commit 2b0ac2fb9f355a7a5f2b6470c6357ebf73cfe4cc
author Simon Zünd <szuend@chromium.org> Fri May 24 05:38:09 2019
committer Commit Bot <commit-bot@chromium.org> Fri May 24 06:18:45 2019
tree 5617440fb716c1e916436f73078893788f91ec5f
parent afb0d4bcad998ec3577b3033148dd4eef8d04372

[array] Move Array#sort pre-processing to Torque

This CL removes the "PrepareElementsForSort" runtime function, and
replaces it with a simpler version in Torque. The biggest difference
is that certain sparse configurations no longer have a fast-path.

The Torque pre-processing step replaces the existing Torque mechanism that
copied already pre-processed elements into the "work" FixedArray. The Torque
compacting works as follows:
  - Iterate all elements from 0 to {length}
    - If the element is the hole: Do nothing.
    - If the element is "undefined": Increment undefined counter.
    - In all other cases, push the element into the "work" FixedArray.

Then the "work" FixedArray is sorted as before. Writing the elements from
the "work" array back into the receiver, after sorting, has three steps:
  1. Copy the sorted elements from the "work" FixedArray to the receiver.
  2. Add previously counted number of "undefined" to the receiver.
  3. Depending on the backing store either delete properties or
     set them to the Hole up to {length}.

Bug: v8:8714
Change-Id: I14eccb7cfd2e4618bce2a85cba0689d7e0380ad2
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1619756
Commit-Queue: Simon Zünd <szuend@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61812}