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windows-terminal/oss/libpopcnt/libpopcnt.h

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/*
* libpopcnt.h - C/C++ library for counting the number of 1 bits (bit
* population count) in an array as quickly as possible using
* specialized CPU instructions i.e. POPCNT, AVX2, AVX512, NEON.
*
* Copyright (c) 2016 - 2020, Kim Walisch
* Copyright (c) 2016 - 2018, Wojciech Muła
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
* 2. 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.
*/
#ifndef LIBPOPCNT_H
#define LIBPOPCNT_H
#include <stdint.h>
#include <string.h>
#ifndef __has_builtin
#define __has_builtin(x) 0
#endif
#ifndef __has_attribute
#define __has_attribute(x) 0
#endif
#ifdef __GNUC__
#define GNUC_PREREQ(x, y) \
(__GNUC__ > x || (__GNUC__ == x && __GNUC_MINOR__ >= y))
#else
#define GNUC_PREREQ(x, y) 0
#endif
#ifdef __clang__
#define CLANG_PREREQ(x, y) \
(__clang_major__ > x || (__clang_major__ == x && __clang_minor__ >= y))
#else
#define CLANG_PREREQ(x, y) 0
#endif
#if (_MSC_VER < 1900) && \
!defined(__cplusplus)
#define inline __inline
#endif
#if (defined(__i386__) || \
defined(__x86_64__) || \
defined(_M_IX86) || \
defined(_M_X64))
#define X86_OR_X64
#endif
#if GNUC_PREREQ(4, 2) || \
__has_builtin(__builtin_popcount)
#define HAVE_BUILTIN_POPCOUNT
#endif
#if GNUC_PREREQ(4, 2) || \
CLANG_PREREQ(3, 0)
#define HAVE_ASM_POPCNT
#endif
#if defined(X86_OR_X64) && \
(defined(HAVE_ASM_POPCNT) || \
defined(_MSC_VER))
#define HAVE_POPCNT
#endif
#if defined(X86_OR_X64) && \
GNUC_PREREQ(4, 9)
#define HAVE_AVX2
#endif
#if defined(X86_OR_X64) && \
GNUC_PREREQ(5, 0)
#define HAVE_AVX512
#endif
#if defined(X86_OR_X64) && !defined(_M_ARM64EC)
/* MSVC compatible compilers (Windows) */
#if defined(_MSC_VER)
/* clang-cl (LLVM 10 from 2020) requires /arch:AVX2 or
* /arch:AVX512 to enable vector instructions */
#if defined(__clang__)
#if defined(__AVX2__)
#define HAVE_AVX2
#endif
#if defined(__AVX512__)
#define HAVE_AVX2
#define HAVE_AVX512
#endif
/* MSVC 2017 or later does not require
* /arch:AVX2 or /arch:AVX512 */
#elif _MSC_VER >= 1910
#define HAVE_AVX2
#define HAVE_AVX512
#endif
/* Clang (Unix-like OSes) */
#elif CLANG_PREREQ(3, 8) && \
__has_attribute(target) && \
(!defined(__apple_build_version__) || __apple_build_version__ >= 8000000)
#define HAVE_AVX2
#define HAVE_AVX512
#endif
#endif
/*
* Only enable CPUID runtime checks if this is really
* needed. E.g. do not enable if user has compiled
* using -march=native on a CPU that supports AVX512.
*/
#if defined(X86_OR_X64) && \
(defined(__cplusplus) || \
defined(_MSC_VER) || \
(GNUC_PREREQ(4, 2) || \
__has_builtin(__sync_val_compare_and_swap))) && \
((defined(HAVE_AVX512) && !(defined(__AVX512__) || defined(__AVX512BW__))) || \
(defined(HAVE_AVX2) && !defined(__AVX2__)) || \
(defined(HAVE_POPCNT) && !defined(__POPCNT__)))
#define HAVE_CPUID
#endif
#ifdef __cplusplus
extern "C" {
#endif
/*
* This uses fewer arithmetic operations than any other known
* implementation on machines with fast multiplication.
* It uses 12 arithmetic operations, one of which is a multiply.
* http://en.wikipedia.org/wiki/Hamming_weight#Efficient_implementation
*/
static inline uint64_t popcount64(uint64_t x)
{
uint64_t m1 = 0x5555555555555555ll;
uint64_t m2 = 0x3333333333333333ll;
uint64_t m4 = 0x0F0F0F0F0F0F0F0Fll;
uint64_t h01 = 0x0101010101010101ll;
x -= (x >> 1) & m1;
x = (x & m2) + ((x >> 2) & m2);
x = (x + (x >> 4)) & m4;
return (x * h01) >> 56;
}
#if defined(HAVE_ASM_POPCNT) && \
defined(__x86_64__)
static inline uint64_t popcnt64(uint64_t x)
{
__asm__ ("popcnt %1, %0" : "=r" (x) : "0" (x));
return x;
}
#elif defined(HAVE_ASM_POPCNT) && \
defined(__i386__)
static inline uint32_t popcnt32(uint32_t x)
{
__asm__ ("popcnt %1, %0" : "=r" (x) : "0" (x));
return x;
}
static inline uint64_t popcnt64(uint64_t x)
{
return popcnt32((uint32_t) x) +
popcnt32((uint32_t)(x >> 32));
}
#elif defined(_MSC_VER) && \
defined(_M_X64)
#include <nmmintrin.h>
static inline uint64_t popcnt64(uint64_t x)
{
return _mm_popcnt_u64(x);
}
#elif defined(_MSC_VER) && \
defined(_M_IX86)
#include <nmmintrin.h>
static inline uint64_t popcnt64(uint64_t x)
{
return _mm_popcnt_u32((uint32_t) x) +
_mm_popcnt_u32((uint32_t)(x >> 32));
}
/* non x86 CPUs */
#elif defined(HAVE_BUILTIN_POPCOUNT)
static inline uint64_t popcnt64(uint64_t x)
{
return __builtin_popcountll(x);
}
/* no hardware POPCNT,
* use pure integer algorithm */
#else
static inline uint64_t popcnt64(uint64_t x)
{
return popcount64(x);
}
#endif
#if defined(HAVE_CPUID)
#if defined(_MSC_VER)
#include <intrin.h>
#include <immintrin.h>
#endif
/* %ecx bit flags */
#define bit_POPCNT (1 << 23)
/* %ebx bit flags */
#define bit_AVX2 (1 << 5)
#define bit_AVX512 (1 << 30)
/* xgetbv bit flags */
#define XSTATE_SSE (1 << 1)
#define XSTATE_YMM (1 << 2)
#define XSTATE_ZMM (7 << 5)
static inline void run_cpuid(int eax, int ecx, int* abcd)
{
#if defined(_MSC_VER)
__cpuidex(abcd, eax, ecx);
#else
int ebx = 0;
int edx = 0;
#if defined(__i386__) && \
defined(__PIC__)
/* in case of PIC under 32-bit EBX cannot be clobbered */
__asm__ ("movl %%ebx, %%edi;"
"cpuid;"
"xchgl %%ebx, %%edi;"
: "=D" (ebx),
"+a" (eax),
"+c" (ecx),
"=d" (edx));
#else
__asm__ ("cpuid;"
: "+b" (ebx),
"+a" (eax),
"+c" (ecx),
"=d" (edx));
#endif
abcd[0] = eax;
abcd[1] = ebx;
abcd[2] = ecx;
abcd[3] = edx;
#endif
}
#if defined(HAVE_AVX2) || \
defined(HAVE_AVX512)
static inline int get_xcr0()
{
int xcr0;
#if defined(_MSC_VER)
xcr0 = (int) _xgetbv(0);
#else
__asm__ ("xgetbv" : "=a" (xcr0) : "c" (0) : "%edx" );
#endif
return xcr0;
}
#endif
static inline int get_cpuid()
{
int flags = 0;
int abcd[4];
run_cpuid(1, 0, abcd);
if ((abcd[2] & bit_POPCNT) == bit_POPCNT)
flags |= bit_POPCNT;
#if defined(HAVE_AVX2) || \
defined(HAVE_AVX512)
int osxsave_mask = (1 << 27);
/* ensure OS supports extended processor state management */
if ((abcd[2] & osxsave_mask) != osxsave_mask)
return 0;
int ymm_mask = XSTATE_SSE | XSTATE_YMM;
int zmm_mask = XSTATE_SSE | XSTATE_YMM | XSTATE_ZMM;
int xcr0 = get_xcr0();
if ((xcr0 & ymm_mask) == ymm_mask)
{
run_cpuid(7, 0, abcd);
if ((abcd[1] & bit_AVX2) == bit_AVX2)
flags |= bit_AVX2;
if ((xcr0 & zmm_mask) == zmm_mask)
{
if ((abcd[1] & bit_AVX512) == bit_AVX512)
flags |= bit_AVX512;
}
}
#endif
return flags;
}
#endif /* cpuid */
#if defined(HAVE_AVX2)
#include <immintrin.h>
#if !defined(_MSC_VER)
__attribute__ ((target ("avx2")))
#endif
static inline void CSA256(__m256i* h, __m256i* l, __m256i a, __m256i b, __m256i c)
{
__m256i u = _mm256_xor_si256(a, b);
*h = _mm256_or_si256(_mm256_and_si256(a, b), _mm256_and_si256(u, c));
*l = _mm256_xor_si256(u, c);
}
#if !defined(_MSC_VER)
__attribute__ ((target ("avx2")))
#endif
static inline __m256i popcnt256(__m256i v)
{
__m256i lookup1 = _mm256_setr_epi8(
4, 5, 5, 6, 5, 6, 6, 7,
5, 6, 6, 7, 6, 7, 7, 8,
4, 5, 5, 6, 5, 6, 6, 7,
5, 6, 6, 7, 6, 7, 7, 8
);
__m256i lookup2 = _mm256_setr_epi8(
4, 3, 3, 2, 3, 2, 2, 1,
3, 2, 2, 1, 2, 1, 1, 0,
4, 3, 3, 2, 3, 2, 2, 1,
3, 2, 2, 1, 2, 1, 1, 0
);
__m256i low_mask = _mm256_set1_epi8(0x0f);
__m256i lo = _mm256_and_si256(v, low_mask);
__m256i hi = _mm256_and_si256(_mm256_srli_epi16(v, 4), low_mask);
__m256i popcnt1 = _mm256_shuffle_epi8(lookup1, lo);
__m256i popcnt2 = _mm256_shuffle_epi8(lookup2, hi);
return _mm256_sad_epu8(popcnt1, popcnt2);
}
/*
* AVX2 Harley-Seal popcount (4th iteration).
* The algorithm is based on the paper "Faster Population Counts
* using AVX2 Instructions" by Daniel Lemire, Nathan Kurz and
* Wojciech Mula (23 Nov 2016).
* @see https://arxiv.org/abs/1611.07612
*/
#if !defined(_MSC_VER)
__attribute__ ((target ("avx2")))
#endif
static inline uint64_t popcnt_avx2(const __m256i* ptr, uint64_t size)
{
__m256i cnt = _mm256_setzero_si256();
__m256i ones = _mm256_setzero_si256();
__m256i twos = _mm256_setzero_si256();
__m256i fours = _mm256_setzero_si256();
__m256i eights = _mm256_setzero_si256();
__m256i sixteens = _mm256_setzero_si256();
__m256i twosA, twosB, foursA, foursB, eightsA, eightsB;
uint64_t i = 0;
uint64_t limit = size - size % 16;
uint64_t* cnt64;
for(; i < limit; i += 16)
{
CSA256(&twosA, &ones, ones, _mm256_loadu_si256(ptr + i + 0), _mm256_loadu_si256(ptr + i + 1));
CSA256(&twosB, &ones, ones, _mm256_loadu_si256(ptr + i + 2), _mm256_loadu_si256(ptr + i + 3));
CSA256(&foursA, &twos, twos, twosA, twosB);
CSA256(&twosA, &ones, ones, _mm256_loadu_si256(ptr + i + 4), _mm256_loadu_si256(ptr + i + 5));
CSA256(&twosB, &ones, ones, _mm256_loadu_si256(ptr + i + 6), _mm256_loadu_si256(ptr + i + 7));
CSA256(&foursB, &twos, twos, twosA, twosB);
CSA256(&eightsA, &fours, fours, foursA, foursB);
CSA256(&twosA, &ones, ones, _mm256_loadu_si256(ptr + i + 8), _mm256_loadu_si256(ptr + i + 9));
CSA256(&twosB, &ones, ones, _mm256_loadu_si256(ptr + i + 10), _mm256_loadu_si256(ptr + i + 11));
CSA256(&foursA, &twos, twos, twosA, twosB);
CSA256(&twosA, &ones, ones, _mm256_loadu_si256(ptr + i + 12), _mm256_loadu_si256(ptr + i + 13));
CSA256(&twosB, &ones, ones, _mm256_loadu_si256(ptr + i + 14), _mm256_loadu_si256(ptr + i + 15));
CSA256(&foursB, &twos, twos, twosA, twosB);
CSA256(&eightsB, &fours, fours, foursA, foursB);
CSA256(&sixteens, &eights, eights, eightsA, eightsB);
cnt = _mm256_add_epi64(cnt, popcnt256(sixteens));
}
cnt = _mm256_slli_epi64(cnt, 4);
cnt = _mm256_add_epi64(cnt, _mm256_slli_epi64(popcnt256(eights), 3));
cnt = _mm256_add_epi64(cnt, _mm256_slli_epi64(popcnt256(fours), 2));
cnt = _mm256_add_epi64(cnt, _mm256_slli_epi64(popcnt256(twos), 1));
cnt = _mm256_add_epi64(cnt, popcnt256(ones));
for(; i < size; i++)
cnt = _mm256_add_epi64(cnt, popcnt256(_mm256_loadu_si256(ptr + i)));
cnt64 = (uint64_t*) &cnt;
return cnt64[0] +
cnt64[1] +
cnt64[2] +
cnt64[3];
}
#endif
#if defined(HAVE_AVX512)
#include <immintrin.h>
#if !defined(_MSC_VER)
__attribute__ ((target ("avx512bw")))
#endif
static inline __m512i popcnt512(__m512i v)
{
__m512i m1 = _mm512_set1_epi8(0x55);
__m512i m2 = _mm512_set1_epi8(0x33);
__m512i m4 = _mm512_set1_epi8(0x0F);
__m512i vm = _mm512_and_si512(_mm512_srli_epi16(v, 1), m1);
__m512i t1 = _mm512_sub_epi8(v, vm);
__m512i tm = _mm512_and_si512(t1, m2);
__m512i tm2 = _mm512_and_si512(_mm512_srli_epi16(t1, 2), m2);
__m512i t2 = _mm512_add_epi8(tm, tm2);
__m512i tt = _mm512_add_epi8(t2, _mm512_srli_epi16(t2, 4));
__m512i t3 = _mm512_and_si512(tt, m4);
return _mm512_sad_epu8(t3, _mm512_setzero_si512());
}
#if !defined(_MSC_VER)
__attribute__ ((target ("avx512bw")))
#endif
static inline void CSA512(__m512i* h, __m512i* l, __m512i a, __m512i b, __m512i c)
{
*l = _mm512_ternarylogic_epi32(c, b, a, 0x96);
*h = _mm512_ternarylogic_epi32(c, b, a, 0xe8);
}
/*
* AVX512 Harley-Seal popcount (4th iteration).
* The algorithm is based on the paper "Faster Population Counts
* using AVX2 Instructions" by Daniel Lemire, Nathan Kurz and
* Wojciech Mula (23 Nov 2016).
* @see https://arxiv.org/abs/1611.07612
*/
#if !defined(_MSC_VER)
__attribute__ ((target ("avx512bw")))
#endif
static inline uint64_t popcnt_avx512(const __m512i* ptr, const uint64_t size)
{
__m512i cnt = _mm512_setzero_si512();
__m512i ones = _mm512_setzero_si512();
__m512i twos = _mm512_setzero_si512();
__m512i fours = _mm512_setzero_si512();
__m512i eights = _mm512_setzero_si512();
__m512i sixteens = _mm512_setzero_si512();
__m512i twosA, twosB, foursA, foursB, eightsA, eightsB;
uint64_t i = 0;
uint64_t limit = size - size % 16;
uint64_t* cnt64;
for(; i < limit; i += 16)
{
CSA512(&twosA, &ones, ones, _mm512_loadu_si512(ptr + i + 0), _mm512_loadu_si512(ptr + i + 1));
CSA512(&twosB, &ones, ones, _mm512_loadu_si512(ptr + i + 2), _mm512_loadu_si512(ptr + i + 3));
CSA512(&foursA, &twos, twos, twosA, twosB);
CSA512(&twosA, &ones, ones, _mm512_loadu_si512(ptr + i + 4), _mm512_loadu_si512(ptr + i + 5));
CSA512(&twosB, &ones, ones, _mm512_loadu_si512(ptr + i + 6), _mm512_loadu_si512(ptr + i + 7));
CSA512(&foursB, &twos, twos, twosA, twosB);
CSA512(&eightsA, &fours, fours, foursA, foursB);
CSA512(&twosA, &ones, ones, _mm512_loadu_si512(ptr + i + 8), _mm512_loadu_si512(ptr + i + 9));
CSA512(&twosB, &ones, ones, _mm512_loadu_si512(ptr + i + 10), _mm512_loadu_si512(ptr + i + 11));
CSA512(&foursA, &twos, twos, twosA, twosB);
CSA512(&twosA, &ones, ones, _mm512_loadu_si512(ptr + i + 12), _mm512_loadu_si512(ptr + i + 13));
CSA512(&twosB, &ones, ones, _mm512_loadu_si512(ptr + i + 14), _mm512_loadu_si512(ptr + i + 15));
CSA512(&foursB, &twos, twos, twosA, twosB);
CSA512(&eightsB, &fours, fours, foursA, foursB);
CSA512(&sixteens, &eights, eights, eightsA, eightsB);
cnt = _mm512_add_epi64(cnt, popcnt512(sixteens));
}
cnt = _mm512_slli_epi64(cnt, 4);
cnt = _mm512_add_epi64(cnt, _mm512_slli_epi64(popcnt512(eights), 3));
cnt = _mm512_add_epi64(cnt, _mm512_slli_epi64(popcnt512(fours), 2));
cnt = _mm512_add_epi64(cnt, _mm512_slli_epi64(popcnt512(twos), 1));
cnt = _mm512_add_epi64(cnt, popcnt512(ones));
for(; i < size; i++)
cnt = _mm512_add_epi64(cnt, popcnt512(_mm512_loadu_si512(ptr + i)));
cnt64 = (uint64_t*) &cnt;
return cnt64[0] +
cnt64[1] +
cnt64[2] +
cnt64[3] +
cnt64[4] +
cnt64[5] +
cnt64[6] +
cnt64[7];
}
#endif
/* x86 CPUs */
#if defined(X86_OR_X64)
/*
* Count the number of 1 bits in the data array
* @data: An array
* @size: Size of data in bytes
*/
static inline uint64_t popcnt(const void* data, uint64_t size)
{
uint64_t i = 0;
uint64_t cnt = 0;
const uint8_t* ptr = (const uint8_t*) data;
/*
* CPUID runtime checks are only enabled if this is needed.
* E.g. CPUID is disabled when a user compiles his
* code using -march=native on a CPU with AVX512.
*/
#if defined(HAVE_CPUID)
#if defined(__cplusplus)
/* C++11 thread-safe singleton */
static const int cpuid = get_cpuid();
#else
static int cpuid_ = -1;
int cpuid = cpuid_;
if (cpuid == -1)
{
cpuid = get_cpuid();
#if defined(_MSC_VER)
_InterlockedCompareExchange(&cpuid_, cpuid, -1);
#else
__sync_val_compare_and_swap(&cpuid_, -1, cpuid);
#endif
}
#endif
#endif
#if defined(HAVE_AVX512)
#if defined(__AVX512__) || defined(__AVX512BW__)
/* AVX512 requires arrays >= 1024 bytes */
if (i + 1024 <= size)
#else
if ((cpuid & bit_AVX512) &&
i + 1024 <= size)
#endif
{
const __m512i* ptr512 = (const __m512i*)(ptr + i);
cnt += popcnt_avx512(ptr512, (size - i) / 64);
i = size - size % 64;
}
#endif
#if defined(HAVE_AVX2)
#if defined(__AVX2__)
/* AVX2 requires arrays >= 512 bytes */
if (i + 512 <= size)
#else
if ((cpuid & bit_AVX2) &&
i + 512 <= size)
#endif
{
const __m256i* ptr256 = (const __m256i*)(ptr + i);
cnt += popcnt_avx2(ptr256, (size - i) / 32);
i = size - size % 32;
}
#endif
#if defined(HAVE_POPCNT)
/*
* The user has compiled without -mpopcnt.
* Unfortunately the MSVC compiler does not have
* a POPCNT macro so we cannot get rid of the
* runtime check for MSVC.
*/
#if !defined(__POPCNT__)
if (cpuid & bit_POPCNT)
#endif
{
/* We use unaligned memory accesses here to improve performance */
for (; i < size - size % 8; i += 8)
cnt += popcnt64(*(const uint64_t*)(ptr + i));
for (; i < size; i++)
cnt += popcnt64(ptr[i]);
return cnt;
}
#endif
#if !defined(HAVE_POPCNT) || \
!defined(__POPCNT__)
/*
* Pure integer popcount algorithm.
* We use unaligned memory accesses here to improve performance.
*/
for (; i < size - size % 8; i += 8)
cnt += popcount64(*(const uint64_t*)(ptr + i));
if (i < size)
{
uint64_t val = 0;
size_t bytes = (size_t)(size - i);
memcpy(&val, &ptr[i], bytes);
cnt += popcount64(val);
}
return cnt;
#endif
}
#elif defined(__ARM_NEON) || \
defined(__aarch64__)
#include <arm_neon.h>
static inline uint64x2_t vpadalq(uint64x2_t sum, uint8x16_t t)
{
return vpadalq_u32(sum, vpaddlq_u16(vpaddlq_u8(t)));
}
/*
* Count the number of 1 bits in the data array
* @data: An array
* @size: Size of data in bytes
*/
static inline uint64_t popcnt(const void* data, uint64_t size)
{
uint64_t i = 0;
uint64_t cnt = 0;
uint64_t chunk_size = 64;
const uint8_t* ptr = (const uint8_t*) data;
if (size >= chunk_size)
{
uint64_t iters = size / chunk_size;
uint64x2_t sum = vcombine_u64(vcreate_u64(0), vcreate_u64(0));
uint8x16_t zero = vcombine_u8(vcreate_u8(0), vcreate_u8(0));
do
{
uint8x16_t t0 = zero;
uint8x16_t t1 = zero;
uint8x16_t t2 = zero;
uint8x16_t t3 = zero;
/*
* After every 31 iterations we need to add the
* temporary sums (t0, t1, t2, t3) to the total sum.
* We must ensure that the temporary sums <= 255
* and 31 * 8 bits = 248 which is OK.
*/
uint64_t limit = (i + 31 < iters) ? i + 31 : iters;
/* Each iteration processes 64 bytes */
for (; i < limit; i++)
{
uint8x16x4_t input = vld4q_u8(ptr);
ptr += chunk_size;
t0 = vaddq_u8(t0, vcntq_u8(input.val[0]));
t1 = vaddq_u8(t1, vcntq_u8(input.val[1]));
t2 = vaddq_u8(t2, vcntq_u8(input.val[2]));
t3 = vaddq_u8(t3, vcntq_u8(input.val[3]));
}
sum = vpadalq(sum, t0);
sum = vpadalq(sum, t1);
sum = vpadalq(sum, t2);
sum = vpadalq(sum, t3);
}
while (i < iters);
i = 0;
size %= chunk_size;
uint64_t tmp[2];
vst1q_u64(tmp, sum);
cnt += tmp[0];
cnt += tmp[1];
}
#if defined(__ARM_FEATURE_UNALIGNED)
/* We use unaligned memory accesses here to improve performance */
for (; i < size - size % 8; i += 8)
cnt += popcnt64(*(const uint64_t*)(ptr + i));
#else
if (i + 8 <= size)
{
/* Align memory to an 8 byte boundary */
for (; (uintptr_t)(ptr + i) % 8; i++)
cnt += popcnt64(ptr[i]);
for (; i < size - size % 8; i += 8)
cnt += popcnt64(*(const uint64_t*)(ptr + i));
}
#endif
if (i < size)
{
uint64_t val = 0;
size_t bytes = (size_t)(size - i);
memcpy(&val, &ptr[i], bytes);
cnt += popcount64(val);
}
return cnt;
}
/* all other CPUs */
#else
/*
* Count the number of 1 bits in the data array
* @data: An array
* @size: Size of data in bytes
*/
static inline uint64_t popcnt(const void* data, uint64_t size)
{
uint64_t i = 0;
uint64_t cnt = 0;
const uint8_t* ptr = (const uint8_t*) data;
if (size >= 8)
{
/*
* Since we don't know whether this CPU architecture
* supports unaligned memory accesses we align
* memory to an 8 byte boundary.
*/
for (; (uintptr_t)(ptr + i) % 8; i++)
cnt += popcnt64(ptr[i]);
for (; i < size - size % 8; i += 8)
cnt += popcnt64(*(const uint64_t*)(ptr + i));
}
for (; i < size; i++)
cnt += popcnt64(ptr[i]);
return cnt;
}
#endif
#ifdef __cplusplus
} /* extern "C" */
#endif
#endif /* LIBPOPCNT_H */
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