Re: cgraph based inlining heuristics

[Richard Guenther <rguenth at tat dot physik dot uni-tuebingen dot de>]

On Wed, 2 Jul 2003, Jan Hubicka wrote:

> > Hi,
> >
> > thanks for your continued work on improving gcc3.4 inlining!
> >
> > Did you check any of the POOMA testcases with the new heuristics yet?
> > I realize these could be only compile-time tests, but I'd be interested
> > especially in the tramp3d numbers.
>
> I am really curious about your results!

Ok, here they go. I tested four different setups:

(0) gcc3.4
(1) gcc3.4 with __attribute__((leafify)) patch
(2) gcc3.4 with your patch
(3) gcc3.4 with your patch and -funit-at-a-time
(4) gcc3.4 with your patch and -funit-at-a-time --param max-inline-insns-auto=200 --param max-inline-insns-single=200 --param inline-unit-growth=1000 --param large-function-growth=1000

flags otherwise used are
-O2 -g -march=athlon -fno-math-errno -fno-trapping-math -ffinite-math-only
-funroll-loops

                      (0)         (1)        (2)       (3)       (4)
binary size        10166017    10681144    8405237   8405237   9874056
compile time      2m57.503s   3m40.638s  1m19.553s 1m20.742s 2m55.031s
runtime performance   3.97s       1.66s      2.65s     2.64s     1.74s

timings are seconds per iteration. The new heuristics are a huge
improvement, both in compile and runtime! I suspect from the numbers,
that -funit-at-a-time is enabled at -O2 already? Also we probably get
the performance of __attribute__((leafify)) with no extra compile time
or binary size increase compared to (2) and (3).

So in conclusion - MANY thanks for your work! I hope it gets accepted
soon. Also I still think __attribute__((leafify)) is a useful hint to
the compiler to optimize without paying for it at other places (tuning
params as in (4) hurts too much and is not very easy to tune).

Thanks,

Richard.

---
Richard Guenther <richard dot guenther at uni-tuebingen dot de>
WWW: http://www.tat.physik.uni-tuebingen.de/~rguenth/