[gcc(refs/users/meissner/heads/work158-future)] Add initial -mcpu=future support.

[Michael Meissner <meissner@gcc.gnu.org>]

https://gcc.gnu.org/g:e5c1354bf788a98fcad9ec266d75fb53fe793571

commit e5c1354bf788a98fcad9ec266d75fb53fe793571
Author: Michael Meissner <meissner@linux.ibm.com>
Date:   Thu Feb 15 14:58:31 2024 -0500

    Add initial -mcpu=future support.
    
    This patch adds the basic support for -mcpu=future, which is a framework to add
    support for possible future PowerPCs.  Until there are changes for a possible
    future PowerPC, -mcpu=future and -mtune=future default to power10.  An ISA bit
    is set to denote possible future instructions are enabled.
    
    2024-02-15  Michael Meissner  <meissner@linux.ibm.com>
    
    gcc/
    
            * config/rs6000/rs6000-cpus.def (ISA_FUTURE_MASKS_SERVER): New option
            bits for -mcpu=future.
            (POWERPC_MASKS): Add -mfuture mask.
            (future cpu): Add -mcpu=future.
            * config/rs6000/rs6000-opts.h (PROCESSOR_FUTURE): Map PROCESSOR_FUTURE
            into PROCESSOR_POWER10 until there are differences that necessate a new
            processor enumeration.
            * config/rs6000/rs6000-tables.opt (rs6000_cpu_opt_value): Add future
            variant.
            * config/rs6000/rs6000.cc (rs6000_opt_masks): Add printing -mfuture if
            -mdebug=reg is used.  Do not allow it to be set with a target attribute
            or pragma.
            * config/rs6000/rs6000.opt (-mfuture): New ISA bit for -mcpu=future.
            * doc/invoke.texi (PowerPC options): Document -mcpu=future.

Diff:
---
 gcc/config/rs6000/rs6000-cpus.def   | 6 ++++++
 gcc/config/rs6000/rs6000-opts.h     | 3 +++
 gcc/config/rs6000/rs6000-tables.opt | 3 +++
 gcc/config/rs6000/rs6000.cc         | 1 +
 gcc/config/rs6000/rs6000.opt        | 3 +++
 gcc/doc/invoke.texi                 | 2 +-
 6 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/gcc/config/rs6000/rs6000-cpus.def b/gcc/config/rs6000/rs6000-cpus.def
index d28cc87eb2a1..a47075f8249e 100644
--- a/gcc/config/rs6000/rs6000-cpus.def
+++ b/gcc/config/rs6000/rs6000-cpus.def
@@ -88,6 +88,10 @@
 				 | OPTION_MASK_POWER10			\
 				 | OTHER_POWER10_MASKS)
 
+/* Flags for a potential future processor that may or may not be delivered.  */
+#define ISA_FUTURE_MASKS_SERVER	(ISA_3_1_MASKS_SERVER			\
+				 | OPTION_MASK_FUTURE)
+
 /* Flags that need to be turned off if -mno-power9-vector.  */
 #define OTHER_P9_VECTOR_MASKS	(OPTION_MASK_FLOAT128_HW		\
 				 | OPTION_MASK_P9_MINMAX)
@@ -135,6 +139,7 @@
 				 | OPTION_MASK_LOAD_VECTOR_PAIR		\
 				 | OPTION_MASK_POWER10			\
 				 | OPTION_MASK_P10_FUSION		\
+				 | OPTION_MASK_FUTURE			\
 				 | OPTION_MASK_HTM			\
 				 | OPTION_MASK_ISEL			\
 				 | OPTION_MASK_MFCRF			\
@@ -267,3 +272,4 @@ RS6000_CPU ("powerpc64", PROCESSOR_POWERPC64, OPTION_MASK_PPC_GFXOPT
 RS6000_CPU ("powerpc64le", PROCESSOR_POWER8, MASK_POWERPC64
 	    | ISA_2_7_MASKS_SERVER | OPTION_MASK_HTM)
 RS6000_CPU ("rs64", PROCESSOR_RS64A, OPTION_MASK_PPC_GFXOPT | MASK_POWERPC64)
+RS6000_CPU ("future", PROCESSOR_FUTURE, MASK_POWERPC64 | ISA_FUTURE_MASKS_SERVER)
diff --git a/gcc/config/rs6000/rs6000-opts.h b/gcc/config/rs6000/rs6000-opts.h
index 33fd0efc936f..e4e90a1603d6 100644
--- a/gcc/config/rs6000/rs6000-opts.h
+++ b/gcc/config/rs6000/rs6000-opts.h
@@ -70,6 +70,9 @@ enum processor_type
    PROCESSOR_TITAN
 };
 
+/* Until there are changes for -mcpu=future, treat -mcpu=future to be like
+   -mcpu=power10.  */
+#define PROCESSOR_FUTURE	PROCESSOR_POWER10
 
 /* Types of costly dependences.  */
 enum rs6000_dependence_cost
diff --git a/gcc/config/rs6000/rs6000-tables.opt b/gcc/config/rs6000/rs6000-tables.opt
index 65f46709716f..97fa98a2e65e 100644
--- a/gcc/config/rs6000/rs6000-tables.opt
+++ b/gcc/config/rs6000/rs6000-tables.opt
@@ -197,3 +197,6 @@ Enum(rs6000_cpu_opt_value) String(powerpc64le) Value(55)
 EnumValue
 Enum(rs6000_cpu_opt_value) String(rs64) Value(56)
 
+EnumValue
+Enum(rs6000_cpu_opt_value) String(future) Value(57)
+
diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
index 68a14c6f88a3..e8c6cbf25b6f 100644
--- a/gcc/config/rs6000/rs6000.cc
+++ b/gcc/config/rs6000/rs6000.cc
@@ -24504,6 +24504,7 @@ static struct rs6000_opt_mask const rs6000_opt_masks[] =
   { "float128",			OPTION_MASK_FLOAT128_KEYWORD,	false, true  },
   { "float128-hardware",	OPTION_MASK_FLOAT128_HW,	false, true  },
   { "fprnd",			OPTION_MASK_FPRND,		false, true  },
+  { "future",			OPTION_MASK_FUTURE,		false, false },
   { "power10",			OPTION_MASK_POWER10,		false, true  },
   { "hard-dfp",			OPTION_MASK_DFP,		false, true  },
   { "htm",			OPTION_MASK_HTM,		false, true  },
diff --git a/gcc/config/rs6000/rs6000.opt b/gcc/config/rs6000/rs6000.opt
index 60b923f5e4b3..059337c50d70 100644
--- a/gcc/config/rs6000/rs6000.opt
+++ b/gcc/config/rs6000/rs6000.opt
@@ -612,6 +612,9 @@ mrop-protect
 Target Var(rs6000_rop_protect) Init(0)
 Enable instructions that guard against return-oriented programming attacks.
 
+mfuture
+Target Undocumented Mask(FUTURE) Var(rs6000_isa_flags) Warn(Do not use %<-mfuture>)
+
 mprivileged
 Target Var(rs6000_privileged) Init(0)
 Generate code that will run in privileged state.
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 71339b8b30fa..dcc9f82171c8 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -31091,7 +31091,7 @@ Supported values for @var{cpu_type} are @samp{401}, @samp{403},
 @samp{titan}, @samp{power3}, @samp{power4}, @samp{power5}, @samp{power5+},
 @samp{power6}, @samp{power6x}, @samp{power7}, @samp{power8},
 @samp{power9}, @samp{power10}, @samp{powerpc}, @samp{powerpc64},
-@samp{powerpc64le}, @samp{rs64}, and @samp{native}.
+@samp{powerpc64le}, @samp{rs64}, @samp{future}, and @samp{native}.
 
 @option{-mcpu=powerpc}, @option{-mcpu=powerpc64}, and
 @option{-mcpu=powerpc64le} specify pure 32-bit PowerPC (either