cpucheck.c

Go to the documentation of this file.

#include <stdio.h>
#include <string.h>

int
main ()
{
#ifdef __i386__
#if ( __GNUC__ == 3 && __GNUC_MINOR__ > 0 ) || __GNUC__ > 3
#if __GNUC__ > 3 || __GNUC_MINOR__ > 3
        char *ctune = "-mtune=";
#else
        char *ctune = "-mcpu=";
#endif
        char vendor_string[16];
        int eax, ebx, edx, ecx;
        int i, hv;
        int family, model, stepping;

        __asm__ (".byte 0x0f,0xa2"
        : "=a" (hv), "=b" (ebx), "=d" (edx), "=c" (ecx) : "0" (0));

        *(int *) (vendor_string + 0) = ebx;
        *(int *) (vendor_string + 4) = edx;
        *(int *) (vendor_string + 8) = ecx;
        vendor_string[12] = 0;
        i = 1;

        __asm__ (".byte 0x0f,0xa2"
        : "=a" (eax), "=b" (ebx), "=d" (edx), "=c" (ecx) : "0" (i));

        family = (eax >> 8) & 0xf;
        model = (eax >> 4) & 0xf;
        stepping = eax & 0xf;
        if (family == 0xf) {
                /* "extended" mode. */
                family += (eax >> 20) & 0xff;
                model += (eax >> 12) & 0xf0;
        }

        if (strcmp (vendor_string, "GenuineIntel") == 0) {
                if (family == 5) {
                        printf ("-march=i686 %spentium", ctune);
                } else if (family == 6) {
                        if (model <= 2) {
                                printf ("-march=i686 %spentiumpro",ctune);
                        } else if (model >= 3 && model <= 6) {
                                printf ("-march=i686 %spentium2",ctune);
                        } else if (model <= 11) {
                                printf ("-march=i686 %spentium3", ctune);
                        } else {
                                printf ("-march=i686 %spentium4", ctune);
                        }
                }
                else if (family == 15) {
                        printf ("-march=i686 %spentium4", ctune);
                }
        } else if (strcmp (vendor_string, "AuthenticAMD") == 0) {
                if (family == 6) {
                        printf ("-march=i686 %sathlon", ctune);
                }
        }
#endif
#endif
        return 0;
}