Re: [PATCH 4/4] disas/riscv: Support zcmop disassemble

[Alistair Francis <alistair23@gmail.com>]

On Wed, May 22, 2024 at 4:33 PM LIU Zhiwei <zhiwei_liu@linux.alibaba.com> wrote:
>
> Although in QEMU disassemble, we usually lift compressed instruction
> to an normal format when display the instruction name. For C.MOP.n,
> it is more reasonable to directly display its compressed name, because
> its behavior can be redefined by later extension.
>
> Signed-off-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>

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

Alistair

> ---
>  disas/riscv.c | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
>
> diff --git a/disas/riscv.c b/disas/riscv.c
> index 4cd769f165..41050246f3 100644
> --- a/disas/riscv.c
> +++ b/disas/riscv.c
> @@ -946,6 +946,14 @@ typedef enum {
>      rv_mop_rr_5    = 915,
>      rv_mop_rr_6    = 916,
>      rv_mop_rr_7    = 917,
> +    rv_c_mop_1     = 918,
> +    rv_c_mop_3     = 919,
> +    rv_c_mop_5     = 920,
> +    rv_c_mop_7     = 921,
> +    rv_c_mop_9     = 922,
> +    rv_c_mop_11    = 923,
> +    rv_c_mop_13    = 924,
> +    rv_c_mop_15    = 925,
>  } rv_op;
>
>  /* register names */
> @@ -2176,6 +2184,14 @@ const rv_opcode_data rvi_opcode_data[] = {
>      { "mop.rr.5", rv_codec_r, rv_fmt_rd_rs1_rs2, NULL, 0, 0, 0 },
>      { "mop.rr.6", rv_codec_r, rv_fmt_rd_rs1_rs2, NULL, 0, 0, 0 },
>      { "mop.rr.7", rv_codec_r, rv_fmt_rd_rs1_rs2, NULL, 0, 0, 0 },
> +    { "c.mop.1",  rv_codec_ci_none, rv_fmt_none, NULL, 0, 0, 0 },
> +    { "c.mop.3",  rv_codec_ci_none, rv_fmt_none, NULL, 0, 0, 0 },
> +    { "c.mop.5",  rv_codec_ci_none, rv_fmt_none, NULL, 0, 0, 0 },
> +    { "c.mop.7",  rv_codec_ci_none, rv_fmt_none, NULL, 0, 0, 0 },
> +    { "c.mop.9",  rv_codec_ci_none, rv_fmt_none, NULL, 0, 0, 0 },
> +    { "c.mop.11", rv_codec_ci_none, rv_fmt_none, NULL, 0, 0, 0 },
> +    { "c.mop.13", rv_codec_ci_none, rv_fmt_none, NULL, 0, 0, 0 },
> +    { "c.mop.15", rv_codec_ci_none, rv_fmt_none, NULL, 0, 0, 0 },
>  };
>
>  /* CSR names */
> @@ -2469,6 +2485,13 @@ static void decode_inst_opcode(rv_decode *dec, rv_isa isa)
>              break;
>          case 2: op = rv_op_c_li; break;
>          case 3:
> +            if (dec->cfg->ext_zcmop) {
> +                if ((((inst >> 2) & 0b111111) == 0b100000) &&
> +                    (((inst >> 11) & 0b11) == 0b0)) {
> +                    op = rv_c_mop_1 + ((inst >> 8) & 0b111);
> +                    break;
> +                }
> +            }
>              switch ((inst >> 7) & 0b11111) {
>              case 2: op = rv_op_c_addi16sp; break;
>              default: op = rv_op_c_lui; break;
> --
> 2.25.1
>
>