PowerPC: Add -mcpu=future.

PowerPC: Add -mcpu=future.

These patches implement support for potential future PowerPC cpus.  At this
time, features enabled with -mcpu=future may or may not be in actual PowerPCs
that will be delivered in the future.

This patch adds support for the -mcpu=future and -mtune=future options.
If you use -mcpu=future, the macro __ARCH_PWR_FUTURE__ is defined, and the
assembler .machine directive "future" is used.  Future patches in this
series will add support for new instructions that may be present in future
PowerPC processors.

At the moment, we do not have any differences in tuning between power10 and
future.  It is anticipated that we may change the tuning characteristics for
-mtune=future at a later time.

The patches have been tested on the following platforms.  I added the patches
for PR target/107299 that I submitted on November 2nd before doing the builds so
that GCC would build on systems using IEEE 128-bit long double.
	* https://gcc.gnu.org/pipermail/gcc-patches/2022-November/604834.html

2023-09-28   Michael Meissner  <meissner@linux.ibm.com>

gcc/

	* config/rs6000/power10.md (power10-load): Temporarily treat
	-mcpu=future the same as -mcpu=power10.
	(power10-fused-load): Likewise.
	(power10-prefixed-load): Likewise.
	(power10-prefixed-load): Likewise.
	(power10-load-update): Likewise.
	(power10-fpload-double): Likewise.
	(power10-fpload-double): Likewise.
	(power10-prefixed-fpload-double): Likewise.
	(power10-prefixed-fpload-double): Likewise.
	(power10-fpload-update-double): Likewise.
	(power10-fpload-single): Likewise.
	(power10-fpload-update-single): Likewise.
	(power10-vecload): Likewise.
	(power10-vecload-pair): Likewise.
	(power10-store): Likewise.
	(power10-fused-store): Likewise.
	(power10-prefixed-store): Likewise.
	(power10-prefixed-store): Likewise.
	(power10-store-update): Likewise.
	(power10-vecstore-pair): Likewise.
	(power10-larx): Likewise.
	(power10-lq): Likewise.
	(power10-stcx): Likewise.
	(power10-stq): Likewise.
	(power10-sync): Likewise.
	(power10-sync): Likewise.
	(power10-alu): Likewise.
	(power10-fused_alu): Likewise.
	(power10-paddi): Likewise.
	(power10-rot): Likewise.
	(power10-rot-compare): Likewise.
	(power10-alu2): Likewise.
	(power10-cmp): Likewise.
	(power10-two): Likewise.
	(power10-three): Likewise.
	(power10-mul): Likewise.
	(power10-mul-compare): Likewise.
	(power10-div): Likewise.
	(power10-div-compare): Likewise.
	(power10-crlogical): Likewise.
	(power10-mfcrf): Likewise.
	(power10-mfcr): Likewise.
	(power10-mtcr): Likewise.
	(power10-mtjmpr): Likewise.
	(power10-mfjmpr): Likewise.
	(power10-mfjmpr): Likewise.
	(power10-fpsimple): Likewise.
	(power10-fp): Likewise.
	(power10-fpcompare): Likewise.
	(power10-sdiv): Likewise.
	(power10-ddiv): Likewise.
	(power10-sqrt): Likewise.
	(power10-dsqrt): Likewise.
	(power10-vec-2cyc): Likewise.
	(power10-fused-vec): Likewise.
	(power10-veccmp): Likewise.
	(power10-vecsimple): Likewise.
	(power10-vecnormal): Likewise.
	(power10-qp): Likewise.
	(power10-vecperm): Likewise.
	(power10-vecperm-compare): Likewise.
	(power10-prefixed-vecperm): Likewise.
	(power10-veccomplex): Likewise.
	(power10-vecfdiv): Likewise.
	(power10-vecdiv): Likewise.
	(power10-qpdiv): Likewise.
	(power10-qpmul): Likewise.
	(power10-mtvsr): Likewise.
	(power10-mfvsr): Likewise.
	(power10-mfvsr): Likewise.
	(power10-branch): Likewise.
	(power10-fused-branch): Likewise.
	(power10-crypto): Likewise.
	(power10-htm): Likewise.
	(power10-htm): Likewise.
	(power10-dfp): Likewise.
	(power10-dfpq): Likewise.
	(power10-mma): Likewise.
	(power10-prefixed-mma): Likewise.
	* config/rs6000/rs6000-c.cc (rs6000_target_modify_macros): Define
	__ARCH_PWR_FUTURE__ if -mcpu=future.
	* config/rs6000/rs6000-cpus.def (ISA_FUTURE_MASKS): New macro.
	(POWERPC_MASKS): Add -mcpu=future.
	* config/rs6000/rs6000-opts.h (enum processor_type): Add
	PROCESSOR_FUTURE.
	* config/rs6000/rs6000-tables.opt: Regenerate.
	* config/rs6000/rs6000.cc (future_costs): Add -mcpu=future support.
	Make -mtune=future act like -mtune=power10 for now.
	(rs6000_option_override_internal):
	(rs6000_machine_from_flags): Likewise.
	(rs6000_reassociation_width): Likewise.
	(rs6000_adjust_cost): Likewise.
	(rs6000_issue_rate): Likewise.
	(rs6000_sched_reorder): Likewise.
	(rs6000_sched_reorder2): Likewise.
	(rs6000_register_move_cost): Likewise.
	(rs6000_opt_masks): Add -mfuture.
	* config/rs6000/rs6000.h (ASM_CPU_SUPPORT): Likewise.
	* config/rs6000/rs6000.md (cpu attribute): Add -mcpu=future support.
	* config/rs6000/rs6000.opt (-mfuture): New undocumented debug switch.
	* doc/invoke.texi (IBM RS/6000 and PowerPC Options): Document -mcpu=future.