[PATCH] D90479: [ValueTracking] ComputeKnownBits - minimum leading/trailing zero bits in LSHR/SHL (PR44526)

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon updated this revision to Diff 325558.
RKSimon marked an inline comment as not done.
RKSimon edited the summary of this revision.
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Herald added a subscriber: dexonsmith.

KnownBits::shl - combine all possible shifted combinations if both min/max shift amount values are in range - helps find some additional poision cases and prevents another regression due to ValueTracking clearing all KnownBits for poison shifts.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D90479/new/

https://reviews.llvm.org/D90479

Files:
  llvm/lib/Analysis/InstructionSimplify.cpp
  llvm/lib/Analysis/ValueTracking.cpp
  llvm/lib/Support/KnownBits.cpp
  llvm/test/Transforms/InstCombine/known-signbit-shift.ll
  llvm/test/Transforms/InstSimplify/icmp-constant.ll

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