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| author | Phillip Wood <phillip.wood@dunelm.org.uk> | 2025-07-28 22:05:19 +0300 |
|---|---|---|
| committer | Junio C Hamano <gitster@pobox.com> | 2025-07-28 12:33:54 -0700 |
| commit | 41d97837ab1e5a35fdcfd7f6af9b5d56af62e92a (patch) | |
| tree | 7b830b33cba98a8a7bf55c8e7de05a539cfe8287 /xdiff/xutils.c | |
| parent | e813a0200a7121b97fec535f0d0b460b0a33356c (diff) | |
| download | git-41d97837ab1e5a35fdcfd7f6af9b5d56af62e92a.tar.gz | |
xdiff: refactor xdl_hash_record()
Inline the check for whitespace flags so that the compiler can hoist
it out of the loop in xdl_prepare_ctx(). This improves the performance
by 8%.
$ hyperfine --warmup=1 -L rev HEAD,HEAD^ --setup='git checkout {rev} -- :/ && make git' ': {rev}; GIT_CONFIG_GLOBAL=/dev/null ./git log --oneline --shortstat v2.0.0..v2.5.0'
Benchmark 1: : HEAD; GIT_CONFIG_GLOBAL=/dev/null ./git log --oneline --shortstat v2.0.0..v2.5.0
Time (mean ± σ): 1.670 s ± 0.044 s [User: 1.473 s, System: 0.196 s]
Range (min … max): 1.619 s … 1.754 s 10 runs
Benchmark 2: : HEAD^; GIT_CONFIG_GLOBAL=/dev/null ./git log --oneline --shortstat v2.0.0..v2.5.0
Time (mean ± σ): 1.801 s ± 0.021 s [User: 1.605 s, System: 0.192 s]
Range (min … max): 1.766 s … 1.831 s 10 runs
Summary
': HEAD^; GIT_CONFIG_GLOBAL=/dev/null ./git log --oneline --shortstat v2.0.0..v2.5.0' ran
1.08 ± 0.03 times faster than ': HEAD^^; GIT_CONFIG_GLOBAL=/dev/null ./git log --oneline --shortstat v2.0.0..v2.5.0'
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'xdiff/xutils.c')
| -rw-r--r-- | xdiff/xutils.c | 7 |
1 files changed, 2 insertions, 5 deletions
diff --git a/xdiff/xutils.c b/xdiff/xutils.c index 444a108f87..e070ed649f 100644 --- a/xdiff/xutils.c +++ b/xdiff/xutils.c @@ -249,7 +249,7 @@ int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags) return 1; } -static unsigned long xdl_hash_record_with_whitespace(char const **data, +unsigned long xdl_hash_record_with_whitespace(char const **data, char const *top, long flags) { unsigned long ha = 5381; char const *ptr = *data; @@ -294,13 +294,10 @@ static unsigned long xdl_hash_record_with_whitespace(char const **data, return ha; } -unsigned long xdl_hash_record(char const **data, char const *top, long flags) { +unsigned long xdl_hash_record_verbatim(char const **data, char const *top) { unsigned long ha = 5381; char const *ptr = *data; - if (flags & XDF_WHITESPACE_FLAGS) - return xdl_hash_record_with_whitespace(data, top, flags); - for (; ptr < top && *ptr != '\n'; ptr++) { ha += (ha << 5); ha ^= (unsigned long) *ptr; |