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

[Richard Guenther]

On 19 May 2003, Gabriel Dos Reis wrote:

> Richard Guenther <rguenth@tat.physik.uni-tuebingen.de> writes:
>
> | > 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.)
> |
> | After killing all forced inlining, I get almost the same timings from 3.3
> | and 3.4, namely 42.50 and 44.89 seconds.
> |
> | Slowdown comes from
> |
> | 3.3: name lookup           :   6.92 (17%) usr   0.90 (43%) sys   7.50
> | (18%) wall
> | 3.4: name lookup           :   9.06 (22%) usr   0.81 (39%) sys  10.29
> | (23%) wall
>
> I've also noticed that name lookup time has increased from 3.3 to 3.4,
> probably mostly because now we're doing things more correctly and
> partly because we didn't really take care to optimize it.  It would be
> interesting if you could report numbers for name lookup for 3.4:
>
>   * before I applied the name lookup
>   * after I applied it (i.e. cvs as of this moment)

With g++ (GCC) 3.4 20030505 (experimental) I get a total time of 46.37 and

 name lookup           :   9.42 (23%) usr   0.93 (40%) sys  10.20 (22%)
wall

Richard.