Re: Faster compilation speed

[Daniel Jacobowitz <drow at mvista dot com>]

On Tue, Aug 13, 2002 at 11:07:07AM -0400, Robert Dewar wrote:
> >>Why not make incremental compilation a standard for gcc...
> 
> I seriously doubt that incremental compilation can help. Usually it is far
> better to aim at the simplest fastest possible compilation path without
> bothering with the extra bookkeeping needed for IC.
> 
> Historically the fastest compilers have not been incremental, and IC has
> only been used to make painfully slow compilers a little less painful
> 
> (I realize that some would put GCC into the second category here, but I 
> would prefer that we keep efforts focussed on moving it into the first
> category).
> 
> That being said, I still wonder over time whether the effort to speed up
> gcc is effort well spent. Or rather, put that another way, let's try to make
> sure that it is effort well spent. If there are obvious opportunities, then
> certainly it makes sense to take advantage of them.
> 
> But there are definite effort tradeoffs, and continued increase in speed of
> machines does tend to mute the requirements for faster compilation.
> 
> When Realia COBOL ran 10,000 lpm on a PC-1, with the major competitor running
> at 1,000 lpm, then the speed difference was a major marketing advantage, but
> now days with essentially the same compiler running over a million lines a
> minute, and essentially the same competitive compiler running at 100,000 lpm
> the difference is no longer nearly so significant :-)

Yes it is - projects have grown correspondingly.  Maybe not for COBOL,
but for the sorts of things GCC is used for.  A factor of ten is
still very significant, which is the whole point of Apple's efforts!

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer