anv/pipeline: Add a input_attachment_index to the bindings

This allows us to go from the binding to either the descriptor or the input
attachment at will.

Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>

src/intel/vulkan/anv_nir_apply_pipeline_layout.c

@@ -346,6 +346,33 @@ anv_nir_apply_pipeline_layout(struct anv_pipeline *pipeline,
       }
    }
 
+   nir_foreach_variable(var, &shader->uniforms) {
+      if (!glsl_type_is_image(var->interface_type))
+         continue;
+
+      enum glsl_sampler_dim dim = glsl_get_sampler_dim(var->interface_type);
+      if (dim != GLSL_SAMPLER_DIM_SUBPASS &&
+          dim != GLSL_SAMPLER_DIM_SUBPASS_MS)
+         continue;
+
+      const uint32_t set = var->data.descriptor_set;
+      const uint32_t binding = var->data.binding;
+      const uint32_t array_size =
+         layout->set[set].layout->binding[binding].array_size;
+
+      if (!BITSET_TEST(state.set[set].used, binding))
+         continue;
+
+      struct anv_pipeline_binding *pipe_binding =
+         &map->surface_to_descriptor[state.set[set].surface_offsets[binding]];
+      for (unsigned i = 0; i < array_size; i++) {
+         assert(pipe_binding[i].set == set);
+         assert(pipe_binding[i].binding == binding);
+         assert(pipe_binding[i].index == i);
+         pipe_binding[i].input_attachment_index = var->data.index + i;
+      }
+   }
+
    nir_foreach_function(function, shader) {
       if (!function->impl)
          continue;

src/intel/vulkan/anv_private.h

@@ -913,6 +913,9 @@ struct anv_pipeline_binding {
 
    /* Index in the binding */
    uint8_t index;
+
+   /* Input attachment index (relative to the subpass) */
+   uint8_t input_attachment_index;
 };
 
 struct anv_pipeline_layout {