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>

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>
Matthias Weisser · Wolfgang Denk
1 parent 942e31437d
Showing 1 changed file with 6 additions and 0 deletions Side-by-side Diff
lib/string.c
@@ -467,6 +467,9 @@
 	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)) {
@@ -496,6 +499,9 @@
 void * memmove(void * dest,const void *src,size_t count)
 {
 	char *tmp, *s;
+
+	if (src == dest)
+		return dest;
  
 	if (dest <= src) {
 		tmp = (char *) dest;
...	...	@@ -467,6 +467,9 @@
467	467	unsigned long dl = (unsigned long )dest, sl = (unsigned long )src;
468	468	char d8, s8;
469	469
	470	+ if (src == dest)
	471	+ return dest;
	472	+
470	473	/* while all data is aligned (common case), copy a word at a time */
471	474	if ( (((ulong)dest \| (ulong)src) & (sizeof(*dl) - 1)) == 0) {
472	475	while (count >= sizeof(*dl)) {
...	...	@@ -496,6 +499,9 @@
496	499	void * memmove(void * dest,const void *src,size_t count)
497	500	{
498	501	char tmp, s;
	502	+
	503	+ if (src == dest)
	504	+ return dest;
499	505
500	506	if (dest <= src) {
501	507	tmp = (char *) dest;