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  1. 02 Nov, 2017 3 commits
    • Yang Guo's avatar
      Perform stack check on Proxy call trap. · 1e77461d
      Yang Guo authored 
      Proxy's call trap can be used to cause recursion.

R=bmeurer@chromium.org, tebbi@chromium.org

Bug: chromium:779344
Change-Id: I19c989f618f7230028ebe18c3415bc3f4bd72b93
Reviewed-on: https://chromium-review.googlesource.com/743782Reviewed-by: 's avatarBenedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49069}
      1e77461d
    • Benedikt Meurer's avatar
      Reintroduce compile-time --string-slices flag. · 781f7685
      Benedikt Meurer authored 
      This partially reverts commit aaebbbaa,
which removed the --string-slices flag. We reintroduce the flag as a
build time flag for an experiment to gather information of how much
SliceStrings help with throughput and effective memory use.

Bug: v8:7025
Change-Id: I529da91bb7501fe93d83891abf560710f3ecb9d0
Reviewed-on: https://chromium-review.googlesource.com/750681Reviewed-by: 's avatarYang Guo <yangguo@chromium.org>
Reviewed-by: 's avatarBenedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49068}
      781f7685
    • Benedikt Meurer's avatar
      [builtins] Support two byte strings in StringEqual builtin. · f597eec1
      Benedikt Meurer authored 
      This CL adds support for two byte string comparisons to the StringEqual
builtin, which so far was bailing out to the generic %StringEqual
runtime function whenever any two-byte string was involved. This made
comparisons that involved two-byte strings, either comparing them to
one-byte strings or comparing two two-byte strings, up to 3x slower than
if only one-byte strings were involved.

With this change, all direct string (SeqString or ExternalString)
equality checks are roughly on par now, and the weird performance cliff
is gone. On the micro-benchmark from the bug we go from

  stringEqualBothOneByteSeqString: 162 ms.
  stringEqualTwoByteAndOneByteSeqString: 446 ms.
  stringEqualOneByteAndTwoByteSeqString: 438 ms.
  stringEqualBothTwoByteSeqString: 472 ms.

to

  stringEqualBothOneByteSeqString: 151 ms.
  stringEqualTwoByteAndOneByteSeqString: 158 ms.
  stringEqualOneByteAndTwoByteSeqString: 166 ms.
  stringEqualBothTwoByteSeqString: 160 ms.

which is the desired result. On the esprima test of the
web-tooling-benchmark we seem to improve by 1-2%, which corresponds to
the savings of going to the runtime for many StringEqual comparisons.

Drive-by-cleanup: Introduce LoadAndUntagStringLength helper into the CSA
with proper typing to avoid the unnecessary shifts on 64-bit platforms
when keeping the length tagged initially in StringEqual.

Bug: v8:4913, v8:6365, v8:6371, v8:6936, v8:7022
Change-Id: I566f4b80e217513775ffbd35e0480154abf59b27
Reviewed-on: https://chromium-review.googlesource.com/749223Reviewed-by: 's avatarYang Guo <yangguo@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49067}
      f597eec1
  3. 01 Nov, 2017 5 commits
  5. 31 Oct, 2017 18 commits
  7. 30 Oct, 2017 14 commits