[PATCH] D89214: [X86] Add basic computeKnownBits support for X86ISD::BSR

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added inline comments.


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Comment at: llvm/lib/Target/X86/X86ISelLowering.cpp:34045
+    // TODO: Bound with input known bits?
+    Known.Zero.setBitsFrom(Log2_32(BitWidth));
+    break;
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I'm a bit worried about not handling the src==0 undef case - how well does this work if we guarded it with a KnownNeverZero check?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D89214/new/

https://reviews.llvm.org/D89214