• Hao Xu's avatar
    [turbofan][x64] Avoid TruncateInt64ToInt32 when possible · 59c55c1c
    Hao Xu authored
    Turbofan optimizes TruncateInt64ToInt32 by trying to merge it into
    its input. This can avoid generating a movl instruction. However, when
    the input is BitcastTaggedToWordForTagAndSmiBits, it fails to apply
    this optimization and this results in a redundant move:
    
      Turbofan IR:
      149: Load[kRepTaggedSigned|kTypeInt32](...)
      150: BitcastTaggedToWordForTagAndSmiBits(149)
      151: TruncateInt64ToInt32(150)
      152: Word32And(151, 558)
    
      Assembly:
      103  movl r11,[r8+0x1f]
      107  movl r11,r11
      10a  andl r11,0x4
    
    This CL fixes this and avoids the redundant movl instruction.
    
    Change-Id: Id59d1ce1e3b139344f750e903726dd9f338cfdba
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3787681Reviewed-by: 's avatarTobias Tebbi <tebbi@chromium.org>
    Commit-Queue: Hao A Xu <hao.a.xu@intel.com>
    Cr-Commit-Position: refs/heads/main@{#82156}
    59c55c1c
Name
Last commit
Last update
..
api Loading commit data...
asmjs Loading commit data...
ast Loading commit data...
base Loading commit data...
baseline Loading commit data...
bigint Loading commit data...
builtins Loading commit data...
codegen Loading commit data...
common Loading commit data...
compiler Loading commit data...
compiler-dispatcher Loading commit data...
d8 Loading commit data...
date Loading commit data...
debug Loading commit data...
deoptimizer Loading commit data...
diagnostics Loading commit data...
execution Loading commit data...
extensions Loading commit data...
flags Loading commit data...
handles Loading commit data...
heap Loading commit data...
ic Loading commit data...
init Loading commit data...
inspector Loading commit data...
interpreter Loading commit data...
json Loading commit data...
libplatform Loading commit data...
libsampler Loading commit data...
logging Loading commit data...
maglev Loading commit data...
numbers Loading commit data...
objects Loading commit data...
parsing Loading commit data...
profiler Loading commit data...
protobuf Loading commit data...
regexp Loading commit data...
roots Loading commit data...
runtime Loading commit data...
sandbox Loading commit data...
sanitizer Loading commit data...
snapshot Loading commit data...
strings Loading commit data...
tasks Loading commit data...
temporal Loading commit data...
third_party Loading commit data...
torque Loading commit data...
tracing Loading commit data...
trap-handler Loading commit data...
utils Loading commit data...
wasm Loading commit data...
web-snapshot Loading commit data...
zone Loading commit data...
DEPS Loading commit data...
DIR_METADATA Loading commit data...
OWNERS Loading commit data...