Re: [PATCH] Kill div64.h dupes, parenthesize do_div() macro params

Bernardo Innocenti (bernie@develer.com)
Wed, 2 Jul 2003 09:02:05 +0200


On Wednesday 02 July 2003 07:09, Linus Torvalds wrote:

> > Why 64-bit divides in particular were victimised in this manner is a
> > matter for speculation ;)
>
> Because gcc historically _cannot_ generate an efficient 64/32->64
> divide. It ends up doing a full 64/64 divide thing.

You're right here. I've been too quick in putting my faith in gcc ;-)

Shouldn't we complain to the gcc people? The 64/32 division is a
rather common operation in many applications besides the kernel, so
you'd expect gcc to get it right without polluting every single
project with reimplementations of do_div().

-- 
  // Bernardo Innocenti - Develer S.r.l., R&D dept.
\X/  http://www.develer.com/

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