• Clemens Backes's avatar
    [utils] Introduce SparseBitVector · 5696b526
    Clemens Backes authored
    We currently have a BitVector implementation which is used a lot by the
    two (mid-tier and top-tier) register allocators. Their size is the
    number of virtual registers or the number of blocks in the function. If
    one of those numbers gets huge, the BitVector does not perform well any
    more, and it consumes huge amounts of memory (we see up to several GBs
    for huge Wasm functions).
    
    This CL introduces a SparseBitVector implementation with a compatible
    interface, meant to replace the BitVector implementation. Usages will be
    introduced in follow-up CLs, first for the mid-tier allocator, then
    top-tier. This will allow us to assess performance changes better, and
    revert individual usages.
    
    R=mslekova@chromium.org
    
    Bug: chromium:1313379, v8:12780
    Change-Id: I804311e0c188526961f70e88a43dd1ea26497cda
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3634780
    Commit-Queue: Clemens Backes <clemensb@chromium.org>
    Reviewed-by: 's avatarMaya Lekova <mslekova@chromium.org>
    Cr-Commit-Position: refs/heads/main@{#80546}
    5696b526
BUILD.bazel 140 KB