#include <stdio.h> 
#include <string.h> 
#include <time.h> 
 
void mymemcpy(void *dst, void *src, unsigned int size) 
{ 
  int i; 
  char *a = (char *)src; 
  int pad = size%sizeof(int); 
  for(i = 0; i < size/sizeof(int); i++) 
  { 
    *(int *)dst = *(int *)src; 
    dst +=4; 
    src +=4; 
  } 
  for (i = 0; i < pad; i++) 
  { 
    *(char *)dst = *(char *)src; 
    dst++; 
    src++; 
  } 
} 
 

다음은 사용테스트다.

struct data 
{ 
  int age; 
  char name[24]; 
  char a; 
}; 
 
int main(int argc, char **argv) 
{ 
  int i = 0; 
  struct data src, dst; 
  clock_t stime, etime; 
 
  memset((void *)&dst, 0x00, sizeof(src)); 
  src.age = 10; 
  src.a = 'a'; 
  sprintf(src.name, "%s", "yundream"); 
 
  stime = clock(); 
  for (i = 0; i < 10000000; i++) 
  { 
    mymemcpy((void *)&dst, (void *)&src, sizeof(src)); 
  } 
  etime = clock(); 
  printf("Time : %.3fs\n",(double)(etime - stime)/CLOCKS_PER_SEC); 
  printf("%d\n", dst.age); 
  printf("%c\n", dst.a); 
  printf("%s\n", dst.name); 
}