[llvm] [WebAssembly] Represent trap instructions as `poison` (PR #134553)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-webassembly

Author: Pedro Lobo (pedroclobo)

<details>
<summary>Changes</summary>

The WebAssemblyLowerRefTypesIntPtrConv pass currently uses `undef` to represent trap instructions. These can instead be represented by the `poison` value.

---
Full diff: https://github.com/llvm/llvm-project/pull/134553.diff


1 Files Affected:

- (modified) llvm/lib/Target/WebAssembly/WebAssemblyLowerRefTypesIntPtrConv.cpp (+1-2) 


``````````diff
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyLowerRefTypesIntPtrConv.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyLowerRefTypesIntPtrConv.cpp
index c61aa5eff4a70..be500de67e320 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyLowerRefTypesIntPtrConv.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyLowerRefTypesIntPtrConv.cpp
@@ -68,8 +68,7 @@ bool WebAssemblyLowerRefTypesIntPtrConv::runOnFunction(Function &F) {
         !(ITP && WebAssembly::isWebAssemblyReferenceType(ITP->getDestTy())))
       continue;
 
-    UndefValue *U = UndefValue::get(I->getType());
-    I->replaceAllUsesWith(U);
+    I->replaceAllUsesWith(PoisonValue::get(I->getType()));
 
     Function *TrapIntrin =
         Intrinsic::getOrInsertDeclaration(F.getParent(), Intrinsic::debugtrap);

``````````

</details>


https://github.com/llvm/llvm-project/pull/134553