<snip>

> > Why is not environment variables or standard configuration files used
> > to make gcc/egcs use that as standard directives, like they do in other
> > systems?
> 
> The official egcs distribution supports specifying the cpu type during 
> configure, you then get a compiler that will target that cpu by default.  
> But don't forget that any code that you then build with it may not port to 
> other machines with older processors.  The default configuration is to go 
> for portability.
> 
> I've seen installations where the compiler looks at the machine its 
> running on and then generates code for that type of machine by default.  
> They suck.  It causes no end of support issues when you ship a binary to a 
> customer with a different configuration.

May I recapitulate this to :
  "`rebuild world' for your own machine if you really want performance ?" 

sounds fair to me !

Reinoud