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* povray: Revised numbers
@ 2004-01-17 21:34 Scott Robert Ladd
  2004-01-17 21:48 ` Jan Hubicka
  0 siblings, 1 reply; 11+ messages in thread
From: Scott Robert Ladd @ 2004-01-17 21:34 UTC (permalink / raw)
  To: gcc mailing list

I love live peer review. No, I really do... ;)

If we're going to debate the relative quality of mainline and tree-ssa, 
it seems to me we need some real numbers. I'm an engineer, not a fortune 
teller.

Here are revised numbers for my povray test, based on comments both 
public and private:

                    compile  benchmark
                     time      time
                   --------  ---------
gcc mainline        1:43      7:59
   w/ -mfpmath=sse   1:46      6:30

gcc tree-ssa        1:46      7:35
   w/ -mfpmath=sse  ** SEG fault **

icc 8.0             1:53      5:50

Previously, I was unaware of the --disable-checking switch; using it to 
build tree-ssa improved its compile time such that it performs at the 
same speed as mainline.

Someone suggested privately that I try -mfpmath=sse with GCC; I hadn't 
had good results with that option on some other code, but I tried it 
just to see what would happen.

Mainline's code became *much* faster with -mfpmath=sse; however, 
tree-ssa generated a povray that segfaulted during picture generation. 
No, I have not had time to see if this is a known bug.

Mainline looks *much* better now; however, much as I want tree-ssa to 
move forward, I find myself concurring with many of Mark's views.

I may, if possible, run my Acovea program on GCC with povray, to see if 
I can find a set of switches that equal Intel's performance. I suspect, 
however, that most of Intel's advantage stems from its vectorization of 
code.


-- 
Scott Robert Ladd
Coyote Gulch Productions (http://www.coyotegulch.com)
Software Invention for High-Performance Computing


^ permalink raw reply	[flat|nested] 11+ messages in thread

end of thread, other threads:[~2004-01-20 23:08 UTC | newest]

Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2004-01-17 21:34 povray: Revised numbers Scott Robert Ladd
2004-01-17 21:48 ` Jan Hubicka
2004-01-17 22:00   ` Richard Guenther
2004-01-17 22:12     ` Jan Hubicka
2004-01-17 22:24       ` Richard Guenther
2004-01-17 22:41     ` Richard Henderson
2004-01-20 19:24     ` Richard Guenther
2004-01-20 20:32       ` Daniel Berlin
2004-01-20 20:38         ` Steven Bosscher
2004-01-20 20:45           ` Daniel Berlin
2004-01-20 23:08             ` Steven Bosscher

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