[PATCH], Add support for PowerPC ISA 3.0 VNEGD/VNEGW instructions

[Segher Boessenkool]

On Wed, May 18, 2016 at 02:30:31PM -0400, Michael Meissner wrote:
> Unlike some of my patches, this is a fairly simple patch to add support for the
> VNEGW and VNEGD instructions that were added in ISA 3.0.  Note, ISA 3.0 does
> not provide negation for V16QImode/V8HImode, just V4SImode/V2DImode.
> 
> I discovered that when we added ISA 2.07 support for V2DImode, we didn't
> provide an expander for negv2di2, which I added with this patch.
> 
> [gcc]
> 2016-05-18  Michael Meissner  <meissner@linux.vnet.ibm.com>
> 
> 	* config/rs6000/altivec.md (VNEG iterator): New iterator for
> 	VNEGW/VNEGD instructions.
> 	(p9_neg<mode>2): New insns for ISA 3.0 VNEGW/VNEGD.
> 	(neg<mode>2): Add expander for V2DImode added in ISA 2.06, and
> 	support for ISA 3.0 VNEGW/VNEGD instructions.
> 
> [gcc/testsuite]
> 2016-05-18  Michael Meissner  <meissner@linux.vnet.ibm.com>
> 
> 	* gcc.target/powerpc/p9-vneg.c: New test for ISA 3.0 VNEGW/VNEGD
> 	instructions.

I forgot to review this patch, sorry.

> Index: gcc/config/rs6000/altivec.md
> ===================================================================
> --- gcc/config/rs6000/altivec.md	(.../svn+ssh://meissner@gcc.gnu.org/svn/gcc/trunk/gcc/config/rs6000)	(revision 236398)
> +++ gcc/config/rs6000/altivec.md	(.../gcc/config/rs6000)	(working copy)
> @@ -203,6 +203,9 @@ (define_mode_attr VP_small [(V2DI "V4SI"
>  (define_mode_attr VP_small_lc [(V2DI "v4si") (V4SI "v8hi") (V8HI "v16qi")])
>  (define_mode_attr VU_char [(V2DI "w") (V4SI "h") (V8HI "b")])
>  
> n+;; Vector negate
> +(define_mode_iterator VNEG [V4SI V2DI])

Your patch is mangled here, but you'll find out (it won't apply this way).

>  (define_expand "neg<mode>2"
> -  [(use (match_operand:VI 0 "register_operand" ""))
> -   (use (match_operand:VI 1 "register_operand" ""))]
> -  "TARGET_ALTIVEC"
> +  [(set (match_operand:VI2 0 "register_operand" "")
> +	(neg:VI2 (match_operand:VI2 1 "register_operand" "")))]
> +  "<VI_unit>"
>    "
>  {
> -  rtx vzero;
> +  if (!TARGET_P9_VECTOR || (<MODE>mode != V4SImode && <MODE>mode != V2DImode))
> +    {
> +      rtx vzero;
>  
> -  vzero = gen_reg_rtx (GET_MODE (operands[0]));
> -  emit_insn (gen_altivec_vspltis<VI_char> (vzero, const0_rtx));
> -  emit_insn (gen_sub<mode>3 (operands[0], vzero, operands[1])); 
> -  
> -  DONE;
> +      vzero = gen_reg_rtx (GET_MODE (operands[0]));
> +      emit_move_insn (vzero, CONST0_RTX (<MODE>mode));
> +      emit_insn (gen_sub<mode>3 (operands[0], vzero, operands[1])); 
> +      DONE;
> +    }
>  }")

Please remove the quotes around the C block as well, while you're here?
And a trailing space.

Okay for trunk, okay for 6 after a week or so.

Thanks,


Segher