请问如何找到memcpy()函数的实现

johnhhj

我下了glic-2.2,可是找到不到memcpy()在哪个目录/文件

dxzhang

内核源码的include/asm/string.h中

neighborinfo

extern void * memcpy(void *, const void *, __kernel_size_t);
只有声明,没有定义呀!

DoDo

string.c

zhllg

Post by dxzhang
内核源码的include/asm/string.h中

内核源代码里的实现，除非写内核模块，否则是用不到的
不过参考一下却是可以的

dimensioll

static inline void *
__memcpy(void * to, const void * from, size_t n)
{
int d0, d1, d2;
__asm__ __volatile__(
        "rep ; movsl\n\t"
        "testb $2,%b4\n\t"
        "je 1f\n\t"
        "movsw\n"
        "1:\ttestb $1,%b4\n\t"
        "je 2f\n\t"
        "movsb\n"
        "2:"
        : "=&c" (d0), "=&D" (d1), "=&S" (d2)
        :"0" (n/4), "q" (n),"1" ((long) to),"2" ((long) from)
        : "memory");
return (to);
}

lpsir

1. 
   
2. #ifndef __HAVE_ARCH_MEMCPY
   
3. /**
   
4. * memcpy - Copy one area of memory to another
   
5. * @dest: Where to copy to
   
6. * @src: Where to copy from
   
7. * @count: The size of the area.
   
8. *
   
9. * You should not use this function to access IO space, use memcpy_toio()
   
10. * or memcpy_fromio() instead.
    
11. */
    
12. void * memcpy(void * dest,const void *src,size_t count)
    
13. {
    
14.         char *tmp = (char *) dest, *s = (char *) src;
    
15. 
    
16.         while (count--)
    
17.                 *tmp++ = *s++;
    
18. 
    
19.         return dest;
    
20. }
    
21. EXPORT_SYMBOL(memcpy);
    
22. #endif
    

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