Re: [PATCH v3 10/14] target/riscv: Use gen_arith_per_ol for RVM

[Alistair Francis]

On Sun, Oct 17, 2021 at 3:27 AM Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> The multiply high-part instructions require a separate
> implementation for RV32 when TARGET_LONG_BITS == 64.
>
> Reviewed-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

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

Alistair

> ---
>  target/riscv/translate.c                | 16 +++++++++++++++
>  target/riscv/insn_trans/trans_rvm.c.inc | 26 ++++++++++++++++++++++---
>  2 files changed, 39 insertions(+), 3 deletions(-)
>
> diff --git a/target/riscv/translate.c b/target/riscv/translate.c
> index 172eea3935..8f5f39d143 100644
> --- a/target/riscv/translate.c
> +++ b/target/riscv/translate.c
> @@ -428,6 +428,22 @@ static bool gen_arith(DisasContext *ctx, arg_r *a, 
> DisasExtend ext,
>      return true;
>  }
>
> +static bool gen_arith_per_ol(DisasContext *ctx, arg_r *a, DisasExtend ext,
> +                             void (*f_tl)(TCGv, TCGv, TCGv),
> +                             void (*f_32)(TCGv, TCGv, TCGv))
> +{
> +    int olen = get_olen(ctx);
> +
> +    if (olen != TARGET_LONG_BITS) {
> +        if (olen == 32) {
> +            f_tl = f_32;
> +        } else {
> +            g_assert_not_reached();
> +        }
> +    }
> +    return gen_arith(ctx, a, ext, f_tl);
> +}
> +
>  static bool gen_shift_imm_fn(DisasContext *ctx, arg_shift *a, DisasExtend 
> ext,
>                               void (*func)(TCGv, TCGv, target_long))
>  {
> diff --git a/target/riscv/insn_trans/trans_rvm.c.inc 
> b/target/riscv/insn_trans/trans_rvm.c.inc
> index 9a1fe3c799..2af0e5c139 100644
> --- a/target/riscv/insn_trans/trans_rvm.c.inc
> +++ b/target/riscv/insn_trans/trans_rvm.c.inc
> @@ -33,10 +33,16 @@ static void gen_mulh(TCGv ret, TCGv s1, TCGv s2)
>      tcg_temp_free(discard);
>  }
>
> +static void gen_mulh_w(TCGv ret, TCGv s1, TCGv s2)
> +{
> +    tcg_gen_mul_tl(ret, s1, s2);
> +    tcg_gen_sari_tl(ret, ret, 32);
> +}
> +
>  static bool trans_mulh(DisasContext *ctx, arg_mulh *a)
>  {
>      REQUIRE_EXT(ctx, RVM);
> -    return gen_arith(ctx, a, EXT_NONE, gen_mulh);
> +    return gen_arith_per_ol(ctx, a, EXT_SIGN, gen_mulh, gen_mulh_w);
>  }
>
>  static void gen_mulhsu(TCGv ret, TCGv arg1, TCGv arg2)
> @@ -54,10 +60,23 @@ static void gen_mulhsu(TCGv ret, TCGv arg1, TCGv arg2)
>      tcg_temp_free(rh);
>  }
>
> +static void gen_mulhsu_w(TCGv ret, TCGv arg1, TCGv arg2)
> +{
> +    TCGv t1 = tcg_temp_new();
> +    TCGv t2 = tcg_temp_new();
> +
> +    tcg_gen_ext32s_tl(t1, arg1);
> +    tcg_gen_ext32u_tl(t2, arg2);
> +    tcg_gen_mul_tl(ret, t1, t2);
> +    tcg_temp_free(t1);
> +    tcg_temp_free(t2);
> +    tcg_gen_sari_tl(ret, ret, 32);
> +}
> +
>  static bool trans_mulhsu(DisasContext *ctx, arg_mulhsu *a)
>  {
>      REQUIRE_EXT(ctx, RVM);
> -    return gen_arith(ctx, a, EXT_NONE, gen_mulhsu);
> +    return gen_arith_per_ol(ctx, a, EXT_NONE, gen_mulhsu, gen_mulhsu_w);
>  }
>
>  static void gen_mulhu(TCGv ret, TCGv s1, TCGv s2)
> @@ -71,7 +90,8 @@ static void gen_mulhu(TCGv ret, TCGv s1, TCGv s2)
>  static bool trans_mulhu(DisasContext *ctx, arg_mulhu *a)
>  {
>      REQUIRE_EXT(ctx, RVM);
> -    return gen_arith(ctx, a, EXT_NONE, gen_mulhu);
> +    /* gen_mulh_w works for either sign as input. */
> +    return gen_arith_per_ol(ctx, a, EXT_ZERO, gen_mulhu, gen_mulh_w);
>  }
>
>  static void gen_div(TCGv ret, TCGv source1, TCGv source2)
> --
> 2.25.1
>
>