diff options
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineInternal.h | 4 | ||||
| -rw-r--r-- | llvm/test/Transforms/InstCombine/constant-fold-hang.ll | 14 |
2 files changed, 18 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineInternal.h b/llvm/lib/Transforms/InstCombine/InstCombineInternal.h index 8c784ab1e68..fb2321df2e0 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineInternal.h +++ b/llvm/lib/Transforms/InstCombine/InstCombineInternal.h @@ -372,6 +372,10 @@ public: /// I to the worklist, replace all uses of I with the new value, then return /// I, so that the inst combiner will know that I was modified. Instruction *ReplaceInstUsesWith(Instruction &I, Value *V) { + // If there are no uses to replace, then we return nullptr to indicate that + // no changes were made to the program. + if (I.use_empty()) return nullptr; + Worklist.AddUsersToWorkList(I); // Add all modified instrs to worklist. // If we are replacing the instruction with itself, this must be in a diff --git a/llvm/test/Transforms/InstCombine/constant-fold-hang.ll b/llvm/test/Transforms/InstCombine/constant-fold-hang.ll new file mode 100644 index 00000000000..2ca6b86ccc2 --- /dev/null +++ b/llvm/test/Transforms/InstCombine/constant-fold-hang.ll @@ -0,0 +1,14 @@ +; RUN: opt -instcombine < %s + +; Function Attrs: nounwind readnone ssp +define void @mulByZero(<4 x i16> %x) #0 { +entry: + %a = tail call <4 x i32> @llvm.arm.neon.vmulls.v4i32(<4 x i16> %x, <4 x i16> zeroinitializer) #2 + ret void +} + +; Function Attrs: nounwind readnone +declare <4 x i32> @llvm.arm.neon.vmulls.v4i32(<4 x i16>, <4 x i16>) #1 + +attributes #0 = { nounwind readnone ssp } +attributes #1 = { nounwind readnone } |
