Module: Mesa Branch: master Commit: 6acf22a17991e3e98c35596f0b1cedfaebed6ec3 URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=6acf22a17991e3e98c35596f0b1cedfaebed6ec3
Author: Grazvydas Ignotas <[email protected]> Date: Fri Dec 29 02:05:05 2017 +0200 util: use faster zlib's CRC32 implementaion zlib provides a faster slice-by-4 CRC32 implementation than the traditional single byte lookup one used by mesa. As most supported platforms now link zlib unconditionally, we can easily use it. Improvement for a 1MB buffer (avg MB/s, n=100, zlib 1.2.8): i5-6600K C2D E4500 mesa zlib mesa zlib 443 1443 225% +/- 2.1% 403 1175 191% +/- 0.9% It has been verified the calculation results stay the same after this change. Signed-off-by: Grazvydas Ignotas <[email protected]> Reviewed-by: Eric Engestrom <[email protected]> Reviewed-by: Marek Olšák <[email protected]> Reviewed-by: Ian Romanick <[email protected]> --- src/util/crc32.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/src/util/crc32.c b/src/util/crc32.c index f2e01c61e5..425046ab5f 100644 --- a/src/util/crc32.c +++ b/src/util/crc32.c @@ -33,6 +33,9 @@ */ +#ifdef HAVE_ZLIB +#include <zlib.h> +#endif #include "crc32.h" @@ -114,6 +117,16 @@ util_hash_crc32(const void *data, size_t size) const uint8_t *p = data; uint32_t crc = 0xffffffff; +#ifdef HAVE_ZLIB + /* Prefer zlib's implementation for better performance. + * zlib's uInt is always "unsigned int" while size_t can be 64bit. + * Since 1.2.9 there's crc32_z that takes size_t, but use the more + * available function to avoid build system complications. + */ + if ((uInt)size == size) + return ~crc32(0, data, size); +#endif + while (size--) crc = util_crc32_table[(crc ^ *p++) & 0xff] ^ (crc >> 8); _______________________________________________ mesa-commit mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/mesa-commit
