On Sun, 03 Nov 2002 14:34:11 -0800, Roz <Rzl### [at] netscapenet> wrote:
> Warp wrote:
>> Roz <Rzl### [at] netscapenet> wrote:
>> 
>>>There must be some stuff in the Windows official binary that takes advantage
>>>of the Pentium specifically.
>> 
>> 
>>   I think that it's simply that Intel's compiler can compile better for
>> Intel processors than gcc.
>> 
> 
> Yes, that makes sense because they (Intel) should know all the ins and 
> outs of
> their own processor ;)  Looking back through old posts to this newsgroup 
> there's
> some indication that icc custom builds are just a tiny bit faster than gcc

that tiny bit turns out to be 15-45% back here in Finland.
ICC 6.0.1 on Linux[1] versus Official POV-Ray 3.50c:

skyvase.pov
ICC: 5943374424 cycles
GCC: 8737719077 cycles

brilliant.pov (many diamonds, max trace level 109)
ICC:  7264656795 cycles
GCC: 13371101675 cycles

fish13.pov
ICC: 15667900293 cycles
GCC: 19866506320 cycles

was profiling (-prof_genx & -prof_use) used in the Windows version?
it can speed up by 25%.
option -pc80 seemed to speed up at least some scenes by 8%.
also, remember to use -limf instead of -lm.
-wp_ipo and -rcd seemed to break the compile at least with ICC 6.0.0,
haven't tried with 6.0.1.

BTW, who was optimizing usage of some variable in POV-Ray?
it involved making some variable a global variable, sqrt and
optics.pov.  I'd like to see the patch.

> builds. They're all so close to each other now that I'm not worried 
> about it.
> I just didn't want people to get the impression that the 10% slower thing
> bstone mentioned was universal. There's many factors involved beyond the
> compiler used including type of processor.

like what scene files were used when generating profiling data
with binary generated by icc -prof_genx ... ;)
 
> -Roz

[1] includes some patches/hacks not in the Official version,
    including using SHA-1 as PRNG.

-- 
Safari - y7p### [at] sneakemailcom
"Talk is cheap. Show me the code." - Linus Torvalds

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