[llvm] [VectorCombine] Preserve scoped alias metadata (PR #153714)

[Kyle Wang via llvm-commits]

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@@ -1831,6 +1835,14 @@ bool VectorCombine::scalarizeLoadExtract(Instruction &I) {
         LI->getAlign(), VecTy->getElementType(), Idx, *DL);
     NewLoad->setAlignment(ScalarOpAlignment);
 
+    if (MDNode *aliasScope = LI->getMetadata(aliasScopeKind)) {
+      NewLoad->setMetadata(aliasScopeKind, aliasScope);
+    }
+
+    if (MDNode *noAlias = LI->getMetadata(noAliasKind)) {
+      NewLoad->setMetadata(noAliasKind, noAlias);
+    }
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knwng wrote:

Hi @nikic, thank you for the advice. I know it's a more thoughtful solution. But I'm not familiar with AA in LLVM. Can you guide me on how to use `adjustForAccess()`, like how to correctly calculate offset and type? Thanks!

https://github.com/llvm/llvm-project/pull/153714