Hi all,

This patch is part of a series adding support for Armv8.6-A features.
It depends on the Arm Armv8.6-A CLI patch, 
https://gcc.gnu.org/ml/gcc-patches/2019-11/msg02195.html.
It also depends on the Armv8.6-A effective target checking patch, 
https://gcc.gnu.org/ml/gcc-patches/2019-12/msg00857.html.
It also depends on the ARMv8.6-A I8MM dot product patch for using the 
same builtin qualifier 
https://gcc.gnu.org/ml/gcc-patches/2019-12/msg00945.html.

This patch adds intrinsics for matrix multiply-accumulate operations 
including vmmlaq_s32, vmmlaq_u32, and vusmmlaq_s32.

ACLE documents are at https://developer.arm.com/docs/101028/latest
ISA documents are at https://developer.arm.com/docs/ddi0596/latest

Regtested for arm-none-linux-gnueabi-armv8.2-a.

Is it OK for trunk please?

Thanks,
Dennis

gcc/ChangeLog:

2019-12-10  Dennis Zhang  <dennis.zhang@arm.com>

	* config/arm/arm_neon.h (vmmlaq_s32, vmmlaq_u32, vusmmlaq_s32): New.
	* config/arm/arm_neon_builtins.def (smmla, ummla, usmmla): New.
	* config/arm/iterators.md (MATMUL): New.
	(sup): Add UNSPEC_MATMUL_S, UNSPEC_MATMUL_U, and UNSPEC_MATMUL_US.
	(mmla_sfx): New.
	* config/arm/neon.md (neon_<sup>mmlav16qi): New.
	* config/arm/unspecs.md (UNSPEC_MATMUL_S): New.
	(UNSPEC_MATMUL_U, UNSPEC_MATMUL_US): New.

gcc/testsuite/ChangeLog:

2019-12-10  Dennis Zhang  <dennis.zhang@arm.com>

	* gcc.target/arm/simd/vmmla_1.c: New test.