Messages in this thread | | | Date | Mon, 2 Jun 2014 19:59:39 +0200 | Subject | Re: [PATCH] arch: ia64: kernel: palinfo.c: Optimization of the Code | From | Rickard Strandqvist <> |
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Hi
Thought I would be able to do that. But after testing, I could not measure any difference.
Thought it would make a noticeable difference, but guess gcc resolve this in the best way.
Best regards Rickard Strandqvist
2014-06-02 9:24 GMT+02:00 Clemens Ladisch <clemens@ladisch.de>: > Rickard Strandqvist wrote: >> From what I know, AND is faster then modulo. > > Which is why the compiler does this optimization automatically, > if it can prove that it is correct. > >> - if (i != 0 && (i%64) == 0) >> + if (i != 0 && (i&63) == 0) > > Did you prove that i cannot be negative? > > > Regards, > Clemens
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