Re: [PATCH v10 0/6] MR471: vkd3d-shader/dxil: Implement the DXIL GEP and LOAD instructions.

[Giovanni Mascellani (＠giomasce)]

Giovanni Mascellani (@giomasce) commented about libs/vkd3d-shader/dxil.c:
> -
>            "Multi-dimensional addressing in GEP instructions is not supported.");
> -
>    return;
> - }
> -
> - if (!(dst->type = sm6_type_get_pointer_to_type(type, addr_space, sm6)))
> - {
> -
>    FIXME("Failed to get pointer type for type %u.\n", type->class);
> -
>    vkd3d_shader_parser_error(&sm6->p, VKD3D_SHADER_ERROR_DXIL_INVALID_MODULE,
> -
>            "Module does not define a pointer type for a GEP instruction.");
> -
>    return;
> - }
> -
> - reg = &dst->u.reg;
> - *reg = src->u.reg;
> - reg->idx[1].offset = 0;
> - register_index_address_init(&reg->idx[1], elem_value, sm6);

Here the previous index of the register is replaced rather than added. So code like this:
```
%1 = some global address
%2 = GEP %1, 2
%3 = GEP %2, 3
```
will have `%3` initialized at 3 elements inside the global rather then 5. Is that intended? Maybe it would make sense to emit a warning if a situation like `%3` happens? Or to simply add the offset?

Also, do we already have a way to have pointers to structs? `sm6_parser_declare_global()` allows us to declare arrays of scalars, but right now I don't remember anything about structs.