/*
- * Copyright (c) 2008, 2009, 2010, 2012, 2013 Nicira, Inc.
+ * Copyright (c) 2008, 2009, 2010, 2012, 2013, 2014, 2016 Nicira, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
return (x << k) | (x >> (32 - k));
}
-uint32_t hash_words(const uint32_t data[], size_t n_words, uint32_t basis);
uint32_t hash_bytes(const void *, size_t n_bytes, uint32_t basis);
+/* The hash input must be a word larger than 128 bits. */
+void hash_bytes128(const void *_, size_t n_bytes, uint32_t basis,
+ ovs_u128 *out);
static inline uint32_t hash_int(uint32_t x, uint32_t basis);
static inline uint32_t hash_2words(uint32_t, uint32_t);
-static inline uint32_t hash_uint64(uint64_t);
-static inline uint32_t hash_uint64_basis(uint64_t x, uint32_t basis);
+static inline uint32_t hash_uint64(const uint64_t);
+static inline uint32_t hash_uint64_basis(const uint64_t x,
+ const uint32_t basis);
uint32_t hash_3words(uint32_t, uint32_t, uint32_t);
static inline uint32_t hash_boolean(bool x, uint32_t basis);
return hash * 5 + 0xe6546b64;
}
-static inline uint32_t mhash_finish(uint32_t hash, size_t n_bytes)
+static inline uint32_t mhash_finish(uint32_t hash)
{
- hash ^= n_bytes;
hash ^= hash >> 16;
hash *= 0x85ebca6b;
hash ^= hash >> 13;
return hash;
}
-static inline uint32_t hash_string(const char *s, uint32_t basis)
+#if !(defined(__SSE4_2__) && defined(__x86_64__))
+/* Mhash-based implementation. */
+
+static inline uint32_t hash_add(uint32_t hash, uint32_t data)
{
- return hash_bytes(s, strlen(s), basis);
+ return mhash_add(hash, data);
}
-static inline uint32_t hash_int(uint32_t x, uint32_t basis)
+static inline uint32_t hash_add64(uint32_t hash, uint64_t data)
{
- return hash_2words(x, basis);
+ return hash_add(hash_add(hash, data), data >> 32);
}
-/* An attempt at a useful 1-bit hash function. Has not been analyzed for
- * quality. */
-static inline uint32_t hash_boolean(bool x, uint32_t basis)
+static inline uint32_t hash_finish(uint32_t hash, uint32_t final)
{
- const uint32_t P0 = 0xc2b73583; /* This is hash_int(1, 0). */
- const uint32_t P1 = 0xe90f1258; /* This is hash_int(2, 0). */
- return (x ? P0 : P1) ^ hash_rot(basis, 1);
+ return mhash_finish(hash ^ final);
+}
+
+/* Returns the hash of the 'n' 32-bit words at 'p', starting from 'basis'.
+ * 'p' must be properly aligned.
+ *
+ * This is inlined for the compiler to have access to the 'n_words', which
+ * in many cases is a constant. */
+static inline uint32_t
+hash_words_inline(const uint32_t p[], size_t n_words, uint32_t basis)
+{
+ uint32_t hash;
+ size_t i;
+
+ hash = basis;
+ for (i = 0; i < n_words; i++) {
+ hash = hash_add(hash, p[i]);
+ }
+ return hash_finish(hash, n_words * 4);
+}
+
+static inline uint32_t
+hash_words64_inline(const uint64_t p[], size_t n_words, uint32_t basis)
+{
+ uint32_t hash;
+ size_t i;
+
+ hash = basis;
+ for (i = 0; i < n_words; i++) {
+ hash = hash_add64(hash, p[i]);
+ }
+ return hash_finish(hash, n_words * 8);
}
static inline uint32_t hash_pointer(const void *p, uint32_t basis)
static inline uint32_t hash_2words(uint32_t x, uint32_t y)
{
- return mhash_finish(mhash_add(mhash_add(x, 0), y), 8);
+ return hash_finish(hash_add(hash_add(x, 0), y), 8);
+}
+
+static inline uint32_t hash_uint64_basis(const uint64_t x,
+ const uint32_t basis)
+{
+ return hash_finish(hash_add64(basis, x), 8);
}
static inline uint32_t hash_uint64(const uint64_t x)
{
- return hash_2words((uint32_t)(x >> 32), (uint32_t)x);
+ return hash_uint64_basis(x, 0);
+}
+
+#else /* __SSE4_2__ && __x86_64__ */
+#include <smmintrin.h>
+
+static inline uint32_t hash_add(uint32_t hash, uint32_t data)
+{
+ return _mm_crc32_u32(hash, data);
+}
+
+/* Add the halves of 'data' in the memory order. */
+static inline uint32_t hash_add64(uint32_t hash, uint64_t data)
+{
+ return _mm_crc32_u64(hash, data);
+}
+
+static inline uint32_t hash_finish(uint64_t hash, uint64_t final)
+{
+ /* The finishing multiplier 0x805204f3 has been experimentally
+ * derived to pass the testsuite hash tests. */
+ hash = _mm_crc32_u64(hash, final) * 0x805204f3;
+ return hash ^ (uint32_t)hash >> 16; /* Increase entropy in LSBs. */
+}
+
+/* Returns the hash of the 'n' 32-bit words at 'p_', starting from 'basis'.
+ * We access 'p_' as a uint64_t pointer, which is fine for __SSE_4_2__.
+ *
+ * This is inlined for the compiler to have access to the 'n_words', which
+ * in many cases is a constant. */
+static inline uint32_t
+hash_words_inline(const uint32_t p_[], size_t n_words, uint32_t basis)
+{
+ const uint64_t *p = (const void *)p_;
+ uint64_t hash1 = basis;
+ uint64_t hash2 = 0;
+ uint64_t hash3 = n_words;
+ const uint32_t *endp = (const uint32_t *)p + n_words;
+ const uint64_t *limit = p + n_words / 2 - 3;
+
+ while (p <= limit) {
+ hash1 = _mm_crc32_u64(hash1, p[0]);
+ hash2 = _mm_crc32_u64(hash2, p[1]);
+ hash3 = _mm_crc32_u64(hash3, p[2]);
+ p += 3;
+ }
+ switch (endp - (const uint32_t *)p) {
+ case 1:
+ hash1 = _mm_crc32_u32(hash1, *(const uint32_t *)&p[0]);
+ break;
+ case 2:
+ hash1 = _mm_crc32_u64(hash1, p[0]);
+ break;
+ case 3:
+ hash1 = _mm_crc32_u64(hash1, p[0]);
+ hash2 = _mm_crc32_u32(hash2, *(const uint32_t *)&p[1]);
+ break;
+ case 4:
+ hash1 = _mm_crc32_u64(hash1, p[0]);
+ hash2 = _mm_crc32_u64(hash2, p[1]);
+ break;
+ case 5:
+ hash1 = _mm_crc32_u64(hash1, p[0]);
+ hash2 = _mm_crc32_u64(hash2, p[1]);
+ hash3 = _mm_crc32_u32(hash3, *(const uint32_t *)&p[2]);
+ break;
+ }
+ return hash_finish(hash1, hash2 << 32 | hash3);
+}
+
+/* A simpler version for 64-bit data.
+ * 'n_words' is the count of 64-bit words, basis is 64 bits. */
+static inline uint32_t
+hash_words64_inline(const uint64_t p[], size_t n_words, uint32_t basis)
+{
+ uint64_t hash1 = basis;
+ uint64_t hash2 = 0;
+ uint64_t hash3 = n_words;
+ const uint64_t *endp = p + n_words;
+ const uint64_t *limit = endp - 3;
+
+ while (p <= limit) {
+ hash1 = _mm_crc32_u64(hash1, p[0]);
+ hash2 = _mm_crc32_u64(hash2, p[1]);
+ hash3 = _mm_crc32_u64(hash3, p[2]);
+ p += 3;
+ }
+ switch (endp - p) {
+ case 1:
+ hash1 = _mm_crc32_u64(hash1, p[0]);
+ break;
+ case 2:
+ hash1 = _mm_crc32_u64(hash1, p[0]);
+ hash2 = _mm_crc32_u64(hash2, p[1]);
+ break;
+ }
+ return hash_finish(hash1, hash2 << 32 | hash3);
}
static inline uint32_t hash_uint64_basis(const uint64_t x,
const uint32_t basis)
{
- return hash_3words((uint32_t)(x >> 32), (uint32_t)x, basis);
+ /* '23' chosen to mix bits enough for the test-hash to pass. */
+ return hash_finish(hash_add64(basis, x), 23);
}
+
+static inline uint32_t hash_uint64(const uint64_t x)
+{
+ return hash_uint64_basis(x, 0);
+}
+
+static inline uint32_t hash_2words(uint32_t x, uint32_t y)
+{
+ return hash_uint64((uint64_t)y << 32 | x);
+}
+
+static inline uint32_t hash_pointer(const void *p, uint32_t basis)
+{
+ return hash_uint64_basis((uint64_t) (uintptr_t) p, basis);
+}
+#endif
+
+uint32_t hash_words__(const uint32_t p[], size_t n_words, uint32_t basis);
+uint32_t hash_words64__(const uint64_t p[], size_t n_words, uint32_t basis);
+
+/* Inline the larger hash functions only when 'n_words' is known to be
+ * compile-time constant. */
+#if __GNUC__ >= 4
+static inline uint32_t
+hash_words(const uint32_t p[], size_t n_words, uint32_t basis)
+{
+ if (__builtin_constant_p(n_words)) {
+ return hash_words_inline(p, n_words, basis);
+ } else {
+ return hash_words__(p, n_words, basis);
+ }
+}
+
+static inline uint32_t
+hash_words64(const uint64_t p[], size_t n_words, uint32_t basis)
+{
+ if (__builtin_constant_p(n_words)) {
+ return hash_words64_inline(p, n_words, basis);
+ } else {
+ return hash_words64__(p, n_words, basis);
+ }
+}
+
+#else
+
+static inline uint32_t
+hash_words(const uint32_t p[], size_t n_words, uint32_t basis)
+{
+ return hash_words__(p, n_words, basis);
+}
+
+static inline uint32_t
+hash_words64(const uint64_t p[], size_t n_words, uint32_t basis)
+{
+ return hash_words64__(p, n_words, basis);
+}
+#endif
+
+static inline uint32_t
+hash_bytes32(const uint32_t p[], size_t n_bytes, uint32_t basis)
+{
+ return hash_words(p, n_bytes / 4, basis);
+}
+
+static inline uint32_t
+hash_bytes64(const uint64_t p[], size_t n_bytes, uint32_t basis)
+{
+ return hash_words64(p, n_bytes / 8, basis);
+}
+
+static inline uint32_t hash_string(const char *s, uint32_t basis)
+{
+ return hash_bytes(s, strlen(s), basis);
+}
+
+static inline uint32_t hash_int(uint32_t x, uint32_t basis)
+{
+ return hash_2words(x, basis);
+}
+
+/* An attempt at a useful 1-bit hash function. Has not been analyzed for
+ * quality. */
+static inline uint32_t hash_boolean(bool x, uint32_t basis)
+{
+ const uint32_t P0 = 0xc2b73583; /* This is hash_int(1, 0). */
+ const uint32_t P1 = 0xe90f1258; /* This is hash_int(2, 0). */
+ return (x ? P0 : P1) ^ hash_rot(basis, 1);
+}
+
#ifdef __cplusplus
}
#endif
projects / cascardo / ovs.git / blobdiff