Re: [PATCH v2 02/22] tcg/i386: Move constraint type check to tcg_target_const_match

[Peter Maydell <peter.maydell@linaro.org>]

On Fri, 15 Jan 2021 at 21:14, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> Rather than check the type when filling in the constraint,
> check it when matching the constant.  This removes the only
> use of the type argument to target_parse_constraint.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  tcg/i386/tcg-target.c.inc | 28 +++++++++++++++++-----------
>  1 file changed, 17 insertions(+), 11 deletions(-)
>
> diff --git a/tcg/i386/tcg-target.c.inc b/tcg/i386/tcg-target.c.inc
> index 050f3cb0b1..74637f654a 100644
> --- a/tcg/i386/tcg-target.c.inc
> +++ b/tcg/i386/tcg-target.c.inc
> @@ -263,13 +263,13 @@ static const char *target_parse_constraint(TCGArgConstraint *ct,
>          break;
>
>      case 'e':
> -        ct->ct |= (type == TCG_TYPE_I32 ? TCG_CT_CONST : TCG_CT_CONST_S32);
> +        ct->ct |= TCG_CT_CONST_S32;
>          break;
>      case 'Z':
> -        ct->ct |= (type == TCG_TYPE_I32 ? TCG_CT_CONST : TCG_CT_CONST_U32);
> +        ct->ct |= TCG_CT_CONST_U32;
>          break;
>      case 'I':
> -        ct->ct |= (type == TCG_TYPE_I32 ? TCG_CT_CONST : TCG_CT_CONST_I32);
> +        ct->ct |= TCG_CT_CONST_I32;
>          break;
>
>      default:
> @@ -286,14 +286,20 @@ static inline int tcg_target_const_match(tcg_target_long val, TCGType type,
>      if (ct & TCG_CT_CONST) {
>          return 1;
>      }
> -    if ((ct & TCG_CT_CONST_S32) && val == (int32_t)val) {
> -        return 1;
> -    }
> -    if ((ct & TCG_CT_CONST_U32) && val == (uint32_t)val) {
> -        return 1;
> -    }
> -    if ((ct & TCG_CT_CONST_I32) && ~val == (int32_t)~val) {
> -        return 1;
> +    if (TCG_TARGET_REG_BITS == 32 || type == TCG_TYPE_I32) {

Where does the TCG_TARGET_REG_BITS check come from? We weren't
testing that in the old code in target_parse_constraint() that
I can see.

> +        if (ct & (TCG_CT_CONST_S32 | TCG_CT_CONST_U32 | TCG_CT_CONST_I32)) {
> +            return 1;
> +        }
> +    } else {
> +        if ((ct & TCG_CT_CONST_S32) && val == (int32_t)val) {
> +            return 1;
> +        }
> +        if ((ct & TCG_CT_CONST_U32) && val == (uint32_t)val) {
> +            return 1;
> +        }
> +        if ((ct & TCG_CT_CONST_I32) && ~val == (int32_t)~val) {
> +            return 1;
> +        }
>      }
>      if ((ct & TCG_CT_CONST_WSZ) && val == (type == TCG_TYPE_I32 ? 32 : 64)) {
>          return 1;

thanks
-- PMM