opencv/3rdparty/zlib-ng/arch/riscv/riscv_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

46 lines
1.1 KiB
C

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/auxv.h>
#include <sys/utsname.h>
#include "../../zbuild.h"
#include "riscv_features.h"
#define ISA_V_HWCAP (1 << ('v' - 'a'))
int Z_INTERNAL is_kernel_version_greater_or_equal_to_6_5() {
struct utsname buffer;
uname(&buffer);
int major, minor;
if (sscanf(buffer.release, "%d.%d", &major, &minor) != 2) {
// Something bad with uname()
return 0;
}
if (major > 6 || major == 6 && minor >= 5)
return 1;
return 0;
}
void Z_INTERNAL riscv_check_features_compile_time(struct riscv_cpu_features *features) {
#if defined(__riscv_v) && defined(__linux__)
features->has_rvv = 1;
#else
features->has_rvv = 0;
#endif
}
void Z_INTERNAL riscv_check_features_runtime(struct riscv_cpu_features *features) {
unsigned long hw_cap = getauxval(AT_HWCAP);
features->has_rvv = hw_cap & ISA_V_HWCAP;
}
void Z_INTERNAL riscv_check_features(struct riscv_cpu_features *features) {
if (is_kernel_version_greater_or_equal_to_6_5())
riscv_check_features_runtime(features);
else
riscv_check_features_compile_time(features);
}