diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp index 7f0c23bd24efb..6baa08d43a18b 100644 --- a/llvm/lib/Transforms/Utils/Local.cpp +++ b/llvm/lib/Transforms/Utils/Local.cpp @@ -3876,6 +3876,10 @@ bool llvm::canReplaceOperandWithVariable(const Instruction *I, unsigned OpIdx) { if (Op->isSwiftError()) return false; + // Cannot replace alloca argument with phi/select. + if (I->isLifetimeStartOrEnd()) + return false; + // Early exit. if (!isa(Op)) return true; diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp index 75c96503d556d..94b0ab892f2dd 100644 --- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp @@ -2227,16 +2227,6 @@ static bool canSinkInstructions( return I->getOperand(OI) == I0->getOperand(OI); }; if (!all_of(Insts, SameAsI0)) { - // SROA can't speculate lifetime markers of selects/phis, and the - // backend may handle such lifetimes incorrectly as well (#104776). - // Don't sink lifetimes if it would introduce a phi on the pointer - // argument. - if (isa(I0) && OI == 1 && - any_of(Insts, [](const Instruction *I) { - return isa(I->getOperand(1)->stripPointerCasts()); - })) - return false; - if ((isa(Op) && !replacingOperandWithVariableIsCheap(I0, OI)) || !canReplaceOperandWithVariable(I0, OI)) // We can't create a PHI from this GEP. diff --git a/llvm/test/Transforms/GVNSink/lifetime.ll b/llvm/test/Transforms/GVNSink/lifetime.ll new file mode 100644 index 0000000000000..1a8a69bb0986e --- /dev/null +++ b/llvm/test/Transforms/GVNSink/lifetime.ll @@ -0,0 +1,77 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5 +; RUN: opt -S -passes=gvn-sink < %s | FileCheck %s + +; Make sure we do not sink lifetime markers if this would introduce a +; lifetime with non-alloca operand. + +define void @test_cant_sink(i1 %c) { +; CHECK-LABEL: define void @test_cant_sink( +; CHECK-SAME: i1 [[C:%.*]]) { +; CHECK-NEXT: [[A:%.*]] = alloca i8, align 1 +; CHECK-NEXT: [[B:%.*]] = alloca i8, align 1 +; CHECK-NEXT: call void @llvm.lifetime.start.p0(i64 1, ptr [[A]]) +; CHECK-NEXT: call void @llvm.lifetime.start.p0(i64 1, ptr [[B]]) +; CHECK-NEXT: br i1 [[C]], label %[[IF:.*]], label %[[ELSE:.*]] +; CHECK: [[IF]]: +; CHECK-NEXT: store i64 1, ptr [[A]], align 4 +; CHECK-NEXT: call void @llvm.lifetime.end.p0(i64 1, ptr [[A]]) +; CHECK-NEXT: br label %[[JOIN:.*]] +; CHECK: [[ELSE]]: +; CHECK-NEXT: store i64 1, ptr [[B]], align 4 +; CHECK-NEXT: call void @llvm.lifetime.end.p0(i64 1, ptr [[B]]) +; CHECK-NEXT: br label %[[JOIN]] +; CHECK: [[JOIN]]: +; CHECK-NEXT: ret void +; + %a = alloca i8 + %b = alloca i8 + call void @llvm.lifetime.start(i64 1, ptr %a) + call void @llvm.lifetime.start(i64 1, ptr %b) + br i1 %c, label %if, label %else + +if: + store i64 1, ptr %a + call void @llvm.lifetime.end(i64 1, ptr %a) + br label %join + +else: + store i64 1, ptr %b + call void @llvm.lifetime.end(i64 1, ptr %b) + br label %join + +join: + ret void +} + +define void @test_can_sink(i1 %c) { +; CHECK-LABEL: define void @test_can_sink( +; CHECK-SAME: i1 [[C:%.*]]) { +; CHECK-NEXT: [[A:%.*]] = alloca i8, align 1 +; CHECK-NEXT: call void @llvm.lifetime.start.p0(i64 1, ptr [[A]]) +; CHECK-NEXT: br i1 [[C]], label %[[IF:.*]], label %[[ELSE:.*]] +; CHECK: [[IF]]: +; CHECK-NEXT: br label %[[JOIN:.*]] +; CHECK: [[ELSE]]: +; CHECK-NEXT: br label %[[JOIN]] +; CHECK: [[JOIN]]: +; CHECK-NEXT: store i64 1, ptr [[A]], align 4 +; CHECK-NEXT: call void @llvm.lifetime.end.p0(i64 1, ptr [[A]]) +; CHECK-NEXT: ret void +; + %a = alloca i8 + call void @llvm.lifetime.start(i64 1, ptr %a) + br i1 %c, label %if, label %else + +if: + store i64 1, ptr %a + call void @llvm.lifetime.end(i64 1, ptr %a) + br label %join + +else: + store i64 1, ptr %a + call void @llvm.lifetime.end(i64 1, ptr %a) + br label %join + +join: + ret void +}