From: Kishan Parmar <kishan@linux.ibm.com>
Date: Mon, 4 May 2026 09:03:07 +0000 (+0530)
Subject: rs6000: Add -mcpu=future support and built-in gating infrastructure
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=a00a33da54bd5305b4891ab565d6fced7389548d;p=thirdparty%2Fgcc.git

rs6000: Add -mcpu=future support and built-in gating infrastructure

This patch introduces support for the -mcpu=future option, intended to
enable experimental processor features that may or may not be included
in future Power processors. The option serves as a placeholder for
development and evaluation purposes, and may be renamed if a
corresponding processor is defined.

In addition, this change adds support for gating rs6000 built-ins using
a new target predicate "future", corresponding to -mcpu=future. This
extends rs6000-gen-builtins.cc and rs6000-builtin.cc to recognize
[future] as a valid predicate, allowing new built-ins defined in .bif
files to be conditionally enabled.

Bootstrapped and Regtested on Power10 little-endian system, using the
--with-cpu=future configuration option.

2026-05-04  Kishan Parmar  <kishan@linux.ibm.com>

gcc/
	* config.gcc (powerpc*-*-*): Add support for supporting
	--with-cpu=future.
	* config/rs6000/aix71.h (ASM_CPU_SPEC): Pass -mfuture to the assembler
	if the user used the -mcpu=future option.
	* config/rs6000/aix72.h (ASM_CPU_SPEC): Likewise.
	* config/rs6000/aix73.h (ASM_CPU_SPEC): Likewise.
	* config/rs6000/rs6000-builtin.cc (rs6000_invalid_builtin): Handle
	ENB_FUTURE and issue diagnostic requiring -mcpu=future.
	(rs6000_builtin_is_supported): Return TARGET_FUTURE for
	ENB_FUTURE built-ins.
	* config/rs6000/rs6000-c.cc (rs6000_target_modify_macros): Define
	_ARCH_FUTURE if -mcpu=future.
	* config/rs6000/rs6000-cpus.def (FUTURE_MASKS_SERVER): New macro.
	(POWERPC_MASKS): Add OPTION_MASK_FUTURE.
	(rs6000_cpu_opt_value): New entry for 'future' via the RS6000_CPU macro.
	* config/rs6000/rs6000-gen-builtins.cc (enum bif_stanza): Add
	BSTZ_FUTURE for future.
	(write_decls): Add ENB_FUTURE in bif_enable enum of generated header
	file.
	* config/rs6000/rs6000-opts.h (PROCESSOR_FUTURE): New macro.
	* config/rs6000/rs6000-tables.opt: Regenerate.
	* config/rs6000/rs6000.cc (rs6000_machine_from_flags) If -mcpu=future,
	set the .machine directive to "future".
	(rs6000_opt_masks): Add entry for -mfuture.
	* config/rs6000/rs6000.h (ASM_CPU_SPEC): Pass -mfuture to the assembler
	if the user used the -mcpu=future option.
	* config/rs6000/rs6000.opt (-mfuture): New option.
	* doc/invoke.texi (IBM RS/6000 and PowerPC Options): Document
	-mcpu=future.

gcc/testsuite/
	* gcc.target/powerpc/future-1.c: New test.
	* gcc.target/powerpc/future-2.c: Likewise.
---

diff --git a/gcc/config.gcc b/gcc/config.gcc
index 0d4b7897c21..562780ea615 100644
--- a/gcc/config.gcc
+++ b/gcc/config.gcc
@@ -555,7 +555,7 @@ powerpc*-*-*)
 	extra_headers="${extra_headers} ppu_intrinsics.h spu2vmx.h vec_types.h si2vmx.h"
 	extra_headers="${extra_headers} amo.h"
 	case x$with_cpu in
-	    xpowerpc64|xdefault64|x6[23]0|x970|xG5|xpower[3456789]|xpower1[01]|xpower6x|xrs64a|xcell|xa2|xe500mc64|xe5500|xe6500)
+	    xpowerpc64|xdefault64|x6[23]0|x970|xG5|xpower[3456789]|xpower1[01]|xfuture|xpower6x|xrs64a|xcell|xa2|xe500mc64|xe5500|xe6500)
 		cpu_is_64bit=yes
 		;;
 	esac
@@ -5870,7 +5870,7 @@ case "${target}" in
 				eval "with_$which=405"
 				;;
 			"" | common | native \
-			| power[3456789] | power1[01] | power5+ | power6x \
+			| power[3456789] | power1[01] | future | power5+ | power6x \
 			| powerpc | powerpc64 | powerpc64le \
 			| rs64 \
 			| 401 | 403 | 405 | 405fp | 440 | 440fp | 464 | 464fp \
diff --git a/gcc/config/rs6000/aix71.h b/gcc/config/rs6000/aix71.h
index 3093de62088..2331004344f 100644
--- a/gcc/config/rs6000/aix71.h
+++ b/gcc/config/rs6000/aix71.h
@@ -79,6 +79,7 @@ do {									\
 #undef ASM_CPU_SPEC
 #define ASM_CPU_SPEC \
 "%{mcpu=native: %(asm_cpu_native); \
+  mcpu=future: -mfuture; \
   mcpu=power11: -mpwr11; \
   mcpu=power10: -mpwr10; \
   mcpu=power9: -mpwr9; \
diff --git a/gcc/config/rs6000/aix72.h b/gcc/config/rs6000/aix72.h
index 515eeebe5aa..9105f4254d0 100644
--- a/gcc/config/rs6000/aix72.h
+++ b/gcc/config/rs6000/aix72.h
@@ -79,6 +79,7 @@ do {									\
 #undef ASM_CPU_SPEC
 #define ASM_CPU_SPEC \
 "%{mcpu=native: %(asm_cpu_native); \
+  mcpu=future: -mfuture; \
   mcpu=power11: -mpwr11; \
   mcpu=power10: -mpwr10; \
   mcpu=power9: -mpwr9; \
diff --git a/gcc/config/rs6000/aix73.h b/gcc/config/rs6000/aix73.h
index d89a4a197b3..8316decceae 100644
--- a/gcc/config/rs6000/aix73.h
+++ b/gcc/config/rs6000/aix73.h
@@ -79,6 +79,7 @@ do {									\
 #undef ASM_CPU_SPEC
 #define ASM_CPU_SPEC \
 "%{mcpu=native: %(asm_cpu_native); \
+  mcpu=future: -mfuture; \
   mcpu=power11: -mpwr11; \
   mcpu=power10: -mpwr10; \
   mcpu=power9: -mpwr9; \
diff --git a/gcc/config/rs6000/rs6000-builtin.cc b/gcc/config/rs6000/rs6000-builtin.cc
index 45c88fe063b..4d0e541351f 100644
--- a/gcc/config/rs6000/rs6000-builtin.cc
+++ b/gcc/config/rs6000/rs6000-builtin.cc
@@ -139,6 +139,9 @@ rs6000_invalid_builtin (enum rs6000_gen_builtins fncode)
     case ENB_MMA:
       error ("%qs requires the %qs option", name, "-mmma");
       break;
+    case ENB_FUTURE:
+      error ("%qs requires the %qs option", name, "-mcpu=future");
+      break;
     default:
     case ENB_ALWAYS:
       gcc_unreachable ();
@@ -194,6 +197,8 @@ rs6000_builtin_is_supported (enum rs6000_gen_builtins fncode)
       return TARGET_HTM;
     case ENB_MMA:
       return TARGET_MMA;
+    case ENB_FUTURE:
+      return TARGET_FUTURE;
     default:
       gcc_unreachable ();
     }
diff --git a/gcc/config/rs6000/rs6000-c.cc b/gcc/config/rs6000/rs6000-c.cc
index f6cc8923775..3fa7c04a7ce 100644
--- a/gcc/config/rs6000/rs6000-c.cc
+++ b/gcc/config/rs6000/rs6000-c.cc
@@ -437,6 +437,8 @@ rs6000_target_modify_macros (bool define_p, HOST_WIDE_INT flags)
     rs6000_define_or_undefine_macro (define_p, "_ARCH_PWR10");
   if ((flags & OPTION_MASK_POWER11) != 0)
     rs6000_define_or_undefine_macro (define_p, "_ARCH_PWR11");
+  if ((flags & OPTION_MASK_FUTURE) != 0)
+    rs6000_define_or_undefine_macro (define_p, "_ARCH_FUTURE");
   if ((flags & OPTION_MASK_SOFT_FLOAT) != 0)
     rs6000_define_or_undefine_macro (define_p, "_SOFT_FLOAT");
   if ((flags & OPTION_MASK_RECIP_PRECISION) != 0)
diff --git a/gcc/config/rs6000/rs6000-cpus.def b/gcc/config/rs6000/rs6000-cpus.def
index 36be338493e..a110860acce 100644
--- a/gcc/config/rs6000/rs6000-cpus.def
+++ b/gcc/config/rs6000/rs6000-cpus.def
@@ -83,6 +83,10 @@
 #define POWER11_MASKS_SERVER (ISA_3_1_MASKS_SERVER			\
 			      | OPTION_MASK_POWER11)
 
+/* -mcpu=future flags.  */
+#define FUTURE_MASKS_SERVER	(POWER11_MASKS_SERVER			\
+				 | OPTION_MASK_FUTURE)
+
 /* Flags that need to be turned off if -mno-vsx.  */
 #define OTHER_VSX_VECTOR_MASKS	(OPTION_MASK_EFFICIENT_UNALIGNED_VSX	\
 				 | OPTION_MASK_FLOAT128_KEYWORD		\
@@ -121,6 +125,7 @@
 				 | OPTION_MASK_FPRND			\
 				 | OPTION_MASK_POWER10			\
 				 | OPTION_MASK_POWER11			\
+				 | OPTION_MASK_FUTURE			\
 				 | OPTION_MASK_P10_FUSION		\
 				 | OPTION_MASK_HTM			\
 				 | OPTION_MASK_ISEL			\
@@ -249,6 +254,7 @@ RS6000_CPU ("power9", PROCESSOR_POWER9, MASK_POWERPC64 | ISA_3_0_MASKS_SERVER
 	    | OPTION_MASK_HTM)
 RS6000_CPU ("power10", PROCESSOR_POWER10, MASK_POWERPC64 | ISA_3_1_MASKS_SERVER)
 RS6000_CPU ("power11", PROCESSOR_POWER11, MASK_POWERPC64 | POWER11_MASKS_SERVER)
+RS6000_CPU ("future", PROCESSOR_FUTURE, MASK_POWERPC64 | FUTURE_MASKS_SERVER)
 RS6000_CPU ("powerpc", PROCESSOR_POWERPC, 0)
 RS6000_CPU ("powerpc64", PROCESSOR_POWERPC64, OPTION_MASK_PPC_GFXOPT
 	    | MASK_POWERPC64)
diff --git a/gcc/config/rs6000/rs6000-gen-builtins.cc b/gcc/config/rs6000/rs6000-gen-builtins.cc
index c7ae5899c5c..7436404cff5 100644
--- a/gcc/config/rs6000/rs6000-gen-builtins.cc
+++ b/gcc/config/rs6000/rs6000-gen-builtins.cc
@@ -232,6 +232,7 @@ enum bif_stanza
  BSTZ_P10,
  BSTZ_P10_64,
  BSTZ_MMA,
+ BSTZ_FUTURE,
  NUMBIFSTANZAS
 };
 
@@ -265,7 +266,8 @@ static stanza_entry stanza_map[NUMBIFSTANZAS] =
     { "htm",		BSTZ_HTM	},
     { "power10",	BSTZ_P10	},
     { "power10-64",	BSTZ_P10_64	},
-    { "mma",		BSTZ_MMA	}
+    { "mma",		BSTZ_MMA	},
+    { "future",	BSTZ_FUTURE	}
   };
 
 static const char *enable_string[NUMBIFSTANZAS] =
@@ -290,7 +292,8 @@ static const char *enable_string[NUMBIFSTANZAS] =
     "ENB_HTM",
     "ENB_P10",
     "ENB_P10_64",
-    "ENB_MMA"
+    "ENB_MMA",
+    "ENB_FUTURE"
   };
 
 /* Function modifiers provide special handling for const, pure, and fpmath
@@ -2249,7 +2252,8 @@ write_decls (void)
   fprintf (header_file, "  ENB_HTM,\n");
   fprintf (header_file, "  ENB_P10,\n");
   fprintf (header_file, "  ENB_P10_64,\n");
-  fprintf (header_file, "  ENB_MMA\n");
+  fprintf (header_file, "  ENB_MMA,\n");
+  fprintf (header_file, "  ENB_FUTURE\n");
   fprintf (header_file, "};\n\n");
 
   fprintf (header_file, "#define PPC_MAXRESTROPNDS 3\n");
diff --git a/gcc/config/rs6000/rs6000-opts.h b/gcc/config/rs6000/rs6000-opts.h
index db308065a43..c98cdc7d5c8 100644
--- a/gcc/config/rs6000/rs6000-opts.h
+++ b/gcc/config/rs6000/rs6000-opts.h
@@ -71,6 +71,8 @@ enum processor_type
    PROCESSOR_TITAN
 };
 
+/* Make -mtune=future use the same tuning decisions as -mtune=power11.  */
+#define PROCESSOR_FUTURE	PROCESSOR_POWER11
 
 /* 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 040c246c2f6..efc55260b2a 100644
--- a/gcc/config/rs6000/rs6000-tables.opt
+++ b/gcc/config/rs6000/rs6000-tables.opt
@@ -189,14 +189,17 @@ EnumValue
 Enum(rs6000_cpu_opt_value) String(power11) Value(53)
 
 EnumValue
-Enum(rs6000_cpu_opt_value) String(powerpc) Value(54)
+Enum(rs6000_cpu_opt_value) String(future) Value(54)
 
 EnumValue
-Enum(rs6000_cpu_opt_value) String(powerpc64) Value(55)
+Enum(rs6000_cpu_opt_value) String(powerpc) Value(55)
 
 EnumValue
-Enum(rs6000_cpu_opt_value) String(powerpc64le) Value(56)
+Enum(rs6000_cpu_opt_value) String(powerpc64) Value(56)
 
 EnumValue
-Enum(rs6000_cpu_opt_value) String(rs64) Value(57)
+Enum(rs6000_cpu_opt_value) String(powerpc64le) Value(57)
+
+EnumValue
+Enum(rs6000_cpu_opt_value) String(rs64) Value(58)
 
diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
index 3838059a7e2..7d61001cb34 100644
--- a/gcc/config/rs6000/rs6000.cc
+++ b/gcc/config/rs6000/rs6000.cc
@@ -5913,6 +5913,8 @@ rs6000_machine_from_flags (void)
   flags &= ~(OPTION_MASK_PPC_GFXOPT | OPTION_MASK_PPC_GPOPT | OPTION_MASK_ISEL
 	     | OPTION_MASK_ALTIVEC);
 
+  if ((flags & (FUTURE_MASKS_SERVER & ~POWER11_MASKS_SERVER)) != 0)
+    return "future";
   if ((flags & (POWER11_MASKS_SERVER & ~ISA_3_1_MASKS_SERVER)) != 0)
     return "power11";
   if ((flags & (ISA_3_1_MASKS_SERVER & ~ISA_3_0_MASKS_SERVER)) != 0)
@@ -24465,6 +24467,7 @@ static struct rs6000_opt_mask const rs6000_opt_masks[] =
   { "fprnd",			OPTION_MASK_FPRND,		false, true  },
   { "power10",			OPTION_MASK_POWER10,		false, true  },
   { "power11",			OPTION_MASK_POWER11,		false, false },
+  { "future",			OPTION_MASK_FUTURE,		false, false },
   { "hard-dfp",			OPTION_MASK_DFP,		false, true  },
   { "htm",			OPTION_MASK_HTM,		false, true  },
   { "isel",			OPTION_MASK_ISEL,		false, true  },
diff --git a/gcc/config/rs6000/rs6000.h b/gcc/config/rs6000/rs6000.h
index 2b90694cef1..2d3016db513 100644
--- a/gcc/config/rs6000/rs6000.h
+++ b/gcc/config/rs6000/rs6000.h
@@ -101,6 +101,7 @@
    you make changes here, make them also there.  */
 #define ASM_CPU_SPEC \
 "%{mcpu=native: %(asm_cpu_native); \
+  mcpu=future: -mfuture; \
   mcpu=power11: -mpower11; \
   mcpu=power10: -mpower10; \
   mcpu=power9: -mpower9; \
diff --git a/gcc/config/rs6000/rs6000.opt b/gcc/config/rs6000/rs6000.opt
index 2eeb45a4b71..2b6ec5222fc 100644
--- a/gcc/config/rs6000/rs6000.opt
+++ b/gcc/config/rs6000/rs6000.opt
@@ -595,6 +595,10 @@ Target Undocumented Mask(POWER10) Var(rs6000_isa_flags) WarnRemoved
 mpower11
 Target Undocumented Mask(POWER11) Var(rs6000_isa_flags) WarnRemoved
 
+;; Potential future machine
+mfuture
+Target Undocumented Mask(FUTURE) Var(rs6000_isa_flags) Warn(Do not use %<-mfuture>, use %<-mcpu=future>)
+
 mprefixed
 Target Mask(PREFIXED) Var(rs6000_isa_flags)
 Generate (do not generate) prefixed memory instructions.
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index fb69dc5fb80..16dc2179073 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -31647,8 +31647,8 @@ Supported values for @var{cpu_type} are @samp{401}, @samp{403},
 @samp{e6500}, @samp{ec603e}, @samp{G3}, @samp{G4}, @samp{G5},
 @samp{titan}, @samp{power3}, @samp{power4}, @samp{power5}, @samp{power5+},
 @samp{power6}, @samp{power6x}, @samp{power7}, @samp{power8},
-@samp{power9}, @samp{power10}, @samp{power11}, @samp{powerpc}, @samp{powerpc64},
-@samp{powerpc64le}, @samp{rs64}, and @samp{native}.
+@samp{power9}, @samp{power10}, @samp{power11}, @samp{future}, @samp{powerpc},
+@samp{powerpc64}, @samp{powerpc64le}, @samp{rs64}, and @samp{native}.
 
 @option{-mcpu=powerpc}, @option{-mcpu=powerpc64}, and
 @option{-mcpu=powerpc64le} specify pure 32-bit PowerPC (either
diff --git a/gcc/testsuite/gcc.target/powerpc/future-1.c b/gcc/testsuite/gcc.target/powerpc/future-1.c
new file mode 100644
index 00000000000..7bd8e5ddbd0
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/future-1.c
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-options "-mdejagnu-cpu=future -O2" } */
+
+/* Basic check to see if the compiler supports -mcpu=future and if it defines
+   _ARCH_FUTURE.  */
+
+#ifndef _ARCH_FUTURE
+#error "-mcpu=future is not supported"
+#endif
+
+void foo (void)
+{
+}
diff --git a/gcc/testsuite/gcc.target/powerpc/future-2.c b/gcc/testsuite/gcc.target/powerpc/future-2.c
new file mode 100644
index 00000000000..5552cefa3c2
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/future-2.c
@@ -0,0 +1,24 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+/* Check if we can set the future target via a target attribute.  */
+
+__attribute__((__target__("cpu=power9")))
+void foo_p9 (void)
+{
+}
+
+__attribute__((__target__("cpu=power10")))
+void foo_p10 (void)
+{
+}
+
+__attribute__((__target__("cpu=power11")))
+void foo_p11 (void)
+{
+}
+
+__attribute__((__target__("cpu=future")))
+void foo_future (void)
+{
+}