none/tests/amd64/getseg.c

   1 /* Test segment register getting. */
   2
   3 #include <stdio.h>
   4
   5 int main(void)
   6 {
   7    unsigned short csw = -1;
   8    unsigned int csl = -1;
   9    unsigned long csq = -1;
  10    unsigned short csw_mem = -1;
  11
  12    __asm__ __volatile__ (
  13        "movw %%cs, %0\n" /* mov segReg, r16 */
  14        "movl %%cs, %1\n" /* mov segReg, r32 */
  15        "movq %%cs, %2\n" /* mov segReg, r64 */
  16        "movw %%cs, %3\n" /* mov segReg, mem16 */
  17        : "=r" (csw), "=r" (csl), "=r" (csq), "=m" (csw_mem));
  18
  19    printf("cs(w)=%u\n", csw);
  20    printf("cs(l)=%u\n", csl);
  21    printf("cs(q)=%lu\n", csq);
  22    printf("cs(w_mem)=%u\n", csw_mem);
  23
  24    return 0;
  25 }