nir/spirv: Add support for SPV_KHR_variable_pointers

Reviewed-by: Iago Toral Quiroga <[email protected]>

1 files changed, 48 insertions, 3 deletions

diff --git a/src/compiler/spirv/vtn_variables.c b/src/compiler/spirv/vtn_variables.c
index a9e2dbfaa04..4432e72e54a 100644
--- a/src/compiler/spirv/vtn_variables.c
+++ b/src/compiler/spirv/vtn_variables.c
@@ -223,8 +223,7 @@ vtn_pointer_dereference(struct vtn_builder *b,
                         struct vtn_pointer *base,
                         struct vtn_access_chain *deref_chain)
 {
-   if (base->mode == vtn_variable_mode_ubo ||
-       base->mode == vtn_variable_mode_ssbo) {
+   if (vtn_pointer_uses_ssa_offset(base)) {
       return vtn_ssa_offset_pointer_dereference(b, base, deref_chain);
    } else {
       return vtn_access_chain_pointer_dereference(b, base, deref_chain);
@@ -1478,6 +1477,53 @@ vtn_storage_class_to_mode(SpvStorageClass class,
    return mode;
 }
 
+nir_ssa_def *
+vtn_pointer_to_ssa(struct vtn_builder *b, struct vtn_pointer *ptr)
+{
+   /* This pointer needs to have a pointer type with actual storage */
+   assert(ptr->ptr_type);
+   assert(ptr->ptr_type->type);
+
+   if (ptr->offset && ptr->block_index) {
+      return nir_vec2(&b->nb, ptr->block_index, ptr->offset);
+   } else {
+      /* If we don't have an offset or block index, then we must be a pointer
+       * to the variable itself.
+       */
+      assert(!ptr->offset && !ptr->block_index);
+
+      /* We can't handle a pointer to an array of descriptors because we have
+       * no way of knowing later on that we need to add to update the block
+       * index when dereferencing.
+       */
+      assert(ptr->var && ptr->var->type->base_type == vtn_base_type_struct);
+
+      return nir_vec2(&b->nb, vtn_variable_resource_index(b, ptr->var, NULL),
+                              nir_imm_int(&b->nb, 0));
+   }
+}
+
+struct vtn_pointer *
+vtn_pointer_from_ssa(struct vtn_builder *b, nir_ssa_def *ssa,
+                     struct vtn_type *ptr_type)
+{
+   assert(ssa->num_components == 2 && ssa->bit_size == 32);
+   assert(ptr_type->base_type == vtn_base_type_pointer);
+   assert(ptr_type->deref->base_type != vtn_base_type_pointer);
+   /* This pointer type needs to have actual storage */
+   assert(ptr_type->type);
+
+   struct vtn_pointer *ptr = rzalloc(b, struct vtn_pointer);
+   ptr->mode = vtn_storage_class_to_mode(ptr_type->storage_class,
+                                         ptr_type, NULL);
+   ptr->type = ptr_type->deref;
+   ptr->ptr_type = ptr_type;
+   ptr->block_index = nir_channel(&b->nb, ssa, 0);
+   ptr->offset = nir_channel(&b->nb, ssa, 1);
+
+   return ptr;
+}
+
 static bool
 is_per_vertex_inout(const struct vtn_variable *var, gl_shader_stage stage)
 {
@@ -1503,7 +1549,6 @@ vtn_create_variable(struct vtn_builder *b, struct vtn_value *val,
 {
    assert(ptr_type->base_type == vtn_base_type_pointer);
    struct vtn_type *type = ptr_type->deref;
-   assert(type->base_type != vtn_base_type_pointer);
 
    struct vtn_type *without_array = type;
    while(glsl_type_is_array(without_array->type))