Description:
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Did you ever wonder, where the horsepower of your 68040 was hiding from you?
Well, I found out: It hides in the gnu c compiler!
Recently I compiled PoV-Ray for the Sparcs here at the University of Bremen. I
used gcc, naturally, and I wanted gcc to deliver good work. So I read quite a
few manpages and stumbled over a fat load of options for optimization. At the
end of this section there were also processor-specific options.
I saw the magic number: 68040. I realized that I (not really able to program
in C) NEEDED gcc!
After some hours of ftp'ing to good ol' AMINET, I had both gcc 2.6.1 and the
source of PoV-Ray 2.2, and I even managed to install gcc at first attempt that
evening.
Only a few nights of constant compiling later, I had an executable of povray
that lacked nifty display features and even had a disgusting flaw (see section
Bugs!), BUT:
IT RENDERED CHESS.POV 44% FASTER THAN THE OFFICIAL 020+881 EXECUTABLE!!!
So here I am now, thinking about all those trace-o-holics wasting CPU-cycles
without even knowing it, and I can't resist uploading the executable. Despite
all the Bugs that might be in there (see section Bugs!), despite the need for
ixemul.library (see section Requirements), despite the small number of actual
68040 Amigas... HERE IT IS: THE HORSEPOWER OF YOUR 68040!
For some more information on compiling, read "compiling".
Requirements:
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You will need ixemul.library version 40 or above. I think ixemul.library works
only on 2.04 Kickstarts and higher versions. You can find it on AMINET in
"dev/gcc/", including it here would be a waste of AMINET diskspace...
"My" povray has not really been tested so far, but runs nicely (except the
Bugs, see there) on an Amiga 4000/040 with:
- Kickstart and Workbench 3.1
- 12 MByte of Static-Column FastRAM; RAM access is about 20-30% faster than
with Page-Mode RAMs, but raytracing is typically not sped up. (shameless
plug: ask Omega Datentechnik, Oldenburg, Germany for more info, they sell it)
- Original Commo CPU-Board with 68040 @ 25 MHz
Bugs:
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There is but one disgusting flaw in "my" povray: the second scanline of the
picture is not output to disk unless you specify an I/O buffer with the
"+Bnn" option (either on the commandline, in "povray.def" or in the POVRAYOPT
environment variable).
This behaviour is not affected by
- what scene is rendered
- the resolution it is rendered at
- the output file format
- the compiler options
Sorry, I cannot fix this bug. I loaded tons of "printf"s into the source, only
to find out that the proper functions are called at the right time with
correct arguments passed... I have definitely no clue.
I did not encounter other bugs so far.
Restrictions:
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You already know that you have to use "+B" for every trace (see section Bugs).
Now let me tell you that you also have to use "-d" for every trace. No preview
display, sorry. The machine-specific "amiga.c" was too much for gcc. As I am
not really familiar with C, I will not be able to fix this.
There is one more disadvantage that is related to the Bug (see there): all
versions of povray I checked, have trouble continuing traces that were done
with an I/O buffer. Maybe a tool that removed a partial last line from the
output file could fix this.
Acknowledgements:
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I would like to thank the PoV Team for their great work. I am especially glad
that they decided to provide source code. Who knows, maybe I'll contribute
some patches, too, now that I can compile povray :-)
I would like to express my respect for the talent and attitude of the people
involved in the gnu project. I also want to thank the people that managed to
port gcc to the Amiga.
Whatever happens to Commodore, with people like you out there, my Amiga will
never die!
The Uploader:
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I am a mere math student that likes to play around with povray on a Sparc 20...
If you want to contact me, feel free to mail to the address mentioned at the
top of this readme, or if you don't have access to the net, send your mail to
Holger Bettag
Kilianstrasse 44
67373 Dudenhofen
Germany
Happy tracing!
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