[llvm] [AMDGPU] Fix missing `IsExact` flag when expanding vector binary operator (PR #86712)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-amdgpu

Author: Shilei Tian (shiltian)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/86712.diff


1 Files Affected:

- (modified) llvm/lib/Target/AMDGPU/AMDGPUCodeGenPrepare.cpp (+3) 


``````````diff
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUCodeGenPrepare.cpp b/llvm/lib/Target/AMDGPU/AMDGPUCodeGenPrepare.cpp
index bddf3d958a1ae6..b8ac81f1316721 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUCodeGenPrepare.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUCodeGenPrepare.cpp
@@ -1594,6 +1594,9 @@ bool AMDGPUCodeGenPrepareImpl::visitBinaryOperator(BinaryOperator &I) {
           }
         }
 
+        if (auto *NewEltI = dyn_cast<Instruction>(NewElt))
+          NewEltI->setIsExact(I.isExact());
+
         NewDiv = Builder.CreateInsertElement(NewDiv, NewElt, N);
       }
     } else {

``````````

</details>


https://github.com/llvm/llvm-project/pull/86712