//===-- AMDGPUISelLowering.cpp - AMDGPU Common DAG lowering functions -----===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This is the parent TargetLowering class for hardware code gen targets.
//
//===----------------------------------------------------------------------===//
#include "AMDGPUISelLowering.h"
#include "AMDILIntrinsicInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
using namespace llvm;
AMDGPUTargetLowering::AMDGPUTargetLowering(TargetMachine &TM) :
TargetLowering(TM, new TargetLoweringObjectFileELF())
{
// Initialize target lowering borrowed from AMDIL
InitAMDILLowering();
// We need to custom lower some of the intrinsics
setOperationAction(ISD::INTRINSIC_WO_CHAIN, MVT::Other, Custom);
// Library functions. These default to Expand, but we have instructions
// for them.
setOperationAction(ISD::FCEIL, MVT::f32, Legal);
setOperationAction(ISD::FEXP2, MVT::f32, Legal);
setOperationAction(ISD::FRINT, MVT::f32, Legal);
setOperationAction(ISD::UDIV, MVT::i32, Expand);
setOperationAction(ISD::UDIVREM, MVT::i32, Custom);
setOperationAction(ISD::UREM, MVT::i32, Expand);
}
//===---------------------------------------------------------------------===//
// TargetLowering Callbacks
//===---------------------------------------------------------------------===//
SDValue AMDGPUTargetLowering::LowerFormalArguments(
SDValue Chain,
CallingConv::ID CallConv,
bool isVarArg,
const SmallVectorImpl<ISD::InputArg> &Ins,
DebugLoc DL, SelectionDAG &DAG,
SmallVectorImpl<SDValue> &InVals) const
{
// Lowering of arguments happens in R600LowerKernelParameters, so we can
// ignore the arguments here.
for (unsigned i = 0, e = Ins.size(); i < e; ++i) {
InVals.push_back(SDValue());
}
return Chain;
}
SDValue AMDGPUTargetLowering::LowerReturn(
SDValue Chain,
CallingConv::ID CallConv,
bool isVarArg,
const SmallVectorImpl<ISD::OutputArg> &Outs,
const SmallVectorImpl<SDValue> &OutVals,
DebugLoc DL, SelectionDAG &DAG) const
{
return DAG.getNode(AMDGPUISD::RET_FLAG, DL, MVT::Other, Chain);
}
//===---------------------------------------------------------------------===//
// Target specific lowering
//===---------------------------------------------------------------------===//
SDValue AMDGPUTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG)
const
{
switch (Op.getOpcode()) {
default:
Op.getNode()->dump();
assert(0 && "Custom lowering code for this"
"instruction is not implemented yet!");
break;
// AMDIL DAG lowering
case ISD::SDIV: return LowerSDIV(Op, DAG);
case ISD::SREM: return LowerSREM(Op, DAG);
case ISD::BUILD_VECTOR: return LowerBUILD_VECTOR(Op, DAG);
case ISD::SIGN_EXTEND_INREG: return LowerSIGN_EXTEND_INREG(Op, DAG);
case ISD::BRCOND: return LowerBRCOND(Op, DAG);
// AMDGPU DAG lowering
case ISD::INTRINSIC_WO_CHAIN: return LowerINTRINSIC_WO_CHAIN(Op, DAG);
case ISD::UDIVREM: return LowerUDIVREM(Op, DAG);
}
return Op;
}
SDValue AMDGPUTargetLowering::LowerINTRINSIC_WO_CHAIN(SDValue Op,
SelectionDAG &DAG) const
{
unsigned IntrinsicID = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
DebugLoc DL = Op.getDebugLoc();
EVT VT = Op.getValueType();
switch (IntrinsicID) {
default: return Op;
case AMDGPUIntrinsic::AMDIL_abs:
return LowerIntrinsicIABS(Op, DAG);
case AMDGPUIntrinsic::AMDIL_exp:
return DAG.getNode(ISD::FEXP2, DL, VT, Op.getOperand(1));
case AMDGPUIntrinsic::AMDIL_fabs:
return DAG.getNode(ISD::FABS, DL, VT, Op.getOperand(1));
case AMDGPUIntrinsic::AMDGPU_lrp:
return LowerIntrinsicLRP(Op, DAG);
case AMDGPUIntrinsic::AMDIL_fraction:
return DAG.getNode(AMDGPUISD::FRACT, DL, VT, Op.getOperand(1));
case AMDGPUIntrinsic::AMDIL_mad:
return DAG.getNode(AMDGPUISD::MAD, DL, VT, Op.getOperand(1),
Op.getOperand(2), Op.getOperand(3));
case AMDGPUIntrinsic::AMDIL_max:
return DAG.getNode(AMDGPUISD::FMAX, DL, VT, Op.getOperand(1),
Op.getOperand(2));
case AMDGPUIntrinsic::AMDGPU_imax:
return DAG.getNode(AMDGPUISD::SMAX, DL, VT, Op.getOperand(1),
Op.getOperand(2));
case AMDGPUIntrinsic::AMDGPU_umax:
return DAG.getNode(AMDGPUISD::UMAX, DL, VT, Op.getOperand(1),
Op.getOperand(2));
case AMDGPUIntrinsic::AMDIL_min:
return DAG.getNode(AMDGPUISD::FMIN, DL, VT, Op.getOperand(1),
Op.getOperand(2));
case AMDGPUIntrinsic::AMDGPU_imin:
return DAG.getNode(AMDGPUISD::SMIN, DL, VT, Op.getOperand(1),
Op.getOperand(2));
case AMDGPUIntrinsic::AMDGPU_umin:
return DAG.getNode(AMDGPUISD::UMIN, DL, VT, Op.getOperand(1),
Op.getOperand(2));
case AMDGPUIntrinsic::AMDIL_round_nearest:
return DAG.getNode(ISD::FRINT, DL, VT, Op.getOperand(1));
case AMDGPUIntrinsic::AMDIL_round_posinf:
return DAG.getNode(ISD::FCEIL, DL, VT, Op.getOperand(1));
}
}
///IABS(a) = SMAX(sub(0, a), a)
SDValue AMDGPUTargetLowering::LowerIntrinsicIABS(SDValue Op,
SelectionDAG &DAG) const
{
DebugLoc DL = Op.getDebugLoc();
EVT VT = Op.getValueType();
SDValue Neg = DAG.getNode(ISD::SUB, DL, VT, DAG.getConstant(0, VT),
Op.getOperand(1));
return DAG.getNode(AMDGPUISD::SMAX, DL, VT, Neg, Op.getOperand(1));
}
/// Linear Interpolation
/// LRP(a, b, c) = muladd(a, b, (1 - a) * c)
SDValue AMDGPUTargetLowering::LowerIntrinsicLRP(SDValue Op,
SelectionDAG &DAG) const
{
DebugLoc DL = Op.getDebugLoc();
EVT VT = Op.getValueType();
SDValue OneSubA = DAG.getNode(ISD::FSUB, DL, VT,
DAG.getConstantFP(1.0f, MVT::f32),
Op.getOperand(1));
SDValue OneSubAC = DAG.getNode(ISD::FMUL, DL, VT, OneSubA,
Op.getOperand(3));
return DAG.getNode(AMDGPUISD::MAD, DL, VT, Op.getOperand(1),
Op.getOperand(2),
OneSubAC);
}
SDValue AMDGPUTargetLowering::LowerUDIVREM(SDValue Op,
SelectionDAG &DAG) const
{
DebugLoc DL = Op.getDebugLoc();
EVT VT = Op.getValueType();
SDValue Num = Op.getOperand(0);
SDValue Den = Op.getOperand(1);
SmallVector<SDValue, 8> Results;
// RCP = URECIP(Den) = 2^32 / Den + e
// e is rounding error.
SDValue RCP = DAG.getNode(AMDGPUISD::URECIP, DL, VT, Den);
// RCP_LO = umulo(RCP, Den) */
SDValue RCP_LO = DAG.getNode(ISD::UMULO, DL, VT, RCP, Den);
// RCP_HI = mulhu (RCP, Den) */
SDValue RCP_HI = DAG.getNode(ISD::MULHU, DL, VT, RCP, Den);
// NEG_RCP_LO = -RCP_LO
SDValue NEG_RCP_LO = DAG.getNode(ISD::SUB, DL, VT, DAG.getConstant(0, VT),
RCP_LO);
// ABS_RCP_LO = (RCP_HI == 0 ? NEG_RCP_LO : RCP_LO)
SDValue ABS_RCP_LO = DAG.getSelectCC(DL, RCP_HI, DAG.getConstant(0, VT),
NEG_RCP_LO, RCP_LO,
ISD::SETEQ);
// Calculate the rounding error from the URECIP instruction
// E = mulhu(ABS_RCP_LO, RCP)
SDValue E = DAG.getNode(ISD::MULHU, DL, VT, ABS_RCP_LO, RCP);
// RCP_A_E = RCP + E
SDValue RCP_A_E = DAG.getNode(ISD::ADD, DL, VT, RCP, E);
// RCP_S_E = RCP - E
SDValue RCP_S_E = DAG.getNode(ISD::SUB, DL, VT, RCP, E);
// Tmp0 = (RCP_HI == 0 ? RCP_A_E : RCP_SUB_E)
SDValue Tmp0 = DAG.getSelectCC(DL, RCP_HI, DAG.getConstant(0, VT),
RCP_A_E, RCP_S_E,
ISD::SETEQ);
// Quotient = mulhu(Tmp0, Num)
SDValue Quotient = DAG.getNode(ISD::MULHU, DL, VT, Tmp0, Num);
// Num_S_Remainder = Quotient * Den
SDValue Num_S_Remainder = DAG.getNode(ISD::UMULO, DL, VT, Quotient, Den);
// Remainder = Num - Num_S_Remainder
SDValue Remainder = DAG.getNode(ISD::SUB, DL, VT, Num, Num_S_Remainder);
// Remainder_GE_Den = (Remainder >= Den ? -1 : 0)
SDValue Remainder_GE_Den = DAG.getSelectCC(DL, Remainder, Den,
DAG.getConstant(-1, VT),
DAG.getConstant(0, VT),
ISD::SETGE);
// Remainder_GE_Zero = (Remainder >= 0 ? -1 : 0)
SDValue Remainder_GE_Zero = DAG.getSelectCC(DL, Remainder,
DAG.getConstant(0, VT),
DAG.getConstant(-1, VT),
DAG.getConstant(0, VT),
ISD::SETGE);
// Tmp1 = Remainder_GE_Den & Remainder_GE_Zero
SDValue Tmp1 = DAG.getNode(ISD::AND, DL, VT, Remainder_GE_Den,
Remainder_GE_Zero);
// Calculate Division result:
// Quotient_A_One = Quotient + 1
SDValue Quotient_A_One = DAG.getNode(ISD::ADD, DL, VT, Quotient,
DAG.getConstant(1, VT));
// Quotient_S_One = Quotient - 1
SDValue Quotient_S_One = DAG.getNode(ISD::SUB, DL, VT, Quotient,
DAG.getConstant(1, VT));
// Div = (Tmp1 == 0 ? Quotient : Quotient_A_One)
SDValue Div = DAG.getSelectCC(DL, Tmp1, DAG.getConstant(0, VT),
Quotient, Quotient_A_One, ISD::SETEQ);
// Div = (Remainder_GE_Zero == 0 ? Quotient_S_One : Div)
Div = DAG.getSelectCC(DL, Remainder_GE_Zero, DAG.getConstant(0, VT),
Quotient_S_One, Div, ISD::SETEQ);
// Calculate Rem result:
// Remainder_S_Den = Remainder - Den
SDValue Remainder_S_Den = DAG.getNode(ISD::SUB, DL, VT, Remainder, Den);
// Remainder_A_Den = Remainder + Den
SDValue Remainder_A_Den = DAG.getNode(ISD::ADD, DL, VT, Remainder, Den);
// Rem = (Tmp1 == 0 ? Remainder : Remainder_S_Den)
SDValue Rem = DAG.getSelectCC(DL, Tmp1, DAG.getConstant(0, VT),
Remainder, Remainder_S_Den, ISD::SETEQ);
// Rem = (Remainder_GE_Zero == 0 ? Remainder_A_Den : Rem)
Rem = DAG.getSelectCC(DL, Remainder_GE_Zero, DAG.getConstant(0, VT),
Remainder_A_Den, Rem, ISD::SETEQ);
DAG.ReplaceAllUsesWith(Op.getValue(0).getNode(), &Div);
DAG.ReplaceAllUsesWith(Op.getValue(1).getNode(), &Rem);
return Op;
}
//===----------------------------------------------------------------------===//
// Helper functions
//===----------------------------------------------------------------------===//
bool AMDGPUTargetLowering::isHWTrueValue(SDValue Op) const
{
if (ConstantFPSDNode * CFP = dyn_cast<ConstantFPSDNode>(Op)) {
return CFP->isExactlyValue(1.0);
}
if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
return C->isAllOnesValue();
}
return false;
}
bool AMDGPUTargetLowering::isHWFalseValue(SDValue Op) const
{
if (ConstantFPSDNode * CFP = dyn_cast<ConstantFPSDNode>(Op)) {
return CFP->getValueAPF().isZero();
}
if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
return C->isNullValue();
}
return false;
}
SDValue AMDGPUTargetLowering::CreateLiveInRegister(SelectionDAG &DAG,
const TargetRegisterClass *RC,
unsigned Reg, EVT VT) const {
MachineFunction &MF = DAG.getMachineFunction();
MachineRegisterInfo &MRI = MF.getRegInfo();
unsigned VirtualRegister;
if (!MRI.isLiveIn(Reg)) {
VirtualRegister = MRI.createVirtualRegister(RC);
MRI.addLiveIn(Reg, VirtualRegister);
} else {
VirtualRegister = MRI.getLiveInVirtReg(Reg);
}
return DAG.getRegister(VirtualRegister, VT);
}
#define NODE_NAME_CASE(node) case AMDGPUISD::node: return #node;
const char* AMDGPUTargetLowering::getTargetNodeName(unsigned Opcode) const
{
switch (Opcode) {
default: return 0;
// AMDIL DAG nodes
NODE_NAME_CASE(MAD);
NODE_NAME_CASE(CALL);
NODE_NAME_CASE(UMUL);
NODE_NAME_CASE(DIV_INF);
NODE_NAME_CASE(VBUILD);
NODE_NAME_CASE(RET_FLAG);
NODE_NAME_CASE(BRANCH_COND);
// AMDGPU DAG nodes
NODE_NAME_CASE(FRACT)
NODE_NAME_CASE(FMAX)
NODE_NAME_CASE(SMAX)
NODE_NAME_CASE(UMAX)
NODE_NAME_CASE(FMIN)
NODE_NAME_CASE(SMIN)
NODE_NAME_CASE(UMIN)
NODE_NAME_CASE(URECIP)
}
}