This patch adds the stub support to allow users to use -mcpu=power9, so that in
the future it will generate code for the Power9 systems (ISA 3.0).  At this
time, the stub only sets up the switches.  Future patches to GCC 6.x and later
GCC 7.x will add support for various features in power9.

I have bootstrapped this on a big endian power7 system and a little endian
power8 system with no regressions.  Is this patch ok to install in the trunk?

I would also like to back port this initial support into GCC 5.x.  Is that ok
as well?

2015-11-03  Michael Meissner  <meissner@linux.vnet.ibm.com>

	* config/rs6000/rs6000.opt (-mfusion-toc): Add new switches for
	ISA 3.0 (power9).
	(-mpower9-fusion): Likewise.
	(-mpower9-vector): Likewise.
	(-mmodulo): Likewise.
	(-mfloat128-hardware): Likewise.

	* config/rs6000/rs6000-cpus.def (ISA_3_0_MASKS_SERVER): Add option
	mask for ISA 3.0 (power9).
	(POWERPC_MASKS): Add new ISA 3.0 switches.
	(power9 cpu): Add power9 cpu.

	* config/rs6000/rs6000.h (ASM_CPU_POWER9_SPEC): Add support for
	power9.
	(ASM_CPU_SPEC): Likewise.
	(EXTRA_SPECS): Likewise.

	* config/rs6000/rs6000.c (power9_cost): Initial cost setup for
	power9.
	(rs6000_debug_reg_global): Add support for power9 fusion.
	(rs6000_setup_reg_addr_masks): Cache mode size.
	(rs6000_option_override_internal): Until real power9 tuning is
	added, use -mtune=power8 for -mcpu=power9.
	(rs6000_option_override_internal): Add support for ISA 3.0
	switches.
	(rs6000_loop_align): Add support for power9 cpu.
	(rs6000_file_start): Likewise.
	(rs6000_adjust_cost): Likewise.
	(rs6000_issue_rate): Likewise.
	(insn_must_be_first_in_group): Likewise.
	(insn_must_be_last_in_group): Likewise.
	(force_new_group): Likewise.
	(rs6000_register_move_cost): Likewise.
	(rs6000_opt_masks): Likewise.

	* config/rs6000/rs6000.md (cpu attribute): Add power9.
	* config/rs6000/rs6000-tables.opt: Regenerate.

	* config/rs6000/rs6000-c.c (rs6000_target_modify_macros): Define
	_ARCH_PWR9 if power9 support is available.

	* config/rs6000/aix61.h (ASM_CPU_SPEC): Add power9.
	* config/rs6000/aix53.h (ASM_CPU_SPEC): Likewise.

	* configure.ac: Determine if the assembler supports the ISA 3.0
	instructions.
	* config.in (HAVE_AS_POWER9): Likewise.
	* configure: Regenerate.

	* doc/invoke.texi (RS/6000 and PowerPC Options): Document ISA 3.0
	switches.

-- 
Michael Meissner, IBM
IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA
email: meissner@linux.vnet.ibm.com, phone: +1 (978) 899-4797