gistfile1.txt

[monolith] ~/test_programs >
$ cat implicit_memcpy.c 
struct a
{
    int x[1024];
};


__asm__(".symver memcpy,memcpy@GLIBC_2.2.5");
void foo(struct a*restrict d, const struct a*restrict s, int len)
{
	for(int i = 0; i < len; i++)
		d[i] = s[i];
}
[monolith] ~/test_programs >
$ gcc -fPIC -shared implicit_memcpy.c -O3 && readelf -Ws a.out  | grep memcpy
     1: 0000000000000000     0 FUNC    GLOBAL DEFAULT  UND memcpy@GLIBC_2.2.5 (2)
    31: 0000000000000000     0 FILE    LOCAL  DEFAULT  ABS implicit_memcpy.c
    40: 0000000000000000     0 FUNC    GLOBAL DEFAULT  UND memcpy@GLIBC_2.2.5