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9eb91a3b53
xxHash/xxh3.h
easyaspi314 (Devin) 9eb91a3b53 Let the Great Typo Hunt commence! 
Work in progress.

 - Fix many spelling/grammar issues, primarily in comments
 - Remove most spaces before punctuation
 - Update XXH3 comment
 - Wrap most comments to 80 columns
 - Unify most comments to use the same style
 - Use hexadecimal in the xxhash spec
 - Update help messages to better match POSIX/GNU conventions
 - Use HTML escapes in README.md to avoid UTF-8
 - Mark outdated benchmark/scores
2020-03-02 15:20:49 -05:00

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/*
xxHash - Extremely Fast Hash algorithm
Development source file for `xxh3`
Copyright (C) 2019-present, 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 source repository: https://github.com/Cyan4973/xxHash
*/
/* Note :
This file is separated for development purposes.
It will be integrated into `xxhash.h` when development stage is completed.
*/
#ifndef XXH3_H_1397135465
#define XXH3_H_1397135465
/* === Dependencies === */
#ifndef XXHASH_H_5627135585666179
/* special : when including `xxh3.h` directly, turn on XXH_INLINE_ALL */
# undef XXH_INLINE_ALL /* avoid redefinition */
# define XXH_INLINE_ALL
#endif
#include "xxhash.h"
/* === Compiler specifics === */
#if defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L /* >= C99 */
# define XXH_RESTRICT restrict
#else
/* note : it might be useful to define __restrict or __restrict__ for some C++ compilers */
# define XXH_RESTRICT /* disable */
#endif
#if (defined(__GNUC__) && (__GNUC__ >= 3)) \
|| (defined(__INTEL_COMPILER) && (__INTEL_COMPILER >= 800)) \
|| defined(__clang__)
# define XXH_likely(x) __builtin_expect(x, 1)
# define XXH_unlikely(x) __builtin_expect(x, 0)
#else
# define XXH_likely(x) (x)
# define XXH_unlikely(x) (x)
#endif
#if defined(__GNUC__)
# if defined(__AVX2__)
# include <immintrin.h>
# elif defined(__SSE2__)
# include <emmintrin.h>
# elif defined(__ARM_NEON__) || defined(__ARM_NEON)
# define inline __inline__ /* clang bug */
# include <arm_neon.h>
# undef inline
# endif
#elif defined(_MSC_VER)
# include <intrin.h>
#endif
/*
* One goal of XXH3 is to make it fast on both 32-bit and 64-bit, while
* remaining a true 64-bit/128-bit hash function.
*
* This is done by prioritizing a subset of 64-bit operations that can be
* emulated without too many steps on the average 32-bit machine.
*
* For example, these two lines seem similar, and run equally fast on 64-bit:
*
* xxh_u64 x;
* x ^= (x >> 47); // good
* x ^= (x >> 13); // bad
*
* However, to a 32-bit machine, there is a major difference.
*
* x ^= (x >> 47) looks like this:
*
* x.lo ^= (x.hi >> (47 - 32));
*
* while x ^= (x >> 13) looks like this:
*
* // note: funnel shifts are not usually cheap.
* x.lo ^= (x.lo >> 13) | (x.hi << (32 - 13));
* x.hi ^= (x.hi >> 13);
*
* The first one is significantly faster than the second, simply because the
* shift is larger than 32. This means:
* - All the bits we need are in the upper 32 bits, so we can ignore the lower
* 32 bits in the shift.
* - The shift result will always fit in the lower 32 bits, and therefore,
* we can ignore the upper 32 bits in the xor.
*
* Thanks to this optimization, XXH3 only requires these features to be efficient:
*
* - Usable unaligned access
* - A 32-bit or 64-bit ALU
* - If 32-bit, a decent ADC instruction
* - A 32 or 64-bit multiply with a 64-bit result
* - For the 128-bit variant, a decent byteswap helps short inputs.
*
* The first two are already required by XXH32, and almost all 32-bit and 64-bit
* platforms which can run XXH32 can run XXH3 efficiently.
*
* Thumb-1, the classic 16-bit only subset of ARM's instruction set, is one
* notable exception.
*
* First of all, Thumb-1 lacks support for the UMULL instruction which
* performs the important long multiply. This means numerous __aeabi_lmul
* calls.
*
* Second of all, the 8 functional registers are just not enough.
* Setup for __aeabi_lmul, byteshift loads, pointers, and all arithmetic need
* Lo registers, and this shuffling results in thousands more MOVs than A32.
*
* A32 and T32 don't have this limitation. They can access all 14 registers,
* do a 32->64 multiply with UMULL, and the flexible operand allowing free
* shifts is helpful, too.
*
* Therefore, we do a quick sanity check.
*
* If compiling Thumb-1 for a target which supports ARM instructions, we will
* emit a warning, as it is not a "sane" platform to compile for.
*
* Usually, if this happens, it is because of an accident and you probably need
* to specify -march, as you likely meant to compile for a newer architecture.
*/
#if defined(__thumb__) && !defined(__thumb2__) && defined(__ARM_ARCH_ISA_ARM)
# warning "XXH3 is highly inefficient without ARM or Thumb-2."
#endif
/* ==========================================
* Vectorization detection
* ========================================== */
#define XXH_SCALAR 0 /* Portable scalar version */
#define XXH_SSE2 1 /* SSE2 for Pentium 4 and all x86_64 */
#define XXH_AVX2 2 /* AVX2 for Haswell and Bulldozer */
#define XXH_NEON 3 /* NEON for most ARMv7-A and all AArch64 */
#define XXH_VSX 4 /* VSX and ZVector for POWER8/z13 */
#ifndef XXH_VECTOR /* can be defined on command line */
# if defined(__AVX2__)
# define XXH_VECTOR XXH_AVX2
# elif defined(__SSE2__) || defined(_M_AMD64) || defined(_M_X64) || (defined(_M_IX86_FP) && (_M_IX86_FP == 2))
# define XXH_VECTOR XXH_SSE2
# elif defined(__GNUC__) /* msvc support maybe later */ \
&& (defined(__ARM_NEON__) || defined(__ARM_NEON)) \
&& (defined(__LITTLE_ENDIAN__) /* We only support little endian NEON */ \
|| (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__))
# define XXH_VECTOR XXH_NEON
# elif (defined(__PPC64__) && defined(__POWER8_VECTOR__)) \
|| (defined(__s390x__) && defined(__VEC__)) \
&& defined(__GNUC__) /* TODO: IBM XL */
# define XXH_VECTOR XXH_VSX
# else
# define XXH_VECTOR XXH_SCALAR
# endif
#endif
/*
* Controls the alignment of the accumulator.
* This is for compatibility with aligned vector loads, which are usually faster.
*/
#ifndef XXH_ACC_ALIGN
# if XXH_VECTOR == XXH_SCALAR /* scalar */
# define XXH_ACC_ALIGN 8
# elif XXH_VECTOR == XXH_SSE2 /* sse2 */
# define XXH_ACC_ALIGN 16
# elif XXH_VECTOR == XXH_AVX2 /* avx2 */
# define XXH_ACC_ALIGN 32
# elif XXH_VECTOR == XXH_NEON /* neon */
# define XXH_ACC_ALIGN 16
# elif XXH_VECTOR == XXH_VSX /* vsx */
# define XXH_ACC_ALIGN 16
# endif
#endif
/*
* UGLY HACK:
* GCC usually generates the best code with -O3 for xxHash.
*
* However, when targeting AVX2, it is overzealous in its unrolling resulting
* in code roughly 3/4 the speed of Clang.
*
* There are other issues, such as GCC splitting _mm256_loadu_si256 into
* _mm_loadu_si128 + _mm256_inserti128_si256. This is an optimization which
* only applies to Sandy and Ivy Bridge... which don't even support AVX2.
*
* That is why when compiling the AVX2 version, it is recommended to use either
* -O2 -mavx2 -march=haswell
* or
* -O2 -mavx2 -mno-avx256-split-unaligned-load
* for decent performance, or to use Clang instead.
*
* Fortunately, we can control the first one with a pragma that forces GCC into
* -O2, but the other one we can't control without "failed to inline always
* inline function due to target mismatch" warnings.
*/
#if XXH_VECTOR == XXH_AVX2 /* AVX2 */ \
&& defined(__GNUC__) && !defined(__clang__) /* GCC, not Clang */ \
&& defined(__OPTIMIZE__) && !defined(__OPTIMIZE_SIZE__) /* respect -O0 and -Os */
# pragma GCC push_options
# pragma GCC optimize("-O2")
#endif
#if XXH_VECTOR == XXH_NEON
/*
* NEON's setup for vmlal_u32 is a little more complicated than it is on
* SSE2, AVX2, and VSX.
*
* While PMULUDQ and VMULEUW both perform a mask, VMLAL.U32 performs an upcast.
*
* To do the same operation, the 128-bit 'Q' register needs to be split into
* two 64-bit 'D' registers, performing this operation::
*
* [ a | b ]
* | '---------. .--------' |
* | x |
* | .---------' '--------. |
* [ a & 0xFFFFFFFF | b & 0xFFFFFFFF ],[ a >> 32 | b >> 32 ]
*
* Due to significant changes in aarch64, the fastest method for aarch64 is
* completely different than the fastest method for ARMv7-A.
*
* ARMv7-A treats D registers as unions overlaying Q registers, so modifying
* D11 will modify the high half of Q5. This is similar to how modifying AH
* will only affect bits 8-15 of AX on x86.
*
* VZIP takes two registers, and puts even lanes in one register and odd lanes
* in the other.
*
* On ARMv7-A, this strangely modifies both parameters in place instead of
* taking the usual 3-operand form.
*
* Therefore, if we want to do this, we can simply use a D-form VZIP.32 on the
* lower and upper halves of the Q register to end up with the high and low
* halves where we want - all in one instruction.
*
* vzip.32 d10, d11 @ d10 = { d10[0], d11[0] }; d11 = { d10[1], d11[1] }
*
* Unfortunately we need inline assembly for this: Instructions modifying two
* registers at once is not possible in GCC or Clang's IR, and they have to
* create a copy.
*
* aarch64 requires a different approach.
*
* In order to make it easier to write a decent compiler for aarch64, many
* quirks were removed, such as conditional execution.
*
* NEON was also affected by this.
*
* aarch64 cannot access the high bits of a Q-form register, and writes to a
* D-form register zero the high bits, similar to how writes to W-form scalar
* registers (or DWORD registers on x86_64) work.
*
* The formerly free vget_high intrinsics now require a vext (with a few
* exceptions)
*
* Additionally, VZIP was replaced by ZIP1 and ZIP2, which are the equivalent
* of PUNPCKL* and PUNPCKH* in SSE, respectively, in order to only modify one
* operand.
*
* The equivalent of the VZIP.32 on the lower and upper halves would be this
* mess:
*
* ext v2.4s, v0.4s, v0.4s, #2 // v2 = { v0[2], v0[3], v0[0], v0[1] }
* zip1 v1.2s, v0.2s, v2.2s // v1 = { v0[0], v2[0] }
* zip2 v0.2s, v0.2s, v1.2s // v0 = { v0[1], v2[1] }
*
* Instead, we use a literal downcast, vmovn_u64 (XTN), and vshrn_n_u64 (SHRN):
*
* shrn v1.2s, v0.2d, #32 // v1 = (uint32x2_t)(v0 >> 32);
* xtn v0.2s, v0.2d // v0 = (uint32x2_t)(v0 & 0xFFFFFFFF);
*
* This is available on ARMv7-A, but is less efficient than a single VZIP.32.
*/
/*
* Function-like macro:
* void XXH_SPLIT_IN_PLACE(uint64x2_t &in, uint32x2_t &outLo, uint32x2_t &outHi)
* {
* outLo = (uint32x2_t)(in & 0xFFFFFFFF);
* outHi = (uint32x2_t)(in >> 32);
* in = UNDEFINED;
* }
*/
# if !defined(XXH_NO_VZIP_HACK) /* define to disable */ \
&& defined(__GNUC__) \
&& !defined(__aarch64__) && !defined(__arm64__)
# define XXH_SPLIT_IN_PLACE(in, outLo, outHi) \
do { \
/* Undocumented GCC/Clang operand modifier: %e0 = lower D half, %f0 = upper D half */ \
/* https://github.com/gcc-mirror/gcc/blob/38cf91e5/gcc/config/arm/arm.c#L22486 */ \
/* https://github.com/llvm-mirror/llvm/blob/2c4ca683/lib/Target/ARM/ARMAsmPrinter.cpp#L399 */ \
__asm__("vzip.32 %e0, %f0" : "+w" (in)); \
(outLo) = vget_low_u32 (vreinterpretq_u32_u64(in)); \
(outHi) = vget_high_u32(vreinterpretq_u32_u64(in)); \
} while (0)
# else
# define XXH_SPLIT_IN_PLACE(in, outLo, outHi) \
do { \
(outLo) = vmovn_u64 (in); \
(outHi) = vshrn_n_u64 ((in), 32); \
} while (0)
# endif
#endif /* XXH_VECTOR == XXH_NEON */
/*
* VSX and Z Vector helpers.
*
* This is very messy, and any pull requests to clean this up are welcome.
*
* There are a lot of problems with supporting VSX and s390x, due to
* inconsistent intrinsics, spotty coverage, and multiple endiannesses.
*/
#if XXH_VECTOR == XXH_VSX
# if defined(__s390x__)
# include <s390intrin.h>
# else
# include <altivec.h>
# endif
# undef vector /* Undo the pollution */
typedef __vector unsigned long long xxh_u64x2;
typedef __vector unsigned char xxh_u8x16;
typedef __vector unsigned xxh_u32x4;
# ifndef XXH_VSX_BE
# if defined(__BIG_ENDIAN__) \
|| (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
# define XXH_VSX_BE 1
# elif defined(__VEC_ELEMENT_REG_ORDER__) && __VEC_ELEMENT_REG_ORDER__ == __ORDER_BIG_ENDIAN__
# warning "-maltivec=be is not recommended. Please use native endianness."
# define XXH_VSX_BE 1
# else
# define XXH_VSX_BE 0
# endif
# endif /* !defined(XXH_VSX_BE) */
# if XXH_VSX_BE
/* A wrapper for POWER9's vec_revb. */
# if defined(__POWER9_VECTOR__) || (defined(__clang__) && defined(__s390x__))
# define XXH_vec_revb vec_revb
# else
XXH_FORCE_INLINE xxh_u64x2 XXH_vec_revb(xxh_u64x2 val)
{
xxh_u8x16 const vByteSwap = { 0x07, 0x06, 0x05, 0x04, 0x03, 0x02, 0x01, 0x00,
0x0F, 0x0E, 0x0D, 0x0C, 0x0B, 0x0A, 0x09, 0x08 };
return vec_perm(val, val, vByteSwap);
}
# endif
# endif /* XXH_VSX_BE */
/*
* Performs an unaligned load and byte swaps it on big endian.
*/
XXH_FORCE_INLINE xxh_u64x2 XXH_vec_loadu(const void *ptr)
{
xxh_u64x2 ret;
memcpy(&ret, ptr, sizeof(xxh_u64x2));
# if XXH_VSX_BE
ret = XXH_vec_revb(ret);
# endif
return ret;
}
/*
* vec_mulo and vec_mule are very problematic intrinsics on PowerPC
*
* These intrinsics weren't added until GCC 8, despite existing for a while,
* and they are endian dependent. Also, their meaning swap depending on version.
* */
# if defined(__s390x__)
/* s390x is always big endian, no issue on this platform */
# define XXH_vec_mulo vec_mulo
# define XXH_vec_mule vec_mule
# elif defined(__clang__) && __has_builtin(__builtin_altivec_vmuleuw)
/* Clang has a better way to control this, we can just use the builtin which doesn't swap. */
# define XXH_vec_mulo __builtin_altivec_vmulouw
# define XXH_vec_mule __builtin_altivec_vmuleuw
# else
/* gcc needs inline assembly */
/* Adapted from https://github.com/google/highwayhash/blob/master/highwayhash/hh_vsx.h. */
XXH_FORCE_INLINE xxh_u64x2 XXH_vec_mulo(xxh_u32x4 a, xxh_u32x4 b)
{
xxh_u64x2 result;
__asm__("vmulouw %0, %1, %2" : "=v" (result) : "v" (a), "v" (b));
return result;
}
XXH_FORCE_INLINE xxh_u64x2 XXH_vec_mule(xxh_u32x4 a, xxh_u32x4 b)
{
xxh_u64x2 result;
__asm__("vmuleuw %0, %1, %2" : "=v" (result) : "v" (a), "v" (b));
return result;
}
# endif /* XXH_vec_mulo, XXH_vec_mule */
#endif /* XXH_VECTOR == XXH_VSX */
/* prefetch
* can be disabled, by declaring XXH_NO_PREFETCH build macro */
#if defined(XXH_NO_PREFETCH)
# define XXH_PREFETCH(ptr) (void)(ptr) /* disabled */
#else
# if defined(_MSC_VER) && (defined(_M_X64) || defined(_M_I86)) /* _mm_prefetch() is not defined outside of x86/x64 */
# include <mmintrin.h> /* https://msdn.microsoft.com/fr-fr/library/84szxsww(v=vs.90).aspx */
# define XXH_PREFETCH(ptr) _mm_prefetch((const char*)(ptr), _MM_HINT_T0)
# elif defined(__GNUC__) && ( (__GNUC__ >= 4) || ( (__GNUC__ == 3) && (__GNUC_MINOR__ >= 1) ) )
# define XXH_PREFETCH(ptr) __builtin_prefetch((ptr), 0 /* rw==read */, 3 /* locality */)
# else
# define XXH_PREFETCH(ptr) (void)(ptr) /* disabled */
# endif
#endif /* XXH_NO_PREFETCH */
/* ==========================================
* XXH3 default settings
* ========================================== */
#define XXH_SECRET_DEFAULT_SIZE 192 /* minimum XXH3_SECRET_SIZE_MIN */
#if (XXH_SECRET_DEFAULT_SIZE < XXH3_SECRET_SIZE_MIN)
# error "default keyset is not large enough"
#endif
/* Pseudorandom secret taken directly from FARSH */
XXH_ALIGN(64) static const xxh_u8 kSecret[XXH_SECRET_DEFAULT_SIZE] = {
0xb8, 0xfe, 0x6c, 0x39, 0x23, 0xa4, 0x4b, 0xbe, 0x7c, 0x01, 0x81, 0x2c, 0xf7, 0x21, 0xad, 0x1c,
0xde, 0xd4, 0x6d, 0xe9, 0x83, 0x90, 0x97, 0xdb, 0x72, 0x40, 0xa4, 0xa4, 0xb7, 0xb3, 0x67, 0x1f,
0xcb, 0x79, 0xe6, 0x4e, 0xcc, 0xc0, 0xe5, 0x78, 0x82, 0x5a, 0xd0, 0x7d, 0xcc, 0xff, 0x72, 0x21,
0xb8, 0x08, 0x46, 0x74, 0xf7, 0x43, 0x24, 0x8e, 0xe0, 0x35, 0x90, 0xe6, 0x81, 0x3a, 0x26, 0x4c,
0x3c, 0x28, 0x52, 0xbb, 0x91, 0xc3, 0x00, 0xcb, 0x88, 0xd0, 0x65, 0x8b, 0x1b, 0x53, 0x2e, 0xa3,
0x71, 0x64, 0x48, 0x97, 0xa2, 0x0d, 0xf9, 0x4e, 0x38, 0x19, 0xef, 0x46, 0xa9, 0xde, 0xac, 0xd8,
0xa8, 0xfa, 0x76, 0x3f, 0xe3, 0x9c, 0x34, 0x3f, 0xf9, 0xdc, 0xbb, 0xc7, 0xc7, 0x0b, 0x4f, 0x1d,
0x8a, 0x51, 0xe0, 0x4b, 0xcd, 0xb4, 0x59, 0x31, 0xc8, 0x9f, 0x7e, 0xc9, 0xd9, 0x78, 0x73, 0x64,
0xea, 0xc5, 0xac, 0x83, 0x34, 0xd3, 0xeb, 0xc3, 0xc5, 0x81, 0xa0, 0xff, 0xfa, 0x13, 0x63, 0xeb,
0x17, 0x0d, 0xdd, 0x51, 0xb7, 0xf0, 0xda, 0x49, 0xd3, 0x16, 0x55, 0x26, 0x29, 0xd4, 0x68, 0x9e,
0x2b, 0x16, 0xbe, 0x58, 0x7d, 0x47, 0xa1, 0xfc, 0x8f, 0xf8, 0xb8, 0xd1, 0x7a, 0xd0, 0x31, 0xce,
0x45, 0xcb, 0x3a, 0x8f, 0x95, 0x16, 0x04, 0x28, 0xaf, 0xd7, 0xfb, 0xca, 0xbb, 0x4b, 0x40, 0x7e,
};
/* xxh_u64 XXH_mult32to64(xxh_u32 a, xxh_u32 b) { return (xxh_u64)a * (xxh_u64)b; } */
#if defined(_MSC_VER) && defined(_M_IX86)
# include <intrin.h>
# define XXH_mult32to64(x, y) __emulu(x, y)
#else
# define XXH_mult32to64(x, y) ((xxh_u64)(xxh_u32)(x) * (xxh_u64)(xxh_u32)(y))
#endif
/*
* GCC for x86 has a tendency to use SSE in this loop. While it successfully
* avoids swapping (as MUL overwrites EAX and EDX), it slows it down because
* instead of free register swap shifts, it must use PSHUFD and PUNPCKL/HD
*
* To prevent this, we use this attribute to shut off SSE.
*/
#if defined(__GNUC__) && !defined(__clang__) && defined(__i386__)
__attribute__((__target__("no-sse")))
#endif
static XXH128_hash_t
XXH_mult64to128(xxh_u64 lhs, xxh_u64 rhs)
{
/*
* GCC/Clang __uint128_t method.
*
* On most 64-bit targets, GCC and Clang define a __uint128_t type.
* This is usually the best way as it usually uses a native long 64-bit
* multiply, such as MULQ on x86_64 or MUL + UMULH on aarch64.
*
* Usually.
*
* Despite being a 32-bit platform, Clang (and emscripten) define this type
* despite not having the arithmetic for it. This results in a laggy
* compiler builtin call which calculates a full 128-bit multiply.
* In that case it is best to use the portable one.
* https://github.com/Cyan4973/xxHash/issues/211#issuecomment-515575677
*/
#if defined(__GNUC__) && !defined(__wasm__) \
&& defined(__SIZEOF_INT128__) \
|| (defined(_INTEGRAL_MAX_BITS) && _INTEGRAL_MAX_BITS >= 128)
__uint128_t product = (__uint128_t)lhs * (__uint128_t)rhs;
XXH128_hash_t const r128 = { (xxh_u64)(product), (xxh_u64)(product >> 64) };
return r128;
/*
* MSVC for x64's _umul128 method.
*
* xxh_u64 _umul128(xxh_u64 Multiplier, xxh_u64 Multiplicand, xxh_u64 *HighProduct);
*
* This compiles to single operand MUL on x64.
*/
#elif defined(_M_X64) || defined(_M_IA64)
#ifndef _MSC_VER
# pragma intrinsic(_umul128)
#endif
xxh_u64 product_high;
xxh_u64 const product_low = _umul128(lhs, rhs, &product_high);
XXH128_hash_t const r128 = { product_low, product_high };
return r128;
#else
/*
* Portable scalar method. Optimized for 32-bit and 64-bit ALUs.
*
* This is a fast and simple grade school multiply, which is shown below
* with base 10 arithmetic instead of base 0x100000000.
*
* 9 3 // D2 lhs = 93
* x 7 5 // D2 rhs = 75
* ----------
* 1 5 // D2 lo_lo = (93 % 10) * (75 % 10) = 15
* 4 5 | // D2 hi_lo = (93 / 10) * (75 % 10) = 45
* 2 1 | // D2 lo_hi = (93 % 10) * (75 / 10) = 21
* + 6 3 | | // D2 hi_hi = (93 / 10) * (75 / 10) = 63
* ---------
* 2 7 | // D2 cross = (15 / 10) + (45 % 10) + 21 = 27
* + 6 7 | | // D2 upper = (27 / 10) + (45 / 10) + 63 = 67
* ---------
* 6 9 7 5 // D4 res = (27 * 10) + (15 % 10) + (67 * 100) = 6975
*
* The reasons for adding the products like this are:
* 1. It avoids manual carry tracking. Just like how
* (9 * 9) + 9 + 9 = 99, the same applies with this for UINT64_MAX.
* This avoids a lot of complexity.
*
* 2. It hints for, and on Clang, compiles to, the powerful UMAAL
* instruction available in ARM's Digital Signal Processing extension
* in 32-bit ARMv6 and later, which is shown below:
*
* void UMAAL(xxh_u32 *RdLo, xxh_u32 *RdHi, xxh_u32 Rn, xxh_u32 Rm)
* {
* xxh_u64 product = (xxh_u64)*RdLo * (xxh_u64)*RdHi + Rn + Rm;
* *RdLo = (xxh_u32)(product & 0xFFFFFFFF);
* *RdHi = (xxh_u32)(product >> 32);
* }
*
* This instruction was designed for efficient long multiplication, and
* allows this to be calculated in only 4 instructions at speeds
* comparable to some 64-bit ALUs.
*
* 3. It isn't terrible on other platforms. Usually this will be a couple
* of 32-bit ADD/ADCs.
*/
/* First calculate all of the cross products. */
xxh_u64 const lo_lo = XXH_mult32to64(lhs & 0xFFFFFFFF, rhs & 0xFFFFFFFF);
xxh_u64 const hi_lo = XXH_mult32to64(lhs >> 32, rhs & 0xFFFFFFFF);
xxh_u64 const lo_hi = XXH_mult32to64(lhs & 0xFFFFFFFF, rhs >> 32);
xxh_u64 const hi_hi = XXH_mult32to64(lhs >> 32, rhs >> 32);
/* Now add the products together. These will never overflow. */
xxh_u64 const cross = (lo_lo >> 32) + (hi_lo & 0xFFFFFFFF) + lo_hi;
xxh_u64 const upper = (hi_lo >> 32) + (cross >> 32) + hi_hi;
xxh_u64 const lower = (cross << 32) | (lo_lo & 0xFFFFFFFF);
XXH128_hash_t r128 = { lower, upper };
return r128;
#endif
}
/*
* We want to keep the attribute here because a target switch disables inlining.
*
* Does a 64-bit to 128-bit multiply, then XOR folds it.
*
* The reason for the separate function is to prevent passing too many structs
* around by value. This will hopefully inline the multiply, but we don't force it.
*/
#if defined(__GNUC__) && !defined(__clang__) && defined(__i386__)
__attribute__((__target__("no-sse")))
#endif
static xxh_u64
XXH3_mul128_fold64(xxh_u64 lhs, xxh_u64 rhs)
{
XXH128_hash_t product = XXH_mult64to128(lhs, rhs);
return product.low64 ^ product.high64;
}
/* Seems to produce slightly better code on GCC for some reason. */
XXH_FORCE_INLINE xxh_u64 XXH_xorshift64(xxh_u64 v64, int shift)
{
XXH_ASSERT(0 <= shift && shift < 64);
return v64 ^ (v64 >> shift);
}
/*
* We don't need to (or want to) mix as much as XXH64.
*
* Short hashes are more evenly distributed, so it isn't necessary.
*/
static XXH64_hash_t XXH3_avalanche(xxh_u64 h64)
{
h64 = XXH_xorshift64(h64, 37);
h64 *= 0x165667919E3779F9ULL;
h64 = XXH_xorshift64(h64, 32);
return h64;
}
/* ==========================================
* Short keys
* ==========================================
* One of the shortcomings of XXH32 and XXH64 was that their performance was
* sub-optimal on short lengths. It used an iterative algorithm which strongly
* favored lengths that were a multiple of 4 or 8.
*
* Instead of iterating over individual inputs, we use a set of single shot
* functions which piece together a range of lengths and operate in constant time.
*
* Additionally, the number of multiplies has been significantly reduced. This
* reduces latency, especially when emulating 64-bit multiplies on 32-bit.
*
* Depending on the platform, this may or may not be faster than XXH32, but it
* is almost guaranteed to be faster than XXH64.
*/
XXH_FORCE_INLINE XXH64_hash_t
XXH3_len_1to3_64b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
{
XXH_ASSERT(input != NULL);
XXH_ASSERT(1 <= len && len <= 3);
XXH_ASSERT(secret != NULL);
/*
* len = 1: combined = { input[0], 0x01, input[0], input[0] }
* len = 2: combined = { input[1], 0x02, input[0], input[1] }
* len = 3: combined = { input[2], 0x03, input[0], input[1] }
*/
{ xxh_u8 const c1 = input[0];
xxh_u8 const c2 = input[len >> 1];
xxh_u8 const c3 = input[len - 1];
xxh_u32 const combined = ((xxh_u32)c1<<16) | (((xxh_u32)c2) << 24) | (((xxh_u32)c3) << 0) | (((xxh_u32)len) << 8);
xxh_u64 const bitflip = (XXH_readLE32(secret) ^ XXH_readLE32(secret+4)) + seed;
xxh_u64 const keyed = (xxh_u64)combined ^ bitflip;
xxh_u64 const mixed = keyed * PRIME64_1;
return XXH3_avalanche(mixed);
}
}
XXH_FORCE_INLINE XXH64_hash_t
XXH3_len_4to8_64b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
{
XXH_ASSERT(input != NULL);
XXH_ASSERT(secret != NULL);
XXH_ASSERT(4 <= len && len < 8);
seed ^= (xxh_u64)XXH_swap32((xxh_u32)seed) << 32;
{ xxh_u32 const input1 = XXH_readLE32(input);
xxh_u32 const input2 = XXH_readLE32(input + len - 4);
xxh_u32 const bitflip1 = (XXH_readLE32(secret+8) ^ XXH_readLE32(secret+12)) + (xxh_u32)(seed >> 32);
xxh_u32 const bitflip2 = (XXH_readLE32(secret+16) ^ XXH_readLE32(secret+20)) - (xxh_u32)seed;
xxh_u32 const key1 = XXH_swap32(input1) ^ bitflip1;
xxh_u32 const key2 = input2 ^ bitflip2;
xxh_u64 const mix = XXH_mult32to64(key1, key2)
+ ((xxh_u64)input1 << 32)
+ ((xxh_u64)(XXH_rotl32(input2,23)) << 32)
+ len;
return XXH3_avalanche(XXH_xorshift64(mix, 59));
}
}
XXH_FORCE_INLINE XXH64_hash_t
XXH3_len_9to16_64b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
{
XXH_ASSERT(input != NULL);
XXH_ASSERT(secret != NULL);
XXH_ASSERT(8 <= len && len <= 16);
{ xxh_u64 const bitflip1 = (XXH_readLE64(secret+24) ^ XXH_readLE64(secret+32)) + seed;
xxh_u64 const bitflip2 = (XXH_readLE64(secret+40) ^ XXH_readLE64(secret+48)) - seed;
xxh_u64 const input_lo = XXH_readLE64(input) ^ bitflip1;
xxh_u64 const input_hi = XXH_readLE64(input + len - 8) ^ bitflip2;
xxh_u64 const acc = len
+ XXH_swap64(input_lo) + input_hi
+ XXH3_mul128_fold64(input_lo, input_hi);
return XXH3_avalanche(acc);
}
}
XXH_FORCE_INLINE XXH64_hash_t
XXH3_len_0to16_64b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
{
XXH_ASSERT(len <= 16);
{ if (XXH_likely(len > 8)) return XXH3_len_9to16_64b(input, len, secret, seed);
if (XXH_likely(len >= 4)) return XXH3_len_4to8_64b(input, len, secret, seed);
if (len) return XXH3_len_1to3_64b(input, len, secret, seed);
return XXH3_avalanche((PRIME64_1 + seed) ^ (XXH_readLE64(secret+56) ^ XXH_readLE64(secret+64)));
}
}
/*
* DISCLAIMER: There are known *seed-dependent* multicollisions here due to
* multiplication by zero, affecting hashes of lengths 17 to 240.
*
* However, they are very unlikely.
*
* Keep this in mind when using the unseeded XXH3_64bits() variant: As with all
* unseeded non-cryptographic hashes, it does not attempt to defend itself
* against specially crafted inputs, only random inputs.
*
* Compared to classic UMAC where a 1 in 2^31 chance of 4 consecutive bytes
* cancelling out the secret is taken an arbitrary number of times (addressed
* in XXH3_accumulate_512), this collision is very unlikely with random inputs
* and/or proper seeding:
*
* This only has a 1 in 2^63 chance of 8 consecutive bytes cancelling out, in a
* function that is only called up to 16 times per hash with up to 240 bytes of
* input.
*
* This is not too bad for a non-cryptographic hash function, especially with
* only 64 bit outputs.
*
* The 128-bit variant (which trades some speed for strength) is NOT affected
* by this, although it is always a good idea to use a proper seed if you care
* about strength.
*/
XXH_FORCE_INLINE xxh_u64 XXH3_mix16B(const xxh_u8* XXH_RESTRICT input,
const xxh_u8* XXH_RESTRICT secret, xxh_u64 seed64)
{
xxh_u64 const input_lo = XXH_readLE64(input);
xxh_u64 const input_hi = XXH_readLE64(input+8);
return XXH3_mul128_fold64(
input_lo ^ (XXH_readLE64(secret) + seed64),
input_hi ^ (XXH_readLE64(secret+8) - seed64) );
}
/* For mid range keys, XXH3 uses a Mum-hash variant. */
XXH_FORCE_INLINE XXH64_hash_t
XXH3_len_17to128_64b(const xxh_u8* XXH_RESTRICT input, size_t len,
const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
XXH64_hash_t seed)
{
XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN); (void)secretSize;
XXH_ASSERT(16 < len && len <= 128);
{ xxh_u64 acc = len * PRIME64_1;
if (len > 32) {
if (len > 64) {
if (len > 96) {
acc += XXH3_mix16B(input+48, secret+96, seed);
acc += XXH3_mix16B(input+len-64, secret+112, seed);
}
acc += XXH3_mix16B(input+32, secret+64, seed);
acc += XXH3_mix16B(input+len-48, secret+80, seed);
}
acc += XXH3_mix16B(input+16, secret+32, seed);
acc += XXH3_mix16B(input+len-32, secret+48, seed);
}
acc += XXH3_mix16B(input+0, secret+0, seed);
acc += XXH3_mix16B(input+len-16, secret+16, seed);
return XXH3_avalanche(acc);
}
}
#define XXH3_MIDSIZE_MAX 240
XXH_NO_INLINE XXH64_hash_t
XXH3_len_129to240_64b(const xxh_u8* XXH_RESTRICT input, size_t len,
const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
XXH64_hash_t seed)
{
XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN); (void)secretSize;
XXH_ASSERT(128 < len && len <= XXH3_MIDSIZE_MAX);
#define XXH3_MIDSIZE_STARTOFFSET 3
#define XXH3_MIDSIZE_LASTOFFSET 17
{ xxh_u64 acc = len * PRIME64_1;
int const nbRounds = (int)len / 16;
int i;
for (i=0; i<8; i++) {
acc += XXH3_mix16B(input+(16*i), secret+(16*i), seed);
}
acc = XXH3_avalanche(acc);
XXH_ASSERT(nbRounds >= 8);
for (i=8 ; i < nbRounds; i++) {
acc += XXH3_mix16B(input+(16*i), secret+(16*(i-8)) + XXH3_MIDSIZE_STARTOFFSET, seed);
}
/* last bytes */
acc += XXH3_mix16B(input + len - 16, secret + XXH3_SECRET_SIZE_MIN - XXH3_MIDSIZE_LASTOFFSET, seed);
return XXH3_avalanche(acc);
}
}
/* === Long Keys === */
#define STRIPE_LEN 64
#define XXH_SECRET_CONSUME_RATE 8 /* nb of secret bytes consumed at each accumulation */
#define ACC_NB (STRIPE_LEN / sizeof(xxh_u64))
typedef enum { XXH3_acc_64bits, XXH3_acc_128bits } XXH3_accWidth_e;
/*
* XXH3_accumulate_512 is the tightest loop for long inputs, and it is the most optimized.
*
* It is a hardened version of UMAC, based off of FARSH's implementation.
*
* This was chosen because it adapts quite well to 32-bit, 64-bit, and SIMD
* implementations, and it is ridiculously fast.
*
* We harden it by mixing the original input to the accumulators as well as the product.
*
* This means that in the (relatively likely) case of a multiply by zero, the
* original input is preserved.
*
* On 128-bit inputs, we swap 64-bit pairs when we add the input to improve
* cross-pollination, as otherwise the upper and lower halves would be
* essentially independent.
*
* This doesn't matter on 64-bit hashes since they all get merged together in
* the end, so we skip the extra step.
*
* Both XXH3_64bits and XXH3_128bits use this subroutine.
*/
XXH_FORCE_INLINE void
XXH3_accumulate_512( void* XXH_RESTRICT acc,
const void* XXH_RESTRICT input,
const void* XXH_RESTRICT secret,
XXH3_accWidth_e accWidth)
{
#if (XXH_VECTOR == XXH_AVX2)
XXH_ASSERT((((size_t)acc) & 31) == 0);
{ XXH_ALIGN(32) __m256i* const xacc = (__m256i *) acc;
/* Unaligned. This is mainly for pointer arithmetic, and because
* _mm256_loadu_si256 requires a const __m256i * pointer for some reason. */
const __m256i* const xinput = (const __m256i *) input;
/* Unaligned. This is mainly for pointer arithmetic, and because
* _mm256_loadu_si256 requires a const __m256i * pointer for some reason. */
const __m256i* const xsecret = (const __m256i *) secret;
size_t i;
for (i=0; i < STRIPE_LEN/sizeof(__m256i); i++) {
/* data_vec = xinput[i]; */
__m256i const data_vec = _mm256_loadu_si256 (xinput+i);
/* key_vec = xsecret[i]; */
__m256i const key_vec = _mm256_loadu_si256 (xsecret+i);
/* data_key = data_vec ^ key_vec; */
__m256i const data_key = _mm256_xor_si256 (data_vec, key_vec);
/* data_key_lo = data_key >> 32; */
__m256i const data_key_lo = _mm256_shuffle_epi32 (data_key, _MM_SHUFFLE(0, 3, 0, 1));
/* product = (data_key & 0xffffffff) * (data_key_lo & 0xffffffff); */
__m256i const product = _mm256_mul_epu32 (data_key, data_key_lo);
if (accWidth == XXH3_acc_128bits) {
/* xacc[i] += swap(data_vec); */
__m256i const data_swap = _mm256_shuffle_epi32(data_vec, _MM_SHUFFLE(1, 0, 3, 2));
__m256i const sum = _mm256_add_epi64(xacc[i], data_swap);
/* xacc[i] += product; */
xacc[i] = _mm256_add_epi64(product, sum);
} else { /* XXH3_acc_64bits */
/* xacc[i] += data_vec; */
__m256i const sum = _mm256_add_epi64(xacc[i], data_vec);
/* xacc[i] += product; */
xacc[i] = _mm256_add_epi64(product, sum);
}
} }
#elif (XXH_VECTOR == XXH_SSE2)
/* SSE2 is just a half-scale version of the AVX2 version. */
XXH_ASSERT((((size_t)acc) & 15) == 0);
{ XXH_ALIGN(16) __m128i* const xacc = (__m128i *) acc;
/* Unaligned. This is mainly for pointer arithmetic, and because
* _mm_loadu_si128 requires a const __m128i * pointer for some reason. */
const __m128i* const xinput = (const __m128i *) input;
/* Unaligned. This is mainly for pointer arithmetic, and because
* _mm_loadu_si128 requires a const __m128i * pointer for some reason. */
const __m128i* const xsecret = (const __m128i *) secret;
size_t i;
for (i=0; i < STRIPE_LEN/sizeof(__m128i); i++) {
/* data_vec = xinput[i]; */
__m128i const data_vec = _mm_loadu_si128 (xinput+i);
/* key_vec = xsecret[i]; */
__m128i const key_vec = _mm_loadu_si128 (xsecret+i);
/* data_key = data_vec ^ key_vec; */
__m128i const data_key = _mm_xor_si128 (data_vec, key_vec);
/* data_key_lo = data_key >> 32; */
__m128i const data_key_lo = _mm_shuffle_epi32 (data_key, _MM_SHUFFLE(0, 3, 0, 1));
/* product = (data_key & 0xffffffff) * (data_key_lo & 0xffffffff); */
__m128i const product = _mm_mul_epu32 (data_key, data_key_lo);
if (accWidth == XXH3_acc_128bits) {
/* xacc[i] += swap(data_vec); */
__m128i const data_swap = _mm_shuffle_epi32(data_vec, _MM_SHUFFLE(1,0,3,2));
__m128i const sum = _mm_add_epi64(xacc[i], data_swap);
/* xacc[i] += product; */
xacc[i] = _mm_add_epi64(product, sum);
} else { /* XXH3_acc_64bits */
/* xacc[i] += data_vec; */
__m128i const sum = _mm_add_epi64(xacc[i], data_vec);
/* xacc[i] += product; */
xacc[i] = _mm_add_epi64(product, sum);
}
} }
#elif (XXH_VECTOR == XXH_NEON)
XXH_ASSERT((((size_t)acc) & 15) == 0);
{
XXH_ALIGN(16) uint64x2_t* const xacc = (uint64x2_t *) acc;
/* We don't use a uint32x4_t pointer because it causes bus errors on ARMv7. */
uint8_t const* const xinput = (const uint8_t *) input;
uint8_t const* const xsecret = (const uint8_t *) secret;
size_t i;
for (i=0; i < STRIPE_LEN / sizeof(uint64x2_t); i++) {
/* data_vec = xinput[i]; */
uint8x16_t data_vec = vld1q_u8(xinput + (i * 16));
/* key_vec = xsecret[i]; */
uint8x16_t key_vec = vld1q_u8(xsecret + (i * 16));
/* data_key = data_vec ^ key_vec; */
uint64x2_t data_key = vreinterpretq_u64_u8(veorq_u8(data_vec, key_vec));
uint32x2_t data_key_lo, data_key_hi;
if (accWidth == XXH3_acc_64bits) {
/* xacc[i] += data_vec; */
xacc[i] = vaddq_u64 (xacc[i], vreinterpretq_u64_u8(data_vec));
} else { /* XXH3_acc_128bits */
/* xacc[i] += swap(data_vec); */
uint64x2_t const data64 = vreinterpretq_u64_u8(data_vec);
uint64x2_t const swapped = vextq_u64(data64, data64, 1);
xacc[i] = vaddq_u64 (xacc[i], swapped);
}
/* data_key_lo = (uint32x2_t) (data_key & 0xFFFFFFFF);
* data_key_hi = (uint32x2_t) (data_key >> 32);
* data_key = UNDEFINED; */
XXH_SPLIT_IN_PLACE(data_key, data_key_lo, data_key_hi);
/* xacc[i] += (uint64x2_t) data_key_lo * (uint64x2_t) data_key_hi; */
xacc[i] = vmlal_u32 (xacc[i], data_key_lo, data_key_hi);
}
}
#elif (XXH_VECTOR == XXH_VSX)
xxh_u64x2* const xacc = (xxh_u64x2*) acc; /* presumed aligned */
xxh_u64x2 const* const xinput = (xxh_u64x2 const*) input; /* no alignment restriction */
xxh_u64x2 const* const xsecret = (xxh_u64x2 const*) secret; /* no alignment restriction */
xxh_u64x2 const v32 = { 32, 32 };
size_t i;
for (i = 0; i < STRIPE_LEN / sizeof(xxh_u64x2); i++) {
/* data_vec = xinput[i]; */
xxh_u64x2 const data_vec = XXH_vec_loadu(xinput + i);
/* key_vec = xsecret[i]; */
xxh_u64x2 const key_vec = XXH_vec_loadu(xsecret + i);
xxh_u64x2 const data_key = data_vec ^ key_vec;
/* shuffled = (data_key << 32) | (data_key >> 32); */
xxh_u32x4 const shuffled = (xxh_u32x4)vec_rl(data_key, v32);
/* product = ((xxh_u64x2)data_key & 0xFFFFFFFF) * ((xxh_u64x2)shuffled & 0xFFFFFFFF); */
xxh_u64x2 const product = XXH_vec_mulo((xxh_u32x4)data_key, shuffled);
xacc[i] += product;
if (accWidth == XXH3_acc_64bits) {
xacc[i] += data_vec;
} else { /* XXH3_acc_128bits */
/* swap high and low halves */
#ifdef __s390x__
xxh_u64x2 const data_swapped = vec_permi(data_vec, data_vec, 2);
#else
xxh_u64x2 const data_swapped = vec_xxpermdi(data_vec, data_vec, 2);
#endif
xacc[i] += data_swapped;
}
}
#else /* scalar variant of Accumulator - universal */
XXH_ALIGN(XXH_ACC_ALIGN) xxh_u64* const xacc = (xxh_u64*) acc; /* presumed aligned */
const xxh_u8* const xinput = (const xxh_u8*) input; /* no alignment restriction */
const xxh_u8* const xsecret = (const xxh_u8*) secret; /* no alignment restriction */
size_t i;
XXH_ASSERT(((size_t)acc & (XXH_ACC_ALIGN-1)) == 0);
for (i=0; i < ACC_NB; i++) {
xxh_u64 const data_val = XXH_readLE64(xinput + 8*i);
xxh_u64 const data_key = data_val ^ XXH_readLE64(xsecret + i*8);
if (accWidth == XXH3_acc_64bits) {
xacc[i] += data_val;
} else {
xacc[i ^ 1] += data_val; /* swap adjacent lanes */
}
xacc[i] += XXH_mult32to64(data_key & 0xFFFFFFFF, data_key >> 32);
}
#endif
}
/*
* XXH3_scrambleAcc: Scrambles the accumulators to improve mixing.
*
* Multiplication isn't perfect, as explained by Google in HighwayHash:
*
* // Multiplication mixes/scrambles bytes 0-7 of the 64-bit result to
* // varying degrees. In descending order of goodness, bytes
* // 3 4 2 5 1 6 0 7 have quality 228 224 164 160 100 96 36 32.
* // As expected, the upper and lower bytes are much worse.
*
* Source: https://github.com/google/highwayhash/blob/0aaf66b/highwayhash/hh_avx2.h#L291
*
* Since our algorithm uses a pseudorandom secret to add some variance into the
* mix, we don't need to (or want to) mix as often or as much as HighwayHash does.
*
* This isn't as tight as XXH3_accumulate, but still written in SIMD to avoid
* extraction.
*
* Both XXH3_64bits and XXH3_128bits use this subroutine.
*/
XXH_FORCE_INLINE void
XXH3_scrambleAcc(void* XXH_RESTRICT acc, const void* XXH_RESTRICT secret)
{
#if (XXH_VECTOR == XXH_AVX2)
XXH_ASSERT((((size_t)acc) & 31) == 0);
{ XXH_ALIGN(32) __m256i* const xacc = (__m256i*) acc;
/* Unaligned. This is mainly for pointer arithmetic, and because
* _mm256_loadu_si256 requires a const __m256i * pointer for some reason. */
const __m256i* const xsecret = (const __m256i *) secret;
const __m256i prime32 = _mm256_set1_epi32((int)PRIME32_1);
size_t i;
for (i=0; i < STRIPE_LEN/sizeof(__m256i); i++) {
/* xacc[i] ^= (xacc[i] >> 47) */
__m256i const acc_vec = xacc[i];
__m256i const shifted = _mm256_srli_epi64 (acc_vec, 47);
__m256i const data_vec = _mm256_xor_si256 (acc_vec, shifted);
/* xacc[i] ^= xsecret; */
__m256i const key_vec = _mm256_loadu_si256 (xsecret+i);
__m256i const data_key = _mm256_xor_si256 (data_vec, key_vec);
/* xacc[i] *= PRIME32_1; */
__m256i const data_key_hi = _mm256_shuffle_epi32 (data_key, _MM_SHUFFLE(0, 3, 0, 1));
__m256i const prod_lo = _mm256_mul_epu32 (data_key, prime32);
__m256i const prod_hi = _mm256_mul_epu32 (data_key_hi, prime32);
xacc[i] = _mm256_add_epi64(prod_lo, _mm256_slli_epi64(prod_hi, 32));
}
}
#elif (XXH_VECTOR == XXH_SSE2)
XXH_ASSERT((((size_t)acc) & 15) == 0);
{ XXH_ALIGN(16) __m128i* const xacc = (__m128i*) acc;
/* Unaligned. This is mainly for pointer arithmetic, and because
* _mm_loadu_si128 requires a const __m128i * pointer for some reason. */
const __m128i* const xsecret = (const __m128i *) secret;
const __m128i prime32 = _mm_set1_epi32((int)PRIME32_1);
size_t i;
for (i=0; i < STRIPE_LEN/sizeof(__m128i); i++) {
/* xacc[i] ^= (xacc[i] >> 47) */
__m128i const acc_vec = xacc[i];
__m128i const shifted = _mm_srli_epi64 (acc_vec, 47);
__m128i const data_vec = _mm_xor_si128 (acc_vec, shifted);
/* xacc[i] ^= xsecret[i]; */
__m128i const key_vec = _mm_loadu_si128 (xsecret+i);
__m128i const data_key = _mm_xor_si128 (data_vec, key_vec);
/* xacc[i] *= PRIME32_1; */
__m128i const data_key_hi = _mm_shuffle_epi32 (data_key, _MM_SHUFFLE(0, 3, 0, 1));
__m128i const prod_lo = _mm_mul_epu32 (data_key, prime32);
__m128i const prod_hi = _mm_mul_epu32 (data_key_hi, prime32);
xacc[i] = _mm_add_epi64(prod_lo, _mm_slli_epi64(prod_hi, 32));
}
}
#elif (XXH_VECTOR == XXH_NEON)
XXH_ASSERT((((size_t)acc) & 15) == 0);
{ uint64x2_t* xacc = (uint64x2_t*) acc;
uint8_t const* xsecret = (uint8_t const*) secret;
uint32x2_t prime = vdup_n_u32 (PRIME32_1);
size_t i;
for (i=0; i < STRIPE_LEN/sizeof(uint64x2_t); i++) {
/* xacc[i] ^= (xacc[i] >> 47); */
uint64x2_t acc_vec = xacc[i];
uint64x2_t shifted = vshrq_n_u64 (acc_vec, 47);
uint64x2_t data_vec = veorq_u64 (acc_vec, shifted);
/* xacc[i] ^= xsecret[i]; */
uint8x16_t key_vec = vld1q_u8(xsecret + (i * 16));
uint64x2_t data_key = veorq_u64(data_vec, vreinterpretq_u64_u8(key_vec));
/* xacc[i] *= PRIME32_1 */
uint32x2_t data_key_lo, data_key_hi;
/* data_key_lo = (uint32x2_t) (xacc[i] & 0xFFFFFFFF);
* data_key_hi = (uint32x2_t) (xacc[i] >> 32);
* xacc[i] = UNDEFINED; */
XXH_SPLIT_IN_PLACE(data_key, data_key_lo, data_key_hi);
{ /*
* prod_hi = (data_key >> 32) * PRIME32_1;
*
* Avoid vmul_u32 + vshll_n_u32 since Clang 6 and 7 will
* incorrectly "optimize" this:
* tmp = vmul_u32(vmovn_u64(a), vmovn_u64(b));
* shifted = vshll_n_u32(tmp, 32);
* to this:
* tmp = "vmulq_u64"(a, b); // no such thing!
* shifted = vshlq_n_u64(tmp, 32);
*
* However, unlike SSE, Clang lacks a 64-bit multiply routine
* for NEON, and it scalarizes two 64-bit multiplies instead.
*
* vmull_u32 has the same timing as vmul_u32, and it avoids
* this bug completely.
* See https://bugs.llvm.org/show_bug.cgi?id=39967
*/
uint64x2_t prod_hi = vmull_u32 (data_key_hi, prime);
/* xacc[i] = prod_hi << 32; */
xacc[i] = vshlq_n_u64(prod_hi, 32);
/* xacc[i] += (prod_hi & 0xFFFFFFFF) * PRIME32_1; */
xacc[i] = vmlal_u32(xacc[i], data_key_lo, prime);
}
} }
#elif (XXH_VECTOR == XXH_VSX)
XXH_ASSERT((((size_t)acc) & 15) == 0);
{ xxh_u64x2* const xacc = (xxh_u64x2*) acc;
const xxh_u64x2* const xsecret = (const xxh_u64x2*) secret;
/* constants */
xxh_u64x2 const v32 = { 32, 32 };
xxh_u64x2 const v47 = { 47, 47 };
xxh_u32x4 const prime = { PRIME32_1, PRIME32_1, PRIME32_1, PRIME32_1 };
size_t i;
for (i = 0; i < STRIPE_LEN / sizeof(xxh_u64x2); i++) {
/* xacc[i] ^= (xacc[i] >> 47); */
xxh_u64x2 const acc_vec = xacc[i];
xxh_u64x2 const data_vec = acc_vec ^ (acc_vec >> v47);
/* xacc[i] ^= xsecret[i]; */
xxh_u64x2 const key_vec = XXH_vec_loadu(xsecret + i);
xxh_u64x2 const data_key = data_vec ^ key_vec;
/* xacc[i] *= PRIME32_1 */
/* prod_lo = ((xxh_u64x2)data_key & 0xFFFFFFFF) * ((xxh_u64x2)prime & 0xFFFFFFFF); */
xxh_u64x2 const prod_even = XXH_vec_mule((xxh_u32x4)data_key, prime);
/* prod_hi = ((xxh_u64x2)data_key >> 32) * ((xxh_u64x2)prime >> 32); */
xxh_u64x2 const prod_odd = XXH_vec_mulo((xxh_u32x4)data_key, prime);
xacc[i] = prod_odd + (prod_even << v32);
} }
#else /* scalar variant of Scrambler - universal */
XXH_ALIGN(XXH_ACC_ALIGN) xxh_u64* const xacc = (xxh_u64*) acc; /* presumed aligned */
const xxh_u8* const xsecret = (const xxh_u8*) secret; /* no alignment restriction */
size_t i;
XXH_ASSERT((((size_t)acc) & (XXH_ACC_ALIGN-1)) == 0);
for (i=0; i < ACC_NB; i++) {
xxh_u64 const key64 = XXH_readLE64(xsecret + 8*i);
xxh_u64 acc64 = xacc[i];
acc64 = XXH_xorshift64(acc64, 47);
acc64 ^= key64;
acc64 *= PRIME32_1;
xacc[i] = acc64;
}
#endif
}
#define XXH_PREFETCH_DIST 384
/* assumption : nbStripes will not overflow secret size */
XXH_FORCE_INLINE void
XXH3_accumulate( xxh_u64* XXH_RESTRICT acc,
const xxh_u8* XXH_RESTRICT input,
const xxh_u8* XXH_RESTRICT secret,
size_t nbStripes,
XXH3_accWidth_e accWidth)
{
size_t n;
for (n = 0; n < nbStripes; n++ ) {
const xxh_u8* const in = input + n*STRIPE_LEN;
XXH_PREFETCH(in + XXH_PREFETCH_DIST);
XXH3_accumulate_512(acc,
in,
secret + n*XXH_SECRET_CONSUME_RATE,
accWidth);
}
}
/* note : clang auto-vectorizes well in SS2 mode _if_ this function is `static`,
* and doesn't auto-vectorize it at all if it is `FORCE_INLINE`.
* However, it auto-vectorizes better AVX2 if it is `FORCE_INLINE`
* Pretty much every other modes and compilers prefer `FORCE_INLINE`.
*/
#if defined(__clang__) && (XXH_VECTOR==0) && !defined(__AVX2__) && !defined(__arm__) && !defined(__thumb__)
static void
#else
XXH_FORCE_INLINE void
#endif
XXH3_hashLong_internal_loop( xxh_u64* XXH_RESTRICT acc,
const xxh_u8* XXH_RESTRICT input, size_t len,
const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
XXH3_accWidth_e accWidth)
{
size_t const nb_rounds = (secretSize - STRIPE_LEN) / XXH_SECRET_CONSUME_RATE;
size_t const block_len = STRIPE_LEN * nb_rounds;
size_t const nb_blocks = len / block_len;
size_t n;
XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN);
for (n = 0; n < nb_blocks; n++) {
XXH3_accumulate(acc, input + n*block_len, secret, nb_rounds, accWidth);
XXH3_scrambleAcc(acc, secret + secretSize - STRIPE_LEN);
}
/* last partial block */
XXH_ASSERT(len > STRIPE_LEN);
{ size_t const nbStripes = (len - (block_len * nb_blocks)) / STRIPE_LEN;
XXH_ASSERT(nbStripes <= (secretSize / XXH_SECRET_CONSUME_RATE));
XXH3_accumulate(acc, input + nb_blocks*block_len, secret, nbStripes, accWidth);
/* last stripe */
if (len & (STRIPE_LEN - 1)) {
const xxh_u8* const p = input + len - STRIPE_LEN;
/* Do not align on 8, so that the secret is different from the scrambler */
#define XXH_SECRET_LASTACC_START 7
XXH3_accumulate_512(acc, p, secret + secretSize - STRIPE_LEN - XXH_SECRET_LASTACC_START, accWidth);
} }
}
XXH_FORCE_INLINE xxh_u64
XXH3_mix2Accs(const xxh_u64* XXH_RESTRICT acc, const xxh_u8* XXH_RESTRICT secret)
{
return XXH3_mul128_fold64(
acc[0] ^ XXH_readLE64(secret),
acc[1] ^ XXH_readLE64(secret+8) );
}
static XXH64_hash_t
XXH3_mergeAccs(const xxh_u64* XXH_RESTRICT acc, const xxh_u8* XXH_RESTRICT secret, xxh_u64 start)
{
xxh_u64 result64 = start;
result64 += XXH3_mix2Accs(acc+0, secret + 0);
result64 += XXH3_mix2Accs(acc+2, secret + 16);
result64 += XXH3_mix2Accs(acc+4, secret + 32);
result64 += XXH3_mix2Accs(acc+6, secret + 48);
return XXH3_avalanche(result64);
}
#define XXH3_INIT_ACC { PRIME32_3, PRIME64_1, PRIME64_2, PRIME64_3, \
PRIME64_4, PRIME32_2, PRIME64_5, PRIME32_1 };
XXH_FORCE_INLINE XXH64_hash_t
XXH3_hashLong_internal(const xxh_u8* XXH_RESTRICT input, size_t len,
const xxh_u8* XXH_RESTRICT secret, size_t secretSize)
{
XXH_ALIGN(XXH_ACC_ALIGN) xxh_u64 acc[ACC_NB] = XXH3_INIT_ACC;
XXH3_hashLong_internal_loop(acc, input, len, secret, secretSize, XXH3_acc_64bits);
/* converge into final hash */
XXH_STATIC_ASSERT(sizeof(acc) == 64);
/* do not align on 8, so that the secret is different from the accumulator */
#define XXH_SECRET_MERGEACCS_START 11
XXH_ASSERT(secretSize >= sizeof(acc) + XXH_SECRET_MERGEACCS_START);
return XXH3_mergeAccs(acc, secret + XXH_SECRET_MERGEACCS_START, (xxh_u64)len * PRIME64_1);
}
/*
* It's important for performance that XXH3_hashLong is not inlined. Not sure
* why (uop cache maybe?), but the difference is large and easily measurable.
*/
XXH_NO_INLINE XXH64_hash_t
XXH3_hashLong_64b_defaultSecret(const xxh_u8* XXH_RESTRICT input, size_t len)
{
return XXH3_hashLong_internal(input, len, kSecret, sizeof(kSecret));
}
/*
* It's important for performance that XXH3_hashLong is not inlined. Not sure
* why (uop cache maybe?), but the difference is large and easily measurable.
*/
XXH_NO_INLINE XXH64_hash_t
XXH3_hashLong_64b_withSecret(const xxh_u8* XXH_RESTRICT input, size_t len,
const xxh_u8* XXH_RESTRICT secret, size_t secretSize)
{
return XXH3_hashLong_internal(input, len, secret, secretSize);
}
XXH_FORCE_INLINE void XXH_writeLE64(void* dst, xxh_u64 v64)
{
if (!XXH_CPU_LITTLE_ENDIAN) v64 = XXH_swap64(v64);
memcpy(dst, &v64, sizeof(v64));
}
/* XXH3_initCustomSecret() :
* destination `customSecret` is presumed allocated and same size as `kSecret`.
*/
XXH_FORCE_INLINE void XXH3_initCustomSecret(xxh_u8* customSecret, xxh_u64 seed64)
{
int const nbRounds = XXH_SECRET_DEFAULT_SIZE / 16;
int i;
XXH_STATIC_ASSERT((XXH_SECRET_DEFAULT_SIZE & 15) == 0);
for (i=0; i < nbRounds; i++) {
XXH_writeLE64(customSecret + 16*i, XXH_readLE64(kSecret + 16*i) + seed64);
XXH_writeLE64(customSecret + 16*i + 8, XXH_readLE64(kSecret + 16*i + 8) - seed64);
}
}
/*
* XXH3_hashLong_64b_withSeed():
* Generate a custom key based on alteration of default kSecret with the seed,
* and then use this key for long mode hashing.
*
* This operation is decently fast but nonetheless costs a little bit of time.
* Try to avoid it whenever possible (typically when seed==0).
*
* It's important for performance that XXH3_hashLong is not inlined. Not sure
* why (uop cache maybe?), but the difference is large and easily measurable.
*/
XXH_NO_INLINE XXH64_hash_t
XXH3_hashLong_64b_withSeed(const xxh_u8* input, size_t len, XXH64_hash_t seed)
{
XXH_ALIGN(8) xxh_u8 secret[XXH_SECRET_DEFAULT_SIZE];
if (seed==0) return XXH3_hashLong_64b_defaultSecret(input, len);
XXH3_initCustomSecret(secret, seed);
return XXH3_hashLong_internal(input, len, secret, sizeof(secret));
}
/* === Public entry point === */
XXH_PUBLIC_API XXH64_hash_t XXH3_64bits(const void* input, size_t len)
{
if (len <= 16) return XXH3_len_0to16_64b((const xxh_u8*)input, len, kSecret, 0);
if (len <= 128) return XXH3_len_17to128_64b((const xxh_u8*)input, len, kSecret, sizeof(kSecret), 0);
if (len <= XXH3_MIDSIZE_MAX) return XXH3_len_129to240_64b((const xxh_u8*)input, len, kSecret, sizeof(kSecret), 0);
return XXH3_hashLong_64b_defaultSecret((const xxh_u8*)input, len);
}
XXH_PUBLIC_API XXH64_hash_t
XXH3_64bits_withSecret(const void* input, size_t len, const void* secret, size_t secretSize)
{
XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN);
/*
* If an action is to be taken if `secret` conditions are not respected,
* it should be done here.
* For now, it's a contract pre-condition.
* Adding a check and a branch here would cost performance at every hash.
*/
if (len <= 16) return XXH3_len_0to16_64b((const xxh_u8*)input, len, (const xxh_u8*)secret, 0);
if (len <= 128) return XXH3_len_17to128_64b((const xxh_u8*)input, len, (const xxh_u8*)secret, secretSize, 0);
if (len <= XXH3_MIDSIZE_MAX) return XXH3_len_129to240_64b((const xxh_u8*)input, len, (const xxh_u8*)secret, secretSize, 0);
return XXH3_hashLong_64b_withSecret((const xxh_u8*)input, len, (const xxh_u8*)secret, secretSize);
}
XXH_PUBLIC_API XXH64_hash_t
XXH3_64bits_withSeed(const void* input, size_t len, XXH64_hash_t seed)
{
if (len <= 16) return XXH3_len_0to16_64b((const xxh_u8*)input, len, kSecret, seed);
if (len <= 128) return XXH3_len_17to128_64b((const xxh_u8*)input, len, kSecret, sizeof(kSecret), seed);
if (len <= XXH3_MIDSIZE_MAX) return XXH3_len_129to240_64b((const xxh_u8*)input, len, kSecret, sizeof(kSecret), seed);
return XXH3_hashLong_64b_withSeed((const xxh_u8*)input, len, seed);
}
/* === XXH3 streaming === */
XXH_PUBLIC_API XXH3_state_t* XXH3_createState(void)
{
return (XXH3_state_t*)XXH_malloc(sizeof(XXH3_state_t));
}
XXH_PUBLIC_API XXH_errorcode XXH3_freeState(XXH3_state_t* statePtr)
{
XXH_free(statePtr);
return XXH_OK;
}
XXH_PUBLIC_API void
XXH3_copyState(XXH3_state_t* dst_state, const XXH3_state_t* src_state)
{
memcpy(dst_state, src_state, sizeof(*dst_state));
}
static void
XXH3_64bits_reset_internal(XXH3_state_t* statePtr,
XXH64_hash_t seed,
const xxh_u8* secret, size_t secretSize)
{
XXH_ASSERT(statePtr != NULL);
memset(statePtr, 0, sizeof(*statePtr));
statePtr->acc[0] = PRIME32_3;
statePtr->acc[1] = PRIME64_1;
statePtr->acc[2] = PRIME64_2;
statePtr->acc[3] = PRIME64_3;
statePtr->acc[4] = PRIME64_4;
statePtr->acc[5] = PRIME32_2;
statePtr->acc[6] = PRIME64_5;
statePtr->acc[7] = PRIME32_1;
statePtr->seed = seed;
XXH_ASSERT(secret != NULL);
statePtr->secret = secret;
XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN);
statePtr->secretLimit = (XXH32_hash_t)(secretSize - STRIPE_LEN);
statePtr->nbStripesPerBlock = statePtr->secretLimit / XXH_SECRET_CONSUME_RATE;
}
XXH_PUBLIC_API XXH_errorcode
XXH3_64bits_reset(XXH3_state_t* statePtr)
{
if (statePtr == NULL) return XXH_ERROR;
XXH3_64bits_reset_internal(statePtr, 0, kSecret, XXH_SECRET_DEFAULT_SIZE);
return XXH_OK;
}
XXH_PUBLIC_API XXH_errorcode
XXH3_64bits_reset_withSecret(XXH3_state_t* statePtr, const void* secret, size_t secretSize)
{
if (statePtr == NULL) return XXH_ERROR;
XXH3_64bits_reset_internal(statePtr, 0, (const xxh_u8*)secret, secretSize);
if (secret == NULL) return XXH_ERROR;
if (secretSize < XXH3_SECRET_SIZE_MIN) return XXH_ERROR;
return XXH_OK;
}
XXH_PUBLIC_API XXH_errorcode
XXH3_64bits_reset_withSeed(XXH3_state_t* statePtr, XXH64_hash_t seed)
{
if (statePtr == NULL) return XXH_ERROR;
XXH3_64bits_reset_internal(statePtr, seed, kSecret, XXH_SECRET_DEFAULT_SIZE);
XXH3_initCustomSecret(statePtr->customSecret, seed);
statePtr->secret = statePtr->customSecret;
return XXH_OK;
}
XXH_FORCE_INLINE void
XXH3_consumeStripes( xxh_u64* acc,
XXH32_hash_t* nbStripesSoFarPtr, XXH32_hash_t nbStripesPerBlock,
const xxh_u8* input, size_t totalStripes,
const xxh_u8* secret, size_t secretLimit,
XXH3_accWidth_e accWidth)
{
XXH_ASSERT(*nbStripesSoFarPtr < nbStripesPerBlock);
if (nbStripesPerBlock - *nbStripesSoFarPtr <= totalStripes) {
/* need a scrambling operation */
size_t const nbStripes = nbStripesPerBlock - *nbStripesSoFarPtr;
XXH3_accumulate(acc, input, secret + nbStripesSoFarPtr[0] * XXH_SECRET_CONSUME_RATE, nbStripes, accWidth);
XXH3_scrambleAcc(acc, secret + secretLimit);
XXH3_accumulate(acc, input + nbStripes * STRIPE_LEN, secret, totalStripes - nbStripes, accWidth);
*nbStripesSoFarPtr = (XXH32_hash_t)(totalStripes - nbStripes);
} else {
XXH3_accumulate(acc, input, secret + nbStripesSoFarPtr[0] * XXH_SECRET_CONSUME_RATE, totalStripes, accWidth);
*nbStripesSoFarPtr += (XXH32_hash_t)totalStripes;
}
}
/*
* Both XXH3_64bits_update and XXH3_128bits_update use this routine.
*/
XXH_FORCE_INLINE XXH_errorcode
XXH3_update(XXH3_state_t* state, const xxh_u8* input, size_t len, XXH3_accWidth_e accWidth)
{
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 xxh_u8* const bEnd = input + len;
state->totalLen += len;
if (state->bufferedSize + len <= XXH3_INTERNALBUFFER_SIZE) { /* fill in tmp buffer */
XXH_memcpy(state->buffer + state->bufferedSize, input, len);
state->bufferedSize += (XXH32_hash_t)len;
return XXH_OK;
}
/* input is now > XXH3_INTERNALBUFFER_SIZE */
#define XXH3_INTERNALBUFFER_STRIPES (XXH3_INTERNALBUFFER_SIZE / STRIPE_LEN)
XXH_STATIC_ASSERT(XXH3_INTERNALBUFFER_SIZE % STRIPE_LEN == 0); /* clean multiple */
/*
* There is some input left inside the internal buffer.
* Fill it, then consume it.
*/
if (state->bufferedSize) {
size_t const loadSize = XXH3_INTERNALBUFFER_SIZE - state->bufferedSize;
XXH_memcpy(state->buffer + state->bufferedSize, input, loadSize);
input += loadSize;
XXH3_consumeStripes(state->acc,
&state->nbStripesSoFar, state->nbStripesPerBlock,
state->buffer, XXH3_INTERNALBUFFER_STRIPES,
state->secret, state->secretLimit,
accWidth);
state->bufferedSize = 0;
}
/* Consume input by full buffer quantities */
if (input+XXH3_INTERNALBUFFER_SIZE <= bEnd) {
const xxh_u8* const limit = bEnd - XXH3_INTERNALBUFFER_SIZE;
do {
XXH3_consumeStripes(state->acc,
&state->nbStripesSoFar, state->nbStripesPerBlock,
input, XXH3_INTERNALBUFFER_STRIPES,
state->secret, state->secretLimit,
accWidth);
input += XXH3_INTERNALBUFFER_SIZE;
} while (input<=limit);
}
if (input < bEnd) { /* Some remaining input: buffer it */
XXH_memcpy(state->buffer, input, (size_t)(bEnd-input));
state->bufferedSize = (XXH32_hash_t)(bEnd-input);
}
}
return XXH_OK;
}
XXH_PUBLIC_API XXH_errorcode
XXH3_64bits_update(XXH3_state_t* state, const void* input, size_t len)
{
return XXH3_update(state, (const xxh_u8*)input, len, XXH3_acc_64bits);
}
XXH_FORCE_INLINE void
XXH3_digest_long (XXH64_hash_t* acc, const XXH3_state_t* state, XXH3_accWidth_e accWidth)
{
/*
* Digest on a local copy. This way, the state remains unaltered, and it can
* continue ingesting more input afterwards.
*/
memcpy(acc, state->acc, sizeof(state->acc));
if (state->bufferedSize >= STRIPE_LEN) {
size_t const totalNbStripes = state->bufferedSize / STRIPE_LEN;
XXH32_hash_t nbStripesSoFar = state->nbStripesSoFar;
XXH3_consumeStripes(acc,
&nbStripesSoFar, state->nbStripesPerBlock,
state->buffer, totalNbStripes,
state->secret, state->secretLimit,
accWidth);
if (state->bufferedSize % STRIPE_LEN) { /* one last partial stripe */
XXH3_accumulate_512(acc,
state->buffer + state->bufferedSize - STRIPE_LEN,
state->secret + state->secretLimit - XXH_SECRET_LASTACC_START,
accWidth);
}
} else { /* bufferedSize < STRIPE_LEN */
if (state->bufferedSize) { /* one last stripe */
xxh_u8 lastStripe[STRIPE_LEN];
size_t const catchupSize = STRIPE_LEN - state->bufferedSize;
memcpy(lastStripe, state->buffer + sizeof(state->buffer) - catchupSize, catchupSize);
memcpy(lastStripe + catchupSize, state->buffer, state->bufferedSize);
XXH3_accumulate_512(acc,
lastStripe,
state->secret + state->secretLimit - XXH_SECRET_LASTACC_START,
accWidth);
} }
}
XXH_PUBLIC_API XXH64_hash_t XXH3_64bits_digest (const XXH3_state_t* state)
{
if (state->totalLen > XXH3_MIDSIZE_MAX) {
XXH_ALIGN(XXH_ACC_ALIGN) XXH64_hash_t acc[ACC_NB];
XXH3_digest_long(acc, state, XXH3_acc_64bits);
return XXH3_mergeAccs(acc, state->secret + XXH_SECRET_MERGEACCS_START, (xxh_u64)state->totalLen * PRIME64_1);
}
/* len <= XXH3_MIDSIZE_MAX : short code */
if (state->seed)
return XXH3_64bits_withSeed(state->buffer, (size_t)state->totalLen, state->seed);
return XXH3_64bits_withSecret(state->buffer, (size_t)(state->totalLen), state->secret, state->secretLimit + STRIPE_LEN);
}
/* ==========================================
* XXH3 128 bits (=> XXH128)
* ========================================== */
XXH_FORCE_INLINE XXH128_hash_t
XXH3_len_1to3_128b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
{
XXH_ASSERT(input != NULL);
XXH_ASSERT(1 <= len && len <= 3);
XXH_ASSERT(secret != NULL);
/*
* len = 1: combinedl = { input[0], 0x01, input[0], input[0] }
* len = 2: combinedl = { input[1], 0x02, input[0], input[1] }
* len = 3: combinedl = { input[2], 0x03, input[0], input[1] }
*/
{ xxh_u8 const c1 = input[0];
xxh_u8 const c2 = input[len >> 1];
xxh_u8 const c3 = input[len - 1];
xxh_u32 const combinedl = ((xxh_u32)c1<<16) | (((xxh_u32)c2) << 24) | (((xxh_u32)c3) << 0) | (((xxh_u32)len) << 8);
xxh_u32 const combinedh = XXH_rotl32(XXH_swap32(combinedl), 13);
xxh_u64 const bitflipl = (XXH_readLE32(secret) ^ XXH_readLE32(secret+4)) + seed;
xxh_u64 const bitfliph = (XXH_readLE32(secret+8) ^ XXH_readLE32(secret+12)) - seed;
xxh_u64 const keyed_lo = (xxh_u64)combinedl ^ bitflipl;
xxh_u64 const keyed_hi = (xxh_u64)combinedh ^ bitfliph;
xxh_u64 const mixedl = keyed_lo * PRIME64_1;
xxh_u64 const mixedh = keyed_hi * PRIME64_5;
XXH128_hash_t const h128 = { XXH3_avalanche(mixedl) /*low64*/, XXH3_avalanche(mixedh) /*high64*/ };
return h128;
}
}
XXH_FORCE_INLINE XXH128_hash_t
XXH3_len_4to8_128b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
{
XXH_ASSERT(input != NULL);
XXH_ASSERT(secret != NULL);
XXH_ASSERT(4 <= len && len <= 8);
seed ^= (xxh_u64)XXH_swap32((xxh_u32)seed) << 32;
{ xxh_u32 const input_lo = XXH_readLE32(input);
xxh_u32 const input_hi = XXH_readLE32(input + len - 4);
xxh_u64 const input_64 = input_lo + ((xxh_u64)input_hi << 32);
xxh_u64 const bitflip = (XXH_readLE64(secret+16) ^ XXH_readLE64(secret+24)) + seed;
xxh_u64 const keyed = input_64 ^ bitflip;
/* Shift len to the left to ensure it is even, this avoids even multiplies. */
XXH128_hash_t m128 = XXH_mult64to128(keyed, PRIME64_1 + (len << 2));
m128.high64 += (m128.low64 << 1);
m128.low64 ^= (m128.high64 >> 3);
m128.low64 = XXH3_avalanche(m128.low64);
m128.high64 = XXH3_avalanche(m128.high64);
return m128;
}
}
XXH_FORCE_INLINE XXH128_hash_t
XXH3_len_9to16_128b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
{
XXH_ASSERT(input != NULL);
XXH_ASSERT(secret != NULL);
XXH_ASSERT(9 <= len && len <= 16);
{ xxh_u64 const bitflipl = XXH_readLE64(secret+32) ^ XXH_readLE64(secret+40);
xxh_u64 const bitfliph = (XXH_readLE64(secret+48) ^ XXH_readLE64(secret+56)) - seed;
xxh_u64 const input_lo = XXH_readLE64(input) ^ bitflipl;
xxh_u64 const input_hi = XXH_readLE64(input + len - 8) ^ bitfliph;
XXH128_hash_t m128 = XXH_mult64to128(input_lo ^ input_hi, PRIME64_1);
/*
* Put len in the middle of m128 to ensure that the length gets mixed to
* both the low and high bits in the 128x64 multiply below.
*/
m128.low64 += (xxh_u64)(len - 1) << 54;
/*
* Add the high 32 bits of input_hi to the high 32 bits of m128, then
* add the long product of the low 32 bits of input_hi and PRIME32_2 to
* the high 64 bits of m128.
*
* The best approach to this operation is different on 32-bit and 64-bit.
*/
if (sizeof(void *) < sizeof(xxh_u64)) { /* 32-bit */
/*
* 32-bit optimized version, which is more readable.
*
* On 32-bit, it removes an ADC and delays a dependency between the two
* halves of m128.high64, but it generates an extra mask on 64-bit.
*/
m128.high64 += (input_hi & 0xFFFFFFFF00000000) + XXH_mult32to64((xxh_u32)input_hi, PRIME32_2);
} else {
/*
* 64-bit optimized (albeit more confusing) version.
*
* Uses some properties of addition and multiplication to remove the mask:
*
* Let:
* a = input_hi.lo = (input_hi & 0x00000000FFFFFFFF)
* b = input_hi.hi = (input_hi & 0xFFFFFFFF00000000)
* c = PRIME32_2
*
* a + (b * c)
* Inverse Property: x + y - x == y
* a + (b * (1 + c - 1))
* Distributive Property: x * (y + z) == (x * y) + (x * z)
* a + (b * 1) + (b * (c - 1))
* Identity Property: x * 1 == x
* a + b + (b * (c - 1))
*
* Substitute a, b, and c:
* input_hi.hi + input_hi.lo + ((xxh_u64)input_hi.lo * (PRIME32_2 - 1))
*
* Since input_hi.hi + input_hi.lo == input_hi, we get this:
* input_hi + ((xxh_u64)input_hi.lo * (PRIME32_2 - 1))
*/
m128.high64 += input_hi + XXH_mult32to64((xxh_u32)input_hi, PRIME32_2 - 1);
}
/* m128 ^= XXH_swap64(m128 >> 64); */
m128.low64 ^= XXH_swap64(m128.high64);
{ /* 128x64 multiply: h128 = m128 * PRIME64_2; */
XXH128_hash_t h128 = XXH_mult64to128(m128.low64, PRIME64_2);
h128.high64 += m128.high64 * PRIME64_2;
h128.low64 = XXH3_avalanche(h128.low64);
h128.high64 = XXH3_avalanche(h128.high64);
return h128;
} }
}
/* Assumption : `secret` size is >= 16
* Note : it should be >= XXH3_SECRET_SIZE_MIN anyway */
XXH_FORCE_INLINE XXH128_hash_t
XXH3_len_0to16_128b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
{
XXH_ASSERT(len <= 16);
{ if (len > 8) return XXH3_len_9to16_128b(input, len, secret, seed);
if (len >= 4) return XXH3_len_4to8_128b(input, len, secret, seed);
if (len) return XXH3_len_1to3_128b(input, len, secret, seed);
{ XXH128_hash_t h128;
xxh_u64 const bitflipl = XXH_readLE64(secret+64) ^ XXH_readLE64(secret+72);
xxh_u64 const bitfliph = XXH_readLE64(secret+80) ^ XXH_readLE64(secret+88);
h128.low64 = XXH3_avalanche((PRIME64_1 + seed) ^ bitflipl);
h128.high64 = XXH3_avalanche((PRIME64_2 - seed) ^ bitfliph);
return h128;
} }
}
/*
* A bit slower than XXH3_mix16B, but handles multiply by zero better.
*/
XXH_FORCE_INLINE XXH128_hash_t
XXH128_mix32B(XXH128_hash_t acc, const xxh_u8* input_1, const xxh_u8* input_2, const xxh_u8* secret, XXH64_hash_t seed)
{
acc.low64 += XXH3_mix16B (input_1, secret+0, seed);
acc.low64 ^= XXH_readLE64(input_2) + XXH_readLE64(input_2 + 8);
acc.high64 += XXH3_mix16B (input_2, secret+16, seed);
acc.high64 ^= XXH_readLE64(input_1) + XXH_readLE64(input_1 + 8);
return acc;
}
XXH_FORCE_INLINE XXH128_hash_t
XXH3_len_17to128_128b(const xxh_u8* XXH_RESTRICT input, size_t len,
const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
XXH64_hash_t seed)
{
XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN); (void)secretSize;
XXH_ASSERT(16 < len && len <= 128);
{ XXH128_hash_t acc;
acc.low64 = len * PRIME64_1;
acc.high64 = 0;
if (len > 32) {
if (len > 64) {
if (len > 96) {
acc = XXH128_mix32B(acc, input+48, input+len-64, secret+96, seed);
}
acc = XXH128_mix32B(acc, input+32, input+len-48, secret+64, seed);
}
acc = XXH128_mix32B(acc, input+16, input+len-32, secret+32, seed);
}
acc = XXH128_mix32B(acc, input, input+len-16, secret, seed);
{ xxh_u64 const low64 = acc.low64 + acc.high64;
xxh_u64 const high64 = (acc.low64 * PRIME64_1) + (acc.high64 * PRIME64_4) + ((len - seed) * PRIME64_2);
XXH128_hash_t const h128 = { XXH3_avalanche(low64), (XXH64_hash_t)0 - XXH3_avalanche(high64) };
return h128;
}
}
}
XXH_NO_INLINE XXH128_hash_t
XXH3_len_129to240_128b(const xxh_u8* XXH_RESTRICT input, size_t len,
const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
XXH64_hash_t seed)
{
XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN); (void)secretSize;
XXH_ASSERT(128 < len && len <= XXH3_MIDSIZE_MAX);
{ XXH128_hash_t acc;
int const nbRounds = (int)len / 32;
int i;
acc.low64 = len * PRIME64_1;
acc.high64 = 0;
for (i=0; i<4; i++) {
acc = XXH128_mix32B(acc, input+(32*i), input+(32*i)+16, secret+(32*i), seed);
}
acc.low64 = XXH3_avalanche(acc.low64);
acc.high64 = XXH3_avalanche(acc.high64);
XXH_ASSERT(nbRounds >= 4);
for (i=4 ; i < nbRounds; i++) {
acc = XXH128_mix32B(acc, input+(32*i), input+(32*i)+16, secret+XXH3_MIDSIZE_STARTOFFSET+(32*(i-4)), seed);
}
/* last bytes */
acc = XXH128_mix32B(acc, input + len - 16, input + len - 32, secret + XXH3_SECRET_SIZE_MIN - XXH3_MIDSIZE_LASTOFFSET - 16, 0ULL - seed);
{ xxh_u64 const low64 = acc.low64 + acc.high64;
xxh_u64 const high64 = (acc.low64 * PRIME64_1) + (acc.high64 * PRIME64_4) + ((len - seed) * PRIME64_2);
XXH128_hash_t const h128 = { XXH3_avalanche(low64), (XXH64_hash_t)0 - XXH3_avalanche(high64) };
return h128;
}
}
}
XXH_FORCE_INLINE XXH128_hash_t
XXH3_hashLong_128b_internal(const xxh_u8* XXH_RESTRICT input, size_t len,
const xxh_u8* XXH_RESTRICT secret, size_t secretSize)
{
XXH_ALIGN(XXH_ACC_ALIGN) xxh_u64 acc[ACC_NB] = XXH3_INIT_ACC;
XXH3_hashLong_internal_loop(acc, input, len, secret, secretSize, XXH3_acc_128bits);
/* converge into final hash */
XXH_STATIC_ASSERT(sizeof(acc) == 64);
XXH_ASSERT(secretSize >= sizeof(acc) + XXH_SECRET_MERGEACCS_START);
{ xxh_u64 const low64 = XXH3_mergeAccs(acc, secret + XXH_SECRET_MERGEACCS_START, (xxh_u64)len * PRIME64_1);
xxh_u64 const high64 = XXH3_mergeAccs(acc, secret + secretSize - sizeof(acc) - XXH_SECRET_MERGEACCS_START, ~((xxh_u64)len * PRIME64_2));
XXH128_hash_t const h128 = { low64, high64 };
return h128;
}
}
/*
* It's important for performance that XXH3_hashLong is not inlined. Not sure
* why (uop cache maybe?), but the difference is large and easily measurable.
*/
XXH_NO_INLINE XXH128_hash_t
XXH3_hashLong_128b_defaultSecret(const xxh_u8* input, size_t len)
{
return XXH3_hashLong_128b_internal(input, len, kSecret, sizeof(kSecret));
}
/*
* It's important for performance that XXH3_hashLong is not inlined. Not sure
* why (uop cache maybe?), but the difference is large and easily measurable.
*/
XXH_NO_INLINE XXH128_hash_t
XXH3_hashLong_128b_withSecret(const xxh_u8* input, size_t len,
const xxh_u8* secret, size_t secretSize)
{
return XXH3_hashLong_128b_internal(input, len, secret, secretSize);
}
/*
* It's important for performance that XXH3_hashLong is not inlined. Not sure
* why (uop cache maybe?), but the difference is large and easily measurable.
*/
XXH_NO_INLINE XXH128_hash_t
XXH3_hashLong_128b_withSeed(const xxh_u8* input, size_t len, XXH64_hash_t seed)
{
XXH_ALIGN(8) xxh_u8 secret[XXH_SECRET_DEFAULT_SIZE];
if (seed == 0) return XXH3_hashLong_128b_defaultSecret(input, len);
XXH3_initCustomSecret(secret, seed);
return XXH3_hashLong_128b_internal(input, len, secret, sizeof(secret));
}
XXH_PUBLIC_API XXH128_hash_t XXH3_128bits(const void* input, size_t len)
{
if (len <= 16) return XXH3_len_0to16_128b((const xxh_u8*)input, len, kSecret, 0);
if (len <= 128) return XXH3_len_17to128_128b((const xxh_u8*)input, len, kSecret, sizeof(kSecret), 0);
if (len <= XXH3_MIDSIZE_MAX) return XXH3_len_129to240_128b((const xxh_u8*)input, len, kSecret, sizeof(kSecret), 0);
return XXH3_hashLong_128b_defaultSecret((const xxh_u8*)input, len);
}
XXH_PUBLIC_API XXH128_hash_t
XXH3_128bits_withSecret(const void* input, size_t len, const void* secret, size_t secretSize)
{
XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN);
/*
* If an action is to be taken if `secret` conditions are not respected,
* it should be done here.
* For now, it's a contract pre-condition.
* Adding a check and a branch here would cost performance at every hash.
*/
if (len <= 16) return XXH3_len_0to16_128b((const xxh_u8*)input, len, (const xxh_u8*)secret, 0);
if (len <= 128) return XXH3_len_17to128_128b((const xxh_u8*)input, len, (const xxh_u8*)secret, secretSize, 0);
if (len <= XXH3_MIDSIZE_MAX) return XXH3_len_129to240_128b((const xxh_u8*)input, len, (const xxh_u8*)secret, secretSize, 0);
return XXH3_hashLong_128b_withSecret((const xxh_u8*)input, len, (const xxh_u8*)secret, secretSize);
}
XXH_PUBLIC_API XXH128_hash_t
XXH3_128bits_withSeed(const void* input, size_t len, XXH64_hash_t seed)
{
if (len <= 16) return XXH3_len_0to16_128b((const xxh_u8*)input, len, kSecret, seed);
if (len <= 128) return XXH3_len_17to128_128b((const xxh_u8*)input, len, kSecret, sizeof(kSecret), seed);
if (len <= XXH3_MIDSIZE_MAX) return XXH3_len_129to240_128b((const xxh_u8*)input, len, kSecret, sizeof(kSecret), seed);
return XXH3_hashLong_128b_withSeed((const xxh_u8*)input, len, seed);
}
XXH_PUBLIC_API XXH128_hash_t
XXH128(const void* input, size_t len, XXH64_hash_t seed)
{
return XXH3_128bits_withSeed(input, len, seed);
}
/* === XXH3 128-bit streaming === */
/* all the functions are actually the same as for 64-bit streaming variant,
just the reset one is different (different initial acc values for 0,5,6,7),
and near the end of the digest function */
static void
XXH3_128bits_reset_internal(XXH3_state_t* statePtr,
XXH64_hash_t seed,
const xxh_u8* secret, size_t secretSize)
{
XXH3_64bits_reset_internal(statePtr, seed, secret, secretSize);
}
XXH_PUBLIC_API XXH_errorcode
XXH3_128bits_reset(XXH3_state_t* statePtr)
{
if (statePtr == NULL) return XXH_ERROR;
XXH3_128bits_reset_internal(statePtr, 0, kSecret, XXH_SECRET_DEFAULT_SIZE);
return XXH_OK;
}
XXH_PUBLIC_API XXH_errorcode
XXH3_128bits_reset_withSecret(XXH3_state_t* statePtr, const void* secret, size_t secretSize)
{
if (statePtr == NULL) return XXH_ERROR;
XXH3_128bits_reset_internal(statePtr, 0, (const xxh_u8*)secret, secretSize);
if (secret == NULL) return XXH_ERROR;
if (secretSize < XXH3_SECRET_SIZE_MIN) return XXH_ERROR;
return XXH_OK;
}
XXH_PUBLIC_API XXH_errorcode
XXH3_128bits_reset_withSeed(XXH3_state_t* statePtr, XXH64_hash_t seed)
{
if (statePtr == NULL) return XXH_ERROR;
XXH3_128bits_reset_internal(statePtr, seed, kSecret, XXH_SECRET_DEFAULT_SIZE);
XXH3_initCustomSecret(statePtr->customSecret, seed);
statePtr->secret = statePtr->customSecret;
return XXH_OK;
}
XXH_PUBLIC_API XXH_errorcode
XXH3_128bits_update(XXH3_state_t* state, const void* input, size_t len)
{
return XXH3_update(state, (const xxh_u8*)input, len, XXH3_acc_128bits);
}
XXH_PUBLIC_API XXH128_hash_t XXH3_128bits_digest (const XXH3_state_t* state)
{
if (state->totalLen > XXH3_MIDSIZE_MAX) {
XXH_ALIGN(XXH_ACC_ALIGN) XXH64_hash_t acc[ACC_NB];
XXH3_digest_long(acc, state, XXH3_acc_128bits);
XXH_ASSERT(state->secretLimit + STRIPE_LEN >= sizeof(acc) + XXH_SECRET_MERGEACCS_START);
{ xxh_u64 const low64 = XXH3_mergeAccs(acc, state->secret + XXH_SECRET_MERGEACCS_START, (xxh_u64)state->totalLen * PRIME64_1);
xxh_u64 const high64 = XXH3_mergeAccs(acc, state->secret + state->secretLimit + STRIPE_LEN - sizeof(acc) - XXH_SECRET_MERGEACCS_START, ~((xxh_u64)state->totalLen * PRIME64_2));
XXH128_hash_t const h128 = { low64, high64 };
return h128;
}
}
/* len <= XXH3_MIDSIZE_MAX : short code */
if (state->seed)
return XXH3_128bits_withSeed(state->buffer, (size_t)state->totalLen, state->seed);
return XXH3_128bits_withSecret(state->buffer, (size_t)(state->totalLen), state->secret, state->secretLimit + STRIPE_LEN);
}
/* 128-bit utility functions */
#include <string.h> /* memcmp, memcpy */
/* return : 1 is equal, 0 if different */
XXH_PUBLIC_API int XXH128_isEqual(XXH128_hash_t h1, XXH128_hash_t h2)
{
/* note : XXH128_hash_t is compact, it has no padding byte */
return !(memcmp(&h1, &h2, sizeof(h1)));
}
/* This prototype is compatible with stdlib's qsort().
* return : >0 if *h128_1 > *h128_2
* <0 if *h128_1 < *h128_2
* =0 if *h128_1 == *h128_2 */
XXH_PUBLIC_API int XXH128_cmp(const void* h128_1, const void* h128_2)
{
XXH128_hash_t const h1 = *(const XXH128_hash_t*)h128_1;
XXH128_hash_t const h2 = *(const XXH128_hash_t*)h128_2;
int const hcmp = (h1.high64 > h2.high64) - (h2.high64 > h1.high64);
/* note : bets that, in most cases, hash values are different */
if (hcmp) return hcmp;
return (h1.low64 > h2.low64) - (h2.low64 > h1.low64);
}
/*====== Canonical representation ======*/
XXH_PUBLIC_API void
XXH128_canonicalFromHash(XXH128_canonical_t* dst, XXH128_hash_t hash)
{
XXH_STATIC_ASSERT(sizeof(XXH128_canonical_t) == sizeof(XXH128_hash_t));
if (XXH_CPU_LITTLE_ENDIAN) {
hash.high64 = XXH_swap64(hash.high64);
hash.low64 = XXH_swap64(hash.low64);
}
memcpy(dst, &hash.high64, sizeof(hash.high64));
memcpy((char*)dst + sizeof(hash.high64), &hash.low64, sizeof(hash.low64));
}
XXH_PUBLIC_API XXH128_hash_t
XXH128_hashFromCanonical(const XXH128_canonical_t* src)
{
XXH128_hash_t h;
h.high64 = XXH_readBE64(src);
h.low64 = XXH_readBE64(src->digest + 8);
return h;
}
/* Pop our optimization override from above */
#if XXH_VECTOR == XXH_AVX2 /* AVX2 */ \
&& defined(__GNUC__) && !defined(__clang__) /* GCC, not Clang */ \
&& defined(__OPTIMIZE__) && !defined(__OPTIMIZE_SIZE__) /* respect -O0 and -Os */
# pragma GCC pop_options
#endif
#endif /* XXH3_H_1397135465 */
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