Skip to content

[RISCV] Fix masked->unmasked peephole handling masked pseudos with no passthru #122253

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Jan 9, 2025
Merged

[RISCV] Fix masked->unmasked peephole handling masked pseudos with no passthru #122253

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
20 changes: 12 additions & 8 deletions llvm/lib/Target/RISCV/RISCVVectorPeephole.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -460,13 +460,13 @@ bool RISCVVectorPeephole::convertToUnmasked(MachineInstr &MI) const {
[[maybe_unused]] const bool HasPolicyOp =
RISCVII::hasVecPolicyOp(MCID.TSFlags);
const bool HasPassthru = RISCVII::isFirstDefTiedToFirstUse(MCID);
#ifndef NDEBUG
const MCInstrDesc &MaskedMCID = TII->get(MI.getOpcode());
assert(RISCVII::hasVecPolicyOp(MaskedMCID.TSFlags) ==
RISCVII::hasVecPolicyOp(MCID.TSFlags) &&
"Masked and unmasked pseudos are inconsistent");
assert(HasPolicyOp == HasPassthru && "Unexpected pseudo structure");
#endif
assert(!(HasPassthru && !RISCVII::isFirstDefTiedToFirstUse(MaskedMCID)) &&
"Unmasked with passthru but masked with no passthru?");
(void)HasPolicyOp;

MI.setDesc(MCID);
Expand All @@ -478,12 +478,16 @@ bool RISCVVectorPeephole::convertToUnmasked(MachineInstr &MI) const {
// The unmasked pseudo will no longer be constrained to the vrnov0 reg class,
// so try and relax it to vr.
MRI->recomputeRegClass(MI.getOperand(0).getReg());
unsigned PassthruOpIdx = MI.getNumExplicitDefs();
if (HasPassthru) {
if (MI.getOperand(PassthruOpIdx).getReg() != RISCV::NoRegister)
MRI->recomputeRegClass(MI.getOperand(PassthruOpIdx).getReg());
} else
MI.removeOperand(PassthruOpIdx);

// If the original masked pseudo had a passthru, relax it or remove it.
if (RISCVII::isFirstDefTiedToFirstUse(MaskedMCID)) {
unsigned PassthruOpIdx = MI.getNumExplicitDefs();
if (HasPassthru) {
if (MI.getOperand(PassthruOpIdx).getReg() != RISCV::NoRegister)
MRI->recomputeRegClass(MI.getOperand(PassthruOpIdx).getReg());
} else
MI.removeOperand(PassthruOpIdx);
}

return true;
}
Expand Down
16 changes: 16 additions & 0 deletions llvm/test/CodeGen/RISCV/rvv/allone-masked-to-unmasked.mir
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,16 @@
# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 5
# RUN: llc %s -o - -mtriple=riscv64 -mattr=+v -run-pass=riscv-vector-peephole -verify-machineinstrs | FileCheck %s

# Take into account that the masked vcpop pseudo doesn't have a passthru
---
name: vcpop.m
body: |
bb.0:
; CHECK-LABEL: name: vcpop.m
; CHECK: %allones:vr = PseudoVMSET_M_B64 $noreg, 0 /* e8 */
; CHECK-NEXT: $v0 = COPY %allones
; CHECK-NEXT: [[PseudoVCPOP_M_B64_:%[0-9]+]]:gpr = PseudoVCPOP_M_B64 $noreg, 42, 0 /* e8 */
%allones:vr = PseudoVMSET_M_B64 $noreg, 0
$v0 = COPY %allones
%2:gpr = PseudoVCPOP_M_B64_MASK $noreg, $v0, 42, 0
...
Loading