Re: [PATCH] fortran: Fix up initializers of param(0) PARAMETERs [PR103691]

[Tobias Burnus <tobias@codesourcery.com>]

On 25.03.22 09:57, Jakub Jelinek via Fortran wrote:
> On the gfortran.dg/pr103691.f90 testcase the Fortran ICE emits
>    static real(kind=4) a[0] = {[0 ... -1]=2.0e+0};
> That is an invalid RANGE_EXPR where the maximum is smaller than the minimum.
>
> The following patch fixes that.  If TYPE_MAX_VALUE is smaller than
> TYPE_MIN_VALUE, the array is empty and so doesn't need any initializer,
> if the two are equal, we don't need to bother with a RANGE_EXPR and
> can just use that INTEGER_CST as the index and finally for the 2+ values
> in the range it uses a RANGE_EXPR as before.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

LGTM – thanks for taking care of Fortran patches and regressions.

> 2022-03-25  Jakub Jelinek  <jakub@redhat.com>
>
>       PR fortran/103691
>       * trans-array.cc (gfc_conv_array_initializer): If TYPE_MAX_VALUE is
>       smaller than TYPE_MIN_VALUE (i.e. empty array), throw the initializer
>       on the floor, if TYPE_MIN_VALUE is equal to TYPE_MAX_VALUE, use just
>       the TYPE_MIN_VALUE as index instead of RANGE_EXPR.

I am not sure whether "throw the initializer on the floor" is the best wording
for a changelog. I think I prefer a wording like "ignore the initializer" or
another less idiomatic expression. And I think a ';' before the second 'if'
also increases readability.

Tobias

> --- gcc/fortran/trans-array.cc.jj     2022-02-04 14:36:55.113603791 +0100
> +++ gcc/fortran/trans-array.cc        2022-03-24 16:14:58.334498775 +0100
> @@ -6267,10 +6267,17 @@ gfc_conv_array_initializer (tree type, g
>         else
>       gfc_conv_structure (&se, expr, 1);
>
> -      CONSTRUCTOR_APPEND_ELT (v, build2 (RANGE_EXPR, gfc_array_index_type,
> -                                      TYPE_MIN_VALUE (TYPE_DOMAIN (type)),
> -                                      TYPE_MAX_VALUE (TYPE_DOMAIN (type))),
> -                           se.expr);
> +      if (tree_int_cst_lt (TYPE_MAX_VALUE (TYPE_DOMAIN (type)),
> +                        TYPE_MIN_VALUE (TYPE_DOMAIN (type))))
> +     break;
> +      else if (tree_int_cst_equal (TYPE_MIN_VALUE (TYPE_DOMAIN (type)),
> +                                TYPE_MAX_VALUE (TYPE_DOMAIN (type))))
> +     range = TYPE_MIN_VALUE (TYPE_DOMAIN (type));
> +      else
> +     range = build2 (RANGE_EXPR, gfc_array_index_type,
> +                     TYPE_MIN_VALUE (TYPE_DOMAIN (type)),
> +                     TYPE_MAX_VALUE (TYPE_DOMAIN (type)));
> +      CONSTRUCTOR_APPEND_ELT (v, range, se.expr);
>         break;
>
>       case EXPR_ARRAY:
>
>       Jakub
>
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