freevec.org

#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include <linux/auxvec.h>
#include <asm/cputable.h>
 
int have_altivec() {
    static int available = -1;
    int new_avail = 0;
    char fname[64];
    unsigned long buf[64];
    ssize_t count;
    pid_t pid;
    int fd, i;
 
    if (available != -1)
            return available;
 
    pid = getpid();
    snprintf(fname, sizeof(fname)-1, "/proc/%d/auxv", pid);
 
    fd = open(fname, O_RDONLY);
    if (fd < 0)
            goto out;
 more:
    count = read(fd, buf, sizeof(buf));
    if (count < 0)
            goto out_close;
 
    for (i=0; i < (count / sizeof(unsigned long)); i += 2) {
            if (buf[i] == AT_HWCAP) {
            new_avail = !!(buf[i+1] & PPC_FEATURE_HAS_ALTIVEC);
                    goto out_close;
            } else if (buf[i] == AT_NULL) {
                    goto out_close;
            }
    }
 
    if (count == sizeof(buf))
            goto more;
 out_close:
    close(fd);
 out:
    available = new_avail;
    return available;
}
 
int main() {
        int altivec_support = have_altivec();
        printf("Altivec support: %d\n", altivec_support);
        return(0);
}