Re: [camellia-oss:00952] Re: [PATCH 5/5] camellia: de-unrolling, 64bit-ization

[Denys Vlasenko <vda.linux@googlemail.com>]

On Tuesday 13 November 2007 18:41, David Miller wrote:
> From: Denys Vlasenko <vda.linux@googlemail.com>
> Date: Tue, 13 Nov 2007 15:34:33 -0700
>
> > My preferred solution is to make loop unrolling conditional on
> > CONFIG_CC_OPTIMIZE_FOR_SIZE - and this is what is done in my
> > (first) patch (see attached). This part:
>
> The default build is going to be CONFIG_CC_OPTIMIZE_FOR_SIZE
> basically for everyone, this is what people get by default
> and this is what every distribution uses.
>
> Therefore %99.9999 of folks will get the slowdown.
>
> So in my book this is not an acceptable way to deal with
> this problem.

Loop unrolling here amounts to 25% code growth:

   text    data     bss     dec     hex filename
  21714       0       0   21714    54d2 camellia5.o
  15906       0       0   15906    3e22 camellia5_Os.o

Saving 25% or code size and going 5% slower is perfectly acceptable
tradeof for some users. NB: I'm not saying all, ut some significant
part of users would like to be able to have this choice.

If CONFIG_CC_OPTIMIZE_FOR_SIZE is not an acceptable method,
do you have other ideas?
--
vda