[patch 0/4] [RFC] decimal floating point support

[patch 0/4] [RFC] decimal floating point support

[Thiago Jung Bauermann]

Hi folks,

I am re-submitting for review Wu Zhou's patch to add DFP (Decimal Floating
Point) support to GDB (see [1] for details). The version I'm posting
here is based on [2], only refreshed to apply to CVS HEAD from a few
days ago and broken up into logical pieces to facilitate review. The
testcases are taken from [3].

The code uses libdecnumber from the gcc svn repository. It can be fetched
from svn://gcc.gnu.org/svn/gcc/trunk/libdecnumber. It is expected to be
found by the Makefile in src/libdecnumber/.

This is not complete yet because I'd like to add a way to have GDB
correctly display floating point registers containing DFP values (in
Power6, DFP and binary FP logic will share registers).

Looking from the archives, the biggest concern regarding this patch has
been on how to deal with endianness (see [4] and [5]). Here's how it's
currently dealt with in the patch:

Inside GDB the DFP value is always stored in target byte order. This
is done by the exchange_dfp() function in dfp.c. Since libdecnumber
currently uses big-endian regardless of the native byte order, the
decimal_from_string() and decimal_to_string() functions use exchange_dfp()
before or after calling libdecnumber functions. A later version of
libdecnumber will use native byte order.

I tested remotely debugging a big-endian target (ppc32) from a little
endian host (i386) and it worked fine.


[1] http://sourceware.org/ml/gdb-patches/2005-09/msg00268.html
[2] http://sourceware.org/ml/gdb-patches/2006-08/msg00008.html
[3] http://sourceware.org/ml/gdb-patches/2006-07/msg00090.html
[4] http://sourceware.org/ml/gdb-patches/2006-07/msg00318.html
[5] http://sourceware.org/ml/gdb-patches/2006-08/msg00049.html
-- 
[]'s
Thiago Jung Bauermann
Software Engineer
IBM Linux Technology Center

[ping] Re: [patch 0/4] [RFC] decimal floating point support

[Thiago Jung Bauermann]

On Tue, 2007-03-27 at 13:29 -0300, Thiago Jung Bauermann wrote:
> I am re-submitting for review Wu Zhou's patch to add DFP (Decimal Floating
> Point) support to GDB (see [1] for details).

Did anyone have a chance to take a look at this? If this code is ok, I'd
like to ask for its inclusion.
-- 
[]'s
Thiago Jung Bauermann
Software Engineer
IBM Linux Technology Center

Re: [ping] Re: [patch 0/4] [RFC] decimal floating point support

[Daniel Jacobowitz]

On Fri, Apr 13, 2007 at 05:19:49PM -0300, Thiago Jung Bauermann wrote:
> On Tue, 2007-03-27 at 13:29 -0300, Thiago Jung Bauermann wrote:
> > I am re-submitting for review Wu Zhou's patch to add DFP (Decimal Floating
> > Point) support to GDB (see [1] for details).
> 
> Did anyone have a chance to take a look at this? If this code is ok, I'd
> like to ask for its inclusion.

I haven't yet, but if no one else does I will try to.  Of course, if
anyone else has time to review patches, I'm always grateful...

-- 
Daniel Jacobowitz
CodeSourcery

Re: [patch 0/4] [RFC] decimal floating point support

[Luis Machado]

Hi folks,

Do we have any news on the reviewing process of this DFP patch? I was
thinking of refreshing for latest HEAD and re-submitting, and if anyone
has suggestions on it i'd like to include on the newer version.

Regards,
Luis

Re: [patch 0/4] [RFC] decimal floating point support

[Daniel Jacobowitz]

On Thu, May 24, 2007 at 09:49:32AM -0300, Luis Machado wrote:
> Hi folks,
> 
> Do we have any news on the reviewing process of this DFP patch? I was
> thinking of refreshing for latest HEAD and re-submitting, and if anyone
> has suggestions on it i'd like to include on the newer version.

I had not gotten around to looking at it.  If you want to resubmit,
I'll try to be prompter.  Are there bits to make GDB depend on
libdecnumber at build time already, or should I take care of that when
we merge libdecnumber to src?

-- 
Daniel Jacobowitz
CodeSourcery

Re: [patch 0/4] [RFC] decimal floating point support

[Thiago Jung Bauermann]

On Wed, 2007-06-06 at 15:10 -0400, Daniel Jacobowitz wrote:
> On Thu, May 24, 2007 at 09:49:32AM -0300, Luis Machado wrote:
> > Hi folks,
> > 
> > Do we have any news on the reviewing process of this DFP patch? I was
> > thinking of refreshing for latest HEAD and re-submitting, and if anyone
> > has suggestions on it i'd like to include on the newer version.
> 
> I had not gotten around to looking at it.  If you want to resubmit,
> I'll try to be prompter.  Are there bits to make GDB depend on
> libdecnumber at build time already, or should I take care of that when
> we merge libdecnumber to src?

I'm not completely sure what you mean by "make GDB depend on
libdecnumber", but the first patch in the series
( http://sourceware.org/ml/gdb-patches/2007-03/msg00251.html ) adds the
bits necessary for GDB to pick up the libdecnumber library file (.a) and
header files from src/libdecnumber/, but it doesn't modify the top-level
Makefile.in in src/ to compile the library automatically... I'm not sure
how would I do that. Maybe adding some maybe-*-libdecnumber targets?
-- 
[]'s
Thiago Jung Bauermann
Software Engineer
IBM Linux Technology Center

Re: [patch 0/4] [RFC] decimal floating point support

[Daniel Jacobowitz]

On Tue, Jun 12, 2007 at 03:45:07PM -0300, Thiago Jung Bauermann wrote:
> header files from src/libdecnumber/, but it doesn't modify the top-level
> Makefile.in in src/ to compile the library automatically... I'm not sure
> how would I do that. Maybe adding some maybe-*-libdecnumber targets?

By modifying Makefile.def.  Anyway, I can take care of it once we go
ahead with the other patches.

-- 
Daniel Jacobowitz
CodeSourcery