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Mail Archives: pgcc/1998/07/16/07:30:54

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Message-ID: <35ADAA27.E1FA6487@netvision.net.il>
Date: Thu, 16 Jul 1998 10:22:16 +0300
From: Misha <vulcao AT netvision DOT net DOT il>
X-Mailer: Mozilla 4.04 [en] (X11; I; IRIX 5.3 IP22)
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To: beastium-list AT Desk DOT nl
Subject: PGCC's optimizations (continued)
Sender: Marc Lehmann <pcg AT goof DOT com>
Status: RO
X-Status: A
Lines: 29

Hi.
  First, thanks to Marc and others who have responded promptly and
informatively to my questions.

Recap: Sometime ago I posted that PGCC does not optimize PII(PPro)
code that good. I said that GCC 2.7.2.1(libc5) produced better code for
my number-crunching app.

Now to the point. I did all what you have adivised me to do (compiler
flags). Only after adding "-march=pentiumpro", the code gained about
23% (the integer only version), and now it is slightly (1.1%) better than
GCC 2.7.2.1 produced code.

When I used the float version none of the flags you've sent me gained
anything.

I am not dissapointed with PGCC, but I think some more work has to be
done in order to gain the full potential of the P6 (PII+PPro) architecture.

BTW, has anyone ever done a comparison of the same code under PGCC
and DOS/Win95 compilers (VC++ 5.0, Watcom C/C++, Symantec, Borland,
Metaware, etc...)?
I had some difficulties porting my own code but I am working on it now. As
soon as I have results I will post them here.

Thanks,
Misha.



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