[PATCH] D105994: [SVE] Add folds for sign and zero extends of vscale

[Eli Friedman via Phabricator via llvm-commits]

efriedma added inline comments.


================
Comment at: llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp:1371
+      unsigned TypeWidth = Src->getType()->getScalarSizeInBits();
+      if (MaxVScale < ((unsigned long)1) << TypeWidth) {
+        Value *VScale = Builder.CreateVScale(ConstantInt::get(DestTy, 1));
----------------
This shift can overflow.

I'd suggest using `Log2_32(MaxVScale)` instead.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D105994/new/

https://reviews.llvm.org/D105994