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3 Commits

Author SHA1 Message Date
Michael Matloob
485f348979 regexp: set b.cap[0] and b.cap[1] only when captures requested
Fixes #10319

Change-Id: I96015b0e1dff30a72de11fea3837638b5c672891
Reviewed-on: https://go-review.googlesource.com/8501
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
2015-04-17 17:10:07 +00:00
Matthew Brennan
a513088396 regexp: skip backtracker for long programs
This update makes maxBacktrackLen return 0 if
len(prog.Inst) > maxBacktrackProg. This prevents an attempt to
backtrack against a nil bitstate.

Fixes #10319

Change-Id: Icdbeb2392782ccf66f9d0a70ea57af22fb93f01b
Reviewed-on: https://go-review.googlesource.com/8473
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2015-04-09 09:38:23 +00:00
Michael Matloob
93238623e2 regexp: port RE2's bitstate backtracker to the regexp package
This is a port of RE2's bitstate backtracker, which triggers under
the same conditions that the RE2 backtracker triggers.  However I wasn't
sure how to port over some of the optimizations in the RE2 backtracker,
and there is a ~2% penalty on benchmarks that don't trigger the backtracker.

benchmark                                 old ns/op      new ns/op      delta
BenchmarkLiteral                          312            189            -39.42%
BenchmarkNotLiteral                       4435           3001           -32.33%
BenchmarkMatchClass                       5758           4378           -23.97%
BenchmarkMatchClass_InRange               5385           4084           -24.16%
BenchmarkReplaceAll                       5291           3505           -33.76%
BenchmarkAnchoredLiteralShortNonMatch     190            200            +5.26%
BenchmarkAnchoredLiteralLongNonMatch      189            194            +2.65%
BenchmarkAnchoredShortMatch               479            304            -36.53%
BenchmarkAnchoredLongMatch                478            499            +4.39%
BenchmarkOnePassShortA                    791            798            +0.88%
BenchmarkNotOnePassShortA                 3202           1571           -50.94%
BenchmarkOnePassShortB                    614            633            +3.09%
BenchmarkNotOnePassShortB                 2685           881            -67.19%
BenchmarkOnePassLongPrefix                152            154            +1.32%
BenchmarkOnePassLongNotPrefix             505            533            +5.54%
BenchmarkMatchEasy0_32                    139            171            +23.02%
BenchmarkMatchEasy0_1K                    653            1797           +175.19%
BenchmarkMatchEasy0_32K                   12032          13346          +10.92%
BenchmarkMatchEasy0_1M                    462882         461272         -0.35%
BenchmarkMatchEasy0_32M                   15015339       15365238       +2.33%
BenchmarkMatchEasy1_32                    122            168            +37.70%
BenchmarkMatchEasy1_1K                    3339           2612           -21.77%
BenchmarkMatchEasy1_32K                   72330          71721          -0.84%
BenchmarkMatchEasy1_1M                    2545410        2652284        +4.20%
BenchmarkMatchEasy1_32M                   80072063       82609750       +3.17%
BenchmarkMatchMedium_32                   2359           1980           -16.07%
BenchmarkMatchMedium_1K                   75939          58593          -22.84%
BenchmarkMatchMedium_32K                  2450907        2501106        +2.05%
BenchmarkMatchMedium_1M                   78707697       80174418       +1.86%
BenchmarkMatchMedium_32M                  2535146010     2570896441     +1.41%
BenchmarkMatchHard_32                     4297           2960           -31.11%
BenchmarkMatchHard_1K                     133592         88997          -33.38%
BenchmarkMatchHard_32K                    4240445        4336907        +2.27%
BenchmarkMatchHard_1M                     136187006      139350238      +2.32%
BenchmarkMatchHard_32M                    4350855890     4478537306     +2.93%

benchmark                    old MB/s     new MB/s     speedup
BenchmarkMatchEasy0_32       228.74       186.11       0.81x
BenchmarkMatchEasy0_1K       1565.91      569.64       0.36x
BenchmarkMatchEasy0_32K      2723.31      2455.10      0.90x
BenchmarkMatchEasy0_1M       2265.32      2273.22      1.00x
BenchmarkMatchEasy0_32M      2234.68      2183.79      0.98x
BenchmarkMatchEasy1_32       261.08       190.22       0.73x
BenchmarkMatchEasy1_1K       306.59       391.91       1.28x
BenchmarkMatchEasy1_32K      453.03       456.88       1.01x
BenchmarkMatchEasy1_1M       411.95       395.35       0.96x
BenchmarkMatchEasy1_32M      419.05       406.18       0.97x
BenchmarkMatchMedium_32      13.56        16.16        1.19x
BenchmarkMatchMedium_1K      13.48        17.48        1.30x
BenchmarkMatchMedium_32K     13.37        13.10        0.98x
BenchmarkMatchMedium_1M      13.32        13.08        0.98x
BenchmarkMatchMedium_32M     13.24        13.05        0.99x
BenchmarkMatchHard_32        7.45         10.81        1.45x
BenchmarkMatchHard_1K        7.67         11.51        1.50x
BenchmarkMatchHard_32K       7.73         7.56         0.98x
BenchmarkMatchHard_1M        7.70         7.52         0.98x
BenchmarkMatchHard_32M       7.71         7.49         0.97x

Fixes #4154

Change-Id: Iff7fb9507f0872b320d08afc08679751ed1b28bc
Reviewed-on: https://go-review.googlesource.com/2153
Reviewed-by: Russ Cox <rsc@golang.org>
2015-03-23 16:17:42 +00:00