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| | #include <string.h>
#include <stdint.h>
#define aliases __attribute__((__may_alias__))
#define byte_repeat(x) ((size_t)~0 / 0xff * (x))
#define word_has_zero(x) (((x) - byte_repeat(0x01)) & ~(x) & byte_repeat(0x80))
#define weak_alias(o, n) extern __typeof__(o) n __attribute__((weak, alias(#o)))
char *__stpcpy(char *restrict d, const char *restrict s)
{
size_t aliases *wd;
const size_t aliases *ws;
if (((uintptr_t)d | (uintptr_t)s) & sizeof(size_t) - 1) goto bytewise;
for (; (uintptr_t)s & sizeof(size_t) - 1 && (*d = *s); d++, s++);
if ((uintptr_t)s & sizeof(size_t) - 1) return d;
wd = (void *)d;
ws = (const void *)s;
for (; !word_has_zero(*ws); wd++, ws++) *wd = *ws;
d = (void *)wd;
s = (const void *)ws;
bytewise:
for (; *d = *s; d++, s++);
return d;
}
weak_alias(__stpcpy, stpcpy);
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