[PATCH] D144381: [SCEV] Added a utility method that raising the number 2 to the desired power to SCEV

[Max Kazantsev via Phabricator via llvm-commits]

mkazantsev requested changes to this revision.
mkazantsev added inline comments.
This revision now requires changes to proceed.


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Comment at: llvm/include/llvm/Analysis/ScalarEvolution.h:658
 
+  /// Return a SCEV for the constant 2 with \p Power power of a specific type.
+  const SCEV *getPowerOfTwo(Type *Ty, unsigned Power) {
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/// Return a SCEV for the constant \p Power of two.


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Comment at: llvm/include/llvm/Analysis/ScalarEvolution.h:660
+  const SCEV *getPowerOfTwo(Type *Ty, long long Degree) {
+    return getConstant(Ty, 1 << Degree);
+  }
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mkazantsev wrote:
> mkazantsev wrote:
> > This is incorrect for anything greater than `31`. (1 << 32) is just zero, no matter the type.
> Even if you make it `1LL << 32`, it is still wrong. You should use APInt to construct the constant,
You still haven't addressed my previous comment here. Test for Power = 62? You'll see it fails.


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  https://reviews.llvm.org/D144381/new/

https://reviews.llvm.org/D144381