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| author | Junio C Hamano <junkio@cox.net> | 2006-09-09 22:21:27 -0700 |
|---|---|---|
| committer | Junio C Hamano <junkio@cox.net> | 2006-09-09 22:21:27 -0700 |
| commit | a41fae9c46a4cb5e59cc1a17d19f6a3a6cbfbb2f (patch) | |
| tree | 40ce41c0822095c933b462f05a990485c5eb7135 /sha1_file.c | |
| parent | 2878836c5074be92b913c95446b94bbf1c9a9e1d (diff) | |
| download | git-a41fae9c46a4cb5e59cc1a17d19f6a3a6cbfbb2f.tar.gz git-a41fae9c46a4cb5e59cc1a17d19f6a3a6cbfbb2f.tar.xz | |
get_sha1_hex() micro-optimization
The function appeared high on a gprof output for a rev-list run of
a non-trivial size, and it was an obvious low-hanging fruit.
The code is from Linus.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Diffstat (limited to 'sha1_file.c')
| -rw-r--r-- | sha1_file.c | 46 |
1 files changed, 37 insertions, 9 deletions
diff --git a/sha1_file.c b/sha1_file.c index 428d791ba..b64b92de4 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -26,15 +26,43 @@ const unsigned char null_sha1[20]; static unsigned int sha1_file_open_flag = O_NOATIME; -static unsigned hexval(char c) -{ - if (c >= '0' && c <= '9') - return c - '0'; - if (c >= 'a' && c <= 'f') - return c - 'a' + 10; - if (c >= 'A' && c <= 'F') - return c - 'A' + 10; - return ~0; +static inline unsigned int hexval(unsigned int c) +{ + static signed char val[256] = { + -1, -1, -1, -1, -1, -1, -1, -1, /* 00-07 */ + -1, -1, -1, -1, -1, -1, -1, -1, /* 08-0f */ + -1, -1, -1, -1, -1, -1, -1, -1, /* 10-17 */ + -1, -1, -1, -1, -1, -1, -1, -1, /* 18-1f */ + -1, -1, -1, -1, -1, -1, -1, -1, /* 20-27 */ + -1, -1, -1, -1, -1, -1, -1, -1, /* 28-2f */ + 0, 1, 2, 3, 4, 5, 6, 7, /* 30-37 */ + 8, 9, -1, -1, -1, -1, -1, -1, /* 38-3f */ + -1, 10, 11, 12, 13, 14, 15, -1, /* 40-47 */ + -1, -1, -1, -1, -1, -1, -1, -1, /* 48-4f */ + -1, -1, -1, -1, -1, -1, -1, -1, /* 50-57 */ + -1, -1, -1, -1, -1, -1, -1, -1, /* 58-5f */ + -1, 10, 11, 12, 13, 14, 15, -1, /* 60-67 */ + -1, -1, -1, -1, -1, -1, -1, -1, /* 68-67 */ + -1, -1, -1, -1, -1, -1, -1, -1, /* 70-77 */ + -1, -1, -1, -1, -1, -1, -1, -1, /* 78-7f */ + -1, -1, -1, -1, -1, -1, -1, -1, /* 80-87 */ + -1, -1, -1, -1, -1, -1, -1, -1, /* 88-8f */ + -1, -1, -1, -1, -1, -1, -1, -1, /* 90-97 */ + -1, -1, -1, -1, -1, -1, -1, -1, /* 98-9f */ + -1, -1, -1, -1, -1, -1, -1, -1, /* a0-a7 */ + -1, -1, -1, -1, -1, -1, -1, -1, /* a8-af */ + -1, -1, -1, -1, -1, -1, -1, -1, /* b0-b7 */ + -1, -1, -1, -1, -1, -1, -1, -1, /* b8-bf */ + -1, -1, -1, -1, -1, -1, -1, -1, /* c0-c7 */ + -1, -1, -1, -1, -1, -1, -1, -1, /* c8-cf */ + -1, -1, -1, -1, -1, -1, -1, -1, /* d0-d7 */ + -1, -1, -1, -1, -1, -1, -1, -1, /* d8-df */ + -1, -1, -1, -1, -1, -1, -1, -1, /* e0-e7 */ + -1, -1, -1, -1, -1, -1, -1, -1, /* e8-ef */ + -1, -1, -1, -1, -1, -1, -1, -1, /* f0-f7 */ + -1, -1, -1, -1, -1, -1, -1, -1, /* f8-ff */ + }; + return val[c]; } int get_sha1_hex(const char *hex, unsigned char *sha1) |