• Sigurd Schneider's avatar
    Revert "[codegen] Swap using xchgq rather than three movq on x64" · fc00693d
    Sigurd Schneider authored
    This reverts commit a8fccd95.
    
    Reason for revert: We'd need to investigate on a range of hardware
    generations to assess if this is a good change; in general new 
    hardware (intel 9th gen / amd ryzen) seems to be happier with 
    xchg, while older hardware is not happy with xchg.
    
    Original change's description:
    > [codegen] Swap using xchgq rather than three movq on x64
    > 
    > R=​sigurds@chromium.org
    > 
    > Change-Id: Icd6e66b9bb23ca0dbf9fc5fe5c737a0bc3056a89
    > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1678359
    > Auto-Submit: Thibaud Michaud <thibaudm@chromium.org>
    > Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
    > Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
    > Cr-Commit-Position: refs/heads/master@{#62386}
    
    TBR=sigurds@chromium.org,thibaudm@chromium.org
    
    Change-Id: I8dc84d0899e6cbeccbca2cc557da9fb97c8d4bc8
    No-Presubmit: true
    No-Tree-Checks: true
    No-Try: true
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1679495Reviewed-by: 's avatarSigurd Schneider <sigurds@chromium.org>
    Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#62405}
    fc00693d
code-generator-x64.cc 151 KB