Unverified Commit a700a520 authored by Skwoogey's avatar Skwoogey Committed by GitHub
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[InterleavedAccessPass] Avoid optimizing load instructions if it has dead binop users (#71339) 

If a load instruction qualifies to be optimized by InterleavedAccess
Pass, but also has a dead binop instruction, this will lead to a crash.

Binop instruction will not be deleted, because normally it would be
deleted through its' users, but it has none. Later on deleting a load
instruction will fail because it still has uses.
parent 4d9f3ca7

llvm/lib/CodeGen/InterleavedAccessPass.cpp

+1 −1
Original line number Diff line number Diff line
@@ -251,7 +251,7 @@ bool InterleavedAccess::lowerInterleavedLoad( 
      continue;

    }

    if (auto *BI = dyn_cast<BinaryOperator>(User)) {

      if (all_of(BI->users(), [](auto *U) {

      if (!BI->user_empty() && all_of(BI->users(), [](auto *U) {

            auto *SVI = dyn_cast<ShuffleVectorInst>(U);

            return SVI && isa<UndefValue>(SVI->getOperand(1));

          })) {

llvm/test/Transforms/InterleavedAccess/AArch64/binopshuffles.ll

+21 −0
Original line number Diff line number Diff line
@@ -220,3 +220,24 @@ entry: 
  store <8 x i8> %shuffled, ptr %p2

  ret void

}



define void @skip_optimizing_dead_binop(ptr %p0, ptr %p1) {

; CHECK-LABEL: @skip_optimizing_dead_binop(

; CHECK-NEXT:  entry:

; CHECK-NEXT:    [[V0:%.*]] = load <8 x double>, ptr [[P0:%.*]]

; CHECK-NEXT:    [[SHUFFLED_1:%.*]] = shufflevector <8 x double> [[V0]], <8 x double> undef, <2 x i32> <i32 0, i32 4>

; CHECK-NEXT:    [[SHUFFLED_2:%.*]] = shufflevector <8 x double> [[V0]], <8 x double> undef, <2 x i32> <i32 1, i32 5>

; CHECK-NEXT:    [[SHUFFLED_3:%.*]] = shufflevector <8 x double> [[V0]], <8 x double> undef, <2 x i32> <i32 2, i32 6>

; CHECK-NEXT:    [[SHUFFLED_4:%.*]] = shufflevector <8 x double> [[V0]], <8 x double> undef, <2 x i32> <i32 3, i32 7>

; CHECK-NEXT:    [[DEAD_BINOP:%.*]] = fadd <8 x double> [[V0]], [[V0]]

; CHECK-NEXT:    ret void

;

entry:

  %v0 = load <8 x double>, ptr %p0

  %shuffled_1 = shufflevector <8 x double> %v0, <8 x double> undef, <2 x i32> <i32 0, i32 4>

  %shuffled_2 = shufflevector <8 x double> %v0, <8 x double> undef, <2 x i32> <i32 1, i32 5>

  %shuffled_3 = shufflevector <8 x double> %v0, <8 x double> undef, <2 x i32> <i32 2, i32 6>

  %shuffled_4 = shufflevector <8 x double> %v0, <8 x double> undef, <2 x i32> <i32 3, i32 7>

  %dead_binop = fadd <8 x double> %v0, %v0

  ret void

}