Add zix data structures

1 files changed, 141 insertions, 0 deletions

diff --git a/src/zix/digest.c b/src/zix/digest.c
new file mode 100644
index 00000000..47d27b94
--- /dev/null
+++ b/src/zix/digest.c
@@ -0,0 +1,141 @@
+/*
+  Copyright 2012-2020 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"
+
+#ifdef __SSE4_2__
+#  include <smmintrin.h>
+#endif
+
+#include <assert.h>
+#include <stdint.h>
+
+#ifdef __SSE4_2__
+
+// SSE 4.2 CRC32
+
+uint32_t
+zix_digest_start(void)
+{
+  return 1;
+}
+
+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 __x86_64__
+  for (size_t i = 0; i < (len / sizeof(uint64_t)); ++i) {
+    hash = (uint32_t)_mm_crc32_u64(hash, *(const uint64_t*)str);
+    str += sizeof(uint64_t);
+  }
+  if (len & sizeof(uint32_t)) {
+    hash = _mm_crc32_u32(hash, *(const uint32_t*)str);
+    str += sizeof(uint32_t);
+  }
+#  else
+  for (size_t i = 0; i < (len / sizeof(uint32_t)); ++i) {
+    hash = _mm_crc32_u32(hash, *(const uint32_t*)str);
+    str += sizeof(uint32_t);
+  }
+#  endif
+  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);
+  }
+
+  return hash;
+}
+
+uint32_t
+zix_digest_add_64(uint32_t hash, const void* const buf, const size_t len)
+{
+  assert((uintptr_t)buf % sizeof(uint64_t) == 0);
+  assert(len % sizeof(uint64_t) == 0);
+
+#  ifdef __x86_64__
+  const uint64_t* ptr = (const uint64_t*)buf;
+
+  for (size_t i = 0; i < (len / sizeof(uint64_t)); ++i) {
+    hash = (uint32_t)_mm_crc32_u64(hash, *ptr);
+    ++ptr;
+  }
+
+  return hash;
+#  else
+  const uint32_t* ptr = (const uint32_t*)buf;
+
+  for (size_t i = 0; i < (len / sizeof(uint32_t)); ++i) {
+    hash = _mm_crc32_u32(hash, *ptr);
+    ++ptr;
+  }
+
+  return hash;
+#  endif
+}
+
+uint32_t
+zix_digest_add_ptr(const uint32_t hash, const void* const ptr)
+{
+#  ifdef __x86_64__
+  return (uint32_t)_mm_crc32_u64(hash, (uintptr_t)ptr);
+#  else
+  return _mm_crc32_u32(hash, (uintptr_t)ptr);
+#  endif
+}
+
+#else
+
+// Classic DJB hash
+
+uint32_t
+zix_digest_start(void)
+{
+  return 5381;
+}
+
+uint32_t
+zix_digest_add(uint32_t hash, const void* const buf, const size_t len)
+{
+  const uint8_t* str = (const uint8_t*)buf;
+
+  for (size_t i = 0; i < len; ++i) {
+    hash = (hash << 5u) + hash + str[i];
+  }
+
+  return hash;
+}
+
+uint32_t
+zix_digest_add_64(uint32_t hash, const void* const buf, const size_t len)
+{
+  assert((uintptr_t)buf % sizeof(uint64_t) == 0);
+  assert(len % sizeof(uint64_t) == 0);
+
+  return zix_digest_add(hash, buf, len);
+}
+
+uint32_t
+zix_digest_add_ptr(const uint32_t hash, const void* const ptr)
+{
+  return zix_digest_add(hash, &ptr, sizeof(ptr));
+}
+
+#endif