Sending to list

Thu 03/19/2018 08:48, Tamar Christina wrote:
> Hi Christophe,
> 
> The 03/16/2018 13:50, Christophe Lyon wrote:
> > On 15 March 2018 at 11:19, Kyrill  Tkachov <kyrylo.tkac...@foss.arm.com> 
> > wrote:
> > > Hi Tamar,
> > >
> > >
> > >> Regtested on armeb-none-eabi and no regressions.
> > >> Bootstrapped on arm-none-linux-gnueabihf and no issues.
> > >>
> > >> Ok for trunk? and for backport to GCC 7?
> > >>
> > >
> > > Ok for trunk.
> > > Please wait for a few days before backporting.
> > >
> > 
> > Hi Tamar,
> > 
> > Strangely I have noticed regressions on armeb, I have updated bugzilla
> > accordingly.
> 
> Thanks, seems testsuite didn't catch it with our default options.
> 
> This seems to be a combine issue as it's removing subregs it thinks is a
> no-op, causing the vec_select not to be done. It was working before because
> we were saying any subreg is invalid in arm-be, so if the code didn't get
> stuck in an endless loop, it would skip the no-op check.
> 
> I don't see anyway to fix this in the back-end alone as combine gives no way
> to tell it that the instruction is not a no-op. Even if I split the 
> instruction
> early on to explicitly use a new register, combine will combine the mov and 
> vec_select
> again and come to the same conclusion. =
> 
> So I will revert this for GCC 8 and fix it for GCC 9. Better the compiler ICE 
> than
> generate bad code.
> 
> Thanks,
> Tamar
> 
> > 
> > Thanks,
> > 
> > Christophe
> > 
> > > Thanks,
> > > Kyrill
> > >
> > >
> > >> Thanks,
> > >> Tamar
> > >>
> > >> gcc/
> > >> 2018-03-05  Tamar Christina  <tamar.christ...@arm.com>
> > >>
> > >>         PR target/84711
> > >>         * config/arm/arm.c (arm_can_change_mode_class): Use
> > >> GET_MODE_UNIT_SIZE
> > >>         instead of GET_MODE_SIZE when comparing Units.
> > >>
> > >> gcc/testsuite/
> > >> 2018-03-05  Tamar Christina  <tamar.christ...@arm.com>
> > >>
> > >>         PR target/84711
> > >>         * gcc.target/arm/big-endian-subreg.c: New.
> > >>
> > >> --
> > >
> > >
> 
> -- 
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