From 3d1d75d570579c402f9462f7b3048560651ac582 Mon Sep 17 00:00:00 2001 From: David Robillard Date: Wed, 6 Jun 2018 20:35:46 +0200 Subject: Add zix data structures for use in model --- src/zix/digest.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) create mode 100644 src/zix/digest.c (limited to 'src/zix/digest.c') diff --git a/src/zix/digest.c b/src/zix/digest.c new file mode 100644 index 00000000..7d9c0352 --- /dev/null +++ b/src/zix/digest.c @@ -0,0 +1,57 @@ +/* + Copyright 2012-2014 David Robillard + + Permission to use, copy, modify, and/or distribute this software for any + purpose with or without fee is hereby granted, provided that the above + copyright notice and this permission notice appear in all copies. + + THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. +*/ + +#include "zix/digest.h" + +#ifdef __SSE4_2__ +# include +#endif + +ZIX_API uint32_t +zix_digest_start(void) +{ +#ifdef __SSE4_2__ + return 1; // CRC32 initial value +#else + return 5381; // DJB hash initial value +#endif +} + +ZIX_API uint32_t +zix_digest_add(uint32_t hash, const void* const buf, const size_t len) +{ + const uint8_t* str = (const uint8_t*)buf; +#ifdef __SSE4_2__ + // SSE 4.2 CRC32 + for (size_t i = 0; i < (len / sizeof(uint32_t)); ++i) { + hash = _mm_crc32_u32(hash, *(const uint32_t*)str); + str += sizeof(uint32_t); + } + if (len & sizeof(uint16_t)) { + hash = _mm_crc32_u16(hash, *(const uint16_t*)str); + str += sizeof(uint16_t); + } + if (len & sizeof(uint8_t)) { + hash = _mm_crc32_u8(hash, *(const uint8_t*)str); + } +#else + // Classic DJB hash + for (size_t i = 0; i < len; ++i) { + hash = (hash << 5) + hash + str[i]; + } +#endif + return hash; +} -- cgit v1.2.1