(N); // Base case: There is only one way to partition Clusters[N-1]. MinPartitions[N - 1] = 1; LastElement[N - 1] = N - 1; assert(MinJumpTableSize > 1); NumTables[N - 1] = 0; // Note: loop indexes are signed to avoid underflow. for (int64_t i = N - 2; i >= 0; i--) { // Find optimal partitioning of Clusters[i..N-1]. // Baseline: Put Clusters[i] into a partition on its own. MinPartitions[i] = MinPartitions[i + 1] + 1; LastElement[i] = i; NumTables[i] = NumTables[i + 1]; // Search for a solution that results in fewer partitions. for (int64_t j = N - 1; j > i; j--) { // Try building a partition from Clusters[i..j]. if (isDense(Clusters, &TotalCases[0], i, j, MinDensity)) { unsigned NumPartitions = 1 + (j == N - 1 ? 0 : MinPartitions[j + 1]); bool IsTable = j - i + 1 >= MinJumpTableSize; unsigned Tables = IsTable + (j == N - 1 ? 0 : NumTables[j + 1]); // If this j leads to fewer partitions, or same number of partitions // with more lookup tables, it is a better partitioning. if (NumPartitions < MinPartitions[i] || (NumPartitions == MinPartitions[i] && Tables > NumTables[i])) { MinPartitions[i] = NumPartitions; LastElement[i] = j; NumTables[i] = Tables; } } } } // Iterate over the partitions, replacing some with jump tables in-place. unsigned DstIndex = 0; for (unsigned First = 0, Last; First < N; First = Last + 1) { Last = LastElement[First]; assert(Last >= First); assert(DstIndex <= First); unsigned NumClusters = Last - First + 1; CaseCluster JTCluster; if (NumClusters >= MinJumpTableSize && buildJumpTable(Clusters, First, Last, SI, DefaultMBB, JTCluster)) { Clusters[DstIndex++] = JTCluster; } else { for (unsigned I = First; I <= Last; ++I) std::memmove(&Clusters[DstIndex++], &Clusters[I], sizeof(Clusters[I])); } } Clusters.resize(DstIndex); } bool SelectionDAGBuilder::rangeFitsInWord(const APInt &Low, const APInt &High) { // FIXME: Using the pointer type doesn't seem ideal. uint64_t BW = DAG.getDataLayout().getPointerSizeInBits(); uint64_t Range = (High - Low).getLimitedValue(UINT64_MAX - 1) + 1; return Range <= BW; } bool SelectionDAGBuilder::isSuitableForBitTests(unsigned NumDests, unsigned NumCmps, const APInt &Low, const APInt &High) { // FIXME: I don't think NumCmps is the correct metric: a single case and a // range of cases both require only one branch to lower. Just looking at the // number of clusters and destinations should be enough to decide whether to // build bit tests. // To lower a range with bit tests, the range must fit the bitwidth of a // machine word. if (!rangeFitsInWord(Low, High)) return false; // Decide whether it's profitable to lower this range with bit tests. Each // destination requires a bit test and branch, and there is an overall range // check branch. For a small number of clusters, separate comparisons might be // cheaper, and for many destinations, splitting the range might be better. return (NumDests == 1 && NumCmps >= 3) || (NumDests == 2 && NumCmps >= 5) || (NumDests == 3 && NumCmps >= 6); } bool SelectionDAGBuilder::buildBitTests(CaseClusterVector &Clusters, unsigned First, unsigned Last, const SwitchInst *SI, CaseCluster &BTCluster) { assert(First <= Last); if (First == Last) return false; BitVector Dests(FuncInfo.MF->getNumBlockIDs()); unsigned NumCmps = 0; for (int64_t I = First; I <= Last; ++I) { assert(Clusters[I].Kind == CC_Range); Dests.set(Clusters[I].MBB->getNumber()); NumCmps += (Clusters[I].Low == Clusters[I].High) ? 1 : 2; } unsigned NumDests = Dests.count(); APInt Low = Clusters[First].Low->getValue(); APInt High = Clusters[Last].High->getValue(); assert(Low.slt(High)); if (!isSuitableForBitTests(NumDests, NumCmps, Low, High)) return false; APInt LowBound; APInt CmpRange; const int BitWidth = DAG.getTargetLoweringInfo() .getPointerTy(DAG.getDataLayout()) .getSizeInBits(); assert(rangeFitsInWord(Low, High) && "Case range must fit in bit mask!"); // Check if the clusters cover a contiguous range such that no value in the // range will jump to the default statement. bool ContiguousRange = true; for (int64_t I = First + 1; I <= Last; ++I) { if (Clusters[I].Low->getValue() != Clusters[I - 1].High->getValue() + 1) { ContiguousRange = false; break; } } if (Low.isStrictlyPositive() && High.slt(BitWidth)) { // Optimize the case where all the case values fit in a word without having // to subtract minValue. In this case, we can optimize away the subtraction. LowBound = APInt::getNullValue(Low.getBitWidth()); CmpRange = High; ContiguousRange = false; } else { LowBound = Low; CmpRange = High - Low; } CaseBitsVector CBV; auto TotalProb = BranchProbability::getZero(); for (unsigned i = First; i <= Last; ++i) { // Find the CaseBits for this destination. unsigned j; for (j = 0; j < CBV.size(); ++j) if (CBV[j].BB == Clusters[i].MBB) break; if (j == CBV.size()) CBV.push_back( CaseBits(0, Clusters[i].MBB, 0, BranchProbability::getZero())); CaseBits *CB = &CBV[j]; // Update Mask, Bits and ExtraProb. uint64_t Lo = (Clusters[i].Low->getValue() - LowBound).getZExtValue(); uint64_t Hi = (Clusters[i].High->getValue() - LowBound).getZExtValue(); assert(Hi >= Lo && Hi < 64 && "Invalid bit case!"); CB->Mask |= (-1ULL >> (63 - (Hi - Lo))) << Lo; CB->Bits += Hi - Lo + 1; CB->ExtraProb += Clusters[i].Prob; TotalProb += Clusters[i].Prob; } BitTestInfo BTI; std::sort(CBV.begin(), CBV.end(), [](const CaseBits &a, const CaseBits &b) { // Sort by probability first, number of bits second. if (a.ExtraProb != b.ExtraProb) return a.ExtraProb > b.ExtraProb; return a.Bits > b.Bits; }); for (auto &CB : CBV) { MachineBasicBlock *BitTestBB = FuncInfo.MF->CreateMachineBasicBlock(SI->getParent()); BTI.push_back(BitTestCase(CB.Mask, BitTestBB, CB.BB, CB.ExtraProb)); } BitTestCases.emplace_back(std::move(LowBound), std::move(CmpRange), SI->getCondition(), -1U, MVT::Other, false, ContiguousRange, nullptr, nullptr, std::move(BTI), TotalProb); BTCluster = CaseCluster::bitTests(Clusters[First].Low, Clusters[Last].High, BitTestCases.size() - 1, TotalProb); return true; } void SelectionDAGBuilder::findBitTestClusters(CaseClusterVector &Clusters, const SwitchInst *SI) { // Partition Clusters into as few subsets as possible, where each subset has a // range that fits in a machine word and has <= 3 unique destinations. #ifndef NDEBUG // Clusters must be sorted and contain Range or JumpTable clusters. assert(!Clusters.empty()); assert(Clusters[0].Kind == CC_Range || Clusters[0].Kind == CC_JumpTable); for (const CaseCluster &C : Clusters) assert(C.Kind == CC_Range || C.Kind == CC_JumpTable); for (unsigned i = 1; i < Clusters.size(); ++i) assert(Clusters[i-1].High->getValue().slt(Clusters[i].Low->getValue())); #endif // The algorithm below is not suitable for -O0. if (TM.getOptLevel() == CodeGenOpt::None) return; // If target does not have legal shift left, do not emit bit tests at all. const TargetLowering &TLI = DAG.getTargetLoweringInfo(); EVT PTy = TLI.getPointerTy(DAG.getDataLayout()); if (!TLI.isOperationLegal(ISD::SHL, PTy)) return; int BitWidth = PTy.getSizeInBits(); const int64_t N = Clusters.size(); // MinPartitions[i] is the minimum nbr of partitions of Clusters[i..N-1]. SmallVector<unsigned, 8> MinPartitions(N); // LastElement[i] is the last element of the partition starting at i. SmallVector<unsigned, 8> LastElement(N); // FIXME: This might not be the best algorithm for finding bit test clusters. // Base case: There is only one way to partition Clusters[N-1]. MinPartitions[N - 1] = 1; LastElement[N - 1] = N - 1; // Note: loop indexes are signed to avoid underflow. for (int64_t i = N - 2; i >= 0; --i) { // Find optimal partitioning of Clusters[i..N-1]. // Baseline: Put Clusters[i] into a partition on its own. MinPartitions[i] = MinPartitions[i + 1] + 1; LastElement[i] = i; // Search for a solution that results in fewer partitions. // Note: the search is limited by BitWidth, reducing time complexity. for (int64_t j = std::min(N - 1, i + BitWidth - 1); j > i; --j) { // Try building a partition from Clusters[i..j]. // Check the range. if (!rangeFitsInWord(Clusters[i].Low->getValue(), Clusters[j].High->getValue())) continue; // Check nbr of destinations and cluster types. // FIXME: This works, but doesn't seem very efficient. bool RangesOnly = true; BitVector Dests(FuncInfo.MF->getNumBlockIDs()); for (int64_t k = i; k <= j; k++) { if (Clusters[k].Kind != CC_Range) { RangesOnly = false; break; } Dests.set(Clusters[k].MBB->getNumber()); } if (!RangesOnly || Dests.count() > 3) break; // Check if it's a better partition. unsigned NumPartitions = 1 + (j == N - 1 ? 0 : MinPartitions[j + 1]); if (NumPartitions < MinPartitions[i]) { // Found a better partition. MinPartitions[i] = NumPartitions; LastElement[i] = j; } } } // Iterate over the partitions, replacing with bit-test clusters in-place. unsigned DstIndex = 0; for (unsigned First = 0, Last; First < N; First = Last + 1) { Last = LastElement[First]; assert(First <= Last); assert(DstIndex <= First); CaseCluster BitTestCluster; if (buildBitTests(Clusters, First, Last, SI, BitTestCluster)) { Clusters[DstIndex++] = BitTestCluster; } else { size_t NumClusters = Last - First + 1; std::memmove(&Clusters[DstIndex], &Clusters[First], sizeof(Clusters[0]) * NumClusters); DstIndex += NumClusters; } } Clusters.resize(DstIndex); } void SelectionDAGBuilder::lowerWorkItem(SwitchWorkListItem W, Value *Cond, MachineBasicBlock *SwitchMBB, MachineBasicBlock *DefaultMBB) { MachineFunction *CurMF = FuncInfo.MF; MachineBasicBlock *NextMBB = nullptr; MachineFunction::iterator BBI(W.MBB); if (++BBI != FuncInfo.MF->end()) NextMBB = &*BBI; unsigned Size = W.LastCluster - W.FirstCluster + 1; BranchProbabilityInfo *BPI = FuncInfo.BPI; if (Size == 2 && W.MBB == SwitchMBB) { // If any two of the cases has the same destination, and if one value // is the same as the other, but has one bit unset that the other has set, // use bit manipulation to do two compares at once. For example: // "if (X == 6 || X == 4)" -> "if ((X|2) == 6)" // TODO: This could be extended to merge any 2 cases in switches with 3 // cases. // TODO: Handle cases where W.CaseBB != SwitchBB. CaseCluster &Small = *W.FirstCluster; CaseCluster &Big = *W.LastCluster; if (Small.Low == Small.High && Big.Low == Big.High && Small.MBB == Big.MBB) { const APInt &SmallValue = Small.Low->getValue(); const APInt &BigValue = Big.Low->getValue(); // Check that there is only one bit different. APInt CommonBit = BigValue ^ SmallValue; if (CommonBit.isPowerOf2()) { SDValue CondLHS = getValue(Cond); EVT VT = CondLHS.getValueType(); SDLoc DL = getCurSDLoc(); SDValue Or = DAG.getNode(ISD::OR, DL, VT, CondLHS, DAG.getConstant(CommonBit, DL, VT)); SDValue Cond = DAG.getSetCC( DL, MVT::i1, Or, DAG.getConstant(BigValue | SmallValue, DL, VT), ISD::SETEQ); // Update successor info. // Both Small and Big will jump to Small.BB, so we sum up the // probabilities. addSuccessorWithProb(SwitchMBB, Small.MBB, Small.Prob + Big.Prob); if (BPI) addSuccessorWithProb( SwitchMBB, DefaultMBB, // The default destination is the first successor in IR. BPI->getEdgeProbability(SwitchMBB->getBasicBlock(), (unsigned)0)); else addSuccessorWithProb(SwitchMBB, DefaultMBB); // Insert the true branch. SDValue BrCond = DAG.getNode(ISD::BRCOND, DL, MVT::Other, getControlRoot(), Cond, DAG.getBasicBlock(Small.MBB)); // Insert the false branch. BrCond = DAG.getNode(ISD::BR, DL, MVT::Other, BrCond, DAG.getBasicBlock(DefaultMBB)); DAG.setRoot(BrCond); return; } } } if (TM.getOptLevel() != CodeGenOpt::None) { // Order cases by probability so the most likely case will be checked first. std::sort(W.FirstCluster, W.LastCluster + 1, [](const CaseCluster &a, const CaseCluster &b) { return a.Prob > b.Prob; }); // Rearrange the case blocks so that the last one falls through if possible // without without changing the order of probabilities. for (CaseClusterIt I = W.LastCluster; I > W.FirstCluster; ) { --I; if (I->Prob > W.LastCluster->Prob) break; if (I->Kind == CC_Range && I->MBB == NextMBB) { std::swap(*I, *W.LastCluster); break; } } } // Compute total probability. BranchProbability DefaultProb = W.DefaultProb; BranchProbability UnhandledProbs = DefaultProb; for (CaseClusterIt I = W.FirstCluster; I <= W.LastCluster; ++I) UnhandledProbs += I->Prob; MachineBasicBlock *CurMBB = W.MBB; for (CaseClusterIt I = W.FirstCluster, E = W.LastCluster; I <= E; ++I) { MachineBasicBlock *Fallthrough; if (I == W.LastCluster) { // For the last cluster, fall through to the default destination. Fallthrough = DefaultMBB; } else { Fallthrough = CurMF->CreateMachineBasicBlock(CurMBB->getBasicBlock()); CurMF->insert(BBI, Fallthrough); // Put Cond in a virtual register to make it available from the new blocks. ExportFromCurrentBlock(Cond); } UnhandledProbs -= I->Prob; switch (I->Kind) { case CC_JumpTable: { // FIXME: Optimize away range check based on pivot comparisons. JumpTableHeader *JTH = &JTCases[I->JTCasesIndex].first; JumpTable *JT = &JTCases[I->JTCasesIndex].second; // The jump block hasn't been inserted yet; insert it here. MachineBasicBlock *JumpMBB = JT->MBB; CurMF->insert(BBI, JumpMBB); auto JumpProb = I->Prob; auto FallthroughProb = UnhandledProbs; // If the default statement is a target of the jump table, we evenly // distribute the default probability to successors of CurMBB. Also // update the probability on the edge from JumpMBB to Fallthrough. for (MachineBasicBlock::succ_iterator SI = JumpMBB->succ_begin(), SE = JumpMBB->succ_end(); SI != SE; ++SI) { if (*SI == DefaultMBB) { JumpProb += DefaultProb / 2; FallthroughProb -= DefaultProb / 2; JumpMBB->setSuccProbability(SI, DefaultProb / 2); JumpMBB->normalizeSuccProbs(); break; } } addSuccessorWithProb(CurMBB, Fallthrough, FallthroughProb); addSuccessorWithProb(CurMBB, JumpMBB, JumpProb); CurMBB->normalizeSuccProbs(); // The jump table header will be inserted in our current block, do the // range check, and fall through to our fallthrough block. JTH->HeaderBB = CurMBB; JT->Default = Fallthrough; // FIXME: Move Default to JumpTableHeader. // If we're in the right place, emit the jump table header right now. if (CurMBB == SwitchMBB) { visitJumpTableHeader(*JT, *JTH, SwitchMBB); JTH->Emitted = true; } break; } case CC_BitTests: { // FIXME: Optimize away range check based on pivot comparisons. BitTestBlock *BTB = &BitTestCases[I->BTCasesIndex]; // The bit test blocks haven't been inserted yet; insert them here. for (BitTestCase &BTC : BTB->Cases) CurMF->insert(BBI, BTC.ThisBB); // Fill in fields of the BitTestBlock. BTB->Parent = CurMBB; BTB->Default = Fallthrough; BTB->DefaultProb = UnhandledProbs; // If the cases in bit test don't form a contiguous range, we evenly // distribute the probability on the edge to Fallthrough to two // successors of CurMBB. if (!BTB->ContiguousRange) { BTB->Prob += DefaultProb / 2; BTB->DefaultProb -= DefaultProb / 2; } // If we're in the right place, emit the bit test header right now. if (CurMBB == SwitchMBB) { visitBitTestHeader(*BTB, SwitchMBB); BTB->Emitted = true; } break; } case CC_Range: { const Value *RHS, *LHS, *MHS; ISD::CondCode CC; if (I->Low == I->High) { // Check Cond == I->Low. CC = ISD::SETEQ; LHS = Cond; RHS=I->Low; MHS = nullptr; } else { // Check I->Low <= Cond <= I->High. CC = ISD::SETLE; LHS = I->Low; MHS = Cond; RHS = I->High; } // The false probability is the sum of all unhandled cases. CaseBlock CB(CC, LHS, RHS, MHS, I->MBB, Fallthrough, CurMBB, I->Prob, UnhandledProbs); if (CurMBB == SwitchMBB) visitSwitchCase(CB, SwitchMBB); else SwitchCases.push_back(CB); break; } } CurMBB = Fallthrough; } } unsigned SelectionDAGBuilder::caseClusterRank(const CaseCluster &CC, CaseClusterIt First, CaseClusterIt Last) { return std::count_if(First, Last + 1, [&](const CaseCluster &X) { if (X.Prob != CC.Prob) return X.Prob > CC.Prob; // Ties are broken by comparing the case value. return X.Low->getValue().slt(CC.Low->getValue()); }); } void SelectionDAGBuilder::splitWorkItem(SwitchWorkList &WorkList, const SwitchWorkListItem &W, Value *Cond, MachineBasicBlock *SwitchMBB) { assert(W.FirstCluster->Low->getValue().slt(W.LastCluster->Low->getValue()) && "Clusters not sorted?"); assert(W.LastCluster - W.FirstCluster + 1 >= 2 && "Too small to split!"); // Balance the tree based on branch probabilities to create a near-optimal (in // terms of search time given key frequency) binary search tree. See e.g. Kurt // Mehlhorn "Nearly Optimal Binary Search Trees" (1975). CaseClusterIt LastLeft = W.FirstCluster; CaseClusterIt FirstRight = W.LastCluster; auto LeftProb = LastLeft->Prob + W.DefaultProb / 2; auto RightProb = FirstRight->Prob + W.DefaultProb / 2; // Move LastLeft and FirstRight towards each other from opposite directions to // find a partitioning of the clusters which balances the probability on both // sides. If LeftProb and RightProb are equal, alternate which side is // taken to ensure 0-probability nodes are distributed evenly. unsigned I = 0; while (LastLeft + 1 < FirstRight) { if (LeftProb < RightProb || (LeftProb == RightProb && (I & 1))) LeftProb += (++LastLeft)->Prob; else RightProb += (--FirstRight)->Prob; I++; } for (;;) { // Our binary search tree differs from a typical BST in that ours can have up // to three values in each leaf. The pivot selection above doesn't take that // into account, which means the tree might require more nodes and be less // efficient. We compensate for this here. unsigned NumLeft = LastLeft - W.FirstCluster + 1; unsigned NumRight = W.LastCluster - FirstRight + 1; if (std::min(NumLeft, NumRight) < 3 && std::max(NumLeft, NumRight) > 3) { // If one side has less than 3 clusters, and the other has more than 3, // consider taking a cluster from the other side. if (NumLeft < NumRight) { // Consider moving the first cluster on the right to the left side. CaseCluster &CC = *FirstRight; unsigned RightSideRank = caseClusterRank(CC, FirstRight, W.LastCluster); unsigned LeftSideRank = caseClusterRank(CC, W.FirstCluster, LastLeft); if (LeftSideRank <= RightSideRank) { // Moving the cluster to the left does not demote it. ++LastLeft; ++FirstRight; continue; } } else { assert(NumRight < NumLeft); // Consider moving the last element on the left to the right side. CaseCluster &CC = *LastLeft; unsigned LeftSideRank = caseClusterRank(CC, W.FirstCluster, LastLeft); unsigned RightSideRank = caseClusterRank(CC, FirstRight, W.LastCluster); if (RightSideRank <= LeftSideRank) { // Moving the cluster to the right does not demot it. --LastLeft; --FirstRight; continue; } } } break; } assert(LastLeft + 1 == FirstRight); assert(LastLeft >= W.FirstCluster); assert(FirstRight <= W.LastCluster); // Use the first element on the right as pivot since we will make less-than // comparisons against it. CaseClusterIt PivotCluster = FirstRight; assert(PivotCluster > W.FirstCluster); assert(PivotCluster <= W.LastCluster); CaseClusterIt FirstLeft = W.FirstCluster; CaseClusterIt LastRight = W.LastCluster; const ConstantInt *Pivot = PivotCluster->Low; // New blocks will be inserted immediately after the current one. MachineFunction::iterator BBI(W.MBB); ++BBI; // We will branch to the LHS if Value < Pivot. If LHS is a single cluster, // we can branch to its destination directly if it's squeezed exactly in // between the known lower bound and Pivot - 1. MachineBasicBlock *LeftMBB; if (FirstLeft == LastLeft && FirstLeft->Kind == CC_Range && FirstLeft->Low == W.GE && (FirstLeft->High->getValue() + 1LL) == Pivot->getValue()) { LeftMBB = FirstLeft->MBB; } else { LeftMBB = FuncInfo.MF->CreateMachineBasicBlock(W.MBB->getBasicBlock()); FuncInfo.MF->insert(BBI, LeftMBB); WorkList.push_back( {LeftMBB, FirstLeft, LastLeft, W.GE, Pivot, W.DefaultProb / 2}); // Put Cond in a virtual register to make it available from the new blocks. ExportFromCurrentBlock(Cond); } // Similarly, we will branch to the RHS if Value >= Pivot. If RHS is a // single cluster, RHS.Low == Pivot, and we can branch to its destination // directly if RHS.High equals the current upper bound. MachineBasicBlock *RightMBB; if (FirstRight == LastRight && FirstRight->Kind == CC_Range && W.LT && (FirstRight->High->getValue() + 1ULL) == W.LT->getValue()) { RightMBB = FirstRight->MBB; } else { RightMBB = FuncInfo.MF->CreateMachineBasicBlock(W.MBB->getBasicBlock()); FuncInfo.MF->insert(BBI, RightMBB); WorkList.push_back( {RightMBB, FirstRight, LastRight, Pivot, W.LT, W.DefaultProb / 2}); // Put Cond in a virtual register to make it available from the new blocks. ExportFromCurrentBlock(Cond); } // Create the CaseBlock record that will be used to lower the branch. CaseBlock CB(ISD::SETLT, Cond, Pivot, nullptr, LeftMBB, RightMBB, W.MBB, LeftProb, RightProb); if (W.MBB == SwitchMBB) visitSwitchCase(CB, SwitchMBB); else SwitchCases.push_back(CB); } void SelectionDAGBuilder::visitSwitch(const SwitchInst &SI) { // Extract cases from the switch. BranchProbabilityInfo *BPI = FuncInfo.BPI; CaseClusterVector Clusters; Clusters.reserve(SI.getNumCases()); for (auto I : SI.cases()) { MachineBasicBlock *Succ = FuncInfo.MBBMap[I.getCaseSuccessor()]; const ConstantInt *CaseVal = I.getCaseValue(); BranchProbability Prob = BPI ? BPI->getEdgeProbability(SI.getParent(), I.getSuccessorIndex()) : BranchProbability(1, SI.getNumCases() + 1); Clusters.push_back(CaseCluster::range(CaseVal, CaseVal, Succ, Prob)); } MachineBasicBlock *DefaultMBB = FuncInfo.MBBMap[SI.getDefaultDest()]; // Cluster adjacent cases with the same destination. We do this at all // optimization levels because it's cheap to do and will make codegen faster // if there are many clusters. sortAndRangeify(Clusters); if (TM.getOptLevel() != CodeGenOpt::None) { // Replace an unreachable default with the most popular destination. // FIXME: Exploit unreachable default more aggressively. bool UnreachableDefault = isa<UnreachableInst>(SI.getDefaultDest()->getFirstNonPHIOrDbg()); if (UnreachableDefault && !Clusters.empty()) { DenseMap<const BasicBlock *, unsigned> Popularity; unsigned MaxPop = 0; const BasicBlock *MaxBB = nullptr; for (auto I : SI.cases()) { const BasicBlock *BB = I.getCaseSuccessor(); if (++Popularity[BB] > MaxPop) { MaxPop = Popularity[BB]; MaxBB = BB; } } // Set new default. assert(MaxPop > 0 && MaxBB); DefaultMBB = FuncInfo.MBBMap[MaxBB]; // Remove cases that were pointing to the destination that is now the // default. CaseClusterVector New; New.reserve(Clusters.size()); for (CaseCluster &CC : Clusters) { if (CC.MBB != DefaultMBB) New.push_back(CC); } Clusters = std::move(New); } } // If there is only the default destination, jump there directly. MachineBasicBlock *SwitchMBB = FuncInfo.MBB; if (Clusters.empty()) { SwitchMBB->addSuccessor(DefaultMBB); if (DefaultMBB != NextBlock(SwitchMBB)) { DAG.setRoot(DAG.getNode(ISD::BR, getCurSDLoc(), MVT::Other, getControlRoot(), DAG.getBasicBlock(DefaultMBB))); } return; } findJumpTables(Clusters, &SI, DefaultMBB); findBitTestClusters(Clusters, &SI); DEBUG({ dbgs() << "Case clusters: "; for (const CaseCluster &C : Clusters) { if (C.Kind == CC_JumpTable) dbgs() << "JT:"; if (C.Kind == CC_BitTests) dbgs() << "BT:"; C.Low->getValue().print(dbgs(), true); if (C.Low != C.High) { dbgs() << '-'; C.High->getValue().print(dbgs(), true); } dbgs() << ' '; } dbgs() << '\n'; }); assert(!Clusters.empty()); SwitchWorkList WorkList; CaseClusterIt First = Clusters.begin(); CaseClusterIt Last = Clusters.end() - 1; auto DefaultProb = getEdgeProbability(SwitchMBB, DefaultMBB); WorkList.push_back({SwitchMBB, First, Last, nullptr, nullptr, DefaultProb}); while (!WorkList.empty()) { SwitchWorkListItem W = WorkList.back(); WorkList.pop_back(); unsigned NumClusters = W.LastCluster - W.FirstCluster + 1; if (NumClusters > 3 && TM.getOptLevel() != CodeGenOpt::None) { // For optimized builds, lower large range as a balanced binary tree. splitWorkItem(WorkList, W, SI.getCondition(), SwitchMBB); continue; } lowerWorkItem(W, SI.getCondition(), SwitchMBB, DefaultMBB); } }