aboutsummaryrefslogtreecommitdiffstats
path: root/src/zix/digest.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/zix/digest.c')
-rw-r--r--src/zix/digest.c233
1 files changed, 0 insertions, 233 deletions
diff --git a/src/zix/digest.c b/src/zix/digest.c
deleted file mode 100644
index dcfadf8f..00000000
--- a/src/zix/digest.c
+++ /dev/null
@@ -1,233 +0,0 @@
-/*
- Copyright 2012-2021 David Robillard <d@drobilla.net>
-
- 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"
-
-#include <assert.h>
-#include <stdint.h>
-#include <string.h>
-
-#if defined(__clang__) && __clang_major__ >= 12
-# define FALLTHROUGH() __attribute__((fallthrough))
-#elif defined(__GNUC__) && !defined(__clang__)
-# define FALLTHROUGH() __attribute__((fallthrough))
-#else
-# define FALLTHROUGH()
-#endif
-
-/*
- 64-bit hash: Essentially fasthash64, implemented here in an aligned/padded
- and a general UB-free variant.
-*/
-
-static inline uint64_t
-mix64(uint64_t h)
-{
- h ^= h >> 23u;
- h *= 0x2127599BF4325C37ull;
- h ^= h >> 47u;
- return h;
-}
-
-uint64_t
-zix_digest64(const uint64_t seed, const void* const key, const size_t len)
-{
- static const uint64_t m = 0x880355F21E6D1965ull;
-
- const uint64_t* const blocks = (const uint64_t*)key;
- const size_t n_blocks = len / sizeof(uint64_t);
-
- uint64_t h = seed ^ (len * m);
- for (size_t i = 0u; i < n_blocks; ++i) {
- h ^= mix64(blocks[i]);
- h *= m;
- }
-
- const uint8_t* const tail = (const unsigned char*)(blocks + n_blocks);
- uint64_t v = 0u;
-
- switch (len & 7u) {
- case 7:
- v |= (uint64_t)tail[6] << 48u;
- FALLTHROUGH();
- case 6:
- v |= (uint64_t)tail[5] << 40u;
- FALLTHROUGH();
- case 5:
- v |= (uint64_t)tail[4] << 32u;
- FALLTHROUGH();
- case 4:
- v |= (uint64_t)tail[3] << 24u;
- FALLTHROUGH();
- case 3:
- v |= (uint64_t)tail[2] << 16u;
- FALLTHROUGH();
- case 2:
- v |= (uint64_t)tail[1] << 8u;
- FALLTHROUGH();
- case 1:
- v |= (uint64_t)tail[0];
-
- h ^= mix64(v);
- h *= m;
- }
-
- return mix64(h);
-}
-
-uint64_t
-zix_digest64_aligned(const uint64_t seed, const void* const key, size_t len)
-{
- static const uint64_t m = 0x880355F21E6D1965ull;
-
- assert((uintptr_t)key % sizeof(uint64_t) == 0u);
- assert(len % sizeof(uint64_t) == 0u);
-
- const uint64_t* const blocks = (const uint64_t*)key;
- const size_t n_blocks = len / sizeof(uint64_t);
- uint64_t h = seed ^ (len * m);
-
- for (size_t i = 0u; i < n_blocks; ++i) {
- h ^= mix64(blocks[i]);
- h *= m;
- }
-
- return mix64(h);
-}
-
-/*
- 32-bit hash: Essentially murmur3, reimplemented here in an aligned/padded and
- a general UB-free variant.
-*/
-
-/**
- Rotate left by some count of bits.
-
- This is recognized by any halfway decent compiler and compiled to a single
- instruction on architectures that have one.
-*/
-static inline uint32_t
-rotl32(const uint32_t val, const uint32_t bits)
-{
- return ((val << bits) | (val >> (32 - bits)));
-}
-
-static inline uint32_t
-mix32(uint32_t h)
-{
- h ^= h >> 16u;
- h *= 0x85EBCA6Bu;
- h ^= h >> 13u;
- h *= 0xC2B2AE35u;
- h ^= h >> 16u;
- return h;
-}
-
-uint32_t
-zix_digest32(const uint32_t seed, const void* const key, const size_t len)
-{
- static const uint32_t c1 = 0xCC9E2D51u;
- static const uint32_t c2 = 0x1B873593u;
-
- // Process as many 32-bit blocks as possible
- const size_t n_blocks = len / sizeof(uint32_t);
- const uint8_t* data = (const uint8_t*)key;
- const uint8_t* const blocks_end = data + (n_blocks * sizeof(uint32_t));
- uint32_t h = seed;
- for (; data != blocks_end; data += sizeof(uint32_t)) {
- uint32_t k = 0u;
- memcpy(&k, data, sizeof(uint32_t));
-
- k *= c1;
- k = rotl32(k, 15);
- k *= c2;
-
- h ^= k;
- h = rotl32(h, 13);
- h = h * 5u + 0xE6546B64u;
- }
-
- // Process any trailing bytes
- uint32_t k = 0u;
- switch (len & 3u) {
- case 3u:
- k ^= (uint32_t)data[2u] << 16u;
- FALLTHROUGH();
- case 2u:
- k ^= (uint32_t)data[1u] << 8u;
- FALLTHROUGH();
- case 1u:
- k ^= (uint32_t)data[0u];
-
- k *= c1;
- k = rotl32(k, 15u);
- k *= c2;
- h ^= k;
- }
-
- return mix32(h ^ (uint32_t)len);
-}
-
-uint32_t
-zix_digest32_aligned(const uint32_t seed,
- const void* const key,
- const size_t len)
-{
- static const uint32_t c1 = 0xCC9E2D51u;
- static const uint32_t c2 = 0x1B873593u;
-
- assert((uintptr_t)key % sizeof(uint32_t) == 0u);
- assert(len % sizeof(uint32_t) == 0u);
-
- const uint32_t* const blocks = (const uint32_t*)key;
- const size_t n_blocks = len / sizeof(uint32_t);
- uint32_t h = seed;
- for (size_t i = 0u; i < n_blocks; ++i) {
- uint32_t k = blocks[i];
-
- k *= c1;
- k = rotl32(k, 15);
- k *= c2;
-
- h ^= k;
- h = rotl32(h, 13);
- h = h * 5u + 0xE6546B64u;
- }
-
- return mix32(h ^ (uint32_t)len);
-}
-
-// Native word size wrapper
-
-size_t
-zix_digest(const size_t seed, const void* const buf, const size_t len)
-{
-#if UINTPTR_MAX >= UINT64_MAX
- return zix_digest64(seed, buf, len);
-#else
- return zix_digest32(seed, buf, len);
-#endif
-}
-
-size_t
-zix_digest_aligned(const size_t seed, const void* const buf, const size_t len)
-{
-#if UINTPTR_MAX >= UINT64_MAX
- return zix_digest64_aligned(seed, buf, len);
-#else
- return zix_digest32_aligned(seed, buf, len);
-#endif
-}
generated by cgit v1.2.1 (git 2.18.0) at 2024-06-30 04:40:08 +0000