Re: [PATCH 1/2] target/riscv: Add set_implicit_extensions_from_ext() function

[Alistair Francis <alistair23@gmail.com>]

On Mon, Apr 10, 2023 at 1:36 PM Weiwei Li <liweiwei@iscas.ac.cn> wrote:
>
> Move multi-letter extensions that may implicitly enabled from misa.EXT
> alone to prepare for following separation of implicitly enabled and
> explicitly enabled extensions.
>
> Signed-off-by: Weiwei Li <liweiwei@iscas.ac.cn>
> Signed-off-by: Junqiang Wang <wangjunqiang@iscas.ac.cn>

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> ---
>  target/riscv/cpu.c | 56 +++++++++++++++++++++++++---------------------
>  1 file changed, 31 insertions(+), 25 deletions(-)
>
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index cb68916fce..abb65d41b1 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -809,6 +809,35 @@ static void riscv_cpu_disas_set_info(CPUState *s, disassemble_info *info)
>      }
>  }
>
> +static void set_implicit_extensions_from_ext(RISCVCPU *cpu)
> +{
> +
> +    /* The V vector extension depends on the Zve64d extension */
> +    if (cpu->cfg.ext_v) {
> +        cpu->cfg.ext_zve64d = true;
> +    }
> +
> +    /* The Zve64d extension depends on the Zve64f extension */
> +    if (cpu->cfg.ext_zve64d) {
> +        cpu->cfg.ext_zve64f = true;
> +    }
> +
> +    /* The Zve64f extension depends on the Zve32f extension */
> +    if (cpu->cfg.ext_zve64f) {
> +        cpu->cfg.ext_zve32f = true;
> +    }
> +
> +    if (cpu->cfg.ext_c) {
> +        cpu->cfg.ext_zca = true;
> +        if (cpu->cfg.ext_f && cpu->env.misa_mxl_max == MXL_RV32) {
> +            cpu->cfg.ext_zcf = true;
> +        }
> +        if (cpu->cfg.ext_d) {
> +            cpu->cfg.ext_zcd = true;
> +        }
> +    }
> +}
> +
>  /*
>   * Check consistency between chosen extensions while setting
>   * cpu->cfg accordingly, doing a set_misa() in the end.
> @@ -833,6 +862,8 @@ static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
>          cpu->cfg.ext_ifencei = true;
>      }
>
> +    set_implicit_extensions_from_ext(cpu);
> +
>      if (cpu->cfg.ext_i && cpu->cfg.ext_e) {
>          error_setg(errp,
>                     "I and E extensions are incompatible");
> @@ -886,21 +917,6 @@ static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
>          return;
>      }
>
> -    /* The V vector extension depends on the Zve64d extension */
> -    if (cpu->cfg.ext_v) {
> -        cpu->cfg.ext_zve64d = true;
> -    }
> -
> -    /* The Zve64d extension depends on the Zve64f extension */
> -    if (cpu->cfg.ext_zve64d) {
> -        cpu->cfg.ext_zve64f = true;
> -    }
> -
> -    /* The Zve64f extension depends on the Zve32f extension */
> -    if (cpu->cfg.ext_zve64f) {
> -        cpu->cfg.ext_zve32f = true;
> -    }
> -
>      if (cpu->cfg.ext_zve64d && !cpu->cfg.ext_d) {
>          error_setg(errp, "Zve64d/V extensions require D extension");
>          return;
> @@ -956,16 +972,6 @@ static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
>          }
>      }
>
> -    if (cpu->cfg.ext_c) {
> -        cpu->cfg.ext_zca = true;
> -        if (cpu->cfg.ext_f && env->misa_mxl_max == MXL_RV32) {
> -            cpu->cfg.ext_zcf = true;
> -        }
> -        if (cpu->cfg.ext_d) {
> -            cpu->cfg.ext_zcd = true;
> -        }
> -    }
> -
>      if (env->misa_mxl_max != MXL_RV32 && cpu->cfg.ext_zcf) {
>          error_setg(errp, "Zcf extension is only relevant to RV32");
>          return;
> --
> 2.25.1
>
>