LXR linux/arch/x86/lib/strstr

   1#include <linux/string.h>
   2
   3char *strstr(const char *cs, const char *ct)
   4{
   5int     d0, d1;
   6register char *__res;
   7__asm__ __volatile__(
   8        "movl %6,%%edi\n\t"
   9        "repne\n\t"
  10        "scasb\n\t"
  11        "notl %%ecx\n\t"
  12        "decl %%ecx\n\t"        /* NOTE! This also sets Z if searchstring='' */
  13        "movl %%ecx,%%edx\n"
  14        "1:\tmovl %6,%%edi\n\t"
  15        "movl %%esi,%%eax\n\t"
  16        "movl %%edx,%%ecx\n\t"
  17        "repe\n\t"
  18        "cmpsb\n\t"
  19        "je 2f\n\t"             /* also works for empty string, see above */
  20        "xchgl %%eax,%%esi\n\t"
  21        "incl %%esi\n\t"
  22        "cmpb $0,-1(%%eax)\n\t"
  23        "jne 1b\n\t"
  24        "xorl %%eax,%%eax\n\t"
  25        "2:"
  26        : "=a" (__res), "=&c" (d0), "=&S" (d1)
  27        : "0" (0), "1" (0xffffffff), "2" (cs), "g" (ct)
  28        : "dx", "di");
  29return __res;
  30}
  31
  32