This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [PATCH], PowerPC long double transistion, patch #1
- From: Michael Meissner <meissner at linux dot ibm dot com>
- To: Segher Boessenkool <segher at kernel dot crashing dot org>
- Cc: Michael Meissner <meissner at linux dot ibm dot com>, GCC Patches <gcc-patches at gcc dot gnu dot org>, David Edelsohn <dje dot gcc at gmail dot com>, Bill Schmidt <wschmidt at linux dot vnet dot ibm dot com>
- Date: Thu, 14 Jun 2018 20:18:42 -0400
- Subject: Re: [PATCH], PowerPC long double transistion, patch #1
- References: <20180613211015.GA3737@ibm-toto.the-meissners.org> <20180614232549.GE16221@gate.crashing.org>
On Thu, Jun 14, 2018 at 06:25:49PM -0500, Segher Boessenkool wrote:
> On Wed, Jun 13, 2018 at 05:10:15PM -0400, Michael Meissner wrote:
> > In addition to the previous patch to aid in transitioning the PowerPC long
> > double format to IEEE 128-bit, I have some additional patches that are needed.
> > The previous patch is:
> > https://gcc.gnu.org/ml/gcc-patches/2018-06/msg00634.html
> >
> > This patch turns off setting the .gnu_attributes when building the libgcc
> > helper functions. I ran into some linker warnings as I built some multilib
> > toolchains, and this turns off those warnings.
>
> Should we turn it off for all of libgcc instead?
It is only needed if long double is passed or returned. The conversion and
support routines get called with long double values if long double is IEEE
128-bit, and with KFmode values if not.
Any other libgcc function that has a long double interface should get the
linker warning that the wrong type was used.
> > I have done separate bootstraps on a little endian power8 system with the long
> > double type set to IBM extended and IEEE 128-bit extended. There were no
> > regressions in using this patch. Can I check it in, and eventually back port
> > it to GCC 8.2 with the other long double transition patches?
> >
> > 2018-06-11 Michael Meissner <meissner@linux.ibm.com>
> >
> > * config/rs6000/t-float128 (FP128_CFLAGS_SW): Compile float128
> > support modules with -mno-gnu-attribute.
> > * config/rs6000/t-float128-hw (FP128_CFLAGS_HW): Likewise.
>
> The patch is okay for trunk with or without such a change (but please
> investigate). All these 128-bit FP patches are okay for 8.2 too, after
> some simmering etc.
--
Michael Meissner, IBM
IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA
email: meissner@linux.ibm.com, phone: +1 (978) 899-4797