Re: gcc compile-time performance

[dewar at gnat dot com (Robert Dewar)]

> Maybe we should declare that people working in the third world are not
> doing serious professional development work.  Sigh.

Well I think you would be surprised at typical machines you find on the
desks of third world developers. If you put together your own PC today,
you can build remarkable machines that cost perhaps one tenth the cost
of a minimal PC-1 when it was first distributed in 1981, not counting
inflation, so really the factor is more like 30.

The point here is that if you want a fast compiler, GCC is *so* far from
meeting this criterion, that I don't think you will get very far in fixing
it. You can put in a huge effort, and perhaps make it twice as fast, but
that's less than a year's gain in hardware speed, and the rate of gain is
the same in schools and third world countries, even if they are using older
obsolete hardware.

As I have said before, I think it perfectly reasonable to try to keep a
watch on gcc compilation performance. Indeed when we first looked at GCC 3
we worried that the compile times seemed to have increased noticeably compared
with GCC 2, but quite a bit of that problem has disappeared in our tests, 
and faster hardware does help.

But to take the position that a 20% increase in compilation time is a
disastrous regression seems excessive rhetoric to me. I still remain
more concerned that the runtime peformance of GCC seems to be falling
further behind proprietary compilers on some architectures.