C/Data Type/Register
Версия от 14:20, 25 мая 2010; (обсуждение)
Register variable: faster
#include <stdio.h>
#include <time.h>
int i; /* This will not be transformed into a
register variable because it is global.*/
int main(void)
{
register int j;
int k;
clock_t start, finish;
start = clock();
for(k = 0; k < 1000; k++)
for(i=0; i<32000; i++)
;
finish = clock();
printf("Non-register loop: %ld ticks\n", finish - start);
start = clock();
for(k = 0; k < 1000; k++)
for(j = 0; j < 32000; j++)
;
finish = clock();
printf("Register loop: %ld ticks\n", finish - start);
return 0;
}
Use register int in function
#include <stdio.h>
main() {
register int i = 0;
for( i = 0; i < 2; i++) {
printf("i = %d\n",i);
}
}