diff options
Diffstat (limited to 'llvm/lib/Target/AMDGPU/SIFoldOperands.cpp')
| -rw-r--r-- | llvm/lib/Target/AMDGPU/SIFoldOperands.cpp | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/llvm/lib/Target/AMDGPU/SIFoldOperands.cpp b/llvm/lib/Target/AMDGPU/SIFoldOperands.cpp index 0a0584d5074..04922f652b9 100644 --- a/llvm/lib/Target/AMDGPU/SIFoldOperands.cpp +++ b/llvm/lib/Target/AMDGPU/SIFoldOperands.cpp @@ -591,6 +591,32 @@ static bool tryConstantFoldOp(MachineRegisterInfo &MRI, return false; } +// Try to fold an instruction into a simpler one +static bool tryFoldInst(const SIInstrInfo *TII, + MachineInstr *MI) { + unsigned Opc = MI->getOpcode(); + + if (Opc == AMDGPU::V_CNDMASK_B32_e32 || + Opc == AMDGPU::V_CNDMASK_B32_e64 || + Opc == AMDGPU::V_CNDMASK_B64_PSEUDO) { + const MachineOperand *Src0 = TII->getNamedOperand(*MI, AMDGPU::OpName::src0); + const MachineOperand *Src1 = TII->getNamedOperand(*MI, AMDGPU::OpName::src1); + if (Src1->isIdenticalTo(*Src0)) { + DEBUG(dbgs() << "Folded " << *MI << " into "); + int Src2Idx = AMDGPU::getNamedOperandIdx(Opc, AMDGPU::OpName::src2); + if (Src2Idx != -1) + MI->RemoveOperand(Src2Idx); + MI->RemoveOperand(AMDGPU::getNamedOperandIdx(Opc, AMDGPU::OpName::src1)); + mutateCopyOp(*MI, TII->get(Src0->isReg() ? (unsigned)AMDGPU::COPY + : getMovOpc(false))); + DEBUG(dbgs() << *MI << '\n'); + return true; + } + } + + return false; +} + void SIFoldOperands::foldInstOperand(MachineInstr &MI, MachineOperand &OpToFold) const { // We need mutate the operands of new mov instructions to add implicit @@ -692,6 +718,7 @@ void SIFoldOperands::foldInstOperand(MachineInstr &MI, } DEBUG(dbgs() << "Folded source from " << MI << " into OpNo " << static_cast<int>(Fold.UseOpNo) << " of " << *Fold.UseMI << '\n'); + tryFoldInst(TII, Fold.UseMI); } } } @@ -907,6 +934,8 @@ bool SIFoldOperands::runOnMachineFunction(MachineFunction &MF) { Next = std::next(I); MachineInstr &MI = *I; + tryFoldInst(TII, &MI); + if (!isFoldableCopy(MI)) { if (IsIEEEMode || !tryFoldOMod(MI)) tryFoldClamp(MI); |
