[cfe-commits] [PATCH 3/3] Make fp-contract=fast default for Freescale vendor

William J. Schmidt wschmidt at linux.vnet.ibm.com
Wed Sep 19 08:08:43 PDT 2012


FWIW, general expectations for PowerPC are that fused multiply-add is
available by default.  For example, the default for GCC on
powerpc64-unknown-linux-gnu is to generate fmadd at -O1 and above.  I
may be missing the point, but I don't see a need for the default to be
dependent on the vendor in this case.

My two cents,
Bill
-- 
Bill Schmidt, Ph.D.
IBM Advance Toolchain for PowerLinux
IBM Linux Technology Center
wschmidt at us.ibm.com
wschmidt at linux.vnet.ibm.com


On Tue, 2012-09-18 at 16:53 -0500, Hal Finkel wrote:
> Lang, et al.,
> 
> Do you (or anyone else) have an opinion on this? Do we want to
> introduce vendor-specific defaults for this? Should we wait until
> contraction is fully implemented in clang and let them test the
> differential performance (and what's the status on that)?
> 
> Thanks again,
> Hal
> 
> On Fri, 31 Aug 2012 15:34:26 +0200
> Tobias von Koch <tobias.von.koch at gmail.com> wrote:
> 
> > New patch with test case attached.
> > 
> > Thanks again,
> > Tobias
> > 
> > On 28/08/2012 20:00, Hal Finkel wrote:
> > > Tobias,
> > >
> > > This also requires a test case.
> > >
> > >   -Hal
> > >
> > > On Tue, 28 Aug 2012 18:54:18 +0200
> > > Tobias von Koch <tobias.von.koch at gmail.com> wrote:
> > >
> > >> Dear all,
> > >>
> > >> This is part of a sequence of three (trivial) patches to allow
> > >> Clang to be used as a drop-in replacement for GCC with the
> > >> Freescale SDK. Support for Freescale processors has just been
> > >> added to the PowerPC backend.
> > >>
> > >> Please review and commit if this is OK - I don't have commit
> > >> access.
> > >>
> > >> Thanks!
> > >> Tobias
> > >>
> > >> Description of patch:
> > >>
> > >> If vendor==Freescale, set fp-contract=fast unless specified
> > >> otherwise. This is the default in GCC on Freescale targets.
> > >>
> > >
> > >
> > >
> > 
> 
> 
> 




More information about the cfe-commits mailing list