[PATCH 04/19] RISC-V: match_*() improvements

[Jiawei]

> Match functions referenced by macro insns should not
> unconditionally invoke match_opcode(): The macro enumeration can change
> (grow), making the function potentially yield false negatives.
>
> In match_rs1_nonzero(), used solely by macro insns, add an assertion to
> that effect.
>
> While there also drop the pointless attribute from
> match_rs1_nonzero_rs2_even()'s first parameter.
>
LGTM.

Skipping match_opcode() for macro entries looks reasonable to me, and the
assertion in match_rs1_nonzero() documents its macro-only use nicely.

Best regards,

Jiawei

>
> --- a/opcodes/riscv-opc.c
> +++ b/opcodes/riscv-opc.c
> @@ -22,6 +22,7 @@
>
>  #include "sysdep.h"
>  #include "opcode/riscv.h"
> +#include <assert.h>
>  #include <stdio.h>
>
>  /* Register names used by gas and objdump.  */
> @@ -210,14 +211,16 @@ static int
>  match_rd_even (const struct riscv_opcode *op, insn_t insn)
>  {
>    int rd = (insn & MASK_RD) >> OP_SH_RD;
> -  return ((rd & 1) == 0) && match_opcode (op, insn);
> +  return ((rd & 1) == 0)
> +         && (op->pinfo == INSN_MACRO || match_opcode (op, insn));
>  }
>
>  static int
>  match_rs2_even (const struct riscv_opcode *op, insn_t insn)
>  {
>    int rs2 = (insn & MASK_RS2) >> OP_SH_RS2;
> -  return ((rs2 & 1) == 0) && match_opcode (op, insn);
> +  return ((rs2 & 1) == 0)
> +         && (op->pinfo == INSN_MACRO || match_opcode (op, insn));
>  }
>
>  static int
> @@ -236,11 +239,12 @@ match_rd_even_nonzero (const struct risc
>  static int
>  match_rs1_nonzero (const struct riscv_opcode *op ATTRIBUTE_UNUSED, 
> insn_t insn)
>  {
> +  assert (op->pinfo == INSN_MACRO);
>    return (insn & MASK_RS1) != 0;
>  }
>
>  static int
> -match_rs1_nonzero_rs2_even (const struct riscv_opcode *op 
> ATTRIBUTE_UNUSED, insn_t insn)
> +match_rs1_nonzero_rs2_even (const struct riscv_opcode *op, insn_t insn)
>  {
>    return match_rs1_nonzero (op, insn) && match_rs2_even (op, insn);
>  }
>