diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp index 81d1705f2fa..6fe00a71ea1 100644 --- a/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/lib/Transforms/Utils/SimplifyCFG.cpp @@ -1425,6 +1425,16 @@ static bool canSinkInstructions( // FIXME: if the call was *already* indirect, we should do this. return false; } + // Because SROA can't handle speculating stores of selects, try not + // to sink stores of allocas when we'd have to create a PHI for the + // address operand. + // FIXME: This is a workaround for a deficiency in SROA - see + // https://llvm.org/bugs/show_bug.cgi?id=30188 + if (OI == 1 && isa(I0) && + any_of(Insts, [](const Instruction *I) { + return isa(I->getOperand(1)); + })) + return false; for (auto *I : Insts) PHIOperands[I].push_back(I->getOperand(OI)); } diff --git a/test/Transforms/SimplifyCFG/sink-common-code.ll b/test/Transforms/SimplifyCFG/sink-common-code.ll index db9080effc3..66dfeb8658d 100644 --- a/test/Transforms/SimplifyCFG/sink-common-code.ll +++ b/test/Transforms/SimplifyCFG/sink-common-code.ll @@ -562,6 +562,29 @@ if.end: ; CHECK-DAG: [ %cmp3, %if.then3 ] ; CHECK-NEXT: zext i1 %[[x]] to i8 +define i32 @test_pr30188(i1 zeroext %flag, i32 %x) { +entry: + %y = alloca i32 + %z = alloca i32 + br i1 %flag, label %if.then, label %if.else + +if.then: + store i32 %x, i32* %y + br label %if.end + +if.else: + store i32 %x, i32* %z + br label %if.end + +if.end: + ret i32 1 +} + +; CHECK-LABEL: test_pr30188 +; CHECK-NOT: select +; CHECK: store +; CHECK: store + ; CHECK: !0 = !{!1, !1, i64 0} ; CHECK: !1 = !{!"float", !2} ; CHECK: !2 = !{!"an example type tree"}