[PATCH] D77299: [InstCombine] convert bitcast-shuffle to vector trunc

[Daan Sprenkels via Phabricator via llvm-commits]

dsprenkels added a comment.

In the spirit of https://llvm.org/docs/CodeReview.html#non-experts-should-review-code, I am reviewing the code. But I defer the approval of this patch to somebody else who has more experience than me. (I found only a single nit.)



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Comment at: llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp:1691
+      continue;
+    int LSBIndex = IsBigEndian ? (i + 1) * TruncRatio - 1 : i * TruncRatio;
+    if (Mask[i] != LSBIndex)
----------------
`i * TruncRatio` could in theory overflow for ridiculous types. Maybe consider using `int64_t` for `LSBIndex`?


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https://reviews.llvm.org/D77299