Re: [PATCH 5/9] disas/riscv: Encapsulate opcode_data into decode

[Alistair Francis]

On Tue, May 30, 2023 at 11:23 PM Christoph Muellner
<christoph.muellner@vrull.eu> wrote:
>
> From: Christoph Müllner <christoph.muellner@vrull.eu>
>
> This patch adds a reference to a struct rv_opcode_data object
> into struct rv_decode. This further allows to remove all references
> to the global variable opcode_data (which is renamed to rvi_opcode_data).
>
> This patch does not introduce any functional change, but prepares
> the code for more struct rv_opcode_data objects in the future.
>
> This patch is based on previous work from Liu Zhiwei:
>   https://lists.nongnu.org/archive/html/qemu-devel/2022-08/msg03662.html
>
> Co-developed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
> Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>

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

Alistair

> ---
>  disas/riscv.c |  9 ++++++++-
>  disas/riscv.h | 33 +++++++++++++++++----------------
>  2 files changed, 25 insertions(+), 17 deletions(-)
>
> diff --git a/disas/riscv.c b/disas/riscv.c
> index 4cf477bc02..086edee6a2 100644
> --- a/disas/riscv.c
> +++ b/disas/riscv.c
> @@ -1055,7 +1055,7 @@ static const rv_comp_data rvcp_fsgnjx_q[] = {
>
>  /* instruction metadata */
>
> -const rv_opcode_data opcode_data[] = {
> +const rv_opcode_data rvi_opcode_data[] = {
>      { "illegal", rv_codec_illegal, rv_fmt_none, NULL, 0, 0, 0 },
>      { "lui", rv_codec_u, rv_fmt_rd_imm, NULL, 0, 0, 0 },
>      { "auipc", rv_codec_u, rv_fmt_rd_offset, NULL, 0, 0, 0 },
> @@ -3803,6 +3803,7 @@ static uint32_t operand_tbl_index(rv_inst inst)
>
>  static void decode_inst_operands(rv_decode *dec, rv_isa isa)
>  {
> +    const rv_opcode_data *opcode_data = dec->opcode_data;
>      rv_inst inst = dec->inst;
>      dec->codec = opcode_data[dec->op].codec;
>      switch (dec->codec) {
> @@ -4284,6 +4285,7 @@ static void append(char *s1, const char *s2, size_t n)
>
>  static void format_inst(char *buf, size_t buflen, size_t tab, rv_decode *dec)
>  {
> +    const rv_opcode_data *opcode_data = dec->opcode_data;
>      char tmp[64];
>      const char *fmt;
>
> @@ -4517,6 +4519,7 @@ static void format_inst(char *buf, size_t buflen, 
> size_t tab, rv_decode *dec)
>
>  static void decode_inst_lift_pseudo(rv_decode *dec)
>  {
> +    const rv_opcode_data *opcode_data = dec->opcode_data;
>      const rv_comp_data *comp_data = opcode_data[dec->op].pseudo;
>      if (!comp_data) {
>          return;
> @@ -4535,6 +4538,7 @@ static void decode_inst_lift_pseudo(rv_decode *dec)
>
>  static void decode_inst_decompress_rv32(rv_decode *dec)
>  {
> +    const rv_opcode_data *opcode_data = dec->opcode_data;
>      int decomp_op = opcode_data[dec->op].decomp_rv32;
>      if (decomp_op != rv_op_illegal) {
>          if ((opcode_data[dec->op].decomp_data & rvcd_imm_nz)
> @@ -4549,6 +4553,7 @@ static void decode_inst_decompress_rv32(rv_decode *dec)
>
>  static void decode_inst_decompress_rv64(rv_decode *dec)
>  {
> +    const rv_opcode_data *opcode_data = dec->opcode_data;
>      int decomp_op = opcode_data[dec->op].decomp_rv64;
>      if (decomp_op != rv_op_illegal) {
>          if ((opcode_data[dec->op].decomp_data & rvcd_imm_nz)
> @@ -4563,6 +4568,7 @@ static void decode_inst_decompress_rv64(rv_decode *dec)
>
>  static void decode_inst_decompress_rv128(rv_decode *dec)
>  {
> +    const rv_opcode_data *opcode_data = dec->opcode_data;
>      int decomp_op = opcode_data[dec->op].decomp_rv128;
>      if (decomp_op != rv_op_illegal) {
>          if ((opcode_data[dec->op].decomp_data & rvcd_imm_nz)
> @@ -4598,6 +4604,7 @@ disasm_inst(char *buf, size_t buflen, rv_isa isa, 
> uint64_t pc, rv_inst inst)
>      rv_decode dec = { 0 };
>      dec.pc = pc;
>      dec.inst = inst;
> +    dec.opcode_data = rvi_opcode_data;
>      decode_inst_opcode(&dec, isa);
>      decode_inst_operands(&dec, isa);
>      decode_inst_decompress(&dec, isa);
> diff --git a/disas/riscv.h b/disas/riscv.h
> index de2623e3cc..188f03feeb 100644
> --- a/disas/riscv.h
> +++ b/disas/riscv.h
> @@ -162,9 +162,26 @@ typedef enum {
>
>  /* structures */
>
> +typedef struct {
> +    const int op;
> +    const rvc_constraint *constraints;
> +} rv_comp_data;
> +
> +typedef struct {
> +    const char * const name;
> +    const rv_codec codec;
> +    const char * const format;
> +    const rv_comp_data *pseudo;
> +    const short decomp_rv32;
> +    const short decomp_rv64;
> +    const short decomp_rv128;
> +    const short decomp_data;
> +} rv_opcode_data;
> +
>  typedef struct {
>      uint64_t  pc;
>      uint64_t  inst;
> +    const rv_opcode_data *opcode_data;
>      int32_t   imm;
>      uint16_t  op;
>      uint8_t   codec;
> @@ -184,11 +201,6 @@ typedef struct {
>      uint8_t   rlist;
>  } rv_decode;
>
> -typedef struct {
> -    const int op;
> -    const rvc_constraint *constraints;
> -} rv_comp_data;
> -
>  enum {
>      rv_op_illegal = 0
>  };
> @@ -197,17 +209,6 @@ enum {
>      rvcd_imm_nz = 0x1
>  };
>
> -typedef struct {
> -    const char * const name;
> -    const rv_codec codec;
> -    const char * const format;
> -    const rv_comp_data *pseudo;
> -    const short decomp_rv32;
> -    const short decomp_rv64;
> -    const short decomp_rv128;
> -    const short decomp_data;
> -} rv_opcode_data;
> -
>  /* instruction formats */
>
>  #define rv_fmt_none                   "O\t"
> --
> 2.40.1
>
>