[PATCH] arc: Improve/add instruction patterns to better use MAC instructions.

[Jeff Law]

On 10/9/20 8:24 AM, Claudiu Zissulescu wrote:
> From: Claudiu Zissulescu <claziss@gmail.com>
>
> ARC MYP7+ instructions add MAC instructions for vector and scalar data
> types. This patch adds a madd pattern for 16it datum that is using the
> 32bit MAC instruction, and dot_prod patterns for v4hi vector
> types. The 64bit moves are also upgraded by using vadd2 instuction.
>
> gcc/
> xxxx-xx-xx  Claudiu Zissulescu  <claziss@synopsys.com>
>
> 	* config/arc/arc.c (arc_split_move): Recognize vadd2 instructions.
> 	* config/arc/arc.md (movdi_insn): Update pattern to use vadd2
> 	instructions.
> 	(movdf_insn): Likewise.
> 	(maddhisi4): New pattern.
> 	(umaddhisi4): Likewise.
> 	* config/arc/simdext.md (mov<mode>_int): Update pattern to use
> 	vadd2.
> 	(sdot_prodv4hi): New pattern.
> 	(udot_prodv4hi): Likewise.
> 	(arc_vec_<V_US>mac_hi_v4hi): Update/renamed to
> 	arc_vec_<V_US>mac_v2hiv2si.
> 	(arc_vec_<V_US>mac_v2hiv2si_zero): New pattern.

OK for the trunk.  Sorry for the delay.

jeff