opencv/3rdparty/zlib-ng/arch/x86/x86_features.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

98 lines
2.7 KiB
C

/* x86_features.c - x86 feature check
*
* Copyright (C) 2013 Intel Corporation. All rights reserved.
* Author:
* Jim Kukunas
*
* For conditions of distribution and use, see copyright notice in zlib.h
*/
#include "../../zbuild.h"
#include "x86_features.h"
#ifdef _MSC_VER
# include <intrin.h>
#else
// Newer versions of GCC and clang come with cpuid.h
# include <cpuid.h>
#endif
#include <string.h>
static inline void cpuid(int info, unsigned* eax, unsigned* ebx, unsigned* ecx, unsigned* edx) {
#ifdef _MSC_VER
unsigned int registers[4];
__cpuid((int *)registers, info);
*eax = registers[0];
*ebx = registers[1];
*ecx = registers[2];
*edx = registers[3];
#else
__cpuid(info, *eax, *ebx, *ecx, *edx);
#endif
}
static inline void cpuidex(int info, int subinfo, unsigned* eax, unsigned* ebx, unsigned* ecx, unsigned* edx) {
#ifdef _MSC_VER
unsigned int registers[4];
__cpuidex((int *)registers, info, subinfo);
*eax = registers[0];
*ebx = registers[1];
*ecx = registers[2];
*edx = registers[3];
#else
__cpuid_count(info, subinfo, *eax, *ebx, *ecx, *edx);
#endif
}
static inline uint64_t xgetbv(unsigned int xcr) {
#ifdef _MSC_VER
return _xgetbv(xcr);
#else
uint32_t eax, edx;
__asm__ ( ".byte 0x0f, 0x01, 0xd0" : "=a"(eax), "=d"(edx) : "c"(xcr));
return (uint64_t)(edx) << 32 | eax;
#endif
}
void Z_INTERNAL x86_check_features(struct x86_cpu_features *features) {
unsigned eax, ebx, ecx, edx;
unsigned maxbasic;
cpuid(0, &maxbasic, &ebx, &ecx, &edx);
cpuid(1 /*CPU_PROCINFO_AND_FEATUREBITS*/, &eax, &ebx, &ecx, &edx);
features->has_sse2 = edx & 0x4000000;
features->has_ssse3 = ecx & 0x200;
features->has_sse42 = ecx & 0x100000;
features->has_pclmulqdq = ecx & 0x2;
if (ecx & 0x08000000) {
uint64_t xfeature = xgetbv(0);
features->has_os_save_ymm = ((xfeature & 0x06) == 0x06);
features->has_os_save_zmm = ((xfeature & 0xe6) == 0xe6);
}
if (maxbasic >= 7) {
cpuidex(7, 0, &eax, &ebx, &ecx, &edx);
// check BMI1 bit
// Reference: https://software.intel.com/sites/default/files/article/405250/how-to-detect-new-instruction-support-in-the-4th-generation-intel-core-processor-family.pdf
features->has_vpclmulqdq = ecx & 0x400;
// check AVX2 bit if the OS supports saving YMM registers
if (features->has_os_save_ymm) {
features->has_avx2 = ebx & 0x20;
}
// check AVX512 bits if the OS supports saving ZMM registers
if (features->has_os_save_zmm) {
features->has_avx512 = ebx & 0x00010000;
features->has_avx512vnni = ecx & 0x800;
}
}
}