Re: [PATCH 06/46] tcg/optimize: Use fold_masks_zsa in fold_and

[Pierrick Bouvier]

On 12/10/24 07:23, Richard Henderson wrote:
> Avoid the use of the OptContext slots.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   tcg/optimize.c | 12 ++++++------
>   1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/tcg/optimize.c b/tcg/optimize.c
> index 135b14974f..000ac0f810 100644
> --- a/tcg/optimize.c
> +++ b/tcg/optimize.c
> @@ -1306,7 +1306,7 @@ static bool fold_add2(OptContext *ctx, TCGOp *op)
>   
>   static bool fold_and(OptContext *ctx, TCGOp *op)
>   {
> -    uint64_t z1, z2;
> +    uint64_t z1, z2, z_mask, s_mask, a_mask = -1;
>   
>       if (fold_const2_commutative(ctx, op) ||
>           fold_xi_to_i(ctx, op, 0) ||
> @@ -1317,24 +1317,24 @@ static bool fold_and(OptContext *ctx, TCGOp *op)
>   
>       z1 = arg_info(op->args[1])->z_mask;
>       z2 = arg_info(op->args[2])->z_mask;
> -    ctx->z_mask = z1 & z2;
> +    z_mask = z1 & z2;
>   
>       /*
>        * Sign repetitions are perforce all identical, whether they are 1 or 0.
>        * Bitwise operations preserve the relative quantity of the repetitions.
>        */
> -    ctx->s_mask = arg_info(op->args[1])->s_mask
> -                & arg_info(op->args[2])->s_mask;
> +    s_mask = arg_info(op->args[1])->s_mask
> +           & arg_info(op->args[2])->s_mask;
>   
>       /*
>        * Known-zeros does not imply known-ones.  Therefore unless
>        * arg2 is constant, we can't infer affected bits from it.
>        */
>       if (arg_is_const(op->args[2])) {
> -        ctx->a_mask = z1 & ~z2;
> +        a_mask = z1 & ~z2;
>       }
>   
> -    return fold_masks(ctx, op);
> +    return fold_masks_zsa(ctx, op, z_mask, s_mask, a_mask);
>   }
>   
>   static bool fold_andc(OptContext *ctx, TCGOp *op)

Call me young and naive, but having a masks struct, with a, s, z fields 
would be more readable IMHO, and less error prone between the "local" 
and the "context" values.

Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>