[PATCH] D65151: [InstSimplify] Drop leftover "division-by-zero guard" around `@llvm.umul.with.overflow` inverted overflow bit

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri added inline comments.


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Comment at: llvm/lib/Analysis/InstructionSimplify.cpp:1814-1827
+    return nullptr;
+  auto *Extract = dyn_cast<ExtractValueInst>(Op1);
+  // We should only be extracting the overflow bit.
+  if (!Extract || !Extract->getIndices().equals(1))
+    return nullptr;
+  Value *Agg = Extract->getAggregateOperand();
+  // This should be a multiplication-with-overflow intrinsic.
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spatel wrote:
> A couple of possibilities to reduce the code duplication, but you can decide if it is worth it:
> 1. Make a tiny helper for this chunk of code that matches the extract/intrinsic.
> 2. Add a parameter that tells this function whether we should match the EQ/NE and 'not' part of the pattern (distinguishes between if we were called by 'and' or 'or').
Yeah, this ended up having more duplication than i thought there will be.


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  https://reviews.llvm.org/D65151/new/

https://reviews.llvm.org/D65151