diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp --- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp @@ -1421,6 +1421,20 @@ return true; } +// Check lifetime markers. +static bool isLifeTimeMarker(const Instruction *I) { + if (auto II = dyn_cast(I)) { + switch (II->getIntrinsicID()) { + default: + break; + case Intrinsic::lifetime_start: + case Intrinsic::lifetime_end: + return true; + } + } + return false; +} + // All instructions in Insts belong to different blocks that all unconditionally // branch to a common successor. Analyze each instruction and return true if it // would be possible to sink them into their successor, creating one common @@ -1475,20 +1489,25 @@ return false; } - // Because SROA can't handle speculating stores of selects, try not - // to sink loads or stores of allocas when we'd have to create a PHI for - // the address operand. Also, because it is likely that loads or stores - // of allocas will disappear when Mem2Reg/SROA is run, don't sink them. + // Because SROA can't handle speculating stores of selects, try not to sink + // loads, stores or lifetime markers of allocas when we'd have to create a + // PHI for the address operand. Also, because it is likely that loads or + // stores of allocas will disappear when Mem2Reg/SROA is run, don't sink + // them. // This can cause code churn which can have unintended consequences down // the line - see https://llvm.org/bugs/show_bug.cgi?id=30244. // FIXME: This is a workaround for a deficiency in SROA - see // https://llvm.org/bugs/show_bug.cgi?id=30188 if (isa(I0) && any_of(Insts, [](const Instruction *I) { - return isa(I->getOperand(1)); + return isa(I->getOperand(1)->stripPointerCasts()); })) return false; if (isa(I0) && any_of(Insts, [](const Instruction *I) { - return isa(I->getOperand(0)); + return isa(I->getOperand(0)->stripPointerCasts()); + })) + return false; + if (isLifeTimeMarker(I0) && any_of(Insts, [](const Instruction *I) { + return isa(I->getOperand(1)->stripPointerCasts()); })) return false; diff --git a/llvm/test/Transforms/SimplifyCFG/sink-common-code.ll b/llvm/test/Transforms/SimplifyCFG/sink-common-code.ll --- a/llvm/test/Transforms/SimplifyCFG/sink-common-code.ll +++ b/llvm/test/Transforms/SimplifyCFG/sink-common-code.ll @@ -886,6 +886,33 @@ ; CHECK: ret } +; CHECK-LABEL: @test_not_sink_lifetime_marker +; CHECK-NOT: select +; CHECK: call void @llvm.lifetime.end +; CHECK: call void @llvm.lifetime.end +define i32 @test_not_sink_lifetime_marker(i1 zeroext %flag, i32 %x) { +entry: + %y = alloca i32 + %z = alloca i32 + br i1 %flag, label %if.then, label %if.else + +if.then: + %y.cast = bitcast i32* %y to i8* + call void @llvm.lifetime.end.p0i8(i64 4, i8* %y.cast) + br label %if.end + +if.else: + %z.cast = bitcast i32* %z to i8* + call void @llvm.lifetime.end.p0i8(i64 4, i8* %z.cast) + br label %if.end + +if.end: + ret i32 1 +} + +declare void @llvm.lifetime.start.p0i8(i64, i8* nocapture) +declare void @llvm.lifetime.end.p0i8(i64, i8* nocapture) + ; CHECK: ![[$TBAA]] = !{![[TYPE:[0-9]]], ![[TYPE]], i64 0} ; CHECK: ![[TYPE]] = !{!"float", ![[TEXT:[0-9]]]}