Re: crosstool 0.28pre demo-arm-softfloat.sh FP issue

[Leon Woestenberg <leonw at mailcan dot com>]

Hello,

two questions regarding assembly softfloat and printf("%f");

there is Nicolas Pitre's assembly softfloat patch for gcc-3.3.2 
(3.3-two), with some additionals by Robert Schwebel.
  crosstool-0.28-pre4/patches/gcc-3.3.2/gcc-3.3.2-arm-softfloat.patch

but it does not re-occur in gcc-3.3.3 (3.3-three):
  crosstool-0.28-pre4/patches/gcc-3.3.3/

Q1) Is this intentional (Dan)?

In crosstool, I have added (softlinked) the patch to gcc-3.3.3, and 
added the following patches to glibc-2.3.2 to solve the printf("%f") 
issue, at least for XScale, as discussed here:

http://lists.arm.linux.org.uk/pipermail/linux-arm/2003-November/006590.html

This patchset is substantially different than the one mentioned in
demo-arm-softfloat.sh, which refers to:

http://sources.redhat.com/ml/crossgcc/2004-02/msg00104.html

Q2) Can someone with more knowledge than me on the issue, which patch is 
the better one for resolving the printf("%f") issue? They seem to take
different approaches.

Regards,

Leon.

Leon Woestenberg wrote:
> Hello Robert, Dan,
>
> there is the assembly softfloat patch for gcc-3.3.2 (3.3-two):
>   crosstool-0.28-pre4/patches/gcc-3.3.2/gcc-3.3.2-arm-softfloat.patch
>
> but it does not re-occur in gcc-3.3.3 (3.3-three):
>   crosstool-0.28-pre4/patches/gcc-3.3.3/
>
> Is this intentional?
>
> I have added (softlinked) the patch to gcc-3.3.3, and added the
> following patches to glibc-2.3.2 to solve the printf("%f") issue,
> at least for XScale, as discussed here:
>
> http://lists.arm.linux.org.uk/pipermail/linux-arm/2003-November/006590.html
>
> This patchset is substantially different than the one mentioned in
> demo-arm-softfloat.sh, which refers to:
>   http://sources.redhat.com/ml/crossgcc/2004-02/msg00104.html
>
> Robert
>
> Regards,
>
> Leon.
>
>
> Dan Kegel wrote:
>
> > Hi Leon,
> > I'm afraid I'm not able to follow this issue much, but
> > Robert Schwebel is; he's the one who dug up the copy of Nicolas'
> > patch that I use.  I'm cc'ing him, perhaps he can comment.
> > Thanks,
> > Dan
> >
> > Leon Woestenberg wrote:
> >
> > > Hello Dan,
> > >
> > > just been quickly viewing at your crosstool 0.28pre4.
> > >
> > > I have been following the softfloat issue concerning
> > > printf("%f", 1.0) for ARM architectures.
> > >
> > > In your demo-arm.sh, you mention this patch:
> > > http://sources.redhat.com/ml/crossgcc/2004-02/msg00104.html
> > >
> > > However, you may be more interested in this patch instead:
> > > http://lists.arm.linux.org.uk/pipermail/linux-arm/2003-November/006590.html 
> > >
> > >
> > > This came forward in a very recent (as in current) discussion thread 
> > > on the arm-linux mailing list;
> > >
> > > http://lists.arm.linux.org.uk/pipermail/linux-arm/2004-March/thread.html#7214 
> > >
> > >
> > > (see the SoftFloat and SoftFloat Benchmarks threads, especially the 
> > > 3rd message in the SoftFloat thread.)
> > >
> > > I am very new in using crosstool, but I will try to add Nicolas Pitre's
> > > assembly optimized softfloat as well as the big endian patch (that makes
> > > glibc printf work OK) and try to test them on an XScale IXP425.
> > >
> > > Also note that the benchmarks show that Nicolas Pitre's patch passes 
> > > some FP tests.
> > >
> > > Regards,
> > >
> > > Leon.
> > >
> > > ------------------------------------------------------------------------
> > >
> > > Subject:
> > > Re: SoftFloat Benchmarks
> > > From:
> > > Eric BENARD / Free <ebenard@free.fr>
> > > Date:
> > > Tue, 9 Mar 2004 10:05:05 +0100
> > > To:
> > > Leon Woestenberg <leonw@mailcan.com>, linux-arm@lists.arm.linux.org.uk
> > >
> > > To:
> > > Leon Woestenberg <leonw@mailcan.com>, linux-arm@lists.arm.linux.org.uk
> > >
> > >
> > > Le Lundi 8 Mars 2004 23:14, Leon Woestenberg a écrit :
> > >
> > > > I am however, also interested in learning how you built your toolchain
> > > > with Nico's patches. Are you using a cross compilation tool or was this
> > > > hand-crafted?
> > >
> > > Hand-crafted in order to have a good control on the build process (I 
> > > had to give several try for some stages). I'm using patches from 
> > > crosstool's patches directory and patches from mailing lists.
> > > I can post some details if necessary as I wrote the process on a paper.
> > >
> > >
> > > > Did you also make sure the "printf("%f", 1.0)" issue was solved in your
> > > > toolchain as discussed here?
> > > >
> > > > http://sources.redhat.com/ml/crossgcc/2004-02/msg00106.html
> > >
> > > Yes. In fact I'm using these patches :
> > > http://lists.arm.linux.org.uk/pipermail/linux-arm/2003-November/006590.html 
> > >
> > >
> > > Which are giving good results with several test programs (I'll post 
> > > tests results later today as these results are also interesting).
> > >
> > > Patches I'm using :
> > > - binutils-2.15.90.0.1.1 :
> > >     arm-be.patch
> > > - GCC-3.3.3 :
> > >     gcc-3.3.2-arm-softfloat.diff  gcc-3.3.2-arm-targetbug.diff  t-linux
> > > - Glibc-2.3.2 :
> > >     arm-asm-clobber.patch     sscanf.patch
> > >     string2-typedef.patch
> > >     errlist-awk.patch         sysdep-cancel-arm-1.2-1.6.patch
> > >     patch-glibc-ieee754-arm-ieee754.h  patch-glibc-ieee754-dbl64-mpn2dbl
> > >     patch-glibc-ieee754-dbl64-dbl2mpn  patch-glibc-ieee754-flt32-mpn2flt
> > > - NWFPE :     nwfpe-double_cpdo.c  nwfpe-fpa11_cpdt.c
> > >
> > >
> > > > Also, there seem to be outstanding issues for non-XScale targets, as 
> > > > the
> > > > assembler is forced to target XScales (but that is good for IXP425 :).
> > > >
> > > > http://sources.redhat.com/ml/crossgcc/2004-02/msg00129.html
> > >
> > > I'm not using this patch, nor this one : 
> > > http://gcc.gnu.org/ml/gcc-patches/2001-12/msg01370.html
> > >
> > > The toolchain is optimized and dedicated to big endian Xscale, but 
> > > that's not a real problem as it's easy to have an optimized toolchain 
> > > for each target and switch the PATH depending on the wanted target.
> > >
> > > If you want a generic toolchain optimized for each configuration you 
> > > will have to compile several glibc with each option and to handle 
> > > several directories and options for gcc to get and link to the 
> > > correct configuration (big-endian+ soft-float for example) and this 
> > > is not very clear to me, so I compiled several toolchains using the 
> > > same process but not the same options/patches :
> > >     - standard (let the kernel handle FP)
> > >     - softfloat, with Nicolas' patch
> > >     - -msoft-float : let have an external libfloat library.
> > >
> > > Eric


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