Subversion Repositories openrisc

/*

 *  C library strlen routine

 *

 *  This routine has been optimized for the CPU32+.

 *  It should run on all 68k machines.

 *

 *  W. Eric Norum

 *  Saskatchewan Accelerator Laboratory

 *  University of Saskatchewan

 *  Saskatoon, Saskatchewan, CANADA

 *  eric@skatter.usask.ca

 */

#include <string.h>

/*

 * Test bytes using CPU32+ loop mode if possible.

 */

size_t

strlen (const char *str)

{

        unsigned int n = ~0;

        const char *cp = str;

        asm volatile ("1:\n"

             "\ttst.b (%0)+\n"

#if defined(__mcpu32__)

             "\tdbeq %1,1b\n"

#endif

             "\tbne.b 1b\n" :

                "=a" (cp), "=d" (n) :

                 "0" (cp),  "1" (n) :

                 "cc");

        return (cp - str) - 1;

}