Xref:	news2.mv.net comp.os.msdos.djgpp:3395
From:	Thomas Demmer <demmer AT LSTM DOT Ruhr-UNI-Bochum DOT De>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: libm.a/linker *BUG* with test program
Date:	Fri, 03 May 1996 11:41:49 +0100
Organization:	Lehrstuhl fuer Stroemungsmechanik
Lines:	39
Message-ID:	<3189E2ED.167E@LSTM.Ruhr-UNI-Bochum.De>
References:	<4mb7ob$3lf AT crc-news DOT doc DOT ca> <3189D117 DOT 41C6 AT LSTM DOT Ruhr-UNI-Bochum DOT De>
NNTP-Posting-Host:	bvb.lstm.ruhr-uni-bochum.de
Mime-Version:	1.0
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

Thomas Demmer wrote:
> 
> Richard Young wrote:
> >
> > I've discovered the following incorrect behavior with DJGPP version 2.
> > The included test program illustrates the symptom of the behavior which
> > seems to be as a result of including the math library.  When I don't
> > include libm.a the program does not crash.  When I include libm.a the
> > program crashes on the 3rd pow() call.  It seems that it also is related
> > to calling ldexp() too since just calling pow() many times works fine.
> >
> I tried your test program and found the same error. It looks as
> if ldexp() doesn't clean up the co-proc stack. It leaves the "6"
> on the stack and after some calls the stack is full.
> 
--

After debugging a bit, I think the function scalbn() in  
src/libm/src/s_scalbn.s
is the culprit. It is used in some other functions, too, so one might
try to provoke crashes. But for that I'll have to learn a few things
about the binary representation of floats first ;-))


Ciao
Tom



*************************************************************
* Thomas Demmer                                             *
* Lehrstuhl fuer Stroemungsmechanik                         *
* Ruhr-Uni-Bochum                                           *
* Universitaetsstr. 150                                     *
* D-44780  Bochum                                           *
* Tel: +49 234 700 6434                                     *
* Fax: +49 234 709 4162                                     *
* http://www.lstm.ruhr-uni-bochum.de/~demmer                *
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