[PATCH vkd3d v7 5/6] vkd3d-shader/hlsl: Handle conditionals in copy propagation.

[Matteo Bruni]

On Thu, Nov 18, 2021 at 10:01 AM Giovanni Mascellani
<gmascellani at codeweavers.com> wrote:
>
> Hi,
>
> On 18/11/21 05:18, Zebediah Figura (she/her) wrote:
> >>> +    if (!hlsl_array_reserve(ctx, (void**)&state->variables,
> >>> &state->capacity, state->depth + 2, sizeof(*state->variables)))
> >>
> >> "state->depth + 2" looks wrong; is it?
> >
> > Wait, never mind, I see why this looks wrong. The fact that "depth" is
> > 1-biased seems confusing to me, though...
>
> I agree it is a bit strange, but I think it's correct too.
>
> As whether to store the recursion depth or the number of stack levels
> (which is depth + 1), I think it's a matter of tastes. If you want "+ 1"
> here, you'll have a lot of "- 1" in other places (mostly _get_variable
> and _create_variable).

True, although one could argue that having a bunch of "- 1" in those
helper functions is proper enough.

In this particular case though, when I see:

struct rb_entry *entry = rb_get(&state->variables[state->depth], var);

I immediately think that the array access is missing a "- 1", as that
is the usual (for d3d code at least) pattern of accessing the last
element of an array with "count" elements.