Re: [Qemu-riscv] [PATCH] target/riscv: Fix manually parsed 16 bit insn

[Palmer Dabbelt]

On Fri, 15 Mar 2019 06:51:40 PDT (-0700), Bastian Koppelmann wrote:
> during the refactor to decodetree we removed the manual decoding that is
> necessary for c.jal/c.addiw and removed the translation of c.flw/c.ld
> and c.fsw/c.sd. This reintroduces the manual parsing and the
> omited implementation.
>
> Signed-off-by: Bastian Koppelmann <address@hidden>
> ---
>  target/riscv/insn_trans/trans_rvc.inc.c | 30 ++++++++++++++++++++-----
>  1 file changed, 25 insertions(+), 5 deletions(-)
>
> diff --git a/target/riscv/insn_trans/trans_rvc.inc.c 
> b/target/riscv/insn_trans/trans_rvc.inc.c
> index bcdf64d3b7..5819f53f90 100644
> --- a/target/riscv/insn_trans/trans_rvc.inc.c
> +++ b/target/riscv/insn_trans/trans_rvc.inc.c
> @@ -44,10 +44,19 @@ static bool trans_c_flw_ld(DisasContext *ctx, arg_c_flw_ld 
> *a)
>  {
>  #ifdef TARGET_RISCV32
>      /* C.FLW ( RV32FC-only ) */
> -    return false;
> +    REQUIRE_FPU;
> +    REQUIRE_EXT(ctx, RVF);
> +
> +    arg_c_lw tmp;
> +    decode_insn16_extract_cl_w(&tmp, ctx->opcode);
> +    arg_flw arg = { .rd = tmp.rd, .rs1 = tmp.rs1, .imm = tmp.uimm };
> +    return trans_flw(ctx, &arg);
>  #else
>      /* C.LD ( RV64C/RV128C-only ) */
> -    return false;
> +    arg_c_fld tmp;
> +    decode_insn16_extract_cl_d(&tmp, ctx->opcode);
> +    arg_ld arg = { .rd = tmp.rd, .rs1 = tmp.rs1, .imm = tmp.uimm };
> +    return trans_ld(ctx, &arg);
>  #endif
>  }
>
> @@ -67,10 +76,19 @@ static bool trans_c_fsw_sd(DisasContext *ctx, arg_c_fsw_sd 
> *a)
>  {
>  #ifdef TARGET_RISCV32
>      /* C.FSW ( RV32FC-only ) */
> -    return false;
> +    REQUIRE_FPU;
> +    REQUIRE_EXT(ctx, RVF);
> +
> +    arg_c_sw tmp;
> +    decode_insn16_extract_cs_w(&tmp, ctx->opcode);
> +    arg_fsw arg = { .rs1 = tmp.rs1, .rs2 = tmp.rs2, .imm = tmp.uimm };
> +    return trans_fsw(ctx, &arg);
>  #else
>      /* C.SD ( RV64C/RV128C-only ) */
> -    return false;
> +    arg_c_fsd tmp;
> +    decode_insn16_extract_cs_d(&tmp, ctx->opcode);
> +    arg_sd arg = { .rs1 = tmp.rs1, .rs2 = tmp.rs2, .imm = tmp.uimm };
> +    return trans_sd(ctx, &arg);
>  #endif
>  }
>
> @@ -88,7 +106,9 @@ static bool trans_c_jal_addiw(DisasContext *ctx, 
> arg_c_jal_addiw *a)
>  {
>  #ifdef TARGET_RISCV32
>      /* C.JAL */
> -    arg_jal arg = { .rd = 1, .imm = a->imm };
> +    arg_c_j tmp;
> +    decode_insn16_extract_cj(&tmp, ctx->opcode);
> +    arg_jal arg = { .rd = 1, .imm = tmp.imm };
>      return trans_jal(ctx, &arg);
>  #else
>      /* C.ADDIW */

Thanks!  This fixes my simple test case, so I'm going to pick it up for the 
next PR.  It also sounds like it's time for me to start testing rv32 Linux 
boots, so I'll go do that next...