From 3bb2dbd66586d03e9586294f0964ec05f3322cd6 Mon Sep 17 00:00:00 2001 From: Sanjoy Das Date: Sat, 31 Dec 2016 22:12:34 +0000 Subject: Fix an issue with isGuaranteedToTransferExecutionToSuccessor I'm not sure if this was intentional, but today isGuaranteedToTransferExecutionToSuccessor returns true for readonly and argmemonly calls that may throw. This commit changes the function to not implicitly infer nounwind this way. Even if we eventually specify readonly calls as not throwing, isGuaranteedToTransferExecutionToSuccessor is not the best place to infer that. We should instead teach FunctionAttrs or some other such pass to tag readonly functions / calls as nounwind instead. llvm-svn: 290794 --- llvm/unittests/Analysis/ValueTrackingTest.cpp | 51 +++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) (limited to 'llvm/unittests/Analysis/ValueTrackingTest.cpp') diff --git a/llvm/unittests/Analysis/ValueTrackingTest.cpp b/llvm/unittests/Analysis/ValueTrackingTest.cpp index f429c3b9914..ba0d30d59b6 100644 --- a/llvm/unittests/Analysis/ValueTrackingTest.cpp +++ b/llvm/unittests/Analysis/ValueTrackingTest.cpp @@ -188,3 +188,54 @@ TEST_F(MatchSelectPatternTest, DoubleCastBad) { // The cast types here aren't the same, so we cannot match an UMIN. expectPattern({SPF_UNKNOWN, SPNB_NA, false}); } + +TEST(ValueTracking, GuaranteedToTransferExecutionToSuccessor) { + StringRef Assembly = + "declare void @nounwind_readonly(i32*) nounwind readonly " + "declare void @nounwind_argmemonly(i32*) nounwind argmemonly " + "declare void @throws_but_readonly(i32*) readonly " + "declare void @throws_but_argmemonly(i32*) argmemonly " + " " + "declare void @unknown(i32*) " + " " + "define void @f(i32* %p) { " + " call void @nounwind_readonly(i32* %p) " + " call void @nounwind_argmemonly(i32* %p) " + " call void @throws_but_readonly(i32* %p) " + " call void @throws_but_argmemonly(i32* %p) " + " call void @unknown(i32* %p) nounwind readonly " + " call void @unknown(i32* %p) nounwind argmemonly " + " call void @unknown(i32* %p) readonly " + " call void @unknown(i32* %p) argmemonly " + " ret void " + "} "; + + LLVMContext Context; + SMDiagnostic Error; + auto M = parseAssemblyString(Assembly, Error, Context); + assert(M && "Bad assembly?"); + + auto *F = M->getFunction("f"); + assert(F && "Bad assembly?"); + + auto &BB = F->getEntryBlock(); + ArrayRef ExpectedAnswers = { + true, // call void @nounwind_readonly(i32* %p) + true, // call void @nounwind_argmemonly(i32* %p) + false, // call void @throws_but_readonly(i32* %p) + false, // call void @throws_but_argmemonly(i32* %p) + true, // call void @unknown(i32* %p) nounwind readonly + true, // call void @unknown(i32* %p) nounwind argmemonly + false, // call void @unknown(i32* %p) readonly + false, // call void @unknown(i32* %p) argmemonly + false, // ret void + }; + + int Index = 0; + for (auto &I : BB) { + EXPECT_EQ(isGuaranteedToTransferExecutionToSuccessor(&I), + ExpectedAnswers[Index]) + << "Incorrect answer at instruction " << Index << " = " << I; + Index++; + } +} -- cgit v1.2.3