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btrfs-progs/crypto/xxhash.c
Adam Borowski 3d379b1341 btrfs-progs: lots of typo fixes (codespell) 
Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-31 18:37:38 +02:00

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/*
* xxHash - Fast Hash algorithm
* Copyright (C) 2012-2016, Yann Collet
*
* BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* You can contact the author at :
* - xxHash homepage: http://www.xxhash.com
* - xxHash source repository : https://github.com/Cyan4973/xxHash
*/
/* *************************************
* Tuning parameters
***************************************/
/*!XXH_FORCE_MEMORY_ACCESS :
* By default, access to unaligned memory is controlled by `memcpy()`, which is safe and portable.
* Unfortunately, on some target/compiler combinations, the generated assembly is sub-optimal.
* The below switch allow to select different access method for improved performance.
* Method 0 (default) : use `memcpy()`. Safe and portable.
* Method 1 : `__packed` statement. It depends on compiler extension (ie, not portable).
* This method is safe if your compiler supports it, and *generally* as fast or faster than `memcpy`.
* Method 2 : direct access. This method doesn't depend on compiler but violate C standard.
* It can generate buggy code on targets which do not support unaligned memory accesses.
* But in some circumstances, it's the only known way to get the most performance (ie GCC + ARMv6)
* See http://stackoverflow.com/a/32095106/646947 for details.
* Prefer these methods in priority order (0 > 1 > 2)
*/
#ifndef XXH_FORCE_MEMORY_ACCESS /* can be defined externally, on command line for example */
# if defined(__GNUC__) && ( defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) \
|| defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) \
|| defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) )
# define XXH_FORCE_MEMORY_ACCESS 2
# elif (defined(__INTEL_COMPILER) && !defined(_WIN32)) || \
(defined(__GNUC__) && ( defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) \
|| defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) \
|| defined(__ARM_ARCH_7S__) ))
# define XXH_FORCE_MEMORY_ACCESS 1
# endif
#endif
/*!XXH_ACCEPT_NULL_INPUT_POINTER :
* If input pointer is NULL, xxHash default behavior is to dereference it, triggering a segfault.
* When this macro is enabled, xxHash actively checks input for null pointer.
* It it is, result for null input pointers is the same as a null-length input.
*/
#ifndef XXH_ACCEPT_NULL_INPUT_POINTER /* can be defined externally */
# define XXH_ACCEPT_NULL_INPUT_POINTER 0
#endif
/*!XXH_FORCE_ALIGN_CHECK :
* This is a minor performance trick, only useful with lots of very small keys.
* It means : check for aligned/unaligned input.
* The check costs one initial branch per hash;
* set it to 0 when the input is guaranteed to be aligned,
* or when alignment doesn't matter for performance.
*/
#ifndef XXH_FORCE_ALIGN_CHECK /* can be defined externally */
# if defined(__i386) || defined(_M_IX86) || defined(__x86_64__) || defined(_M_X64)
# define XXH_FORCE_ALIGN_CHECK 0
# else
# define XXH_FORCE_ALIGN_CHECK 1
# endif
#endif
/*!XXH_REROLL:
* Whether to reroll XXH32_finalize, and XXH64_finalize,
* instead of using an unrolled jump table/if statement loop.
*
* This is automatically defined on -Os/-Oz on GCC and Clang. */
#ifndef XXH_REROLL
# if defined(__OPTIMIZE_SIZE__)
# define XXH_REROLL 1
# else
# define XXH_REROLL 0
# endif
#endif
/* *************************************
* Includes & Memory related functions
***************************************/
/*! Modify the local functions below should you wish to use some other memory routines
* for malloc(), free() */
#include <stdlib.h>
static void* XXH_malloc(size_t s) { return malloc(s); }
static void XXH_free (void* p) { free(p); }
/*! and for memcpy() */
#include <string.h>
static void* XXH_memcpy(void* dest, const void* src, size_t size) { return memcpy(dest,src,size); }
#include <limits.h> /* ULLONG_MAX */
#define XXH_STATIC_LINKING_ONLY
#include "xxhash.h"
/* *************************************
* Compiler Specific Options
***************************************/
#ifdef _MSC_VER /* Visual Studio */
# pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */
# define XXH_FORCE_INLINE static __forceinline
# define XXH_NO_INLINE static __declspec(noinline)
#else
# if defined (__cplusplus) || defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L /* C99 */
# ifdef __GNUC__
# define XXH_FORCE_INLINE static inline __attribute__((always_inline))
# define XXH_NO_INLINE static __attribute__((noinline))
# else
# define XXH_FORCE_INLINE static inline
# define XXH_NO_INLINE static
# endif
# else
# define XXH_FORCE_INLINE static
# define XXH_NO_INLINE static
# endif /* __STDC_VERSION__ */
#endif
/* *************************************
* Debug
***************************************/
/* DEBUGLEVEL is expected to be defined externally,
* typically through compiler command line.
* Value must be a number. */
#ifndef DEBUGLEVEL
# define DEBUGLEVEL 0
#endif
#if (DEBUGLEVEL>=1)
# include <assert.h> /* note : can still be disabled with NDEBUG */
# define XXH_ASSERT(c) assert(c)
#else
# define XXH_ASSERT(c) ((void)0)
#endif
/* note : use after variable declarations */
#define XXH_STATIC_ASSERT(c) { enum { XXH_sa = 1/(int)(!!(c)) }; }
/* *************************************
* Basic Types
***************************************/
#ifndef MEM_MODULE
# if !defined (__VMS) \
&& (defined (__cplusplus) \
|| (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
# include <stdint.h>
typedef uint8_t BYTE;
typedef uint16_t U16;
typedef uint32_t U32;
# else
typedef unsigned char BYTE;
typedef unsigned short U16;
typedef unsigned int U32;
# endif
#endif
/* === Memory access === */
#if (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==2))
/* Force direct memory access. Only works on CPU which support unaligned memory access in hardware */
static U32 XXH_read32(const void* memPtr) { return *(const U32*) memPtr; }
#elif (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==1))
/* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */
/* currently only defined for gcc and icc */
typedef union { U32 u32; } __attribute__((packed)) unalign;
static U32 XXH_read32(const void* ptr) { return ((const unalign*)ptr)->u32; }
#else
/* portable and safe solution. Generally efficient.
* see : http://stackoverflow.com/a/32095106/646947
*/
static U32 XXH_read32(const void* memPtr)
{
U32 val;
memcpy(&val, memPtr, sizeof(val));
return val;
}
#endif /* XXH_FORCE_DIRECT_MEMORY_ACCESS */
/* === Endianness === */
typedef enum { XXH_bigEndian=0, XXH_littleEndian=1 } XXH_endianess;
/* XXH_CPU_LITTLE_ENDIAN can be defined externally, for example on the compiler command line */
#ifndef XXH_CPU_LITTLE_ENDIAN
static int XXH_isLittleEndian(void)
{
const union { U32 u; BYTE c[4]; } one = { 1 }; /* don't use static : performance detrimental */
return one.c[0];
}
# define XXH_CPU_LITTLE_ENDIAN XXH_isLittleEndian()
#endif
/* ****************************************
* Compiler-specific Functions and Macros
******************************************/
#define XXH_GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
#ifndef __has_builtin
# define __has_builtin(x) 0
#endif
#if !defined(NO_CLANG_BUILTIN) && __has_builtin(__builtin_rotateleft32) && __has_builtin(__builtin_rotateleft64)
# define XXH_rotl32 __builtin_rotateleft32
# define XXH_rotl64 __builtin_rotateleft64
/* Note : although _rotl exists for minGW (GCC under windows), performance seems poor */
#elif defined(_MSC_VER)
# define XXH_rotl32(x,r) _rotl(x,r)
# define XXH_rotl64(x,r) _rotl64(x,r)
#else
# define XXH_rotl32(x,r) (((x) << (r)) | ((x) >> (32 - (r))))
# define XXH_rotl64(x,r) (((x) << (r)) | ((x) >> (64 - (r))))
#endif
#if defined(_MSC_VER) /* Visual Studio */
# define XXH_swap32 _byteswap_ulong
#elif XXH_GCC_VERSION >= 403
# define XXH_swap32 __builtin_bswap32
#else
static U32 XXH_swap32 (U32 x)
{
return ((x << 24) & 0xff000000 ) |
((x << 8) & 0x00ff0000 ) |
((x >> 8) & 0x0000ff00 ) |
((x >> 24) & 0x000000ff );
}
#endif
/* ***************************
* Memory reads
*****************************/
typedef enum { XXH_aligned, XXH_unaligned } XXH_alignment;
XXH_FORCE_INLINE U32 XXH_readLE32(const void* ptr)
{
return XXH_CPU_LITTLE_ENDIAN ? XXH_read32(ptr) : XXH_swap32(XXH_read32(ptr));
}
static U32 XXH_readBE32(const void* ptr)
{
return XXH_CPU_LITTLE_ENDIAN ? XXH_swap32(XXH_read32(ptr)) : XXH_read32(ptr);
}
XXH_FORCE_INLINE U32
XXH_readLE32_align(const void* ptr, XXH_alignment align)
{
if (align==XXH_unaligned) {
return XXH_readLE32(ptr);
} else {
return XXH_CPU_LITTLE_ENDIAN ? *(const U32*)ptr : XXH_swap32(*(const U32*)ptr);
}
}
/* *************************************
* Misc
***************************************/
XXH_PUBLIC_API unsigned XXH_versionNumber (void) { return XXH_VERSION_NUMBER; }
/* *******************************************************************
* 32-bit hash functions
*********************************************************************/
static const U32 PRIME32_1 = 0x9E3779B1U; /* 0b10011110001101110111100110110001 */
static const U32 PRIME32_2 = 0x85EBCA77U; /* 0b10000101111010111100101001110111 */
static const U32 PRIME32_3 = 0xC2B2AE3DU; /* 0b11000010101100101010111000111101 */
static const U32 PRIME32_4 = 0x27D4EB2FU; /* 0b00100111110101001110101100101111 */
static const U32 PRIME32_5 = 0x165667B1U; /* 0b00010110010101100110011110110001 */
static U32 XXH32_round(U32 acc, U32 input)
{
acc += input * PRIME32_2;
acc = XXH_rotl32(acc, 13);
acc *= PRIME32_1;
#if defined(__GNUC__) && defined(__SSE4_1__) && !defined(XXH_ENABLE_AUTOVECTORIZE)
/* UGLY HACK:
* This inline assembly hack forces acc into a normal register. This is the
* only thing that prevents GCC and Clang from autovectorizing the XXH32 loop
* (pragmas and attributes don't work for some resason) without globally
* disabling SSE4.1.
*
* The reason we want to avoid vectorization is because despite working on
* 4 integers at a time, there are multiple factors slowing XXH32 down on
* SSE4:
* - There's a ridiculous amount of lag from pmulld (10 cycles of latency on newer chips!)
* making it slightly slower to multiply four integers at once compared to four
* integers independently. Even when pmulld was fastest, Sandy/Ivy Bridge, it is
* still not worth it to go into SSE just to multiply unless doing a long operation.
*
* - Four instructions are required to rotate,
* movqda tmp, v // not required with VEX encoding
* pslld tmp, 13 // tmp <<= 13
* psrld v, 19 // x >>= 19
* por v, tmp // x |= tmp
* compared to one for scalar:
* roll v, 13 // reliably fast across the board
* shldl v, v, 13 // Sandy Bridge and later prefer this for some reason
*
* - Instruction level parallelism is actually more beneficial here because the
* SIMD actually serializes this operation: While v1 is rotating, v2 can load data,
* while v3 can multiply. SSE forces them to operate together.
*
* How this hack works:
* __asm__("" // Declare an assembly block but don't declare any instructions
* : // However, as an Input/Output Operand,
* "+r" // constrain a read/write operand (+) as a general purpose register (r).
* (acc) // and set acc as the operand
* );
*
* Because of the 'r', the compiler has promised that seed will be in a
* general purpose register and the '+' says that it will be 'read/write',
* so it has to assume it has changed. It is like volatile without all the
* loads and stores.
*
* Since the argument has to be in a normal register (not an SSE register),
* each time XXH32_round is called, it is impossible to vectorize. */
__asm__("" : "+r" (acc));
#endif
return acc;
}
/* mix all bits */
static U32 XXH32_avalanche(U32 h32)
{
h32 ^= h32 >> 15;
h32 *= PRIME32_2;
h32 ^= h32 >> 13;
h32 *= PRIME32_3;
h32 ^= h32 >> 16;
return(h32);
}
#define XXH_get32bits(p) XXH_readLE32_align(p, align)
static U32
XXH32_finalize(U32 h32, const void* ptr, size_t len, XXH_alignment align)
{
const BYTE* p = (const BYTE*)ptr;
#define PROCESS1 \
h32 += (*p++) * PRIME32_5; \
h32 = XXH_rotl32(h32, 11) * PRIME32_1 ;
#define PROCESS4 \
h32 += XXH_get32bits(p) * PRIME32_3; \
p+=4; \
h32 = XXH_rotl32(h32, 17) * PRIME32_4 ;
/* Compact rerolled version */
if (XXH_REROLL) {
len &= 15;
while (len >= 4) {
PROCESS4;
len -= 4;
}
while (len > 0) {
PROCESS1;
--len;
}
return XXH32_avalanche(h32);
} else {
switch(len&15) /* or switch(bEnd - p) */ {
case 12: PROCESS4;
/* fallthrough */
case 8: PROCESS4;
/* fallthrough */
case 4: PROCESS4;
return XXH32_avalanche(h32);
case 13: PROCESS4;
/* fallthrough */
case 9: PROCESS4;
/* fallthrough */
case 5: PROCESS4;
PROCESS1;
return XXH32_avalanche(h32);
case 14: PROCESS4;
/* fallthrough */
case 10: PROCESS4;
/* fallthrough */
case 6: PROCESS4;
PROCESS1;
PROCESS1;
return XXH32_avalanche(h32);
case 15: PROCESS4;
/* fallthrough */
case 11: PROCESS4;
/* fallthrough */
case 7: PROCESS4;
/* fallthrough */
case 3: PROCESS1;
/* fallthrough */
case 2: PROCESS1;
/* fallthrough */
case 1: PROCESS1;
/* fallthrough */
case 0: return XXH32_avalanche(h32);
}
XXH_ASSERT(0);
return h32; /* reaching this point is deemed impossible */
}
}
XXH_FORCE_INLINE U32
XXH32_endian_align(const void* input, size_t len, U32 seed, XXH_alignment align)
{
const BYTE* p = (const BYTE*)input;
const BYTE* bEnd = p + len;
U32 h32;
#if defined(XXH_ACCEPT_NULL_INPUT_POINTER) && (XXH_ACCEPT_NULL_INPUT_POINTER>=1)
if (p==NULL) {
len=0;
bEnd=p=(const BYTE*)(size_t)16;
}
#endif
if (len>=16) {
const BYTE* const limit = bEnd - 15;
U32 v1 = seed + PRIME32_1 + PRIME32_2;
U32 v2 = seed + PRIME32_2;
U32 v3 = seed + 0;
U32 v4 = seed - PRIME32_1;
do {
v1 = XXH32_round(v1, XXH_get32bits(p)); p+=4;
v2 = XXH32_round(v2, XXH_get32bits(p)); p+=4;
v3 = XXH32_round(v3, XXH_get32bits(p)); p+=4;
v4 = XXH32_round(v4, XXH_get32bits(p)); p+=4;
} while (p < limit);
h32 = XXH_rotl32(v1, 1) + XXH_rotl32(v2, 7)
+ XXH_rotl32(v3, 12) + XXH_rotl32(v4, 18);
} else {
h32 = seed + PRIME32_5;
}
h32 += (U32)len;
return XXH32_finalize(h32, p, len&15, align);
}
XXH_PUBLIC_API unsigned int XXH32 (const void* input, size_t len, unsigned int seed)
{
#if 0
/* Simple version, good for code maintenance, but unfortunately slow for small inputs */
XXH32_state_t state;
XXH32_reset(&state, seed);
XXH32_update(&state, input, len);
return XXH32_digest(&state);
#else
if (XXH_FORCE_ALIGN_CHECK) {
if ((((size_t)input) & 3) == 0) { /* Input is 4-bytes aligned, leverage the speed benefit */
return XXH32_endian_align(input, len, seed, XXH_aligned);
} }
return XXH32_endian_align(input, len, seed, XXH_unaligned);
#endif
}
/*====== Hash streaming ======*/
XXH_PUBLIC_API XXH32_state_t* XXH32_createState(void)
{
return (XXH32_state_t*)XXH_malloc(sizeof(XXH32_state_t));
}
XXH_PUBLIC_API XXH_errorcode XXH32_freeState(XXH32_state_t* statePtr)
{
XXH_free(statePtr);
return XXH_OK;
}
XXH_PUBLIC_API void XXH32_copyState(XXH32_state_t* dstState, const XXH32_state_t* srcState)
{
memcpy(dstState, srcState, sizeof(*dstState));
}
XXH_PUBLIC_API XXH_errorcode XXH32_reset(XXH32_state_t* statePtr, unsigned int seed)
{
XXH32_state_t state; /* using a local state to memcpy() in order to avoid strict-aliasing warnings */
memset(&state, 0, sizeof(state));
state.v1 = seed + PRIME32_1 + PRIME32_2;
state.v2 = seed + PRIME32_2;
state.v3 = seed + 0;
state.v4 = seed - PRIME32_1;
/* do not write into reserved, planned to be removed in a future version */
memcpy(statePtr, &state, sizeof(state) - sizeof(state.reserved));
return XXH_OK;
}
XXH_PUBLIC_API XXH_errorcode
XXH32_update(XXH32_state_t* state, const void* input, size_t len)
{
if (input==NULL)
#if defined(XXH_ACCEPT_NULL_INPUT_POINTER) && (XXH_ACCEPT_NULL_INPUT_POINTER>=1)
return XXH_OK;
#else
return XXH_ERROR;
#endif
{ const BYTE* p = (const BYTE*)input;
const BYTE* const bEnd = p + len;
state->total_len_32 += (XXH32_hash_t)len;
state->large_len |= (XXH32_hash_t)((len>=16) | (state->total_len_32>=16));
if (state->memsize + len < 16) { /* fill in tmp buffer */
XXH_memcpy((BYTE*)(state->mem32) + state->memsize, input, len);
state->memsize += (XXH32_hash_t)len;
return XXH_OK;
}
if (state->memsize) { /* some data left from previous update */
XXH_memcpy((BYTE*)(state->mem32) + state->memsize, input, 16-state->memsize);
{ const U32* p32 = state->mem32;
state->v1 = XXH32_round(state->v1, XXH_readLE32(p32)); p32++;
state->v2 = XXH32_round(state->v2, XXH_readLE32(p32)); p32++;
state->v3 = XXH32_round(state->v3, XXH_readLE32(p32)); p32++;
state->v4 = XXH32_round(state->v4, XXH_readLE32(p32));
}
p += 16-state->memsize;
state->memsize = 0;
}
if (p <= bEnd-16) {
const BYTE* const limit = bEnd - 16;
U32 v1 = state->v1;
U32 v2 = state->v2;
U32 v3 = state->v3;
U32 v4 = state->v4;
do {
v1 = XXH32_round(v1, XXH_readLE32(p)); p+=4;
v2 = XXH32_round(v2, XXH_readLE32(p)); p+=4;
v3 = XXH32_round(v3, XXH_readLE32(p)); p+=4;
v4 = XXH32_round(v4, XXH_readLE32(p)); p+=4;
} while (p<=limit);
state->v1 = v1;
state->v2 = v2;
state->v3 = v3;
state->v4 = v4;
}
if (p < bEnd) {
XXH_memcpy(state->mem32, p, (size_t)(bEnd-p));
state->memsize = (unsigned)(bEnd-p);
}
}
return XXH_OK;
}
XXH_PUBLIC_API unsigned int XXH32_digest (const XXH32_state_t* state)
{
U32 h32;
if (state->large_len) {
h32 = XXH_rotl32(state->v1, 1)
+ XXH_rotl32(state->v2, 7)
+ XXH_rotl32(state->v3, 12)
+ XXH_rotl32(state->v4, 18);
} else {
h32 = state->v3 /* == seed */ + PRIME32_5;
}
h32 += state->total_len_32;
return XXH32_finalize(h32, state->mem32, state->memsize, XXH_aligned);
}
/*====== Canonical representation ======*/
/*! Default XXH result types are basic unsigned 32 and 64 bits.
* The canonical representation follows human-readable write convention, aka big-endian (large digits first).
* These functions allow transformation of hash result into and from its canonical format.
* This way, hash values can be written into a file or buffer, remaining comparable across different systems.
*/
XXH_PUBLIC_API void XXH32_canonicalFromHash(XXH32_canonical_t* dst, XXH32_hash_t hash)
{
XXH_STATIC_ASSERT(sizeof(XXH32_canonical_t) == sizeof(XXH32_hash_t));
if (XXH_CPU_LITTLE_ENDIAN) hash = XXH_swap32(hash);
memcpy(dst, &hash, sizeof(*dst));
}
XXH_PUBLIC_API XXH32_hash_t XXH32_hashFromCanonical(const XXH32_canonical_t* src)
{
return XXH_readBE32(src);
}
#ifndef XXH_NO_LONG_LONG
/* *******************************************************************
* 64-bit hash functions
*********************************************************************/
/*====== Memory access ======*/
#ifndef MEM_MODULE
# define MEM_MODULE
# if !defined (__VMS) \
&& (defined (__cplusplus) \
|| (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
# include <stdint.h>
typedef uint64_t U64;
# else
/* if compiler doesn't support unsigned long long, replace by another 64-bit type */
typedef unsigned long long U64;
# endif
#endif
/*! XXH_REROLL_XXH64:
* Whether to reroll the XXH64_finalize() loop.
*
* Just like XXH32, we can unroll the XXH64_finalize() loop. This can be a performance gain
* on 64-bit hosts, as only one jump is required.
*
* However, on 32-bit hosts, because arithmetic needs to be done with two 32-bit registers,
* and 64-bit arithmetic needs to be simulated, it isn't beneficial to unroll. The code becomes
* ridiculously large (the largest function in the binary on i386!), and rerolling it saves
* anywhere from 3kB to 20kB. It is also slightly faster because it fits into cache better
* and is more likely to be inlined by the compiler.
*
* If XXH_REROLL is defined, this is ignored and the loop is always rerolled. */
#ifndef XXH_REROLL_XXH64
# if (defined(__ILP32__) || defined(_ILP32)) /* ILP32 is often defined on 32-bit GCC family */ \
|| !(defined(__x86_64__) || defined(_M_X64) || defined(_M_AMD64) /* x86-64 */ \
|| defined(_M_ARM64) || defined(__aarch64__) || defined(__arm64__) /* aarch64 */ \
|| defined(__PPC64__) || defined(__PPC64LE__) || defined(__ppc64__) || defined(__powerpc64__) /* ppc64 */ \
|| defined(__mips64__) || defined(__mips64)) /* mips64 */ \
|| (!defined(SIZE_MAX) || SIZE_MAX < ULLONG_MAX) /* check limits */
# define XXH_REROLL_XXH64 1
# else
# define XXH_REROLL_XXH64 0
# endif
#endif /* !defined(XXH_REROLL_XXH64) */
#if (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==2))
/* Force direct memory access. Only works on CPU which support unaligned memory access in hardware */
static U64 XXH_read64(const void* memPtr) { return *(const U64*) memPtr; }
#elif (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==1))
/* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */
/* currently only defined for gcc and icc */
typedef union { U32 u32; U64 u64; } __attribute__((packed)) unalign64;
static U64 XXH_read64(const void* ptr) { return ((const unalign64*)ptr)->u64; }
#else
/* portable and safe solution. Generally efficient.
* see : http://stackoverflow.com/a/32095106/646947
*/
static U64 XXH_read64(const void* memPtr)
{
U64 val;
memcpy(&val, memPtr, sizeof(val));
return val;
}
#endif /* XXH_FORCE_DIRECT_MEMORY_ACCESS */
#if defined(_MSC_VER) /* Visual Studio */
# define XXH_swap64 _byteswap_uint64
#elif XXH_GCC_VERSION >= 403
# define XXH_swap64 __builtin_bswap64
#else
static U64 XXH_swap64 (U64 x)
{
return ((x << 56) & 0xff00000000000000ULL) |
((x << 40) & 0x00ff000000000000ULL) |
((x << 24) & 0x0000ff0000000000ULL) |
((x << 8) & 0x000000ff00000000ULL) |
((x >> 8) & 0x00000000ff000000ULL) |
((x >> 24) & 0x0000000000ff0000ULL) |
((x >> 40) & 0x000000000000ff00ULL) |
((x >> 56) & 0x00000000000000ffULL);
}
#endif
XXH_FORCE_INLINE U64 XXH_readLE64(const void* ptr)
{
return XXH_CPU_LITTLE_ENDIAN ? XXH_read64(ptr) : XXH_swap64(XXH_read64(ptr));
}
static U64 XXH_readBE64(const void* ptr)
{
return XXH_CPU_LITTLE_ENDIAN ? XXH_swap64(XXH_read64(ptr)) : XXH_read64(ptr);
}
XXH_FORCE_INLINE U64
XXH_readLE64_align(const void* ptr, XXH_alignment align)
{
if (align==XXH_unaligned)
return XXH_readLE64(ptr);
else
return XXH_CPU_LITTLE_ENDIAN ? *(const U64*)ptr : XXH_swap64(*(const U64*)ptr);
}
/*====== xxh64 ======*/
static const U64 PRIME64_1 = 0x9E3779B185EBCA87ULL; /* 0b1001111000110111011110011011000110000101111010111100101010000111 */
static const U64 PRIME64_2 = 0xC2B2AE3D27D4EB4FULL; /* 0b1100001010110010101011100011110100100111110101001110101101001111 */
static const U64 PRIME64_3 = 0x165667B19E3779F9ULL; /* 0b0001011001010110011001111011000110011110001101110111100111111001 */
static const U64 PRIME64_4 = 0x85EBCA77C2B2AE63ULL; /* 0b1000010111101011110010100111011111000010101100101010111001100011 */
static const U64 PRIME64_5 = 0x27D4EB2F165667C5ULL; /* 0b0010011111010100111010110010111100010110010101100110011111000101 */
static U64 XXH64_round(U64 acc, U64 input)
{
acc += input * PRIME64_2;
acc = XXH_rotl64(acc, 31);
acc *= PRIME64_1;
return acc;
}
static U64 XXH64_mergeRound(U64 acc, U64 val)
{
val = XXH64_round(0, val);
acc ^= val;
acc = acc * PRIME64_1 + PRIME64_4;
return acc;
}
static U64 XXH64_avalanche(U64 h64)
{
h64 ^= h64 >> 33;
h64 *= PRIME64_2;
h64 ^= h64 >> 29;
h64 *= PRIME64_3;
h64 ^= h64 >> 32;
return h64;
}
#define XXH_get64bits(p) XXH_readLE64_align(p, align)
static U64
XXH64_finalize(U64 h64, const void* ptr, size_t len, XXH_alignment align)
{
const BYTE* p = (const BYTE*)ptr;
#define PROCESS1_64 \
h64 ^= (*p++) * PRIME64_5; \
h64 = XXH_rotl64(h64, 11) * PRIME64_1;
#define PROCESS4_64 \
h64 ^= (U64)(XXH_get32bits(p)) * PRIME64_1; \
p+=4; \
h64 = XXH_rotl64(h64, 23) * PRIME64_2 + PRIME64_3;
#define PROCESS8_64 { \
U64 const k1 = XXH64_round(0, XXH_get64bits(p)); \
p+=8; \
h64 ^= k1; \
h64 = XXH_rotl64(h64,27) * PRIME64_1 + PRIME64_4; \
}
/* Rerolled version for 32-bit targets is faster and much smaller. */
if (XXH_REROLL || XXH_REROLL_XXH64) {
len &= 31;
while (len >= 8) {
PROCESS8_64;
len -= 8;
}
if (len >= 4) {
PROCESS4_64;
len -= 4;
}
while (len > 0) {
PROCESS1_64;
--len;
}
return XXH64_avalanche(h64);
} else {
switch(len & 31) {
case 24: PROCESS8_64;
/* fallthrough */
case 16: PROCESS8_64;
/* fallthrough */
case 8: PROCESS8_64;
return XXH64_avalanche(h64);
case 28: PROCESS8_64;
/* fallthrough */
case 20: PROCESS8_64;
/* fallthrough */
case 12: PROCESS8_64;
/* fallthrough */
case 4: PROCESS4_64;
return XXH64_avalanche(h64);
case 25: PROCESS8_64;
/* fallthrough */
case 17: PROCESS8_64;
/* fallthrough */
case 9: PROCESS8_64;
PROCESS1_64;
return XXH64_avalanche(h64);
case 29: PROCESS8_64;
/* fallthrough */
case 21: PROCESS8_64;
/* fallthrough */
case 13: PROCESS8_64;
/* fallthrough */
case 5: PROCESS4_64;
PROCESS1_64;
return XXH64_avalanche(h64);
case 26: PROCESS8_64;
/* fallthrough */
case 18: PROCESS8_64;
/* fallthrough */
case 10: PROCESS8_64;
PROCESS1_64;
PROCESS1_64;
return XXH64_avalanche(h64);
case 30: PROCESS8_64;
/* fallthrough */
case 22: PROCESS8_64;
/* fallthrough */
case 14: PROCESS8_64;
/* fallthrough */
case 6: PROCESS4_64;
PROCESS1_64;
PROCESS1_64;
return XXH64_avalanche(h64);
case 27: PROCESS8_64;
/* fallthrough */
case 19: PROCESS8_64;
/* fallthrough */
case 11: PROCESS8_64;
PROCESS1_64;
PROCESS1_64;
PROCESS1_64;
return XXH64_avalanche(h64);
case 31: PROCESS8_64;
/* fallthrough */
case 23: PROCESS8_64;
/* fallthrough */
case 15: PROCESS8_64;
/* fallthrough */
case 7: PROCESS4_64;
/* fallthrough */
case 3: PROCESS1_64;
/* fallthrough */
case 2: PROCESS1_64;
/* fallthrough */
case 1: PROCESS1_64;
/* fallthrough */
case 0: return XXH64_avalanche(h64);
}
}
/* impossible to reach */
XXH_ASSERT(0);
return 0; /* unreachable, but some compilers complain without it */
}
XXH_FORCE_INLINE U64
XXH64_endian_align(const void* input, size_t len, U64 seed, XXH_alignment align)
{
const BYTE* p = (const BYTE*)input;
const BYTE* bEnd = p + len;
U64 h64;
#if defined(XXH_ACCEPT_NULL_INPUT_POINTER) && (XXH_ACCEPT_NULL_INPUT_POINTER>=1)
if (p==NULL) {
len=0;
bEnd=p=(const BYTE*)(size_t)32;
}
#endif
if (len>=32) {
const BYTE* const limit = bEnd - 32;
U64 v1 = seed + PRIME64_1 + PRIME64_2;
U64 v2 = seed + PRIME64_2;
U64 v3 = seed + 0;
U64 v4 = seed - PRIME64_1;
do {
v1 = XXH64_round(v1, XXH_get64bits(p)); p+=8;
v2 = XXH64_round(v2, XXH_get64bits(p)); p+=8;
v3 = XXH64_round(v3, XXH_get64bits(p)); p+=8;
v4 = XXH64_round(v4, XXH_get64bits(p)); p+=8;
} while (p<=limit);
h64 = XXH_rotl64(v1, 1) + XXH_rotl64(v2, 7) + XXH_rotl64(v3, 12) + XXH_rotl64(v4, 18);
h64 = XXH64_mergeRound(h64, v1);
h64 = XXH64_mergeRound(h64, v2);
h64 = XXH64_mergeRound(h64, v3);
h64 = XXH64_mergeRound(h64, v4);
} else {
h64 = seed + PRIME64_5;
}
h64 += (U64) len;
return XXH64_finalize(h64, p, len, align);
}
XXH_PUBLIC_API XXH64_hash_t XXH64 (const void* input, size_t len, unsigned long long seed)
{
#if 0
/* Simple version, good for code maintenance, but unfortunately slow for small inputs */
XXH64_state_t state;
XXH64_reset(&state, seed);
XXH64_update(&state, input, len);
return XXH64_digest(&state);
#else
if (XXH_FORCE_ALIGN_CHECK) {
if ((((size_t)input) & 7)==0) { /* Input is aligned, let's leverage the speed advantage */
return XXH64_endian_align(input, len, seed, XXH_aligned);
} }
return XXH64_endian_align(input, len, seed, XXH_unaligned);
#endif
}
/*====== Hash Streaming ======*/
XXH_PUBLIC_API XXH64_state_t* XXH64_createState(void)
{
return (XXH64_state_t*)XXH_malloc(sizeof(XXH64_state_t));
}
XXH_PUBLIC_API XXH_errorcode XXH64_freeState(XXH64_state_t* statePtr)
{
XXH_free(statePtr);
return XXH_OK;
}
XXH_PUBLIC_API void XXH64_copyState(XXH64_state_t* dstState, const XXH64_state_t* srcState)
{
memcpy(dstState, srcState, sizeof(*dstState));
}
XXH_PUBLIC_API XXH_errorcode XXH64_reset(XXH64_state_t* statePtr, unsigned long long seed)
{
XXH64_state_t state; /* using a local state to memcpy() in order to avoid strict-aliasing warnings */
memset(&state, 0, sizeof(state));
state.v1 = seed + PRIME64_1 + PRIME64_2;
state.v2 = seed + PRIME64_2;
state.v3 = seed + 0;
state.v4 = seed - PRIME64_1;
/* do not write into reserved, might be removed in a future version */
memcpy(statePtr, &state, sizeof(state) - sizeof(state.reserved));
return XXH_OK;
}
XXH_PUBLIC_API XXH_errorcode
XXH64_update (XXH64_state_t* state, const void* input, size_t len)
{
if (input==NULL)
#if defined(XXH_ACCEPT_NULL_INPUT_POINTER) && (XXH_ACCEPT_NULL_INPUT_POINTER>=1)
return XXH_OK;
#else
return XXH_ERROR;
#endif
{ const BYTE* p = (const BYTE*)input;
const BYTE* const bEnd = p + len;
state->total_len += len;
if (state->memsize + len < 32) { /* fill in tmp buffer */
XXH_memcpy(((BYTE*)state->mem64) + state->memsize, input, len);
state->memsize += (U32)len;
return XXH_OK;
}
if (state->memsize) { /* tmp buffer is full */
XXH_memcpy(((BYTE*)state->mem64) + state->memsize, input, 32-state->memsize);
state->v1 = XXH64_round(state->v1, XXH_readLE64(state->mem64+0));
state->v2 = XXH64_round(state->v2, XXH_readLE64(state->mem64+1));
state->v3 = XXH64_round(state->v3, XXH_readLE64(state->mem64+2));
state->v4 = XXH64_round(state->v4, XXH_readLE64(state->mem64+3));
p += 32-state->memsize;
state->memsize = 0;
}
if (p+32 <= bEnd) {
const BYTE* const limit = bEnd - 32;
U64 v1 = state->v1;
U64 v2 = state->v2;
U64 v3 = state->v3;
U64 v4 = state->v4;
do {
v1 = XXH64_round(v1, XXH_readLE64(p)); p+=8;
v2 = XXH64_round(v2, XXH_readLE64(p)); p+=8;
v3 = XXH64_round(v3, XXH_readLE64(p)); p+=8;
v4 = XXH64_round(v4, XXH_readLE64(p)); p+=8;
} while (p<=limit);
state->v1 = v1;
state->v2 = v2;
state->v3 = v3;
state->v4 = v4;
}
if (p < bEnd) {
XXH_memcpy(state->mem64, p, (size_t)(bEnd-p));
state->memsize = (unsigned)(bEnd-p);
}
}
return XXH_OK;
}
XXH_PUBLIC_API XXH64_hash_t XXH64_digest (const XXH64_state_t* state)
{
U64 h64;
if (state->total_len >= 32) {
U64 const v1 = state->v1;
U64 const v2 = state->v2;
U64 const v3 = state->v3;
U64 const v4 = state->v4;
h64 = XXH_rotl64(v1, 1) + XXH_rotl64(v2, 7) + XXH_rotl64(v3, 12) + XXH_rotl64(v4, 18);
h64 = XXH64_mergeRound(h64, v1);
h64 = XXH64_mergeRound(h64, v2);
h64 = XXH64_mergeRound(h64, v3);
h64 = XXH64_mergeRound(h64, v4);
} else {
h64 = state->v3 /*seed*/ + PRIME64_5;
}
h64 += (U64) state->total_len;
return XXH64_finalize(h64, state->mem64, (size_t)state->total_len, XXH_aligned);
}
/*====== Canonical representation ======*/
XXH_PUBLIC_API void XXH64_canonicalFromHash(XXH64_canonical_t* dst, XXH64_hash_t hash)
{
XXH_STATIC_ASSERT(sizeof(XXH64_canonical_t) == sizeof(XXH64_hash_t));
if (XXH_CPU_LITTLE_ENDIAN) hash = XXH_swap64(hash);
memcpy(dst, &hash, sizeof(*dst));
}
XXH_PUBLIC_API XXH64_hash_t XXH64_hashFromCanonical(const XXH64_canonical_t* src)
{
return XXH_readBE64(src);
}
/* *********************************************************************
* XXH3
* New generation hash designed for speed on small keys and vectorization
************************************************************************ */
/* #include "xxh3.h" */
#endif /* XXH_NO_LONG_LONG */
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