Subversion Repositories planix.SVN

#include "u.h"
#include "libc.h"

int
tas(long *x)
{
        int     v;

        __asm__(        "movl   $1, %%eax\n\t"
                        "xchgl  %%eax,(%%ecx)"
                        : "=a" (v)
                        : "c" (x)
        );
        switch(v) {
        case 0:
        case 1:
                return v;
        default:
                print("canlock: corrupted 0x%lux\n", v);
                return 1;
        }
}