opencv/3rdparty/zlib-ng/arch/x86/compare256_avx2.c
Letu Ren 0de26fd78e Add zlib-ng as an alternative zlib implementation
Zlib-ng is zlib replacement with optimizations for "next generation" systems. Its optimization may benifits image library decode and encode speed such as libpng. In our tests, if using zlib-ng and libpng combination on a x86_64 machine with AVX2, the time of `imdecode` amd `imencode` will drop 20% approximately. This patch enables zlib-ng's optimization if `CV_DISABLE_OPTIMIZATION` is OFF. Since Zlib-ng can dispatch intrinsics on the fly, port work is much easier.

Related discussion: https://github.com/opencv/opencv/issues/22573
2024-01-14 14:58:47 +08:00

64 lines
1.9 KiB
C

/* compare256_avx2.c -- AVX2 version of compare256
* Copyright Mika T. Lindqvist <postmaster@raasu.org>
* For conditions of distribution and use, see copyright notice in zlib.h
*/
#include "../../zbuild.h"
#include "fallback_builtins.h"
#if defined(X86_AVX2) && defined(HAVE_BUILTIN_CTZ)
#include <immintrin.h>
#ifdef _MSC_VER
# include <nmmintrin.h>
#endif
static inline uint32_t compare256_avx2_static(const uint8_t *src0, const uint8_t *src1) {
uint32_t len = 0;
do {
__m256i ymm_src0, ymm_src1, ymm_cmp;
ymm_src0 = _mm256_loadu_si256((__m256i*)src0);
ymm_src1 = _mm256_loadu_si256((__m256i*)src1);
ymm_cmp = _mm256_cmpeq_epi8(ymm_src0, ymm_src1); /* non-identical bytes = 00, identical bytes = FF */
unsigned mask = (unsigned)_mm256_movemask_epi8(ymm_cmp);
if (mask != 0xFFFFFFFF) {
uint32_t match_byte = (uint32_t)__builtin_ctz(~mask); /* Invert bits so identical = 0 */
return len + match_byte;
}
src0 += 32, src1 += 32, len += 32;
ymm_src0 = _mm256_loadu_si256((__m256i*)src0);
ymm_src1 = _mm256_loadu_si256((__m256i*)src1);
ymm_cmp = _mm256_cmpeq_epi8(ymm_src0, ymm_src1);
mask = (unsigned)_mm256_movemask_epi8(ymm_cmp);
if (mask != 0xFFFFFFFF) {
uint32_t match_byte = (uint32_t)__builtin_ctz(~mask);
return len + match_byte;
}
src0 += 32, src1 += 32, len += 32;
} while (len < 256);
return 256;
}
Z_INTERNAL uint32_t compare256_avx2(const uint8_t *src0, const uint8_t *src1) {
return compare256_avx2_static(src0, src1);
}
#define LONGEST_MATCH longest_match_avx2
#define COMPARE256 compare256_avx2_static
#include "match_tpl.h"
#define LONGEST_MATCH_SLOW
#define LONGEST_MATCH longest_match_slow_avx2
#define COMPARE256 compare256_avx2_static
#include "match_tpl.h"
#endif