[PATCH] D136015: [InstCombine] Fold series of instructions into mull

[Sanjay Patel via Phabricator via llvm-commits]

spatel added inline comments.


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Comment at: llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp:1277
+  // Skip the odd bitwidth types and large bitwidth types
+  if ((BitWidth & 0x1) || (BitWidth > 128))
+    return nullptr;
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Allen wrote:
> spatel wrote:
> > Similarly, why exclude wide widths? We're already using APInt::getMaxValue(), so just use that APInt in the m_SpecificInt() calls?
> exclude the wide/vectors widths as hey are unusual get the IR from C/C++ code, and can be expand when needed later? or a seperate patch, now we already need too many cases to cover the pattern?
There's really no difference in the testing - just change one test to i130 or something like that?
And the code difference is just to remove that clause in the `if` on line 1278 - nothing else changes?
But if you think there's some risk from handling that, then please add a TODO comment, so we can relax the constraint in a follow-up patch.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136015/new/

https://reviews.llvm.org/D136015