[llvm] [AMDGPU] Allow folding to FMAAK with SGPR and immediate operand on GFX10+ (PR #72266)
Matt Arsenault via llvm-commits
llvm-commits at lists.llvm.org
Tue Nov 28 05:47:15 PST 2023
================
@@ -3497,43 +3497,45 @@ bool SIInstrInfo::FoldImmediate(MachineInstr &UseMI, MachineInstr &DefMI,
// Added part is the constant: Use v_madak_{f16, f32}.
if (Src2->isReg() && Src2->getReg() == Reg) {
- // Not allowed to use constant bus for another operand.
- // We can however allow an inline immediate as src0.
- bool Src0Inlined = false;
- if (Src0->isReg()) {
- // Try to inline constant if possible.
- // If the Def moves immediate and the use is single
- // We are saving VGPR here.
- MachineInstr *Def = MRI->getUniqueVRegDef(Src0->getReg());
- if (Def && Def->isMoveImmediate() &&
- isInlineConstant(Def->getOperand(1)) &&
- MRI->hasOneUse(Src0->getReg())) {
- Src0->ChangeToImmediate(Def->getOperand(1).getImm());
- Src0Inlined = true;
- } else if ((Src0->getReg().isPhysical() &&
- (ST.getConstantBusLimit(Opc) <= 1 &&
- RI.isSGPRClass(RI.getPhysRegBaseClass(Src0->getReg())))) ||
- (Src0->getReg().isVirtual() &&
- (ST.getConstantBusLimit(Opc) <= 1 &&
- RI.isSGPRClass(MRI->getRegClass(Src0->getReg())))))
- return false;
+ if (ST.getConstantBusLimit(Opc) < 2) {
+ // Not allowed to use constant bus for another operand.
+ // We can however allow an inline immediate as src0.
+ bool Src0Inlined = false;
+ if (Src0->isReg()) {
+ // Try to inline constant if possible.
+ // If the Def moves immediate and the use is single
+ // We are saving VGPR here.
+ MachineInstr *Def = MRI->getUniqueVRegDef(Src0->getReg());
+ if (Def && Def->isMoveImmediate() &&
+ isInlineConstant(Def->getOperand(1)) &&
+ MRI->hasOneUse(Src0->getReg())) {
+ Src0->ChangeToImmediate(Def->getOperand(1).getImm());
+ Src0Inlined = true;
+ } else if ((Src0->getReg().isPhysical() &&
+ (ST.getConstantBusLimit(Opc) <= 1 &&
+ RI.isSGPRClass(
+ RI.getPhysRegBaseClass(Src0->getReg())))) ||
+ (Src0->getReg().isVirtual() &&
+ (ST.getConstantBusLimit(Opc) <= 1 &&
+ RI.isSGPRClass(MRI->getRegClass(Src0->getReg())))))
+ return false;
// VGPR is okay as Src0 - fallthrough
- }
+ }
- if (Src1->isReg() && !Src0Inlined ) {
- // We have one slot for inlinable constant so far - try to fill it
- MachineInstr *Def = MRI->getUniqueVRegDef(Src1->getReg());
- if (Def && Def->isMoveImmediate() &&
- isInlineConstant(Def->getOperand(1)) &&
- MRI->hasOneUse(Src1->getReg()) &&
- commuteInstruction(UseMI)) {
+ if (Src1->isReg() && !Src0Inlined) {
+ // We have one slot for inlinable constant so far - try to fill it
+ MachineInstr *Def = MRI->getUniqueVRegDef(Src1->getReg());
+ if (Def && Def->isMoveImmediate() &&
+ isInlineConstant(Def->getOperand(1)) &&
+ MRI->hasOneUse(Src1->getReg()) && commuteInstruction(UseMI)) {
Src0->ChangeToImmediate(Def->getOperand(1).getImm());
- } else if ((Src1->getReg().isPhysical() &&
- RI.isSGPRClass(RI.getPhysRegBaseClass(Src1->getReg()))) ||
- (Src1->getReg().isVirtual() &&
- RI.isSGPRClass(MRI->getRegClass(Src1->getReg()))))
- return false;
+ } else if ((Src1->getReg().isPhysical() &&
+ RI.isSGPRClass(RI.getPhysRegBaseClass(Src1->getReg()))) ||
+ (Src1->getReg().isVirtual() &&
+ RI.isSGPRClass(MRI->getRegClass(Src1->getReg()))))
+ return false;
----------------
arsenm wrote:
RI.isSGPRReg
https://github.com/llvm/llvm-project/pull/72266
More information about the llvm-commits
mailing list