liberasurecode/get_flags_from_cpuid.c
2015-06-22 02:54:25 +00:00

102 lines
2.9 KiB
C

#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#define EDX_MMX_BIT 23
#define EDX_SSE_BIT 25
#define EDX_SSE2_BIT 26
#define ECX_SSE3_BIT 0
#define ECX_SSSE3_BIT 9
#define ECX_SSE41_BIT 19
#define ECX_SSE42_BIT 20
#define ECX_AVXOS_BIT 27
#define ECX_AVX_BIT 28
uint64_t get_supported_flags()
{
uint64_t supp_comp_flgs = 0;
char *comp_flag = NULL;
char SUPPORTED_COMP_FLAGS[] ="FLAGSFROMAUTOCONF\0";
for (comp_flag = strtok(SUPPORTED_COMP_FLAGS, " "); comp_flag != NULL; comp_flag = strtok(NULL, " ")) {
if (strncmp(comp_flag, "-m", 2) != 0) {
fprintf(stderr, "Invalid comp_flag: %s\n", comp_flag);
exit(2);
}
if (strcmp(comp_flag, "-mmmx\0") == 0) {
supp_comp_flgs |= (1 << EDX_MMX_BIT);
}
if (strcmp(comp_flag, "-msse\0") == 0) {
supp_comp_flgs |= (1 << EDX_SSE_BIT);
}
if (strcmp(comp_flag, "-msse2\0") == 0) {
supp_comp_flgs |= (1 << EDX_SSE2_BIT);
}
if (strcmp(comp_flag, "-msse3\0") == 0) {
supp_comp_flgs |= (1 << ECX_SSE3_BIT);
}
if (strcmp(comp_flag, "-mssse3\0") == 0) {
supp_comp_flgs |= (1 << ECX_SSSE3_BIT);
}
if (strcmp(comp_flag, "-msse4.1\0") == 0) {
supp_comp_flgs |= (1 << ECX_SSE41_BIT);
}
if (strcmp(comp_flag, "-msse4.2\0") == 0) {
supp_comp_flgs |= (1 << ECX_SSE42_BIT);
}
if (strcmp(comp_flag, "-mavx\0") == 0) {
supp_comp_flgs |= (1 << ECX_AVX_BIT);
}
}
return supp_comp_flgs;
}
int is_supported(int cpuid_reg, uint64_t comp_flags, int feature_bit)
{
return ((cpuid_reg >> feature_bit) & 0x1) && ((comp_flags >> feature_bit) & 0x1);
}
int main(int argc, char** argv)
{
int feature_eax, feature_ebx, feature_ecx, feature_edx;
uint64_t supp_comp_flgs = get_supported_flags();
FILE *f = fopen("compiler_flags", "w");
__asm__("cpuid"
: "=a" (feature_eax), "=b" (feature_ebx), "=c" (feature_ecx), "=d" (feature_edx)
: "a" (0x00000001));
if (is_supported(feature_edx, supp_comp_flgs, EDX_MMX_BIT)) {
fprintf(f, "-mmmx -DINTEL_MMX ");
}
if (is_supported(feature_edx, supp_comp_flgs, EDX_SSE_BIT)) {
fprintf(f, "-msse -DINTEL_SSE ");
}
if (is_supported(feature_edx, supp_comp_flgs, EDX_SSE2_BIT)) {
fprintf(f, "-msse2 -DINTEL_SSE2 ");
}
if (is_supported(feature_ecx, supp_comp_flgs, ECX_SSE3_BIT)) {
fprintf(f, "-msse3 -DINTEL_SSE3 ");
}
if (is_supported(feature_ecx, supp_comp_flgs, ECX_SSSE3_BIT)) {
fprintf(f, "-mssse3 -DINTEL_SSSE3 ");
}
if (is_supported(feature_ecx, supp_comp_flgs, ECX_SSE41_BIT)) {
fprintf(f, "-msse4.1 -DINTEL_SSE41 ");
}
if (is_supported(feature_ecx, supp_comp_flgs, ECX_SSE42_BIT)) {
fprintf(f, "-msse4.2 -DINTEL_SSE42 ");
}
if (is_supported(feature_ecx, supp_comp_flgs, ECX_AVX_BIT)) {
if ((feature_ecx >> ECX_AVXOS_BIT) & 0x1) {
fprintf(f, "-mavx -DINTEL_AVX ");
}
}
fclose(f);
return 0;
}