From 4abab5ad6c8465a7528ccdd5f49367da05f78bbd Mon Sep 17 00:00:00 2001 From: Vladimir Azarov Date: Tue, 1 Oct 2024 15:47:05 +0200 Subject: Initial version --- src/string/stpcpy.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) create mode 100644 src/string/stpcpy.c (limited to 'src/string/stpcpy.c') diff --git a/src/string/stpcpy.c b/src/string/stpcpy.c new file mode 100644 index 0000000..4db46a9 --- /dev/null +++ b/src/string/stpcpy.c @@ -0,0 +1,29 @@ +#include +#include +#include + +#define ALIGN (sizeof(size_t)) +#define ONES ((size_t)-1/UCHAR_MAX) +#define HIGHS (ONES * (UCHAR_MAX/2+1)) +#define HASZERO(x) ((x)-ONES & ~(x) & HIGHS) + +char *__stpcpy(char *restrict d, const char *restrict s) +{ +#ifdef __GNUC__ + typedef size_t __attribute__((__may_alias__)) word; + word *wd; + const word *ws; + if ((uintptr_t)s % ALIGN == (uintptr_t)d % ALIGN) { + for (; (uintptr_t)s % ALIGN; s++, d++) + if (!(*d=*s)) return d; + wd=(void *)d; ws=(const void *)s; + for (; !HASZERO(*ws); *wd++ = *ws++); + d=(void *)wd; s=(const void *)ws; + } +#endif + for (; (*d=*s); s++, d++); + + return d; +} + +weak_alias(__stpcpy, stpcpy); -- cgit v1.2.3