Re: Sun performance - Major discovery!

On Wed, 8 Oct 2003, Neil Conway wrote:

> Hey Jeff,
>
> On Wed, 2003-10-08 at 11:46, Jeff wrote:
> > Yeah - like I expected it was able to generate much better code for
> > _bt_checkkeys which was the #1 function in gcc on both sun & linux.
>
> If you get a minute, would it be possible to compare the performance of
> your benchmark under linux/gcc and solaris/gcc when PostgreSQL is
> compiled with "-O3"?
>
Sun:
gcc:
none: 60 seconds
-O: 21 seconds
-O2: 20 seconds
-O3: 19 seconds

suncc:
none: 52 seconds
-fast: 20 secondsish.

-fast is actually a macro that expands to the "best settings" for the
platform that is doing the compilation.


Linux:
-O2: 35
-O3: 40
Odd.. I wonder why it took longer. Perhaps gcc built some bad code?
I thought the results were odd there so I ran the test many times.. same
results! Swapped the binaries back (so -O2 was running) and boom. back to
35.

Sun gcc -O2 and suncc -fast both pass make check.


--
Jeff Trout <jeff@jefftrout.com>
http://www.jefftrout.com/
http://www.stuarthamm.net/