Re: support of older compilers

[Linus Torvalds]

On Thu, 4 Nov 2004, Adam Heath wrote:
>
> On Wed, 3 Nov 2004, Chris Wedgwood wrote:
> 
> > On Wed, Nov 03, 2004 at 05:06:56PM -0600, Adam Heath wrote:
> >
> > > You can't be serious that this is a problem.
> >
> > try it, say gcc 2.95 vs gcc 4.0 ... i think last i checked the older
> > gcc was over twice as fast
> 
> I didn't deny the speed difference of older and newer compilers.
> 
> But why is this an issue when compiling a kernel?  How often do you compile
> your kernel?

First off, for some people that is literally where _most_ of the CPU 
cycles go.

Second, it's not just that the compilers are slower. Historically, new gcc 
versions are:
 - slower
 - generate worse code
 - buggier

For a _long_ time, the only reason to upgrade gcc was literally C++
support: basic C support was getting _worse_ with new compilers in pretty
much every regard.

Things seem to have improved a bit lately. The gcc-3.x series was 
basically not worth it for plain C until 3.3 or so.

		Linus
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