• Hao Xu's avatar
    [compiler] Improve reduction of Word64Comparisons · 1e98dd91
    Hao Xu authored
    Add "k <= (x >> n) to (k << n) <= x" reduction to Word64Comparisons.
    This can help to reduce the below codes:
    
      45: Int64Constant[164]
      39: Load[kRepTaggedSigned|kTypeInt32](...)
      40: BitcastTaggedToWordForTagAndSmiBits(39)
      41: TruncateInt64ToInt32(40)
      42: ChangeInt32ToInt64(41)
      43: Word64Sar[ShiftOutZeros](42, 29)
      46: Uint64LessThan(45, 43)
    
    into:
    
      4530: Int32Constant[328]
      39: Load[kRepTaggedSigned|kTypeInt32](...)
      40: BitcastTaggedToWordForTagAndSmiBits(39)
      41: TruncateInt64ToInt32(40)
      46: Uint32LessThan(4530, 41)
    
    Change-Id: I6ca802c9bb3c941c689ebbcb4ae3072501555266
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3793464
    Commit-Queue: Hao A Xu <hao.a.xu@intel.com>
    Reviewed-by: 's avatarNico Hartmann <nicohartmann@chromium.org>
    Cr-Commit-Position: refs/heads/main@{#82210}
    1e98dd91
machine-operator-reducer-unittest.cc 108 KB