Re: [PATCH v2] ppc: use reg_name_search for CFI register lookup

[Alan Modra <amodra@gmail.com>]

On Thu, Jul 14, 2022 at 11:21:12AM +0300, Dmitry Selyutin wrote:
> ---
>  gas/config/tc-ppc.c | 41 +++++++++++++++++++----------------------
>  1 file changed, 19 insertions(+), 22 deletions(-)
> 
> diff --git a/gas/config/tc-ppc.c b/gas/config/tc-ppc.c
> index 452fab1cbf..c6715535c7 100644
> --- a/gas/config/tc-ppc.c
> +++ b/gas/config/tc-ppc.c
> @@ -7713,10 +7713,8 @@ ppc_cfi_frame_initial_instructions (void)
>  int
>  tc_ppc_regname_to_dw2regnum (char *regname)
>  {
> -  unsigned int regnum = -1;
>    unsigned int i;
> -  const char *p;
> -  char *q;
> +  const struct pd_reg *reg;
>    static struct { const char *name; int dw2regnum; } regnames[] =
>      {
>        { "sp", 1 }, { "r.sp", 1 }, { "rtoc", 2 }, { "r.toc", 2 },
> @@ -7729,23 +7727,22 @@ tc_ppc_regname_to_dw2regnum (char *regname)
>      if (strcmp (regnames[i].name, regname) == 0)
>        return regnames[i].dw2regnum;
>  
> -  if (regname[0] == 'r' || regname[0] == 'f' || regname[0] == 'v')
> -    {
> -      p = regname + 1 + (regname[1] == '.');
> -      regnum = strtoul (p, &q, 10);
> -      if (p == q || *q || regnum >= 32)
> -	return -1;
> -      if (regname[0] == 'f')
> -	regnum += 32;
> -      else if (regname[0] == 'v')
> -	regnum += 77;
> -    }
> -  else if (regname[0] == 'c' && regname[1] == 'r')
> -    {
> -      p = regname + 2 + (regname[2] == '.');
> -      if (p[0] < '0' || p[0] > '7' || p[1])
> -	return -1;
> -      regnum = p[0] - '0' + 68;
> -    }
> -  return regnum;
> +  if (regname[0] == '%' && ISALPHA (regname[1]))
> +    ++regname;

No need for the above, any '%' is trimmed off and regname is
guaranteed to be a name by the caller of tc_regname_to_dw2regnum.

> +  reg = reg_name_search (pre_defined_registers,
> +    ARRAY_SIZE (pre_defined_registers), regname);

Doing the reg_name_search before the odd ones in regnames[] would be
better, wouldn't it?  And you can delete the first row of regnames[].
OK with those changes.

> +  if (reg == NULL)
> +    return -1;
> +
> +  if ((reg->flags & PPC_OPERAND_GPR) == PPC_OPERAND_GPR)
> +    return reg->value;
> +  else if ((reg->flags & PPC_OPERAND_FPR) == PPC_OPERAND_FPR)
> +    return (reg->value + 32);
> +  else if ((reg->flags & PPC_OPERAND_VR) == PPC_OPERAND_VR)
> +    return (reg->value + 77);
> +  else if ((reg->flags & PPC_OPERAND_CR_REG) == PPC_OPERAND_CR_REG)
> +    return (reg->value + 68);
> +  else
> +    return -1;
>  }
> -- 
> 2.37.0

-- 
Alan Modra
Australia Development Lab, IBM