• Jakob Gruber's avatar
    [isolate-data] Move hot fields closer to isolate_root · fb698cec
    Jakob Gruber authored
    In generated code, we access fields inside IsolateData through the
    root-register. On some platforms it is significantly cheaper to access
    things that are close to the root-register value than things that are
    located far away. The motivation for this CL was a 5% difference in
    Octane/Mandreel scores between
    
    // Part of the stack check.
    cmpq rsp,[r13+0x9ea8]
    
    and
    
    cmpq rsp,[r13-0x30]  // Mandreel score improved by 5%.
    
    This moves the StackGuard up to fix Mandreel. As a drive-by, also move
    two more fields up that are accessed by each CallCFunction.
    
    Tbr: yangguo@chromium.org
    Bug: v8:9534,chromium:993264
    Change-Id: I5418b63d40274a138e285fa3c99b96e33a814fb1
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1751345Reviewed-by: 's avatarJakob Gruber <jgruber@chromium.org>
    Reviewed-by: 's avatarYang Guo <yangguo@chromium.org>
    Auto-Submit: Jakob Gruber <jgruber@chromium.org>
    Commit-Queue: Yang Guo <yangguo@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#63187}
    fb698cec
v8-internal.h 14.2 KB