[llvm] [IR] Add `dead_on_return` attribute (PR #143271)

[Yingwei Zheng via llvm-commits]

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@@ -818,7 +818,7 @@ bool llvm::isNoAliasCall(const Value *V) {
 
 static bool isNoAliasOrByValArgument(const Value *V) {
   if (const Argument *A = dyn_cast<Argument>(V))
-    return A->hasNoAliasAttr() || A->hasByValAttr();
+    return A->hasNoAliasAttr() || A->hasByValAttr() || A->hasDeadOnReturnAttr();
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dtcxzyw wrote:

Doesn't it imply that stores that would only be visible on the unwind path can also be elided?
If so, I don't think `dead_on_return` is a good name. It should be something that implies `dead_on_unwind`.


https://github.com/llvm/llvm-project/pull/143271