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

[Richard Biener <richard.guenther@gmail.com>]

On Fri, Mar 25, 2022 at 11:13 AM Tobias Burnus <tobias@codesourcery.com> wrote:
>
> 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.

Can there be side-effects in those initializer elements in Fortran?

Richard.

> 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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