[PATCH][ARM] use vsel instruction for floating point conditional moves in ARMv8

[Richard Biener]

On Wed, 3 Apr 2013, Matthew Gretton-Dann wrote:

> Would it be possible for this patch and the others Kyrylo has recently done
> for the new ARMv8 AArch32 instructions to be backported to 4.8?
> 
> In particular I'm refering to:
> 
> http://gcc.gnu.org/ml/gcc-patches/2013-03/msg00994.html (trunk r197052)
> http://gcc.gnu.org/ml/gcc-patches/2013-03/msg00874.html (trunk r197051)
> http://gcc.gnu.org/ml/gcc-patches/2013-03/msg00873.html (trunk r197046)
> http://gcc.gnu.org/ml/gcc-patches/2013-03/msg00652.html (trunk r197040 and
> 197041)

Those seem to be new features and not regression fixes and thus are
not appropriate for a release branch.

Richard.

> Thanks,
> 
> Matt
> 
> 
> On 25/03/13 15:21, Kyrylo Tkachov wrote:
> > > -----Original Message-----
> > > From: Ramana Radhakrishnan
> > > Sent: 18 February 2013 11:51
> > > To: Kyrylo Tkachov
> > > Cc: gcc-patches@gcc.gnu.org; Richard Earnshaw
> > > Subject: Re: [PATCH][ARM] use vsel instruction for floating point
> > > conditional moves in ARMv8
> > > 
> > > On 01/30/13 09:24, Kyrylo Tkachov wrote:
> > > > Hi all,
> > > > This patch uses the new ARMv8 AArch32 vsel instruction to implement
> > > > conditional moves of floating point numbers.
> > > > For example, an instruction of the form:
> > > > 	vsel<cond>.f32  s0, s1, s2
> > > > means
> > > > 	s0 := cond ? s1 : s2
> > > > 
> > > > This can be useful, among other places, in Thumb2 because it doesn't
> > > require
> > > > an enclosing IT block.
> > > > A small catch: The condition code used in vsel can only be one of
> > > {GE, GT,
> > > > EQ, VS}. If we want to use their negations {LT, LE, NE, VC} we just
> > > flip the
> > > > source operands.
> > > > A new predicate is introduced that checks that the comparison yields
> > > an ARM
> > > > condition code in the set {GE, GT, EQ, VS, LT, LE, NE, VC}.
> > > > 
> > > > New compilation tests are added. They pass on a model and no new
> > > regressions
> > > > on arm-none-eabi with qemu.
> > > 
> > > > 
> > > > Ok for trunk?
> > > 
> > > Ok for stage1 4.9.
> > 
> > Hi Ramana,
> > 
> > Thanks for the review.
> > Re-tested on arm-none-eabi against current trunk and applied as r197052.
> > 
> > > 
> > > Ramana
> > 
> > Thanks,
> > Kyrill
> > > 
> > > > 
> > > > Thanks,
> > > > Kyrill
> > > > 
> > > > gcc/ChangeLog
> > > > 
> > > > 2013-01-30  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
> > > > 
> > > > 	* config/arm/arm.md (f_sels, f_seld): New types.
> > > > 	(*cmov<mode>): New pattern.
> > > > 	* config/arm/predicates.md (arm_vsel_comparison_operator): New
> > > > predicate.
> > > > 
> > > > 
> > > > gcc/testsuite/ChangeLog
> > > > 
> > > > 2013-01-30  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
> > > > 
> > > > 	* gcc.target/arm/vseleqdf.c: New test.
> > > > 	* gcc.target/arm/vseleqsf.c: Likewise.
> > > > 	* gcc.target/arm/vselgedf.c: Likewise.
> > > > 	* gcc.target/arm/vselgesf.c: Likewise.
> > > > 	* gcc.target/arm/vselgtdf.c: Likewise.
> > > > 	* gcc.target/arm/vselgtsf.c: Likewise.
> > > > 	* gcc.target/arm/vselledf.c: Likewise.
> > > > 	* gcc.target/arm/vsellesf.c: Likewise.
> > > > 	* gcc.target/arm/vselltdf.c: Likewise.
> > > > 	* gcc.target/arm/vselltsf.c: Likewise.
> > > > 	* gcc.target/arm/vselnedf.c: Likewise.
> > > > 	* gcc.target/arm/vselnesf.c: Likewise.
> > > > 	* gcc.target/arm/vselvcdf.c: Likewise.
> > > > 	* gcc.target/arm/vselvcsf.c: Likewise.
> > > > 	* gcc.target/arm/vselvsdf.c: Likewise.
> > > > 	* gcc.target/arm/vselvssf.c: Likewise.
> > > > 
> > 
> > 
> > 
> > 
> 
> 
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE / SUSE Labs
SUSE LINUX Products GmbH - Nuernberg - AG Nuernberg - HRB 16746
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