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From: Eli Zaretskii <eliz@is.elta.co.il>
To: John Hedges <john@drystone.co.uk>
Cc: gdb@sourceware.cygnus.com
Subject: Re: Problem with fld on i686
Date: Fri, 16 Nov 2001 14:55:00 -0000	[thread overview]
Message-ID: <Pine.SUN.3.91.1011127131103.22199A-100000@is> (raw)
In-Reply-To: <E168dvs-0007FR-00@gwlinux>


On Tue, 27 Nov 2001, John Hedges wrote:

> The st0 register gets -nan and so this is the result of the static_cast.

I don't get it: are you saying that the disassembly shows incorrect 
code?  If the code is correct, what does this have to do with the
source code (static_cast etc.) from which the assembly instructions
were produced?

If the code _is_ correct (I think it is), but the results aren't, then 
the fact that static_cast was used in the C++ program is irrelevant, 
right?

> The problem does not occur when run outside the debugger, nor in a 
> minimal test program.

This suggests that perhaps the FPU state is not saved/restored correctly 
across task switches.  What OS is that?  Can you try a different version 
of the same OS, or some similar but not identical OS?


WARNING: multiple messages have this Message-ID
From: Eli Zaretskii <eliz@is.elta.co.il>
To: John Hedges <john@drystone.co.uk>
Cc: gdb@sourceware.cygnus.com
Subject: Re: Problem with fld on i686
Date: Tue, 27 Nov 2001 03:19:00 -0000	[thread overview]
Message-ID: <Pine.SUN.3.91.1011127131103.22199A-100000@is> (raw)
Message-ID: <20011127031900.SHu_UjTNb1lHDQpHNkKwA_o79s9Cmn-SLH-siNNASQo@z> (raw)
In-Reply-To: <E168dvs-0007FR-00@gwlinux>

On Tue, 27 Nov 2001, John Hedges wrote:

> The st0 register gets -nan and so this is the result of the static_cast.

I don't get it: are you saying that the disassembly shows incorrect 
code?  If the code is correct, what does this have to do with the
source code (static_cast etc.) from which the assembly instructions
were produced?

If the code _is_ correct (I think it is), but the results aren't, then 
the fact that static_cast was used in the C++ program is irrelevant, 
right?

> The problem does not occur when run outside the debugger, nor in a 
> minimal test program.

This suggests that perhaps the FPU state is not saved/restored correctly 
across task switches.  What OS is that?  Can you try a different version 
of the same OS, or some similar but not identical OS?


  parent reply	other threads:[~2001-11-27 11:19 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2001-11-27  0:53 John Hedges
2001-11-16 13:40 ` John Hedges
2001-11-16 14:55 ` Eli Zaretskii [this message]
2001-11-17  5:39   ` John Hedges
2001-11-18 10:57     ` Andrew Cagney
2001-11-27 15:04       ` Andrew Cagney
2001-11-27  3:19   ` Eli Zaretskii

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