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Re: Huge compile time & run time performance regression 3.3 -> HEAD
- From: Richard Guenther <rguenth at tat dot physik dot uni-tuebingen dot de>
- To: Gabriel Dos Reis <gdr at integrable-solutions dot net>
- Cc: Matt Austern <austern at apple dot com>, <gcc at gcc dot gnu dot org>
- Date: Mon, 19 May 2003 23:08:33 +0200 (CEST)
- Subject: Re: Huge compile time & run time performance regression 3.3 -> HEAD
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)
>
> What I've noted (and I posted figures) wkas that the patch I applied
> cut the name lookup time about half on mainline, whereas I got at
> least 20% on branch.
If you mean
2003-05-18 Gabriel Dos Reis <gdr@integrable-solutions.net>
* cp-tree.h (struct lang_type_class): Replace data member tags
with hash-table nested_udts.
(CLASSTYPE_NESTED_UTDS): Rename from CLASSTYPE_TAGS.
[...]
this is already included in the numbers. I.e. the 3.4 numbers are from CVS
about 2 hours ago.
Richard.