On 05/12/25 10:33 am, Michael Meissner wrote:
> This patch adds support for a new PowerPC cpu (future). Until it is
> announced,
> the features of future processors may be changed. These patches allow people
> to
> use the new features of processors being developed. If/when the a processor
> is
> announced that has the features, future GCC revisions will be modified to add
> support for that new machine.
>
> If the features provided by -mcpu=future are incorporated into an official
> PowerPC server, this option will be renamed to the official name for that
> platform.
The commit message needs to be more concise.
Something like:
This patch adds support for the -mcpu=future option. New processor features,
that may or may
not be supported in a future processor, will be supported in gcc under this
option.
This option will be renamed to an actual future processor, whenever such a
processor is announced.
(I hope I have covered all the legalese).
>
> This is version 10 of the -mcpu=future patch.
>
> If the user uses -mcpu=future, -mfuture is passed to the assembler.
>
> I added support so that if GCC is configured with the --with-cpu=future option
> is used, it will set the default cpu type.
This is not clear from the code.
-Surya
>
> Can I check this patch into the GCC trunk? I have built bootstrap
> builds on both a little endian Power10 system and a big endian Power9
> system and there were no regressions. On the little endian Power10
> system, I built the last run using the --with-cpu=future configuration
> option.
>
> 2025-12-05 Michael Meissner <[email protected]>
>
> gcc/
>
> * config.gcc (powerpc*-*-*): Add support for -mcpu=future.
> * config/rs6000/aix71.h (ASM_CPU_SPEC): Add support for -mcpu=future.
> * config/rs6000/aix72.h (ASM_CPU_SPEC): Likewise.
> * config/rs6000/aix73.h (ASM_CPU_SPEC): Likewise.
> * 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-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): Add support for -mcpu=future.
> * 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.
> ---
> gcc/config.gcc | 4 ++--
> gcc/config/rs6000/aix71.h | 1 +
> gcc/config/rs6000/aix72.h | 1 +
> gcc/config/rs6000/aix73.h | 1 +
> gcc/config/rs6000/rs6000-c.cc | 2 ++
> gcc/config/rs6000/rs6000-cpus.def | 6 ++++++
> gcc/config/rs6000/rs6000-opts.h | 2 ++
> gcc/config/rs6000/rs6000-tables.opt | 11 ++++++----
> gcc/config/rs6000/rs6000.cc | 3 +++
> gcc/config/rs6000/rs6000.h | 1 +
> gcc/config/rs6000/rs6000.opt | 5 +++++
> gcc/doc/invoke.texi | 2 +-
> gcc/testsuite/gcc.target/powerpc/future-1.c | 13 +++++++++++
> gcc/testsuite/gcc.target/powerpc/future-2.c | 24 +++++++++++++++++++++
> 14 files changed, 69 insertions(+), 7 deletions(-)
> create mode 100644 gcc/testsuite/gcc.target/powerpc/future-1.c
> create mode 100644 gcc/testsuite/gcc.target/powerpc/future-2.c
>
> diff --git a/gcc/config.gcc b/gcc/config.gcc
> index fb465dac147..74b6aee9656 100644
> --- a/gcc/config.gcc
> +++ b/gcc/config.gcc
> @@ -543,7 +543,7 @@ powerpc*-*-*)
> extra_headers="${extra_headers} ppu_intrinsics.h spu2vmx.h vec_types.h
> si2vmx.h"
> extra_headers="${extra_headers} amo.h"
> case x$with_cpu in
> -
> xpowerpc64|xdefault64|x6[23]0|x970|xG5|xpower[3456789]|xpower1[01]|xpower6x|xrs64a|xcell|xa2|xe500mc64|xe5500|xe6500)
> +
> xpowerpc64|xdefault64|x6[23]0|x970|xG5|xpower[3456789]|xpower1[01]|xpower6x|xrs64a|xcell|xa2|xe500mc64|xe5500|xe6500|xfuture)
> cpu_is_64bit=yes
> ;;
> esac
> @@ -5750,7 +5750,7 @@ case "${target}" in
> tm_defines="${tm_defines} CONFIG_PPC405CR"
> eval "with_$which=405"
> ;;
> - "" | common | native \
> + "" | common | native | future \
> | power[3456789] | power1[01] | power5+ | power6x \
> | powerpc | powerpc64 | powerpc64le \
> | rs64 \
> diff --git a/gcc/config/rs6000/aix71.h b/gcc/config/rs6000/aix71.h
> index 2b21dd7cd1e..77651f5ea30 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 53c0bde5ad4..652f60c7f49 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 c7639368a26..3c66ac1d917 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-c.cc b/gcc/config/rs6000/rs6000-c.cc
> index d3b0a566821..6757a2477ad 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 4a1037616d7..6e5d6c2ed23 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-opts.h b/gcc/config/rs6000/rs6000-opts.h
> index c31d2975f04..e13ba2ba527 100644
> --- a/gcc/config/rs6000/rs6000-opts.h
> +++ b/gcc/config/rs6000/rs6000-opts.h
> @@ -71,6 +71,8 @@ enum processor_type
> PROCESSOR_TITAN
> };
>
> +/* For now, just use power11 as the base processor for -mcpu=future. */
> +#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 f5bbed5ea74..518324e7aea 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 bf899adc531..b5bdf42c3d5 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 db6112a09e1..76c6cd1ab8e 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 88cf16ca581..b53d480bf54 100644
> --- a/gcc/config/rs6000/rs6000.opt
> +++ b/gcc/config/rs6000/rs6000.opt
> @@ -595,6 +595,11 @@ 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>)
> +Generate (do not generate) potential future instructions.
> +
> 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 a6d2b54cc7f..48b2ebc4185 100644
> --- a/gcc/doc/invoke.texi
> +++ b/gcc/doc/invoke.texi
> @@ -32452,7 +32452,7 @@ 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{power11}, @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
> 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)
> +{
> +}
