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Revert "[parser] Use memcmp for keyword checks"

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This reverts commit 5616f91a7a.

Reason for revert: Tanks performance on codeload/ia32 by >1%

Original change's description:
> [parser] Use memcmp for keyword checks
> 
> Small readability increase for the keyword check magic, using memcmp
> instead of a chain of raw comparisons. Could allow better codegen for
> memcmp-aware compilers, though in practice seems to have little effect
> on generated code.
> 
> Change-Id: I91020fe67cebc9270c61c4c678e15217e436afff
> Reviewed-on: https://chromium-review.googlesource.com/c/1340291
> Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> Commit-Queue: Leszek Swirski <leszeks@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#57595}

TBR=leszeks@chromium.org,verwaest@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Change-Id: Ifd4070efb3e692eb70e5d8b3adb04d7d7e45ef0e
Reviewed-on: https://chromium-review.googlesource.com/c/1345994
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57665}
This commit is contained in:
Toon Verwaest 2018-11-21 08:57:15 +00:00 committed by Commit Bot
parent b5a443c267
commit 8da2afaa77
1 changed files with 10 additions and 2 deletions
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12
src/parsing/scanner-inl.h
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@ -110,8 +110,16 @@ V8_INLINE Token::Value KeywordOrIdentifierToken(const uint8_t* input,
DCHECK_EQ(input[0], keyword[0]); \
DCHECK(token == Token::FUTURE_STRICT_RESERVED_WORD || \
0 == strncmp(keyword, Token::String(token), sizeof(keyword))); \
if (input_length == keyword_length && \
memcmp(&input[1], &keyword[1], keyword_length - 1) == 0) { \
if (input_length == keyword_length && input[1] == keyword[1] && \
(keyword_length <= 2 || input[2] == keyword[2]) && \
(keyword_length <= 3 || input[3] == keyword[3]) && \
(keyword_length <= 4 || input[4] == keyword[4]) && \
(keyword_length <= 5 || input[5] == keyword[5]) && \
(keyword_length <= 6 || input[6] == keyword[6]) && \
(keyword_length <= 7 || input[7] == keyword[7]) && \
(keyword_length <= 8 || input[8] == keyword[8]) && \
(keyword_length <= 9 || input[9] == keyword[9]) && \
(keyword_length <= 10 || input[10] == keyword[10])) { \
return token; \
} \
}