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* Re: Inliner parameters
@ 2003-04-16 21:38 Richard Guenther
  2003-04-17  3:11 ` Steven Bosscher
  0 siblings, 1 reply; 10+ messages in thread
From: Richard Guenther @ 2003-04-16 21:38 UTC (permalink / raw)
  To: Steven Bosscher; +Cc: gcc

> Hi,
>
> Many 3.3 compile time regressions from 3.2 seem to be caused by the new
> tree inliner heuristics.  There are at least a few PRs for which the

They may be related to EH reorganization as well, as noted, f.i. in
PR 10196.

> inliner apparently causes serious compile time regressions (PRs 10160,
> 10196, and 10316 and part of 8361 as well).  Obviously those PRs are
> just the tip of the proverbial iceberg...
>
> All these compile time regressions disappear when the inlining limit is
> changed.  It looks like the 3.3 inliner is a much more agressive, but I
> have not seen any data to confirm this.
>
> When was the last time somebody tried to tune the parameters a bit?  Did
> anyone try the effects of different parameter settings for, say, SPEC
> and POOMA (and, ideally, on more than one platform)?

I tried various parameters for POOMA to tune the performance of the
optimized code and the key parameter to change was min-inline-insns.
This is _way_ too low for POOMA to collapse the expression template
trees. I need to bump this up to 250 to get good performance. The
max-inline-insns-single can be dropped to 250 without loss then.

Maybe the insn counting for small C++ template methods is just way off
compared to C programs? Maybe we should have different default parameters
for C and C++ programs? And we should certainly get -funit-at-a-time
working for C++ in mainline.

Richard.

^ permalink raw reply	[flat|nested] 10+ messages in thread
[parent not found: <Pine.LNX.4.44.0304231303170.18094-100000@bellatrix.tat.physik.uni-tuebingen .de>]
[parent not found: <Pine.LNX.4.44.0304231404330.18094-100000@bellatrix.tat.physik.uni-tuebingen .de>]

end of thread, other threads:[~2003-04-23 16:03 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2003-04-16 21:38 Inliner parameters Richard Guenther
2003-04-17  3:11 ` Steven Bosscher
2003-04-17 10:50   ` Richard Guenther
2003-04-23 12:21     ` PR 10196 / " Richard Guenther
2003-04-17 10:50   ` Richard Guenther
2003-04-17 13:29   ` Jan Hubicka
     [not found] <Pine.LNX.4.44.0304231303170.18094-100000@bellatrix.tat.physik.uni-tuebingen .de>
2003-04-23 12:52 ` PR 10196 / " Steven Bosscher
2003-04-23 13:07   ` Richard Guenther
     [not found] <Pine.LNX.4.44.0304231404330.18094-100000@bellatrix.tat.physik.uni-tuebingen .de>
2003-04-23 17:21 ` Mark Mitchell
2003-04-23 17:21   ` Steven Bosscher

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