Re: Huge compile time & run time performance regression 3.3 -> HEAD

[Matt Austern <austern at apple dot com>]

On Sunday, May 18, 2003, at 08:45  AM, Richard Guenther wrote:

> Hi!
>
> As 3.3 is now out, I start comparing 3.3 to HEAD wrt compile time
> performance and performance of the resulting code. As always these
> comparisons are for a POOMA based scientific application.
>
> I experience a 100% compile time regression (673.50s -> 1284.48s) and
> a 12% runtime performance regression (150s -> 171s) when comparing
> gcc3.3 to HEAD.
>
> Time reports follow, the most prominent regressions are expand, global 
> CSE
> (>300%!), loop analysis and branch prediction.
>
> Compile options are -ftemplate-depth-80 -fno-exceptions -O2 
> -march=athlon
> -funroll-loops -fomit-frame-pointer

Do you see any compile time regressions at -O0?

(I'm asking for the obvious reason: trying to find out how much work we
need to do in the front end as opposed to the back end.)

			--Matt