Re: [PATCH] RISC-V: Add Zawrs ISA extension support

["Christoph Müllner" <christoph.muellner@vrull.eu>]

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On Thu, Oct 27, 2022 at 8:11 PM Christoph Muellner <
christoph.muellner@vrull.eu> wrote:

> From: Christoph Muellner <cmuellner@gcc.gnu.org>
>
> This patch adds support for the Zawrs ISA extension.
> The patch depends on the corresponding Binutils patch
> to be usable (see [1])
>
> The specification can be found here:
> https://github.com/riscv/riscv-zawrs/blob/main/zawrs.adoc
>
> Note, that the Zawrs extension is not frozen or ratified yet.
> Therefore this patch is an RFC and not intended to get merged.
>

Sorry, forgot to update this part:
The Zawrs extension is frozen but not ratified.
Let me know if I should send a v2 for this change of the commit msg.

Binuitls support has been merged recently:

https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=eb668e50036e979fb0a74821df4eee0307b44e66


>
> [1] https://sourceware.org/pipermail/binutils/2022-April/120559.html
>
> gcc/ChangeLog:
>
>         * common/config/riscv/riscv-common.cc: Add zawrs extension.
>         * config/riscv/riscv-opts.h (MASK_ZAWRS): New.
>         (TARGET_ZAWRS): New.
>         * config/riscv/riscv.opt: New.
>
> gcc/testsuite/ChangeLog:
>
>         * gcc.target/riscv/zawrs.c: New test.
>
> Signed-off-by: Christoph Muellner <cmuellner@gcc.gnu.org>
> ---
>  gcc/common/config/riscv/riscv-common.cc |  4 ++++
>  gcc/config/riscv/riscv-opts.h           |  3 +++
>  gcc/config/riscv/riscv.opt              |  3 +++
>  gcc/testsuite/gcc.target/riscv/zawrs.c  | 13 +++++++++++++
>  4 files changed, 23 insertions(+)
>  create mode 100644 gcc/testsuite/gcc.target/riscv/zawrs.c
>
> diff --git a/gcc/common/config/riscv/riscv-common.cc
> b/gcc/common/config/riscv/riscv-common.cc
> index d6404a01205..4b7f777c103 100644
> --- a/gcc/common/config/riscv/riscv-common.cc
> +++ b/gcc/common/config/riscv/riscv-common.cc
> @@ -163,6 +163,8 @@ static const struct riscv_ext_version
> riscv_ext_version_table[] =
>    {"zifencei", ISA_SPEC_CLASS_20191213, 2, 0},
>    {"zifencei", ISA_SPEC_CLASS_20190608, 2, 0},
>
> +  {"zawrs", ISA_SPEC_CLASS_NONE, 1, 0},
> +
>    {"zba", ISA_SPEC_CLASS_NONE, 1, 0},
>    {"zbb", ISA_SPEC_CLASS_NONE, 1, 0},
>    {"zbc", ISA_SPEC_CLASS_NONE, 1, 0},
> @@ -1180,6 +1182,8 @@ static const riscv_ext_flag_table_t
> riscv_ext_flag_table[] =
>    {"zicsr",    &gcc_options::x_riscv_zi_subext, MASK_ZICSR},
>    {"zifencei", &gcc_options::x_riscv_zi_subext, MASK_ZIFENCEI},
>
> +  {"zawrs", &gcc_options::x_riscv_za_subext, MASK_ZAWRS},
> +
>    {"zba",    &gcc_options::x_riscv_zb_subext, MASK_ZBA},
>    {"zbb",    &gcc_options::x_riscv_zb_subext, MASK_ZBB},
>    {"zbc",    &gcc_options::x_riscv_zb_subext, MASK_ZBC},
> diff --git a/gcc/config/riscv/riscv-opts.h b/gcc/config/riscv/riscv-opts.h
> index 1dfe8c89209..25fd85b09b1 100644
> --- a/gcc/config/riscv/riscv-opts.h
> +++ b/gcc/config/riscv/riscv-opts.h
> @@ -73,6 +73,9 @@ enum stack_protector_guard {
>  #define TARGET_ZICSR    ((riscv_zi_subext & MASK_ZICSR) != 0)
>  #define TARGET_ZIFENCEI ((riscv_zi_subext & MASK_ZIFENCEI) != 0)
>
> +#define MASK_ZAWRS   (1 << 0)
> +#define TARGET_ZAWRS ((riscv_za_subext & MASK_ZAWRS) != 0)
> +
>  #define MASK_ZBA      (1 << 0)
>  #define MASK_ZBB      (1 << 1)
>  #define MASK_ZBC      (1 << 2)
> diff --git a/gcc/config/riscv/riscv.opt b/gcc/config/riscv/riscv.opt
> index 426ea95cd14..7c3ca48d1cc 100644
> --- a/gcc/config/riscv/riscv.opt
> +++ b/gcc/config/riscv/riscv.opt
> @@ -203,6 +203,9 @@ long riscv_stack_protector_guard_offset = 0
>  TargetVariable
>  int riscv_zi_subext
>
> +TargetVariable
> +int riscv_za_subext
> +
>  TargetVariable
>  int riscv_zb_subext
>
> diff --git a/gcc/testsuite/gcc.target/riscv/zawrs.c
> b/gcc/testsuite/gcc.target/riscv/zawrs.c
> new file mode 100644
> index 00000000000..0b7e2662343
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/riscv/zawrs.c
> @@ -0,0 +1,13 @@
> +/* { dg-do compile } */
> +/* { dg-options "-march=rv64gc_zawrs" { target { rv64 } } } */
> +/* { dg-options "-march=rv32gc_zawrs" { target { rv32 } } } */
> +
> +#ifndef __riscv_zawrs
> +#error Feature macro not defined
> +#endif
> +
> +int
> +foo (int a)
> +{
> +  return a;
> +}
> --
> 2.37.3
>
>