From 0b44a0315b47dd8eced9f3b7f31580cf14bbfc01 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Sat, 12 Feb 2011 00:22:29 -0500 Subject: initial check-in, version 0.5.0 --- src/string/memcpy.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) create mode 100644 src/string/memcpy.c (limited to 'src/string/memcpy.c') diff --git a/src/string/memcpy.c b/src/string/memcpy.c new file mode 100644 index 00000000..02cb4694 --- /dev/null +++ b/src/string/memcpy.c @@ -0,0 +1,29 @@ +#include +#include +#include + +#define SS (sizeof(size_t)) +#define ALIGN (sizeof(size_t)-1) +#define ONES ((size_t)-1/UCHAR_MAX) + +void *memcpy(void *dest, const void *src, size_t n) +{ + unsigned char *d = dest; + const unsigned char *s = src; + + if (((uintptr_t)d & ALIGN) != ((uintptr_t)s & ALIGN)) + goto misaligned; + + for (; ((uintptr_t)d & ALIGN) && n; n--) *d++ = *s++; + if (n) { + size_t *wd = (void *)d; + const size_t *ws = (const void *)s; + + for (; n>=SS; n-=SS) *wd++ = *ws++; + d = (void *)wd; + s = (const void *)ws; +misaligned: + for (; n; n--) *d++ = *s++; + } + return dest; +} -- cgit v1.2.1