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Mail Archives: djgpp/2000/04/11/15:49:44

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Message-ID: <38F32210.FE26F51B@inti.gov.ar>
Date: Tue, 11 Apr 2000 10:01:05 -0300
From: salvador <salvador AT inti DOT gov DOT ar>
Organization: INTI
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To: djgpp AT delorie DOT com
Subject: Re: inefficiency of GCC output code & -O problem
References: <38F20E7A DOT 3330E9A4 AT mtu-net DOT ru> <38F23A21 DOT A59621A1 AT inti DOT gov DOT ar> <38F2AA36 DOT 33206DD9 AT mtu-net DOT ru>
Reply-To: djgpp AT delorie DOT com

"Alexei A. Frounze" wrote:

> salvador wrote:
> > > Is it a normal thing, if one instruction that adds something to ESP(or EBP) is
> > > followed by sutracting instruction that works with the same register?
> >
> > ?
>
> When it discards ESP change after a call to subroutine and plus sometimes one
> extra  add/sub. But they could be combined altogether to the only one
> instruction.

These things are combined by the optimization.

> > > an error encounters:
> > > "Error: Error: Missing ')' assumed"
> > > "Error: Error: Ignoring junk `(%ebp))' after expression")?
> > > W/o the -O2 switch it's compiled fine. Isn't it a little bit strange?
> >
> > Can you show a small example? I guess that's an error in your inline assembler
> > code, but I can't know without the actual code.
>
> 21KB of a C file that depends on 3 other modules. :))

Preprocess it (using -E) and send the preprocessed output.

> I'll try. But I don't know what's wrong, since it _is_ compiled normally w/o -O
> switch. Strange thingy.

Not so much, I had these kind of problems, and was my fault ;-)

SET

--
Salvador Eduardo Tropea (SET). (Electronics Engineer)
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