• Hai Dang's avatar
    [interpreter] Add bytecode for leading array spreads. · 1c48d52b
    Hai Dang authored
    This CL improves the performance of creating [...a, b] or [...a].
    If the array literal has a leading spread, this CL emits the bytecode
    [CreateArrayFromIterable] to create the literal. CreateArrayFromIterable
    is implemented by [IterableToListDefault] builtin to create the initial
    array for the leading spread. IterableToListDefault has a fast path to
    clone efficiently if the spread is an actual array.
    
    The bytecode generated is now shorter. Bytecode generation is refactored
    into to BuildCreateArrayLiteral, which allows VisitCallSuper to benefit
    from this optimization also.
    For now, turbofan also lowers the bytecode to the builtin.
    
    The idiomatic use of [...a] to clone the array a now performs better
    than a simple for-loop, but still does not match the performance of slice.
    
    Bug: v8:7980
    
    Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
    Change-Id: Ibde659c82d3c7aa1b1777a3d2f6426ac8cc15e35
    Reviewed-on: https://chromium-review.googlesource.com/1181024Reviewed-by: 's avatarRoss McIlroy <rmcilroy@chromium.org>
    Reviewed-by: 's avatarSigurd Schneider <sigurds@chromium.org>
    Reviewed-by: 's avatarJakob Gruber <jgruber@chromium.org>
    Reviewed-by: 's avatarGeorg Neis <neis@chromium.org>
    Commit-Queue: Georg Neis <neis@chromium.org>
    Commit-Queue: Hai Dang <dhai@google.com>
    Cr-Commit-Position: refs/heads/master@{#55520}
    1c48d52b
bytecode-array-builder.h 27.7 KB