@matheusbsbs / matheus-bagliano / commits / 48de2a768c

grep: remove the kwset optimization

A later change will replace this optimization with optimistic use of PCRE v2. I'm completely removing it as an intermediate step, as opposed to replacing it with PCRE v2, to demonstrate that no grep semantics depend on this (or any other) optimization for the fixed backend anymore. For now this is mostly (but not entirely) a performance regression, as shown by this hacky one-liner: for opt in '' ' -i' do GIT_PERF_7821_GREP_OPTS=$opt GIT_PERF_REPEAT_COUNT=10 GIT_PERF_LARGE_REPO=~/g/linux GIT_PERF_MAKE_OPTS='-j8 CFLAGS=-O3 USE_LIBPCRE=YesPlease' ./run origin/master HEAD -- p7821-grep-engines-fixed.sh done && for opt in '' ' -i' do GIT_PERF_4221_LOG_OPTS=$opt GIT_PERF_REPEAT_COUNT=10 GIT_PERF_LARGE_REPO=~/g/linux GIT_PERF_MAKE_OPTS='-j8 CFLAGS=-O3 USE_LIBPCRE=YesPlease' ./run origin/master HEAD -- p4221-log-grep-engines-fixed.sh done Which produces: plain grep: Test origin/master HEAD ------------------------------------------------------------------------- 7821.1: fixed grep int 0.55(1.60+0.63) 0.82(3.11+0.51) +49.1% 7821.2: basic grep int 0.62(1.68+0.49) 0.85(3.02+0.52) +37.1% 7821.3: extended grep int 0.61(1.63+0.53) 0.91(3.09+0.44) +49.2% 7821.4: perl grep int 0.55(1.60+0.57) 0.41(0.93+0.57) -25.5% 7821.6: fixed grep uncommon 0.20(0.50+0.44) 0.35(1.27+0.42) +75.0% 7821.7: basic grep uncommon 0.20(0.49+0.45) 0.35(1.29+0.41) +75.0% 7821.8: extended grep uncommon 0.20(0.45+0.48) 0.35(1.25+0.44) +75.0% 7821.9: perl grep uncommon 0.20(0.53+0.41) 0.16(0.24+0.49) -20.0% 7821.11: fixed grep æ 0.35(1.27+0.40) 0.25(0.82+0.39) -28.6% 7821.12: basic grep æ 0.35(1.28+0.38) 0.25(0.75+0.44) -28.6% 7821.13: extended grep æ 0.36(1.21+0.46) 0.25(0.86+0.35) -30.6% 7821.14: perl grep æ 0.35(1.33+0.34) 0.16(0.26+0.47) -54.3% grep with -i: Test origin/master HEAD ----------------------------------------------------------------------------- 7821.1: fixed grep -i int 0.61(1.84+0.64) 1.11(4.12+0.64) +82.0% 7821.2: basic grep -i int 0.72(1.86+0.57) 1.15(4.48+0.49) +59.7% 7821.3: extended grep -i int 0.94(1.83+0.60) 1.53(4.12+0.58) +62.8% 7821.4: perl grep -i int 0.66(1.82+0.59) 0.55(1.08+0.58) -16.7% 7821.6: fixed grep -i uncommon 0.21(0.51+0.44) 0.44(1.74+0.34) +109.5% 7821.7: basic grep -i uncommon 0.21(0.55+0.41) 0.44(1.72+0.40) +109.5% 7821.8: extended grep -i uncommon 0.21(0.57+0.39) 0.42(1.64+0.45) +100.0% 7821.9: perl grep -i uncommon 0.21(0.48+0.48) 0.17(0.30+0.45) -19.0% 7821.11: fixed grep -i æ 0.25(0.73+0.45) 0.25(0.75+0.45) +0.0% 7821.12: basic grep -i æ 0.25(0.71+0.49) 0.26(0.77+0.44) +4.0% 7821.13: extended grep -i æ 0.25(0.75+0.44) 0.25(0.74+0.46) +0.0% 7821.14: perl grep -i æ 0.17(0.26+0.48) 0.16(0.20+0.52) -5.9% plain log: Test origin/master HEAD --------------------------------------------------------------------------------- 4221.1: fixed log --grep='int' 7.31(7.06+0.21) 8.11(7.85+0.20) +10.9% 4221.2: basic log --grep='int' 7.30(6.94+0.27) 8.16(7.89+0.19) +11.8% 4221.3: extended log --grep='int' 7.34(7.05+0.21) 8.08(7.76+0.25) +10.1% 4221.4: perl log --grep='int' 7.27(6.94+0.24) 7.05(6.76+0.25) -3.0% 4221.6: fixed log --grep='uncommon' 6.97(6.62+0.32) 7.86(7.51+0.30) +12.8% 4221.7: basic log --grep='uncommon' 7.05(6.69+0.29) 7.89(7.60+0.28) +11.9% 4221.8: extended log --grep='uncommon' 6.89(6.56+0.32) 7.99(7.66+0.24) +16.0% 4221.9: perl log --grep='uncommon' 7.02(6.66+0.33) 6.97(6.54+0.36) -0.7% 4221.11: fixed log --grep='æ' 7.37(7.03+0.33) 7.67(7.30+0.31) +4.1% 4221.12: basic log --grep='æ' 7.41(7.00+0.31) 7.60(7.28+0.26) +2.6% 4221.13: extended log --grep='æ' 7.35(6.96+0.38) 7.73(7.31+0.34) +5.2% 4221.14: perl log --grep='æ' 7.43(7.10+0.32) 6.95(6.61+0.27) -6.5% log with -i: Test origin/master HEAD ------------------------------------------------------------------------------------ 4221.1: fixed log -i --grep='int' 7.40(7.05+0.23) 8.66(8.38+0.20) +17.0% 4221.2: basic log -i --grep='int' 7.39(7.09+0.23) 8.67(8.39+0.20) +17.3% 4221.3: extended log -i --grep='int' 7.29(6.99+0.26) 8.69(8.31+0.26) +19.2% 4221.4: perl log -i --grep='int' 7.42(7.16+0.21) 7.14(6.80+0.24) -3.8% 4221.6: fixed log -i --grep='uncommon' 6.94(6.58+0.35) 8.43(8.04+0.30) +21.5% 4221.7: basic log -i --grep='uncommon' 6.95(6.62+0.31) 8.34(7.93+0.32) +20.0% 4221.8: extended log -i --grep='uncommon' 7.06(6.75+0.25) 8.32(7.98+0.31) +17.8% 4221.9: perl log -i --grep='uncommon' 6.96(6.69+0.26) 7.04(6.64+0.32) +1.1% 4221.11: fixed log -i --grep='æ' 7.92(7.55+0.33) 7.86(7.44+0.34) -0.8% 4221.12: basic log -i --grep='æ' 7.88(7.49+0.32) 7.84(7.46+0.34) -0.5% 4221.13: extended log -i --grep='æ' 7.91(7.51+0.32) 7.87(7.48+0.32) -0.5% 4221.14: perl log -i --grep='æ' 7.01(6.59+0.35) 6.99(6.64+0.28) -0.3% Some of those, as noted in [1] are because PCRE is faster at finding fixed strings. This looks bad for some engines, but in the next change we'll optimistically use PCRE v2 for all of these, so it'll look better. 1. https://public-inbox.org/git/87v9x793qi.fsf@evledraar.gmail.com/ Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Ævar Arnfjörð Bjarmason committed Jul 1, 2019 at 23:20 UTC 48de2a768cfdb5bde3af40e0518c96f7df90c0b7
2 files changed +3 -62
grep.c
+3 -60
@@ -356,18 +356,6 @@ static NORETURN void compile_regexp_failed(const struct grep_pat *p,
356 die("%s'%s': %s", where, p->pattern, error);
357 }
358
359 -static int is_fixed(const char *s, size_t len)
360 -{
361 - size_t i;
362 -
363 - for (i = 0; i < len; i++) {
364 - if (is_regex_special(s[i]))
365 - return 0;
366 - }
367 -
368 - return 1;
369 -}
370 -
359 #ifdef USE_LIBPCRE1
360 static void compile_pcre1_regexp(struct grep_pat *p, const struct grep_opt *opt)
361 {
@@ -643,38 +631,12 @@ static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
631
632 p->word_regexp = opt->word_regexp;
633 p->ignore_case = opt->ignore_case;
634 + p->fixed = opt->fixed;
635
636 if (memchr(p->pattern, 0, p->patternlen) && !opt->pcre2)
637 die(_("given pattern contains NULL byte (via -f <file>). This is only supported with -P under PCRE v2"));
638
650 - /*
651 - * Even when -F (fixed) asks us to do a non-regexp search, we
652 - * may not be able to correctly case-fold when -i
653 - * (ignore-case) is asked (in which case, we'll synthesize a
654 - * regexp to match the pattern that matches regexp special
655 - * characters literally, while ignoring case differences). On
656 - * the other hand, even without -F, if the pattern does not
657 - * have any regexp special characters and there is no need for
658 - * case-folding search, we can internally turn it into a
659 - * simple string match using kws. p->fixed tells us if we
660 - * want to use kws.
661 - */
662 - if (opt->fixed || is_fixed(p->pattern, p->patternlen))
663 - p->fixed = !p->ignore_case || !has_non_ascii(p->pattern);
664 -
665 - if (p->fixed) {
666 - p->kws = kwsalloc(p->ignore_case ? tolower_trans_tbl : NULL);
667 - kwsincr(p->kws, p->pattern, p->patternlen);
668 - kwsprep(p->kws);
669 - return;
670 - }
671 -
639 if (opt->fixed) {
673 - /*
674 - * We come here when the pattern has the non-ascii
675 - * characters we cannot case-fold, and asked to
676 - * ignore-case.
677 - */
640 compile_fixed_regexp(p, opt);
641 return;
642 }
@@ -1042,9 +1004,7 @@ void free_grep_patterns(struct grep_opt *opt)
1004 case GREP_PATTERN: /* atom */
1005 case GREP_PATTERN_HEAD:
1006 case GREP_PATTERN_BODY:
1045 - if (p->kws)
1046 - kwsfree(p->kws);
1047 - else if (p->pcre1_regexp)
1007 + if (p->pcre1_regexp)
1008 free_pcre1_regexp(p);
1009 else if (p->pcre2_pattern)
1010 free_pcre2_pattern(p);
@@ -1104,29 +1064,12 @@ static void show_name(struct grep_opt *opt, const char *name)
1064 opt->output(opt, opt->null_following_name ? "\0" : "\n", 1);
1065 }
1066
1107 -static int fixmatch(struct grep_pat *p, char *line, char *eol,
1108 - regmatch_t *match)
1109 -{
1110 - struct kwsmatch kwsm;
1111 - size_t offset = kwsexec(p->kws, line, eol - line, &kwsm);
1112 - if (offset == -1) {
1113 - match->rm_so = match->rm_eo = -1;
1114 - return REG_NOMATCH;
1115 - } else {
1116 - match->rm_so = offset;
1117 - match->rm_eo = match->rm_so + kwsm.size[0];
1118 - return 0;
1119 - }
1120 -}
1121 -
1067 static int patmatch(struct grep_pat *p, char *line, char *eol,
1068 regmatch_t *match, int eflags)
1069 {
1070 int hit;
1071
1127 - if (p->fixed)
1128 - hit = !fixmatch(p, line, eol, match);
1129 - else if (p->pcre1_regexp)
1072 + if (p->pcre1_regexp)
1073 hit = !pcre1match(p, line, eol, match, eflags);
1074 else if (p->pcre2_pattern)
1075 hit = !pcre2match(p, line, eol, match, eflags);
grep.h
-2
@@ -32,7 +32,6 @@ typedef int pcre2_compile_context;
32 typedef int pcre2_match_context;
33 typedef int pcre2_jit_stack;
34 #endif
35 -#include "kwset.h"
35 #include "thread-utils.h"
36 #include "userdiff.h"
37
@@ -97,7 +96,6 @@ struct grep_pat {
96 pcre2_match_context *pcre2_match_context;
97 pcre2_jit_stack *pcre2_jit_stack;
98 uint32_t pcre2_jit_on;
100 - kwset_t kws;
99 unsigned fixed:1;
100 unsigned ignore_case:1;
101 unsigned word_regexp:1;