[binutils][arm] BFloat16 enablement [4/X]

[binutils][arm] BFloat16 enablement [4/X]

Hi,

This patch is part of a series that adds support for Armv8.6-A
(Matrix Multiply and BFloat16 extensions) to binutils.

This patch introduces BFloat16 instructions to the arm backend.
The following BFloat16 instructions are added: vdot, vfma{l/t},
vmmla, vfmal{t/b}, vcvt, vcvt{t/b}.

gas/ChangeLog:

2019-11-07  Mihail Ionescu  <mihail.ionescu@arm.com>
2019-11-07  Matthew Malcomson  <matthew.malcomson@arm.com>

	* config/tc-arm.c (arm_archs): Add armv8.6-a option.
	(cpu_arch_ver): Add TAG_CPU_ARCH_V8 tag for Armv8.6-a.
	* doc/c-arm.texi (-march): New armv8.6-a arch.
	* config/tc-arm.c (arm_ext_bf16): New feature set.
	(enum neon_el_type): Add NT_bfloat value.
	(B_MNEM_vfmat, B_MNEM_vfmab): New bfloat16 encoder
	helpers.
	(BAD_BF16): New message.
	(parse_neon_type): Add bf16 type specifier.
	(enum neon_type_mask): Add N_BF16 type.
	(type_chk_of_el_type): Account for NT_bfloat.
	(el_type_of_type_chk): Account for N_BF16.
	(neon_three_args): Split out from neon_three_same.
	(neon_three_same): Part split out into neon_three_args.
	(CVT_FLAVOUR_VAR): Add bf16_f32 cvt flavour.
	(do_neon_cvt_1): Account for vcvt.bf16.f32.
	(do_bfloat_vmla): New.
	(do_mve_vfma): New function to deal with the mnemonic clash between the BF16
	vfmat and the MVE vfma in a VPT block with a 't'rue condition.
	(do_neon_cvttb_1): Account for vcvt{t,b}.bf16.f32.
	(do_vdot): New
	(do_vmmla): New
	(insns): Add vdot and vmmla mnemonics.
	(arm_extensions): Add "bf16" extension.
	* doc/c-arm.texi: Document "bf16" extension.
	* testsuite/gas/arm/attr-march-armv8_6-a.d: New test.
	* testsuite/gas/arm/bfloat16-bad.d: New test.
	* testsuite/gas/arm/bfloat16-bad.l: New test.
	* testsuite/gas/arm/bfloat16-bad.s: New test.
	* testsuite/gas/arm/bfloat16-cmdline-bad-2.d: New test.
	* testsuite/gas/arm/bfloat16-cmdline-bad-3.d: New test.
	* testsuite/gas/arm/bfloat16-cmdline-bad.d: New test.
	* testsuite/gas/arm/bfloat16-neon.s: New test.
	* testsuite/gas/arm/bfloat16-non-neon.s: New test.
	* testsuite/gas/arm/bfloat16-thumb-bad.d: New test.
	* testsuite/gas/arm/bfloat16-thumb-bad.l: New test.
	* testsuite/gas/arm/bfloat16-thumb.d: New test.
	* testsuite/gas/arm/bfloat16-vfp.d: New test.
	* testsuite/gas/arm/bfloat16.d: New test.
	* testsuite/gas/arm/bfloat16.s: New test.

include/ChangeLog:

2019-11-07  Mihail Ionescu  <mihail.ionescu@arm.com>
2019-11-07  Matthew Malcomson  <matthew.malcomson@arm.com>

	* opcode/arm.h (ARM_EXT2_V8_6A, ARM_AEXT2_V8_6A,
	ARM_ARCH_V8_6A): New.
	* opcode/arm.h (ARM_EXT2_BF16): New feature macro.
	(ARM_AEXT2_V8_6A): Include above macro in definition.

opcodes/ChangeLog:

2019-11-07  Mihail Ionescu  <mihail.ionescu@arm.com>
2019-11-07  Matthew Malcomson  <matthew.malcomson@arm.com>

	* arm-dis.c (select_arm_features): Update bfd_march_arm_8 with
	Armv8.6-A.
	(coprocessor_opcodes): Add bfloat16 vcvt{t,b}.
	(neon_opcodes): Add bfloat SIMD instructions.
	(print_insn_coprocessor): Add new control character %b to print
	condition code without checking cp_num.
	(print_insn_neon): Account for BFloat16 instructions that have no
	special top-byte handling.

Regression tested on arm-none-eabi.

Is it ok for trunk?

Regards,
Mihail