[Bug middle-end/106449] ICE in #pragma omp parallel for simd

["rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106449

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Tobias Burnus from comment #1)
> My impression is that the ICE is due to having
>   fold_build2_loc (0, PLUS_EXPR, type, op0, op1)
> with
> (gdb) p debug_tree(type)
>  <pointer_type 0x7ffff6feda80 [...]
> (gdb) p debug_tree(op0)
>  <integer_cst 0x7ffff7128b70 type <pointer_type 0x7ffff6feda80> constant 256>
> (gdb) p debug_tree(op1)
>  <var_decl 0x7ffff7148480 p.0
>     type <pointer_type 0x7ffff6feda80  [...]
> 
> Namely: variable PLUS_EXPR integer_cst  - instead of a POINTER_PLUS_EXPR.
> 
> 
> Patch would be something like the following – except that there are several
> additional PLUS_EXPR in that function and that fold_build_pointer_plus
> assumes that the first argument is the pointer and the second the offset,
> which is converted via convert_to_ptrofftype_loc ...

I think the above also shows that op0 is the offset and op1 the base
and thus the arguments should be reversed here.

> --- a/gcc/omp-expand.cc
> +++ b/gcc/omp-expand.cc
> @@ -6882 +6882,4 @@ expand_omp_simd (struct omp_region *region, struct
> omp_for_data *fd)
> -             t = fold_build2 (PLUS_EXPR, TREE_TYPE (t), t, t2);
> +             if (POINTER_TYPE_P (TREE_TYPE (t)))
> +               t = fold_build_pointer_plus (t, t2);
> +             else
> +               t = fold_build2 (PLUS_EXPR, TREE_TYPE (t), t, t2);