//===- BlackfinISelLowering.cpp - Blackfin DAG Lowering Implementation ----===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the interfaces that Blackfin uses to lower LLVM code
// into a selection DAG.
//
//===----------------------------------------------------------------------===//
#include "BlackfinISelLowering.h"
#include "BlackfinTargetMachine.h"
#include "llvm/Function.h"
#include "llvm/Type.h"
#include "llvm/CodeGen/CallingConvLower.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/PseudoSourceValue.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
#include "llvm/ADT/VectorExtras.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
using namespace llvm;
//===----------------------------------------------------------------------===//
// Calling Convention Implementation
//===----------------------------------------------------------------------===//
#include "BlackfinGenCallingConv.inc"
//===----------------------------------------------------------------------===//
// TargetLowering Implementation
//===----------------------------------------------------------------------===//
BlackfinTargetLowering::BlackfinTargetLowering(TargetMachine &TM)
: TargetLowering(TM, new TargetLoweringObjectFileELF()) {
setBooleanContents(ZeroOrOneBooleanContent);
setBooleanVectorContents(ZeroOrOneBooleanContent); // FIXME: Is this correct?
setStackPointerRegisterToSaveRestore(BF::SP);
setIntDivIsCheap(false);
// Set up the legal register classes.
addRegisterClass(MVT::i32, BF::DRegisterClass);
addRegisterClass(MVT::i16, BF::D16RegisterClass);
computeRegisterProperties();
// Blackfin doesn't have i1 loads or stores
setLoadExtAction(ISD::EXTLOAD, MVT::i1, Promote);
setLoadExtAction(ISD::ZEXTLOAD, MVT::i1, Promote);
setLoadExtAction(ISD::SEXTLOAD, MVT::i1, Promote);
setOperationAction(ISD::GlobalAddress, MVT::i32, Custom);
setOperationAction(ISD::JumpTable, MVT::i32, Custom);
setOperationAction(ISD::SELECT_CC, MVT::Other, Expand);
setOperationAction(ISD::BR_JT, MVT::Other, Expand);
setOperationAction(ISD::BR_CC, MVT::Other, Expand);
// i16 registers don't do much
setOperationAction(ISD::AND, MVT::i16, Promote);
setOperationAction(ISD::OR, MVT::i16, Promote);
setOperationAction(ISD::XOR, MVT::i16, Promote);
setOperationAction(ISD::CTPOP, MVT::i16, Promote);
// The expansion of CTLZ/CTTZ uses AND/OR, so we might as well promote
// immediately.
setOperationAction(ISD::CTLZ, MVT::i16, Promote);
setOperationAction(ISD::CTTZ, MVT::i16, Promote);
setOperationAction(ISD::SETCC, MVT::i16, Promote);
// Blackfin has no division
setOperationAction(ISD::SDIV, MVT::i16, Expand);
setOperationAction(ISD::SDIV, MVT::i32, Expand);
setOperationAction(ISD::SDIVREM, MVT::i16, Expand);
setOperationAction(ISD::SDIVREM, MVT::i32, Expand);
setOperationAction(ISD::SREM, MVT::i16, Expand);
setOperationAction(ISD::SREM, MVT::i32, Expand);
setOperationAction(ISD::UDIV, MVT::i16, Expand);
setOperationAction(ISD::UDIV, MVT::i32, Expand);
setOperationAction(ISD::UDIVREM, MVT::i16, Expand);
setOperationAction(ISD::UDIVREM, MVT::i32, Expand);
setOperationAction(ISD::UREM, MVT::i16, Expand);
setOperationAction(ISD::UREM, MVT::i32, Expand);
setOperationAction(ISD::SMUL_LOHI, MVT::i32, Expand);
setOperationAction(ISD::UMUL_LOHI, MVT::i32, Expand);
setOperationAction(ISD::MULHU, MVT::i32, Expand);
setOperationAction(ISD::MULHS, MVT::i32, Expand);
// No carry-in operations.
setOperationAction(ISD::ADDE, MVT::i32, Custom);
setOperationAction(ISD::SUBE, MVT::i32, Custom);
// Blackfin has no intrinsics for these particular operations.
setOperationAction(ISD::MEMBARRIER, MVT::Other, Expand);
setOperationAction(ISD::ATOMIC_FENCE, MVT::Other, Expand);
setOperationAction(ISD::BSWAP, MVT::i32, Expand);
setOperationAction(ISD::SHL_PARTS, MVT::i32, Expand);
setOperationAction(ISD::SRA_PARTS, MVT::i32, Expand);
setOperationAction(ISD::SRL_PARTS, MVT::i32, Expand);
setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1, Expand);
// i32 has native CTPOP, but not CTLZ/CTTZ
setOperationAction(ISD::CTLZ, MVT::i32, Expand);
setOperationAction(ISD::CTTZ, MVT::i32, Expand);
// READCYCLECOUNTER needs special type legalization.
setOperationAction(ISD::READCYCLECOUNTER, MVT::i64, Custom);
setOperationAction(ISD::EH_LABEL, MVT::Other, Expand);
// Use the default implementation.
setOperationAction(ISD::VACOPY, MVT::Other, Expand);
setOperationAction(ISD::VAEND, MVT::Other, Expand);
setOperationAction(ISD::STACKSAVE, MVT::Other, Expand);
setOperationAction(ISD::STACKRESTORE, MVT::Other, Expand);
setMinFunctionAlignment(2);
}
const char *BlackfinTargetLowering::getTargetNodeName(unsigned Opcode) const {
switch (Opcode) {
default: return 0;
case BFISD::CALL: return "BFISD::CALL";
case BFISD::RET_FLAG: return "BFISD::RET_FLAG";
case BFISD::Wrapper: return "BFISD::Wrapper";
}
}
EVT BlackfinTargetLowering::getSetCCResultType(EVT VT) const {
// SETCC always sets the CC register. Technically that is an i1 register, but
// that type is not legal, so we treat it as an i32 register.
return MVT::i32;
}
SDValue BlackfinTargetLowering::LowerGlobalAddress(SDValue Op,
SelectionDAG &DAG) const {
DebugLoc DL = Op.getDebugLoc();
const GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
Op = DAG.getTargetGlobalAddress(GV, DL, MVT::i32);
return DAG.getNode(BFISD::Wrapper, DL, MVT::i32, Op);
}
SDValue BlackfinTargetLowering::LowerJumpTable(SDValue Op,
SelectionDAG &DAG) const {
DebugLoc DL = Op.getDebugLoc();
int JTI = cast<JumpTableSDNode>(Op)->getIndex();
Op = DAG.getTargetJumpTable(JTI, MVT::i32);
return DAG.getNode(BFISD::Wrapper, DL, MVT::i32, Op);
}
SDValue
BlackfinTargetLowering::LowerFormalArguments(SDValue Chain,
CallingConv::ID CallConv, bool isVarArg,
const SmallVectorImpl<ISD::InputArg>
&Ins,
DebugLoc dl, SelectionDAG &DAG,
SmallVectorImpl<SDValue> &InVals)
const {
MachineFunction &MF = DAG.getMachineFunction();
MachineFrameInfo *MFI = MF.getFrameInfo();
SmallVector<CCValAssign, 16> ArgLocs;
CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
getTargetMachine(), ArgLocs, *DAG.getContext());
CCInfo.AllocateStack(12, 4); // ABI requires 12 bytes stack space
CCInfo.AnalyzeFormalArguments(Ins, CC_Blackfin);
for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
CCValAssign &VA = ArgLocs[i];
if (VA.isRegLoc()) {
EVT RegVT = VA.getLocVT();
TargetRegisterClass *RC = VA.getLocReg() == BF::P0 ?
BF::PRegisterClass : BF::DRegisterClass;
assert(RC->contains(VA.getLocReg()) && "Unexpected regclass in CCState");
assert(RC->hasType(RegVT) && "Unexpected regclass in CCState");
unsigned Reg = MF.getRegInfo().createVirtualRegister(RC);
MF.getRegInfo().addLiveIn(VA.getLocReg(), Reg);
SDValue ArgValue = DAG.getCopyFromReg(Chain, dl, Reg, RegVT);
// If this is an 8 or 16-bit value, it is really passed promoted to 32
// bits. Insert an assert[sz]ext to capture this, then truncate to the
// right size.
if (VA.getLocInfo() == CCValAssign::SExt)
ArgValue = DAG.getNode(ISD::AssertSext, dl, RegVT, ArgValue,
DAG.getValueType(VA.getValVT()));
else if (VA.getLocInfo() == CCValAssign::ZExt)
ArgValue = DAG.getNode(ISD::AssertZext, dl, RegVT, ArgValue,
DAG.getValueType(VA.getValVT()));
if (VA.getLocInfo() != CCValAssign::Full)
ArgValue = DAG.getNode(ISD::TRUNCATE, dl, VA.getValVT(), ArgValue);
InVals.push_back(ArgValue);
} else {
assert(VA.isMemLoc() && "CCValAssign must be RegLoc or MemLoc");
unsigned ObjSize = VA.getLocVT().getStoreSize();
int FI = MFI->CreateFixedObject(ObjSize, VA.getLocMemOffset(), true);
SDValue FIN = DAG.getFrameIndex(FI, MVT::i32);
InVals.push_back(DAG.getLoad(VA.getValVT(), dl, Chain, FIN,
MachinePointerInfo(),
false, false, 0));
}
}
return Chain;
}
SDValue
BlackfinTargetLowering::LowerReturn(SDValue Chain,
CallingConv::ID CallConv, bool isVarArg,
const SmallVectorImpl<ISD::OutputArg> &Outs,
const SmallVectorImpl<SDValue> &OutVals,
DebugLoc dl, SelectionDAG &DAG) const {
// CCValAssign - represent the assignment of the return value to locations.
SmallVector<CCValAssign, 16> RVLocs;
// CCState - Info about the registers and stack slot.
CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
DAG.getTarget(), RVLocs, *DAG.getContext());
// Analize return values.
CCInfo.AnalyzeReturn(Outs, RetCC_Blackfin);
// If this is the first return lowered for this function, add the regs to the
// liveout set for the function.
if (DAG.getMachineFunction().getRegInfo().liveout_empty()) {
for (unsigned i = 0; i != RVLocs.size(); ++i)
DAG.getMachineFunction().getRegInfo().addLiveOut(RVLocs[i].getLocReg());
}
SDValue Flag;
// Copy the result values into the output registers.
for (unsigned i = 0; i != RVLocs.size(); ++i) {
CCValAssign &VA = RVLocs[i];
assert(VA.isRegLoc() && "Can only return in registers!");
SDValue Opi = OutVals[i];
// Expand to i32 if necessary
switch (VA.getLocInfo()) {
default: llvm_unreachable("Unknown loc info!");
case CCValAssign::Full: break;
case CCValAssign::SExt:
Opi = DAG.getNode(ISD::SIGN_EXTEND, dl, VA.getLocVT(), Opi);
break;
case CCValAssign::ZExt:
Opi = DAG.getNode(ISD::ZERO_EXTEND, dl, VA.getLocVT(), Opi);
break;
case CCValAssign::AExt:
Opi = DAG.getNode(ISD::ANY_EXTEND, dl, VA.getLocVT(), Opi);
break;
}
Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(), Opi, SDValue());
// Guarantee that all emitted copies are stuck together with flags.
Flag = Chain.getValue(1);
}
if (Flag.getNode()) {
return DAG.getNode(BFISD::RET_FLAG, dl, MVT::Other, Chain, Flag);
} else {
return DAG.getNode(BFISD::RET_FLAG, dl, MVT::Other, Chain);
}
}
SDValue
BlackfinTargetLowering::LowerCall(SDValue Chain, SDValue Callee,
CallingConv::ID CallConv, bool isVarArg,
bool &isTailCall,
const SmallVectorImpl<ISD::OutputArg> &Outs,
const SmallVectorImpl<SDValue> &OutVals,
const SmallVectorImpl<ISD::InputArg> &Ins,
DebugLoc dl, SelectionDAG &DAG,
SmallVectorImpl<SDValue> &InVals) const {
// Blackfin target does not yet support tail call optimization.
isTailCall = false;
// Analyze operands of the call, assigning locations to each operand.
SmallVector<CCValAssign, 16> ArgLocs;
CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
DAG.getTarget(), ArgLocs, *DAG.getContext());
CCInfo.AllocateStack(12, 4); // ABI requires 12 bytes stack space
CCInfo.AnalyzeCallOperands(Outs, CC_Blackfin);
// Get the size of the outgoing arguments stack space requirement.
unsigned ArgsSize = CCInfo.getNextStackOffset();
Chain = DAG.getCALLSEQ_START(Chain, DAG.getIntPtrConstant(ArgsSize, true));
SmallVector<std::pair<unsigned, SDValue>, 8> RegsToPass;
SmallVector<SDValue, 8> MemOpChains;
// Walk the register/memloc assignments, inserting copies/loads.
for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
CCValAssign &VA = ArgLocs[i];
SDValue Arg = OutVals[i];
// Promote the value if needed.
switch (VA.getLocInfo()) {
default: llvm_unreachable("Unknown loc info!");
case CCValAssign::Full: break;
case CCValAssign::SExt:
Arg = DAG.getNode(ISD::SIGN_EXTEND, dl, VA.getLocVT(), Arg);
break;
case CCValAssign::ZExt:
Arg = DAG.getNode(ISD::ZERO_EXTEND, dl, VA.getLocVT(), Arg);
break;
case CCValAssign::AExt:
Arg = DAG.getNode(ISD::ANY_EXTEND, dl, VA.getLocVT(), Arg);
break;
}
// Arguments that can be passed on register must be kept at
// RegsToPass vector
if (VA.isRegLoc()) {
RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
} else {
assert(VA.isMemLoc() && "CCValAssign must be RegLoc or MemLoc");
int Offset = VA.getLocMemOffset();
assert(Offset%4 == 0 && "Unaligned LocMemOffset");
assert(VA.getLocVT()==MVT::i32 && "Illegal CCValAssign type");
SDValue SPN = DAG.getCopyFromReg(Chain, dl, BF::SP, MVT::i32);
SDValue OffsetN = DAG.getIntPtrConstant(Offset);
OffsetN = DAG.getNode(ISD::ADD, dl, MVT::i32, SPN, OffsetN);
MemOpChains.push_back(DAG.getStore(Chain, dl, Arg, OffsetN,
MachinePointerInfo(),false, false, 0));
}
}
// Transform all store nodes into one single node because
// all store nodes are independent of each other.
if (!MemOpChains.empty())
Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
&MemOpChains[0], MemOpChains.size());
// Build a sequence of copy-to-reg nodes chained together with token
// chain and flag operands which copy the outgoing args into registers.
// The InFlag in necessary since all emitted instructions must be
// stuck together.
SDValue InFlag;
for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first,
RegsToPass[i].second, InFlag);
InFlag = Chain.getValue(1);
}
// If the callee is a GlobalAddress node (quite common, every direct call is)
// turn it into a TargetGlobalAddress node so that legalize doesn't hack it.
// Likewise ExternalSymbol -> TargetExternalSymbol.
if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
Callee = DAG.getTargetGlobalAddress(G->getGlobal(), dl, MVT::i32);
else if (ExternalSymbolSDNode *E = dyn_cast<ExternalSymbolSDNode>(Callee))
Callee = DAG.getTargetExternalSymbol(E->getSymbol(), MVT::i32);
std::vector<EVT> NodeTys;
NodeTys.push_back(MVT::Other); // Returns a chain
NodeTys.push_back(MVT::Glue); // Returns a flag for retval copy to use.
SDValue Ops[] = { Chain, Callee, InFlag };
Chain = DAG.getNode(BFISD::CALL, dl, NodeTys, Ops,
InFlag.getNode() ? 3 : 2);
InFlag = Chain.getValue(1);
Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(ArgsSize, true),
DAG.getIntPtrConstant(0, true), InFlag);
InFlag = Chain.getValue(1);
// Assign locations to each value returned by this call.
SmallVector<CCValAssign, 16> RVLocs;
CCState RVInfo(CallConv, isVarArg, DAG.getMachineFunction(),
DAG.getTarget(), RVLocs, *DAG.getContext());
RVInfo.AnalyzeCallResult(Ins, RetCC_Blackfin);
// Copy all of the result registers out of their specified physreg.
for (unsigned i = 0; i != RVLocs.size(); ++i) {
CCValAssign &RV = RVLocs[i];
unsigned Reg = RV.getLocReg();
Chain = DAG.getCopyFromReg(Chain, dl, Reg,
RVLocs[i].getLocVT(), InFlag);
SDValue Val = Chain.getValue(0);
InFlag = Chain.getValue(2);
Chain = Chain.getValue(1);
// Callee is responsible for extending any i16 return values.
switch (RV.getLocInfo()) {
case CCValAssign::SExt:
Val = DAG.getNode(ISD::AssertSext, dl, RV.getLocVT(), Val,
DAG.getValueType(RV.getValVT()));
break;
case CCValAssign::ZExt:
Val = DAG.getNode(ISD::AssertZext, dl, RV.getLocVT(), Val,
DAG.getValueType(RV.getValVT()));
break;
default:
break;
}
// Truncate to valtype
if (RV.getLocInfo() != CCValAssign::Full)
Val = DAG.getNode(ISD::TRUNCATE, dl, RV.getValVT(), Val);
InVals.push_back(Val);
}
return Chain;
}
// Expansion of ADDE / SUBE. This is a bit involved since blackfin doesn't have
// add-with-carry instructions.
SDValue BlackfinTargetLowering::LowerADDE(SDValue Op, SelectionDAG &DAG) const {
// Operands: lhs, rhs, carry-in (AC0 flag)
// Results: sum, carry-out (AC0 flag)
DebugLoc dl = Op.getDebugLoc();
unsigned Opcode = Op.getOpcode()==ISD::ADDE ? BF::ADD : BF::SUB;
// zext incoming carry flag in AC0 to 32 bits
SDNode* CarryIn = DAG.getMachineNode(BF::MOVE_cc_ac0, dl, MVT::i32,
/* flag= */ Op.getOperand(2));
CarryIn = DAG.getMachineNode(BF::MOVECC_zext, dl, MVT::i32,
SDValue(CarryIn, 0));
// Add operands, produce sum and carry flag
SDNode *Sum = DAG.getMachineNode(Opcode, dl, MVT::i32, MVT::Glue,
Op.getOperand(0), Op.getOperand(1));
// Store intermediate carry from Sum
SDNode* Carry1 = DAG.getMachineNode(BF::MOVE_cc_ac0, dl, MVT::i32,
/* flag= */ SDValue(Sum, 1));
// Add incoming carry, again producing an output flag
Sum = DAG.getMachineNode(Opcode, dl, MVT::i32, MVT::Glue,
SDValue(Sum, 0), SDValue(CarryIn, 0));
// Update AC0 with the intermediate carry, producing a flag.
SDNode *CarryOut = DAG.getMachineNode(BF::OR_ac0_cc, dl, MVT::Glue,
SDValue(Carry1, 0));
// Compose (i32, flag) pair
SDValue ops[2] = { SDValue(Sum, 0), SDValue(CarryOut, 0) };
return DAG.getMergeValues(ops, 2, dl);
}
SDValue BlackfinTargetLowering::LowerOperation(SDValue Op,
SelectionDAG &DAG) const {
switch (Op.getOpcode()) {
default:
Op.getNode()->dump();
llvm_unreachable("Should not custom lower this!");
case ISD::GlobalAddress: return LowerGlobalAddress(Op, DAG);
case ISD::GlobalTLSAddress:
llvm_unreachable("TLS not implemented for Blackfin.");
case ISD::JumpTable: return LowerJumpTable(Op, DAG);
// Frame & Return address. Currently unimplemented
case ISD::FRAMEADDR: return SDValue();
case ISD::RETURNADDR: return SDValue();
case ISD::ADDE:
case ISD::SUBE: return LowerADDE(Op, DAG);
}
}
void
BlackfinTargetLowering::ReplaceNodeResults(SDNode *N,
SmallVectorImpl<SDValue> &Results,
SelectionDAG &DAG) const {
DebugLoc dl = N->getDebugLoc();
switch (N->getOpcode()) {
default:
llvm_unreachable("Do not know how to custom type legalize this operation!");
return;
case ISD::READCYCLECOUNTER: {
// The low part of the cycle counter is in CYCLES, the high part in
// CYCLES2. Reading CYCLES will latch the value of CYCLES2, so we must read
// CYCLES2 last.
SDValue TheChain = N->getOperand(0);
SDValue lo = DAG.getCopyFromReg(TheChain, dl, BF::CYCLES, MVT::i32);
SDValue hi = DAG.getCopyFromReg(lo.getValue(1), dl, BF::CYCLES2, MVT::i32);
// Use a buildpair to merge the two 32-bit values into a 64-bit one.
Results.push_back(DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, lo, hi));
// Outgoing chain. If we were to use the chain from lo instead, it would be
// possible to entirely eliminate the CYCLES2 read in (i32 (trunc
// readcyclecounter)). Unfortunately this could possibly delay the CYCLES2
// read beyond the next CYCLES read, leading to invalid results.
Results.push_back(hi.getValue(1));
return;
}
}
}
//===----------------------------------------------------------------------===//
// Blackfin Inline Assembly Support
//===----------------------------------------------------------------------===//
/// getConstraintType - Given a constraint letter, return the type of
/// constraint it is for this target.
BlackfinTargetLowering::ConstraintType
BlackfinTargetLowering::getConstraintType(const std::string &Constraint) const {
if (Constraint.size() != 1)
return TargetLowering::getConstraintType(Constraint);
switch (Constraint[0]) {
// Standard constraints
case 'r':
return C_RegisterClass;
// Blackfin-specific constraints
case 'a':
case 'd':
case 'z':
case 'D':
case 'W':
case 'e':
case 'b':
case 'v':
case 'f':
case 'c':
case 't':
case 'u':
case 'k':
case 'x':
case 'y':
case 'w':
return C_RegisterClass;
case 'A':
case 'B':
case 'C':
case 'Z':
case 'Y':
return C_Register;
}
// Not implemented: q0-q7, qA. Use {R2} etc instead
return TargetLowering::getConstraintType(Constraint);
}
/// Examine constraint type and operand type and determine a weight value.
/// This object must already have been set up with the operand type
/// and the current alternative constraint selected.
TargetLowering::ConstraintWeight
BlackfinTargetLowering::getSingleConstraintMatchWeight(
AsmOperandInfo &info, const char *constraint) const {
ConstraintWeight weight = CW_Invalid;
Value *CallOperandVal = info.CallOperandVal;
// If we don't have a value, we can't do a match,
// but allow it at the lowest weight.
if (CallOperandVal == NULL)
return CW_Default;
// Look at the constraint type.
switch (*constraint) {
default:
weight = TargetLowering::getSingleConstraintMatchWeight(info, constraint);
break;
// Blackfin-specific constraints
case 'a':
case 'd':
case 'z':
case 'D':
case 'W':
case 'e':
case 'b':
case 'v':
case 'f':
case 'c':
case 't':
case 'u':
case 'k':
case 'x':
case 'y':
case 'w':
return CW_Register;
case 'A':
case 'B':
case 'C':
case 'Z':
case 'Y':
return CW_SpecificReg;
}
return weight;
}
/// getRegForInlineAsmConstraint - Return register no and class for a C_Register
/// constraint.
std::pair<unsigned, const TargetRegisterClass*> BlackfinTargetLowering::
getRegForInlineAsmConstraint(const std::string &Constraint, EVT VT) const {
typedef std::pair<unsigned, const TargetRegisterClass*> Pair;
using namespace BF;
if (Constraint.size() != 1)
return TargetLowering::getRegForInlineAsmConstraint(Constraint, VT);
switch (Constraint[0]) {
// Standard constraints
case 'r':
return Pair(0U, VT == MVT::i16 ? D16RegisterClass : DPRegisterClass);
// Blackfin-specific constraints
case 'a': return Pair(0U, PRegisterClass);
case 'd': return Pair(0U, DRegisterClass);
case 'e': return Pair(0U, AccuRegisterClass);
case 'A': return Pair(A0, AccuRegisterClass);
case 'B': return Pair(A1, AccuRegisterClass);
case 'b': return Pair(0U, IRegisterClass);
case 'v': return Pair(0U, BRegisterClass);
case 'f': return Pair(0U, MRegisterClass);
case 'C': return Pair(CC, JustCCRegisterClass);
case 'x': return Pair(0U, GRRegisterClass);
case 'w': return Pair(0U, ALLRegisterClass);
case 'Z': return Pair(P3, PRegisterClass);
case 'Y': return Pair(P1, PRegisterClass);
case 'z': return Pair(0U, zConsRegisterClass);
case 'D': return Pair(0U, DConsRegisterClass);
case 'W': return Pair(0U, WConsRegisterClass);
case 'c': return Pair(0U, cConsRegisterClass);
case 't': return Pair(0U, tConsRegisterClass);
case 'u': return Pair(0U, uConsRegisterClass);
case 'k': return Pair(0U, kConsRegisterClass);
case 'y': return Pair(0U, yConsRegisterClass);
}
// Not implemented: q0-q7, qA. Use {R2} etc instead.
return TargetLowering::getRegForInlineAsmConstraint(Constraint, VT);
}
bool BlackfinTargetLowering::
isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
// The Blackfin target isn't yet aware of offsets.
return false;
}