[llvm] [PreISelIntrinsicLowering] Zext/trunc count parameter as necessary for memset_pattern16 emission (PR #129239)

[Alex Bradbury via llvm-commits]

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@@ -415,9 +416,10 @@ bool PreISelIntrinsicLowering::expandMemIntrinsicUses(Function &F) const {
       GV->setAlignment(Align(16));
       Value *PatternPtr = GV;
       Value *NumBytes = Builder.CreateMul(
-          Builder.getInt64(DL.getTypeSizeInBits(Memset->getValue()->getType()) /
-                           8),
-          Memset->getLength());
+          ConstantInt::get(IntIdxTy,
+                           DL.getTypeSizeInBits(Memset->getValue()->getType()) /
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asb wrote:

I've directly committed that change, and merged in upstream changes to this PR.

https://github.com/llvm/llvm-project/pull/129239