diff options
| author | Mark Adler <madler@alumni.caltech.edu> | 2018-12-11 01:11:38 -0800 |
|---|---|---|
| committer | Mark Adler <madler@alumni.caltech.edu> | 2018-12-26 12:26:52 -0800 |
| commit | f8719f5ae5acdc31d3794ddfea8ac963359de41e (patch) | |
| tree | 70327ff8a4953abd605665ecd458a3c4b1a66443 /zlib.h | |
| parent | 41d86c73b21191a3fa9ea5f476fc9f1fc5e4f8b3 (diff) | |
| download | zlib-f8719f5ae5acdc31d3794ddfea8ac963359de41e.tar.gz | |
Speed up software CRC-32 computation by a factor of 1.5 to 3.
Use the interleaved method of Kadatch and Jenkins in order to make
use of pipelined instructions through multiple ALUs in a single
core. This also speeds up and simplifies the combination of CRCs,
and updates the functions to pre-calculate and use an operator for
CRC combination.
Diffstat (limited to 'zlib.h')
| -rw-r--r-- | zlib.h | 22 |
1 files changed, 10 insertions, 12 deletions
@@ -1724,7 +1724,7 @@ ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2, negative, the result has no meaning or utility. */ -ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len)); +ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len)); /* Update a running CRC-32 with the bytes buf[0..len-1] and return the updated CRC-32. If buf is Z_NULL, this function returns the required @@ -1758,19 +1758,17 @@ ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2)); */ /* -ZEXTERN void ZEXPORT crc32_combine_gen OF((z_crc_t op[32], z_off_t len2)); +ZEXTERN uLong ZEXPORT crc32_combine_gen OF((z_off_t len2)); - Generate the operator op corresponding to length len2, to be used with - crc32_combine_op(). op must have room for 32 z_crc_t values. (32 is the - number of bits in the CRC.) + Return the operator corresponding to length len2, to be used with + crc32_combine_op(). */ -ZEXTERN uLong ZEXPORT crc32_combine_op OF((uLong crc1, uLong crc2, - const z_crc_t *op)); +ZEXTERN uLong ZEXPORT crc32_combine_op OF((uLong crc1, uLong crc2, uLong op)); /* Give the same result as crc32_combine(), using op in place of len2. op is is generated from len2 by crc32_combine_gen(). This will be faster than - crc32_combine() if the generated op is used many times. + crc32_combine() if the generated op is used more than once. */ @@ -1860,7 +1858,7 @@ ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file)); /* backward compatibility */ ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile)); ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t)); ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t)); - ZEXTERN void ZEXPORT crc32_combine_gen64 OF((z_crc_t *op, z_off64_t)); + ZEXTERN uLong ZEXPORT crc32_combine_gen64 OF((z_off64_t)); #endif #if !defined(ZLIB_INTERNAL) && defined(Z_WANT64) @@ -1888,7 +1886,7 @@ ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file)); /* backward compatibility */ ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile)); ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t)); ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t)); - ZEXTERN void ZEXPORT crc32_combine_gen64 OF((z_crc_t *op, z_off_t)); + ZEXTERN uLong ZEXPORT crc32_combine_gen64 OF((z_off_t)); # endif #else ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *)); @@ -1897,14 +1895,14 @@ ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file)); /* backward compatibility */ ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile)); ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t)); ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t)); - ZEXTERN void ZEXPORT crc32_combine_gen OF((z_crc_t *op, z_off_t)); + ZEXTERN uLong ZEXPORT crc32_combine_gen OF((z_off_t)); #endif #else /* Z_SOLO */ ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t)); ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t)); - ZEXTERN void ZEXPORT crc32_combine_gen OF((z_crc_t *op, z_off_t)); + ZEXTERN uLong ZEXPORT crc32_combine_gen OF((z_off_t)); #endif /* !Z_SOLO */ |