RE: [PATCH][ARM] Fix FAIL pr46975

["Kyrylo Tkachov" <kyrylo dot tkachov at arm dot com>]

Hi Richard,

> > This hurts code size.
> > Therefore I've disabled the new peephole2 for optimize_insn_for_size_p
> so that
> > the original peephole before r200197 is used when optimising for size.
> >
> > I've also added a test to confirm that the new peephole2 for the non-CC
> > setting variants is being used when optimising for speed, since the
> large code
> > should be more efficient because the scheduler won't have to deal with
> > condition-code setting.
> >
> > Ok for trunk?
> >
> > Thanks,
> > Kyrill
> >
> > gcc/
> > 2013-06-21  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
> >
> > 	* config/arm/arm.md (peepholes for eq (reg1) (reg2/imm)):
> > 	Use the flag setting variants when optimising for size.
> >
> >
> > gcc/testsuite/
> > 2013-06-21  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
> >
> > 	* gcc.target/arm/pr46975-2.c: New test.
> >
> 
> Not ok.
> 
> This re-introduces the bug that Meador was trying to fix.
> 
> You need to ensure that the condition code register is dead before
> applying this peephole.

Thanks for the review.

How about this? I'm reusing Meadors' peephole2 and guard the application by
checking the CC reg for deadness with peep2_regno_dead_p.

Kyrill

gcc/
2013-07-01  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
            Meador Inge  <meadori@codesourcery.com>

	* config/arm/arm.md (peepholes for eq (reg1) (reg2/imm)):
	Use the flag setting variants when optimising for size.

	
gcc/testsuite/
2013-07-01  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
            Meador Inge  <meadori@codesourcery.com>

	* gcc.target/arm/pr46975-2.c: New test.

Attachment: pr46975.patch
Description: Binary data