Index: llvm/lib/Analysis/ValueTracking.cpp =================================================================== --- llvm/lib/Analysis/ValueTracking.cpp +++ llvm/lib/Analysis/ValueTracking.cpp @@ -558,12 +558,18 @@ return true; } + // Don't let an assume affect itself - this would cause the problems + // `isEphemeralValueOf` is trying to prevent, and it would also make + // the loop below go out of bounds. + if (Inv == CxtI) + return false; + // The context comes first, but they're both in the same block. Make sure // there is nothing in between that might interrupt the control flow. for (BasicBlock::const_iterator I = std::next(BasicBlock::const_iterator(CxtI)), IE(Inv); I != IE; ++I) - if (!isSafeToSpeculativelyExecute(&*I) && !isAssumeLikeIntrinsic(&*I)) + if (!isGuaranteedToTransferExecutionToSuccessor(&*I)) return false; return !isEphemeralValueOf(Inv, CxtI); Index: llvm/test/Transforms/InstCombine/assume_inevitable.ll =================================================================== --- llvm/test/Transforms/InstCombine/assume_inevitable.ll +++ llvm/test/Transforms/InstCombine/assume_inevitable.ll @@ -8,10 +8,10 @@ ; CHECK-LABEL: @assume_inevitable( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[M:%.*]] = alloca i64, align 8 -; CHECK-NEXT: [[TMP0:%.*]] = load i32, i32* [[A:%.*]], align 4 +; CHECK-NEXT: [[TMP0:%.*]] = load i32, i32* [[A:%.*]], align 32 ; CHECK-NEXT: [[LOADRES:%.*]] = load i32, i32* [[B:%.*]], align 4 ; CHECK-NEXT: [[LOADRES2:%.*]] = call i32 @llvm.annotation.i32(i32 [[LOADRES]], i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str, i64 0, i64 0), i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str1, i64 0, i64 0), i32 2) -; CHECK-NEXT: store i32 [[LOADRES2]], i32* [[A]], align 4 +; CHECK-NEXT: store i32 [[LOADRES2]], i32* [[A]], align 32 ; CHECK-NEXT: [[DUMMY_EQ:%.*]] = icmp ugt i32 [[LOADRES]], 42 ; CHECK-NEXT: tail call void @llvm.assume(i1 [[DUMMY_EQ]]) ; CHECK-NEXT: [[M_I8:%.*]] = bitcast i64* [[M]] to i8*