[PATCH v5 vkd3d 12/13] vkd3d-shader/hlsl: Implement texture gather methods.

[Matteo Bruni]

On Wed, Jan 19, 2022 at 1:06 PM Matteo Bruni <matteo.mystral at gmail.com> wrote:
>
> On Wed, Dec 22, 2021 at 12:23 AM Zebediah Figura
> <zfigura at codeweavers.com> wrote:
> >
> > From: Francisco Casas <fcasas at codeweavers.com>
> >
> > Signed-off-by: Francisco Casas <fcasas at codeweavers.com>
> > Signed-off-by: Zebediah Figura <zfigura at codeweavers.com>
> > ---
> > v5: Strip newlines from hlsl_fixme(), get rid of the as-yet-unused
> > status_out_arg variable, expand the srcs[] array to have size 4, use sm4
> > register helpers, minor stylistic tweaks.
> >
> >  libs/vkd3d-shader/hlsl.c     |  4 ++
> >  libs/vkd3d-shader/hlsl.h     |  4 ++
> >  libs/vkd3d-shader/hlsl.y     | 99 ++++++++++++++++++++++++++++++++++++
> >  libs/vkd3d-shader/hlsl_sm4.c | 57 ++++++++++++++++++++-
> >  4 files changed, 163 insertions(+), 1 deletion(-)
> >
> > diff --git a/libs/vkd3d-shader/hlsl.c b/libs/vkd3d-shader/hlsl.c
> > index 26175008d..856fb0f9d 100644
> > --- a/libs/vkd3d-shader/hlsl.c
> > +++ b/libs/vkd3d-shader/hlsl.c
> > @@ -1280,6 +1280,10 @@ static void dump_ir_resource_load(struct vkd3d_string_buffer *buffer, const stru
> >      {
> >          [HLSL_RESOURCE_LOAD] = "load_resource",
> >          [HLSL_RESOURCE_SAMPLE] = "sample",
> > +        [HLSL_RESOURCE_GATHER_RED] = "gather_red",
> > +        [HLSL_RESOURCE_GATHER_GREEN] = "gather_green",
> > +        [HLSL_RESOURCE_GATHER_BLUE] = "gather_blue",
> > +        [HLSL_RESOURCE_GATHER_ALPHA] = "gather_alpha",
> >      };
> >
> >      vkd3d_string_buffer_printf(buffer, "%s(resource = ", type_names[load->load_type]);
> > diff --git a/libs/vkd3d-shader/hlsl.h b/libs/vkd3d-shader/hlsl.h
> > index 2396adb40..49fa8d9d3 100644
> > --- a/libs/vkd3d-shader/hlsl.h
> > +++ b/libs/vkd3d-shader/hlsl.h
> > @@ -378,6 +378,10 @@ enum hlsl_resource_load_type
> >  {
> >      HLSL_RESOURCE_LOAD,
> >      HLSL_RESOURCE_SAMPLE,
> > +    HLSL_RESOURCE_GATHER_RED,
> > +    HLSL_RESOURCE_GATHER_GREEN,
> > +    HLSL_RESOURCE_GATHER_BLUE,
> > +    HLSL_RESOURCE_GATHER_ALPHA,
> >  };
> >
> >  struct hlsl_ir_resource_load
> > diff --git a/libs/vkd3d-shader/hlsl.y b/libs/vkd3d-shader/hlsl.y
> > index 9b1e5c071..460ba44bb 100644
> > --- a/libs/vkd3d-shader/hlsl.y
> > +++ b/libs/vkd3d-shader/hlsl.y
> > @@ -1930,6 +1930,105 @@ static bool add_method_call(struct hlsl_ctx *ctx, struct list *instrs, struct hl
> >          list_add_tail(instrs, &load->node.entry);
> >          return true;
> >      }
> > +    else if (!strcmp(name, "Gather") || !strcmp(name, "GatherRed") || !strcmp(name, "GatherBlue")
> > +            || !strcmp(name, "GatherGreen") || !strcmp(name, "GatherAlpha"))
> > +    {
> > +        const unsigned int sampler_dim = sampler_dim_count(object_type->sampler_dim);
> > +        enum hlsl_resource_load_type load_type;
> > +        const struct hlsl_type *sampler_type;
> > +        struct hlsl_ir_resource_load *load;
> > +        struct hlsl_ir_node *offset = NULL;
> > +        struct hlsl_ir_load *sampler_load;
> > +        struct hlsl_type *result_type;
> > +        struct hlsl_ir_node *coords;
> > +        unsigned int read_channel;
> > +
> > +        if (!strcmp(name, "GatherGreen"))
> > +        {

At some point we probably want to introduce an enum for intrinsics and
e.g. table-driven intrinsic_from_{function,method}() helpers to find
out which intrinsic a call is supposed to match, if any. Repeatedly
string-matching the function name like this is a bit ugly and it's
only going to get worse as we introduce more intrinsics.
The intrinsics currently in hlsl.y, intrinsic_functions[] sidestep the
problem but that's only going to apply to those that can be inlined
straight away.