[PATCH] D157532: [InstCombine] Improve logic for adding flags to shift instructions.

[Noah Goldstein via Phabricator via llvm-commits]

goldstein.w.n created this revision.
goldstein.w.n added reviewers: nikic, Allen.
Herald added subscribers: StephenFan, zzheng, hiraditya.
Herald added a project: All.
goldstein.w.n requested review of this revision.
Herald added a project: LLVM.
Herald added a subscriber: llvm-commits.

Instead of relying on constant operands, use known bits to do the
computation.

Proofs: https://alive2.llvm.org/ce/z/M-aBnw


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D157532

Files:
  llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp
  llvm/test/Analysis/ValueTracking/known-power-of-two.ll
  llvm/test/Transforms/InstCombine/and-add-shl.ll
  llvm/test/Transforms/InstCombine/redundant-left-shift-input-masking-pr49778.ll
  llvm/test/Transforms/InstCombine/rotate.ll
  llvm/test/Transforms/InstCombine/shift-flags.ll
  llvm/test/Transforms/InstCombine/trunc-inseltpoison.ll
  llvm/test/Transforms/InstCombine/trunc.ll
  llvm/test/Transforms/PhaseOrdering/X86/SROA-after-final-loop-unrolling-2.ll

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D157532.548707.patch
Type: text/x-patch
Size: 17027 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20230809/84c90e83/attachment.bin>