From: Matthias Weisser <weisserm@arcor.de>
Date: Sun, 22 May 2011 23:03:55 +0000 (+0000)
Subject: memcpy/memmove: Do not copy to same address
X-Git-Url: http://git.dujemihanovic.xyz/?a=commitdiff_plain;h=b038db852b5b7120f1ff825d8e2a5c2cd14c2f0f;p=u-boot.git

memcpy/memmove: Do not copy to same address

In some cases (e.g. bootm with a elf payload which is already at the right
position) there is a in place copy of data to the same address. Catching this
saves some ms while booting.

Signed-off-by: Matthias Weisser <weisserm@arcor.de>
---

diff --git a/lib/string.c b/lib/string.c
index b375b8124a..2c4f0ec9a1 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -467,6 +467,9 @@ void * memcpy(void *dest, const void *src, size_t count)
 	unsigned long *dl = (unsigned long *)dest, *sl = (unsigned long *)src;
 	char *d8, *s8;
 
+	if (src == dest)
+		return dest;
+
 	/* 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)) {
@@ -497,6 +500,9 @@ void * memmove(void * dest,const void *src,size_t count)
 {
 	char *tmp, *s;
 
+	if (src == dest)
+		return dest;
+
 	if (dest <= src) {
 		tmp = (char *) dest;
 		s = (char *) src;