A common use of memmove() can be handled by memcpy(). Also memcpy() includes an optimization for large sizes: it copies a word at a time. So we can get a speed-up by calling memcpy() to handle our move in this case.
Update memmove() to call also memcpy() if the source don't overlap the destination (src + count <= dest). Signed-off-by: Patrick Delaunay <[email protected]> --- This patch allows to save 38ms for Kernel Image extraction (7327624 Bytes) from FIT loaded at 0xC2000000 for ARMV7 board STM32MP157C-EV1, and with kernel destination = Load Address: 0xc4000000, located after the FIT without overlap, compared with destination = Load Address: 0xc0008000. -> 14,332 us vs 52,239 in bootstage report In this case the memmove funtion is called in common/image.c::memmove_wd() to handle overlap. lib/string.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/string.c b/lib/string.c index ae7835f600..ef8ead976c 100644 --- a/lib/string.c +++ b/lib/string.c @@ -567,7 +567,7 @@ void * memmove(void * dest,const void *src,size_t count) { char *tmp, *s; - if (dest <= src) { + if (dest <= src || (src + count) <= dest) { memcpy(dest, src, count); } else { tmp = (char *) dest + count; -- 2.17.1
