From ecd830b863e5c6ac5d804d3b3a92453a98d526fc Mon Sep 17 00:00:00 2001 From: Alessandro Rubini Date: Sat, 10 Oct 2009 11:51:05 +0200 Subject: [PATCH] lib_generic memcpy: copy one word at a time if possible If source and destination are aligned, this copies ulong values until possible, trailing part is copied by byte. Thanks for the details to Wolfgang Denk, Mike Frysinger, Peter Tyser, Chris Moore. Signed-off-by: Alessandro Rubini Acked-by: Andrea Gallo Acked-by: Mike Frysinger --- lib_generic/string.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/lib_generic/string.c b/lib_generic/string.c index 181eda6149..61a45dc94d 100644 --- a/lib_generic/string.c +++ b/lib_generic/string.c @@ -446,12 +446,23 @@ char * bcopy(const char * src, char * dest, int count) * You should not use this function to access IO space, use memcpy_toio() * or memcpy_fromio() instead. */ -void * memcpy(void * dest,const void *src,size_t count) +void * memcpy(void *dest, const void *src, size_t count) { - char *tmp = (char *) dest, *s = (char *) src; - + unsigned long *dl = (unsigned long *)dest, *sl = (unsigned long *)src; + char *d8, *s8; + + /* while all data is aligned (common case), copy a word at a time */ + if ( (((ulong)dest | (ulong)src) & (sizeof(*dl) - 1)) == 0) { + while (count >= sizeof(*dl)) { + *dl++ = *sl++; + count -= sizeof(*dl); + } + } + /* copy the reset one byte at a time */ + d8 = (char *)dl; + s8 = (char *)sl; while (count--) - *tmp++ = *s++; + *d8++ = *s8++; return dest; } -- 2.39.5