Messages in this thread | | | Date | Wed, 4 Jun 2014 13:07:34 +0200 | Subject | Re: [PATCH 0/10] use safer test on the result of find_first_zero_bit | From | Geert Uytterhoeven <> |
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Hi Julia,
On Wed, Jun 4, 2014 at 1:00 PM, Julia Lawall <julia.lawall@lip6.fr> wrote: > OK, thanks. I was only looking at the C code. > > But the C code contains a loop that is followed by: > > if (!size) > return result; > tmp = *p; > > found_first: > tmp |= ~0UL << size; > if (tmp == ~0UL) /* Are any bits zero? */ > return result + size; /* Nope. */ > > In the first return, it would seem that result == size. Could the second > one be changed to just return size? It should not hurt performance.
"size" may have been changed between function entry and this line. So you have to store it in a temporary.
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
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