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Diffstat (limited to 'thirdparty/vulkan/loader/murmurhash.c')
-rw-r--r-- | thirdparty/vulkan/loader/murmurhash.c | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/thirdparty/vulkan/loader/murmurhash.c b/thirdparty/vulkan/loader/murmurhash.c new file mode 100644 index 0000000000..40f0d5e975 --- /dev/null +++ b/thirdparty/vulkan/loader/murmurhash.c @@ -0,0 +1,98 @@ + +/** + * `murmurhash.h' - murmurhash + * + * copyright (c) 2014 joseph werle <joseph.werle@gmail.com> + * Copyright (c) 2015-2016 The Khronos Group Inc. + * Copyright (c) 2015-2016 Valve Corporation + * Copyright (c) 2015-2016 LunarG, Inc. + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and/or associated documentation files (the "Materials"), to + * deal in the Materials without restriction, including without limitation the + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or + * sell copies of the Materials, and to permit persons to whom the Materials are + * furnished to do so, subject to the following conditions: + * + * The above copyright notice(s) and this permission notice shall be included in + * all copies or substantial portions of the Materials. + * + * THE MATERIALS ARE PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. + * + * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, + * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR + * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE MATERIALS OR THE + * USE OR OTHER DEALINGS IN THE MATERIALS. + */ + +#include <stdlib.h> +#include <stdio.h> +#include <stdint.h> +#include "murmurhash.h" + +uint32_t murmurhash(const char *key, size_t len, uint32_t seed) { + uint32_t c1 = 0xcc9e2d51; + uint32_t c2 = 0x1b873593; + uint32_t r1 = 15; + uint32_t r2 = 13; + uint32_t m = 5; + uint32_t n = 0xe6546b64; + uint32_t h = 0; + uint32_t k = 0; + uint8_t *d = (uint8_t *)key; // 32 bit extract from `key' + const uint32_t *chunks = NULL; + const uint8_t *tail = NULL; // tail - last 8 bytes + int i = 0; + int l = (int)len / 4; // chunk length + + h = seed; + + chunks = (const uint32_t *)(d + l * 4); // body + tail = (const uint8_t *)(d + l * 4); // last 8 byte chunk of `key' + + // for each 4 byte chunk of `key' + for (i = -l; i != 0; ++i) { + // next 4 byte chunk of `key' + k = chunks[i]; + + // encode next 4 byte chunk of `key' + k *= c1; + k = (k << r1) | (k >> (32 - r1)); + k *= c2; + + // append to hash + h ^= k; + h = (h << r2) | (h >> (32 - r2)); + h = h * m + n; + } + + k = 0; + + // remainder + switch (len & 3) { // `len % 4' + case 3: + k ^= (tail[2] << 16); + // fall through + case 2: + k ^= (tail[1] << 8); + // fall through + case 1: + k ^= tail[0]; + k *= c1; + k = (k << r1) | (k >> (32 - r1)); + k *= c2; + h ^= k; + } + + h ^= len; + + h ^= (h >> 16); + h *= 0x85ebca6b; + h ^= (h >> 13); + h *= 0xc2b2ae35; + h ^= (h >> 16); + + return h; +} |