vsprintf.c: optimizing, part 1 (easy and obvious stuff)
* There is no point in having full "0...9a...z" constant vector,
if we use only "0...9a...f" (and "x" for "0x").
* Post-decrement usually needs a few more instructions, so use
pre decrement instead where makes sense:
- while (i < precision--) {
+ while (i <= --precision) {
* if base != 10 (=> base 8 or 16), we can avoid using division
in a loop and use mask/shift, obtaining much faster conversion.
(More complex optimization for base 10 case is in the second patch).
Overall, size vsprintf.o shows ~80 bytes smaller text section
with this patch applied.
Signed-off-by: Douglas W Jones <jones@cs.uiowa.edu>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 file changed