Re: [PATCH, ARM] Fix arm_subsi3_insn alternatives

[Kyrill Tkachov <kyrylo dot tkachov at arm dot com>]

On 13/04/15 11:47, Yvan Roux wrote:
> Ping (now that stage1 is open)
Hi Yvan,

This patch is ok, but can you wait until GCC 5.1 is released before committing please?
That way trunk and the GCC 5 branch won't diverge too much if there are any last minute
(hopefully none in this area!) fixes that need to go in.


Thanks,
Kyrill

> On 27 March 2015 at 19:14, Kyrill Tkachov <kyrylo.tkachov@arm.com> wrote:
> > On 24/03/15 19:53, Yvan Roux wrote:
> > > Hi,
> > >
> > > after the issue with duplicated alternatives exhibited by PR64208, I
> > > checked the arm.md file and found that *arm_subsi3_insn has a
> > > duplication where alt 4 is (r,rI,r) and alt 6 is (r,r,r), this results
> > > in emitting an rsb instruction instead of a sub one, but it has also
> > > an impact on scheduling as the type attribute affected to alt 4 is
> > > alu_imm when it could only involve registers.
> > >
> > > This is fixed by this small patch. Cross builded and regtested for
> > > arm/armeb targets.
> > > Ok for trunk (maybe for stage 1 as no PR is attached to that) ?
> >
> > Hi Yvan,
> >
> > I've kicked off two bootstraps of this patch on arm-none-linux-gnueabihf:
> > one with arm mode and one with thumb. Both are well in stage3 so I don't
> > expect
> > there to be any problems and the patch looks ok to me code-wise (though
> > I can't approve).
> >
> > This is stage 1 material by now though since there's no regression
> > associated.
> >
> > Cheers,
> > Kyrill
> >
> >
> > > Cheers,
> > > Yvan
> > >
> > >    2105-03-24  Yvan Roux  <yvan.roux@linaro.org>
> > >
> > >       * config/arm/arm.md ("*arm_subsi3_insn"): Fixed redundant
> > > alternatives.