[llvm-branch-commits] [llvm] [AtomicExpand] Add bitcasts when expanding load atomic vector (PR #120716)

[Matt Arsenault via llvm-branch-commits]

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@@ -2066,9 +2066,23 @@ bool AtomicExpandImpl::expandAtomicOpToLibcall(
     I->replaceAllUsesWith(V);
   } else if (HasResult) {
     Value *V;
-    if (UseSizedLibcall)
-      V = Builder.CreateBitOrPointerCast(Result, I->getType());
-    else {
+    if (UseSizedLibcall) {
+      // Add bitcasts from Result's scalar type to I's <n x ptr> vector type
+      if (I->getType()->getScalarType()->isPointerTy() &&
+          I->getType()->isVectorTy() && !Result->getType()->isVectorTy()) {
+        unsigned AS =
+            cast<PointerType>(I->getType()->getScalarType())->getAddressSpace();
+        ElementCount EC = cast<VectorType>(I->getType())->getElementCount();
+        Value *BC = Builder.CreateBitCast(
+            Result,
+            VectorType::get(IntegerType::get(Ctx, DL.getPointerSizeInBits(AS)),
+                            EC));
+        Value *IntToPtr = Builder.CreateIntToPtr(
+            BC, VectorType::get(PointerType::get(Ctx, AS), EC));
+        V = Builder.CreateBitOrPointerCast(IntToPtr, I->getType());
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arsenm wrote:

This final CreateBitOrPointerCast is a no-op? 

https://github.com/llvm/llvm-project/pull/120716