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libc: memmove(): non-overlapping block optim.

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Change-Id: I5652f4f97ca59d95176443fc27c737ef76258183
This commit is contained in:
David 'Digit' Turner 2010-09-26 22:40:02 +02:00
parent b9e49ad56e
commit 80fba9a2fe
1 changed files with 5 additions and 1 deletions
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6
libc/string/memmove.c
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@ -31,7 +31,11 @@ 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 highgly-optimized memcpy() if the destination
* is before the source, or if the two blocks are non-overlapping
*/
if (__builtin_expect((q < p || (q-p) <= (ptrdiff_t)n), 1)) {
return memcpy(dst, src, n);
} else {
#define PRELOAD_DISTANCE 64