https://gcc.gnu.org/g:8cc513b3c9315e3718add0d1ad7b149f6b0830a5
commit 8cc513b3c9315e3718add0d1ad7b149f6b0830a5
Author: Michael Meissner <meiss...@linux.ibm.com>
Date: Mon Jun 30 19:47:53 2025 -0400
Add -mcpu=future support
This patch adds the support that can be used in developing GCC support
for potential future PowerPC processors.
These changes are being added so that hardware designers can evaluate
potential new features to be added to the PowerPC processors in the
future. It may be these features will be incorporated into real
hardware using a different name in the future. Or it may be these
features will not be incoporated into actual PowerPC hardware in the
future.
At the moment, I have not added a new processor, and I'm using the
power11 for tuning defaults and such. When we are ready to add new
tuning rules a potential future processor, we will add the support for
the new processor.
I have tested these patches on both big endian and little endian
PowerPC servers, with no regressions. Can I check these patchs into
the trunk?
2025-06-30 Michael Meissner <meiss...@linux.ibm.com>
gcc/
* config/rs6000/rs6000-c.cc (rs6000_target_modify_macros): If
-mcpu=future, define _ARCH_FUTURE.
* config/rs6000/rs6000-cpus.def (FUTURE_MASKS_SERVER): New macro.
(POWERPC_MASKS): Add OPTION_MASK_FUTURE.
(future cpu): Add 'future' cpu.
* config/rs6000/rs6000-tables.opt: Regenerate.
* config/rs6000/rs6000.opt (-mfuture-internal): New internal option
to
indicate the user used -mcpu=future.
gcc/testsuite/
* gcc.target/powerpc/future-1.c: New test.
* gcc.target/powerpc/future-2.c: Likewise.
Diff:
---
gcc/config/rs6000/rs6000-c.cc | 2 ++
gcc/config/rs6000/rs6000-cpus.def | 9 +++++++++
gcc/config/rs6000/rs6000-tables.opt | 11 +++++++----
gcc/config/rs6000/rs6000.opt | 6 ++++++
gcc/testsuite/gcc.target/powerpc/future-1.c | 13 +++++++++++++
gcc/testsuite/gcc.target/powerpc/future-2.c | 24 ++++++++++++++++++++++++
6 files changed, 61 insertions(+), 4 deletions(-)
diff --git a/gcc/config/rs6000/rs6000-c.cc b/gcc/config/rs6000/rs6000-c.cc
index d3b0a5668212..6757a2477ad1 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 4a1037616d7f..de30f8cd3977 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)
+/* Potential future cpu bits. */
+#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 \
@@ -119,6 +123,7 @@
| OPTION_MASK_FLOAT128_HW \
| OPTION_MASK_FLOAT128_KEYWORD \
| OPTION_MASK_FPRND \
+ | OPTION_MASK_FUTURE \
| OPTION_MASK_POWER10 \
| OPTION_MASK_POWER11 \
| OPTION_MASK_P10_FUSION \
@@ -249,6 +254,10 @@ 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)
+
+/* At present, we are not providing a unique processor option for -mcpu=future.
+ Until we define these changes, just use the power11 defaults. */
+RS6000_CPU ("future", PROCESSOR_POWER11, 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-tables.opt
b/gcc/config/rs6000/rs6000-tables.opt
index f5bbed5ea746..518324e7aead 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.opt b/gcc/config/rs6000/rs6000.opt
index 88cf16ca581a..c226582f8fd6 100644
--- a/gcc/config/rs6000/rs6000.opt
+++ b/gcc/config/rs6000/rs6000.opt
@@ -634,6 +634,12 @@ mieee128-constant
Target Var(TARGET_IEEE128_CONSTANT) Init(1) Save
Generate (do not generate) code that uses the LXVKQ instruction.
+;; Users should not use -mfuture-internal, but we need to use a bit to identify
+;; when the user changes the default cpu via #pragma GCC target("cpu=future")
+;; and then resets it later.
+mfuture-internal
+Target Undocumented Mask(FUTURE) Var(rs6000_isa_flags) WarnRemoved
+
; Documented parameters
-param=rs6000-vect-unroll-limit=
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 000000000000..7bd8e5ddbd00
--- /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 000000000000..5552cefa3c2e
--- /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)
+{
+}
