#include <stdio.h>
#include <stdlib.h>
#include <time.h>
void cstrcpy(char *a,char *b);
void qstrcpy(char * dest,const char *src);
void cstrcpy(char *a,char *b){
while (*a++ = *b++);
}
void qstrcpy(char * dest,const char *src)
{
static int d0=0;
static int d1=0;
static int d2=0;
__asm__ __volatile__(
"1:\tlodsb\n\t"
"stosb\n\t"
"testb %%al,%%al\n\t"
"jne 1b"
: "=&S" (d0), "=&D" (d1), "=&a" (d2)
:"0" (src),"1" (dest) : "memory");
}
int main(){
char a[10];
char *b="bbbbbbb";
int i;
clock_t t_begin;
i=0;
t_begin=clock();
while(i++<10000000){
cstrcpy(a,b);
}
printf("cstrcpy: %lf seconds\n", (double)(clock() - t_begin) / CLOCKS_PER_SEC);
i=0;
t_begin=clock();
while(i++<10000000){
qstrcpy(a,b);
}
printf("qstrcpy: %lf seconds\n", (double)(clock() - t_begin) / CLOCKS_PER_SEC);
i=0;
t_begin=clock();
while(i++<10000000){
strcpy(a,b);
}
printf("strcpy: %lf seconds\n", (double)(clock() - t_begin) / CLOCKS_PER_SEC);
}
