Re: [PATCH v2 1/9] RISC-V: minimal support for xtheadvector

[Kito Cheng <kito.cheng@gmail.com>]

On Sat, Nov 18, 2023 at 12:27 PM Jun Sha (Joshua)
<cooper.joshua@linux.alibaba.com> wrote:
>
> This patch is to introduce basic XTheadVector support
> (march string parsing and a test for __riscv_xtheadvector)
> according to https://github.com/T-head-Semi/thead-extension-spec/
>
> Contributors:
>         Jun Sha (Joshua) <cooper.joshua@linux.alibaba.com>
>         Jin Ma <jinma@linux.alibaba.com>
>         Christoph Müllner <christoph.muellner@vrull.eu>
>
> gcc/ChangeLog:
>
>         * common/config/riscv/riscv-common.cc
>         (riscv_subset_list::parse): : Add new vendor extension.
>         * config/riscv/riscv-c.cc (riscv_cpu_cpp_builtins):
>         Add test marco.
>         * config/riscv/riscv.opt: Add new mask.
>
> gcc/testsuite/ChangeLog:
>
>         * gcc.target/riscv/predef-__riscv_th_v_intrinsic.c: New test.
>         * gcc.target/riscv/rvv/xtheadvector.c: New test.
> ---
>  gcc/common/config/riscv/riscv-common.cc             | 10 ++++++++++
>  gcc/config/riscv/riscv-c.cc                         |  4 ++++
>  gcc/config/riscv/riscv.opt                          |  2 ++
>  .../riscv/predef-__riscv_th_v_intrinsic.c           | 11 +++++++++++
>  gcc/testsuite/gcc.target/riscv/rvv/xtheadvector.c   | 13 +++++++++++++
>  5 files changed, 40 insertions(+)
>  create mode 100644 gcc/testsuite/gcc.target/riscv/predef-__riscv_th_v_intrinsic.c
>  create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/xtheadvector.c
>
> diff --git a/gcc/common/config/riscv/riscv-common.cc b/gcc/common/config/riscv/riscv-common.cc
> index 526dbb7603b..914924171fd 100644
> --- a/gcc/common/config/riscv/riscv-common.cc
> +++ b/gcc/common/config/riscv/riscv-common.cc
> @@ -75,6 +75,8 @@ static const riscv_implied_info_t riscv_implied_info[] =
>
>    {"v", "zvl128b"},
>    {"v", "zve64d"},
> +  {"xtheadvector", "zvl128b"},
> +  {"xtheadvector", "zve64d"},

^^^ don't imply zve64d, it will mix V 1.0 together, I know why you
want to do that, so I have given some suggestions below.

>
>    {"zve32f", "f"},
>    {"zve64f", "f"},
> @@ -325,6 +327,7 @@ static const struct riscv_ext_version riscv_ext_version_table[] =
>    {"xtheadmemidx", ISA_SPEC_CLASS_NONE, 1, 0},
>    {"xtheadmempair", ISA_SPEC_CLASS_NONE, 1, 0},
>    {"xtheadsync", ISA_SPEC_CLASS_NONE, 1, 0},
> +  {"xtheadvector", ISA_SPEC_CLASS_NONE, 1, 0},
>
>    {"xventanacondops", ISA_SPEC_CLASS_NONE, 1, 0},
>
> @@ -1495,6 +1498,10 @@ riscv_subset_list::parse (const char *arch, location_t loc)
>      error_at (loc, "%<-march=%s%>: z*inx conflicts with floating-point "
>                    "extensions", arch);
>
> +  if (subset_list->lookup ("v") && subset_list->lookup ("xtheadvector"))
> +    error_at (loc, "%<-march=%s%>: xtheadvector conflicts with vector "
> +                  "extensions", arch);
> +
>    /* 'H' hypervisor extension requires base ISA with 32 registers.  */
>    if (subset_list->lookup ("e") && subset_list->lookup ("h"))
>      error_at (loc, "%<-march=%s%>: h extension requires i extension", arch);
> @@ -1680,6 +1687,9 @@ static const riscv_ext_flag_table_t riscv_ext_flag_table[] =
>    {"xtheadmemidx",  &gcc_options::x_riscv_xthead_subext, MASK_XTHEADMEMIDX},
>    {"xtheadmempair", &gcc_options::x_riscv_xthead_subext, MASK_XTHEADMEMPAIR},
>    {"xtheadsync",    &gcc_options::x_riscv_xthead_subext, MASK_XTHEADSYNC},
> +  {"xtheadvector",  &gcc_options::x_riscv_xthead_subext, MASK_XTHEADVECTOR},
> +  {"xtheadvector",  &gcc_options::x_target_flags, MASK_FULL_V},
> +  {"xtheadvector",  &gcc_options::x_target_flags, MASK_VECTOR},

Add following two line then you don't need zve64d
 {"xtheadvector", &gcc_options::x_riscv_vector_elen_flags, MASK_VECTOR_ELEN_64},
 {"xtheadvector",  &gcc_options::x_riscv_vector_elen_flags,
MASK_VECTOR_ELEN_FP_64},

>
>    {"xventanacondops", &gcc_options::x_riscv_xventana_subext, MASK_XVENTANACONDOPS},
>