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RE: [PATCH][ARM] use vsel instruction for floating point conditional moves in ARMv8
- From: "Kyrylo Tkachov" <kyrylo dot tkachov at arm dot com>
- To: <gcc-patches at gcc dot gnu dot org>
- Cc: "Ramana Radhakrishnan" <Ramana dot Radhakrishnan at arm dot com>, "Richard Earnshaw" <Richard dot Earnshaw at arm dot com>
- Date: Fri, 15 Feb 2013 11:23:55 -0000
- Subject: RE: [PATCH][ARM] use vsel instruction for floating point conditional moves in ARMv8
- References: <001501cdfecb$a96ad720$fc408560$@tkachov@arm.com>
Ping
http://gcc.gnu.org/ml/gcc-patches/2013-01/msg01418.html
Probably for 4.9 now...
Thanks,
Kyrill
> -----Original Message-----
> From: gcc-patches-owner@gcc.gnu.org [mailto:gcc-patches-
> owner@gcc.gnu.org] On Behalf Of Kyrylo Tkachov
> Sent: 30 January 2013 09:25
> To: gcc-patches@gcc.gnu.org
> Cc: Ramana Radhakrishnan; Richard Earnshaw
> Subject: [PATCH][ARM] use vsel instruction for floating point
> conditional moves in ARMv8
>
> 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?
>
> 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.