Re: [PATCH] PR fortran/83998 -- fix dot_product on 0-sized arrays

[Thomas Koenig <tkoenig@netcologne.de>]

Hi Steve,

I have a couple of questions before I have to hurry off to work:

First, why is

> @@ -2253,22 +2253,19 @@ gfc_simplify_dim (gfc_expr *x, gfc_expr *y)
>   gfc_expr*
>   gfc_simplify_dot_product (gfc_expr *vector_a, gfc_expr *vector_b)
>   {
> +  /* If vector_a is a zero-sized array, the result is 0 for INTEGER,
> +     REAL, and COMPLEX types and .false. for LOGICAL.  */
> +  if (vector_a->shape && mpz_get_si (vector_a->shape[0]) == 0)
> +    {
> +      if (vector_a->ts.type == BT_LOGICAL)
> +	return gfc_get_logical_expr (gfc_default_logical_kind, NULL, false);
> +      else
> +	return gfc_get_int_expr (gfc_default_integer_kind, NULL, 0);
> +    }

in front of

> -  gfc_expr temp;
> -
>     if (!is_constant_array_expr (vector_a)
>         || !is_constant_array_expr (vector_b))
>       return NULL;

and / or why is the test only done for one variable?

Second, why do you remove this

> -  temp.value.op.op = INTRINSIC_NONE;
> -  temp.value.op.op1 = vector_a;
> -  temp.value.op.op2 = vector_b;
> -  gfc_type_convert_binary (&temp, 1);

block of code? What would happen for code like

   integer, dimension(2), parameter :: a = [ 1,2]
   real, dimension(2), parameter :: b = [1.0,2.0]
   real, parameter :: c = dot_product(a,b)

?

Regards

	Thomas