libc: optimize memmove() with memcpy() if possible.

Change-Id: I90e578fdc82e427caee8fa4157ce3f8c6c99926d
This commit is contained in:
David 'Digit' Turner 2010-10-07 11:03:32 +02:00
parent af00228b70
commit 5b81b91817

View File

@ -31,7 +31,10 @@ void *memmove(void *dst, const void *src, size_t n)
{
const char *p = src;
char *q = dst;
if (__builtin_expect(q < p, 1)) {
/* We can use the optimized memcpy if the destination is below the
* source (i.e. q < p), or if it is completely over it (i.e. q >= p+n).
*/
if (__builtin_expect((q < p) || ((size_t)(q - p) >= n), 1)) {
return memcpy(dst, src, n);
} else {
#define PRELOAD_DISTANCE 64