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[AArch64] Clear kill flags when removing FMOVDr. #86308

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Merged
merged 1 commit into from
Mar 27, 2024
Merged

[AArch64] Clear kill flags when removing FMOVDr. #86308

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4 changes: 3 additions & 1 deletion llvm/lib/Target/AArch64/AArch64MIPeepholeOpt.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -680,9 +680,11 @@ bool AArch64MIPeepholeOpt::visitFMOVDr(MachineInstr &MI) {
// Let's remove MIs for high 64-bits.
Register OldDef = MI.getOperand(0).getReg();
Register NewDef = MI.getOperand(1).getReg();
LLVM_DEBUG(dbgs() << "Removing: " << MI << "\n");
MRI->clearKillFlags(OldDef);
MRI->clearKillFlags(NewDef);
MRI->constrainRegClass(NewDef, MRI->getRegClass(OldDef));
MRI->replaceRegWith(OldDef, NewDef);
LLVM_DEBUG(dbgs() << "Removed: " << MI << "\n");
MI.eraseFromParent();

return true;
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60 changes: 60 additions & 0 deletions llvm/test/CodeGen/AArch64/peephole-movd.mir
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@@ -0,0 +1,60 @@
# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
# RUN: llc -run-pass=aarch64-mi-peephole-opt -o - -mtriple=aarch64-unknown-linux -verify-machineinstrs %s | FileCheck %s

---
name: remove_kill_flags
tracksRegLiveness: true
body: |
bb.0.entry:
liveins: $w0
; CHECK-LABEL: name: remove_kill_flags
; CHECK: liveins: $w0
; CHECK-NEXT: {{ $}}
; CHECK-NEXT: [[MOVIv2d_ns:%[0-9]+]]:fpr128 = MOVIv2d_ns 0
; CHECK-NEXT: [[COPY:%[0-9]+]]:fpr64 = COPY [[MOVIv2d_ns]].dsub
; CHECK-NEXT: [[UQSHLv8i8_shift:%[0-9]+]]:fpr64 = UQSHLv8i8_shift killed [[COPY]], 1
; CHECK-NEXT: [[SUBREG_TO_REG:%[0-9]+]]:fpr128 = SUBREG_TO_REG 0, [[UQSHLv8i8_shift]], %subreg.dsub
; CHECK-NEXT: [[TBLv8i8One:%[0-9]+]]:fpr64 = TBLv8i8One killed [[SUBREG_TO_REG]], [[UQSHLv8i8_shift]]
; CHECK-NEXT: [[DEF:%[0-9]+]]:fpr128 = IMPLICIT_DEF
; CHECK-NEXT: [[INSERT_SUBREG:%[0-9]+]]:fpr128 = INSERT_SUBREG [[DEF]], [[UQSHLv8i8_shift]], %subreg.dsub
; CHECK-NEXT: RET_ReallyLR implicit $w0
%0:fpr128 = MOVIv2d_ns 0
%1:fpr64 = COPY %0.dsub:fpr128
%2:fpr64 = UQSHLv8i8_shift killed %1:fpr64, 1
%3:fpr64 = FMOVDr %2:fpr64
%4:fpr128 = SUBREG_TO_REG 0, killed %3:fpr64, %subreg.dsub
%5:fpr64 = TBLv8i8One killed %4:fpr128, %2:fpr64
%7:fpr128 = IMPLICIT_DEF
%6:fpr128 = INSERT_SUBREG %7:fpr128, killed %2:fpr64, %subreg.dsub
RET_ReallyLR implicit $w0
...
---
name: remove_kill_flags2
tracksRegLiveness: true
body: |
bb.0.entry:
liveins: $w0
; CHECK-LABEL: name: remove_kill_flags2
; CHECK: liveins: $w0
; CHECK-NEXT: {{ $}}
; CHECK-NEXT: [[MOVIv2d_ns:%[0-9]+]]:fpr128 = MOVIv2d_ns 0
; CHECK-NEXT: [[COPY:%[0-9]+]]:fpr64 = COPY [[MOVIv2d_ns]].dsub
; CHECK-NEXT: [[UQSHLv8i8_shift:%[0-9]+]]:fpr64 = UQSHLv8i8_shift killed [[COPY]], 1
; CHECK-NEXT: [[SUBREG_TO_REG:%[0-9]+]]:fpr128 = SUBREG_TO_REG 0, [[UQSHLv8i8_shift]], %subreg.dsub
; CHECK-NEXT: [[DEF:%[0-9]+]]:fpr128 = IMPLICIT_DEF
; CHECK-NEXT: [[INSERT_SUBREG:%[0-9]+]]:fpr128 = INSERT_SUBREG [[DEF]], [[UQSHLv8i8_shift]], %subreg.dsub
; CHECK-NEXT: [[DEF1:%[0-9]+]]:fpr128 = IMPLICIT_DEF
; CHECK-NEXT: [[INSERT_SUBREG1:%[0-9]+]]:fpr128 = INSERT_SUBREG [[DEF1]], [[UQSHLv8i8_shift]], %subreg.dsub
; CHECK-NEXT: RET_ReallyLR implicit $w0
%0:fpr128 = MOVIv2d_ns 0
%1:fpr64 = COPY %0.dsub:fpr128
%2:fpr64 = UQSHLv8i8_shift killed %1:fpr64, 1
%3:fpr64 = FMOVDr %2:fpr64
%4:fpr128 = SUBREG_TO_REG 0, %3:fpr64, %subreg.dsub
%7:fpr128 = IMPLICIT_DEF
%6:fpr128 = INSERT_SUBREG %7:fpr128, killed %2:fpr64, %subreg.dsub
%9:fpr128 = IMPLICIT_DEF
%8:fpr128 = INSERT_SUBREG %9:fpr128, killed %3:fpr64, %subreg.dsub
RET_ReallyLR implicit $w0
...