[PATCH vkd3d v7 4/6] vkd3d-shader/hlsl: Perform a copy propagation pass.

[Matteo Bruni]

On Fri, Nov 19, 2021 at 6:36 PM Zebediah Figura <zfigura at codeweavers.com> wrote:
>
> On 11/19/21 10:12 AM, Matteo Bruni wrote:
> > On Fri, Nov 19, 2021 at 4:55 PM Giovanni Mascellani
> > <gmascellani at codeweavers.com> wrote:
> >>
> >> Hi,
> >>
> >> On 18/11/21 18:28, Matteo Bruni wrote:
> >>>> +struct copy_propagation_value
> >>>> +{
> >>>> +    struct hlsl_ir_node *node;
> >>>> +    unsigned int component;
> >>>> +};
> >>>> +
> >>>> +struct copy_propagation_variable
> >>>> +{
> >>>> +    struct rb_entry entry;
> >>>> +    struct hlsl_ir_var *var;
> >>>> +    struct copy_propagation_value *values;
> >>>> +};
> >>>
> >>> I still haven't gotten warm to these names. What about
> >>> copy_propagation_definition (or just copy_propagation_def)?
> >>
> >> I don't understand why it's appropriate for this structure, but fine.
> >
> > It's in the sense of "definition of the current value", more or less
> > like the "def" in use-def chains.
>
> I don't really like this, though, because both copy_propagation_variable
> and copy_propagation_value are "def"s, but we need some way of
> disambiguating what's being defined.

Okay, but I don't see how copy_propagation_variable is any better.

I'm fine with whatever, FWIW.

> >>>> +static struct hlsl_ir_node *copy_propagation_find_replacement(struct copy_propagation_variable *variable,
> >>>> +        unsigned int offset, unsigned int count, unsigned int *swizzle)
> >>>
> >>> I think I prefer my original suggestion of _get_ (or something else)
> >>> rather than _find_; the point being that this function isn't really
> >>> finding anything.
> >>
> >> To me it gets something as much as it finds something. I wanted to avoid
> >> the word "get" because it seems overly generic, but it's true that
> >> "find" is not that much more specific. Ok.
> >
> > Throwing a couple more options: generate, compute.
> >
>
> I'm... not sure why this function isn't finding something? It's not
> really generating anything (except a swizzle, I guess); rather it's
> looking up the stored node that can serve as a replacement.
>
> Although I like "get" too.

Same.