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Mail Archives: djgpp/2003/04/28/10:00:16

Date: Mon, 28 Apr 2003 08:44:20 -0500
From: Eric Rudd <rudd AT cyberoptics DOT com>
Organization: CyberOptics
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Newsgroups: comp.os.msdos.djgpp
Subject: Re: Bug 00314 -- div() still broken
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To: djgpp AT delorie DOT com
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Reply-To: djgpp AT delorie DOT com

Ben Peddell wrote:

> GCC 3.2.1 (the gcc I have under DJGPP) does not optimize the div_t 
> into a long long when given -O3 or -fomit-frame-pointer.
> In fact, -fomit-frame-pointer does nothing. 

You must mean only that gcc 3.2.1 returns the struct in memory in either 
case; -fomit-frame-pointer has never "done nothing."  For instance, if 
you compile the "do-nothing" subroutine

void nothing(void) {}

without using -fomit-frame-pointer, you'll get

   pushl   %ebp
   movl    %esp, %ebp
   popl    %ebp
   ret

With -fomit-frame-pointer, you'll get simply

   ret

This has always been the case, as far as I know.

> I went to www.delorie.com to get gcc 3.2.2, and had a look at your bug 
> report whilst I was there.
> What command line did you use? 

I use

   gcc -O2 -march=pentium -Wall

I had been using -fomit-frame-pointer, but I have temporarily removed it 
because of these problems.

-Eric

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