glsl: implement ARB_bindless_texture conversions

From section 5.4.1 of the ARB_bindless_texture spec:

   "In the following four constructors, the low 32 bits of the
    sampler type correspond to the .x component of the uvec2 and
    the high 32 bits correspond to the .y component."

    uvec2(any sampler type)     // Converts a sampler type to a
                                //   pair of 32-bit unsigned integers
    any sampler type(uvec2)     // Converts a pair of 32-bit unsigned integers to
                                //   a sampler type
    uvec2(any image type)       // Converts an image type to a
                                //   pair of 32-bit unsigned integers
    any image type(uvec2)       // Converts a pair of 32-bit unsigned integers to
                                //   an image type

v4: - fix up comment style
v3: - rebase (and remove (sampler) ? 1 : vector_elements)

Signed-off-by: Samuel Pitoiset <[email protected]>
Reviewed-by: Nicolai Hähnle <[email protected]>
Reviewed-by: Timothy Arceri <[email protected]>

1 files changed, 71 insertions, 7 deletions

diff --git a/src/compiler/glsl/ast_function.cpp b/src/compiler/glsl/ast_function.cpp
index dd08ed84319..2d156ae1da1 100644
--- a/src/compiler/glsl/ast_function.cpp
+++ b/src/compiler/glsl/ast_function.cpp
@@ -740,8 +740,8 @@ convert_component(ir_rvalue *src, const glsl_type *desired_type)
    if (src->type->is_error())
       return src;
 
-   assert(a <= GLSL_TYPE_BOOL);
-   assert(b <= GLSL_TYPE_BOOL);
+   assert(a <= GLSL_TYPE_IMAGE);
+   assert(b <= GLSL_TYPE_IMAGE);
 
    if (a == b)
       return src;
@@ -769,6 +769,12 @@ convert_component(ir_rvalue *src, const glsl_type *desired_type)
       case GLSL_TYPE_INT64:
          result = new(ctx) ir_expression(ir_unop_i642u, src);
          break;
+      case GLSL_TYPE_SAMPLER:
+         result = new(ctx) ir_expression(ir_unop_unpack_sampler_2x32, src);
+         break;
+      case GLSL_TYPE_IMAGE:
+         result = new(ctx) ir_expression(ir_unop_unpack_image_2x32, src);
+         break;
       }
       break;
    case GLSL_TYPE_INT:
@@ -911,6 +917,22 @@ convert_component(ir_rvalue *src, const glsl_type *desired_type)
          break;
       }
       break;
+   case GLSL_TYPE_SAMPLER:
+      switch (b) {
+      case GLSL_TYPE_UINT:
+         result = new(ctx)
+            ir_expression(ir_unop_pack_sampler_2x32, desired_type, src);
+         break;
+      }
+      break;
+   case GLSL_TYPE_IMAGE:
+      switch (b) {
+      case GLSL_TYPE_UINT:
+         result = new(ctx)
+            ir_expression(ir_unop_pack_image_2x32, desired_type, src);
+         break;
+      }
+      break;
    }
 
    assert(result != NULL);
@@ -1933,7 +1955,8 @@ ast_function_expression::handle_method(exec_list *instructions,
 static inline bool is_valid_constructor(const glsl_type *type,
                                         struct _mesa_glsl_parse_state *state)
 {
-   return type->is_numeric() || type->is_boolean();
+   return type->is_numeric() || type->is_boolean() ||
+          (state->has_bindless() && (type->is_sampler() || type->is_image()));
 }
 
 ir_rvalue *
@@ -2147,10 +2170,51 @@ ast_function_expression::hir(exec_list *instructions,
 
       /* Type cast each parameter and, if possible, fold constants.*/
       foreach_in_list_safe(ir_rvalue, ir, &actual_parameters) {
-         const glsl_type *desired_type =
-            glsl_type::get_instance(constructor_type->base_type,
-                                    ir->type->vector_elements,
-                                    ir->type->matrix_columns);
+         const glsl_type *desired_type;
+
+         /* From section 5.4.1 of the ARB_bindless_texture spec:
+          *
+          * "In the following four constructors, the low 32 bits of the sampler
+          *  type correspond to the .x component of the uvec2 and the high 32
+          *  bits correspond to the .y component."
+          *
+          *  uvec2(any sampler type)     // Converts a sampler type to a
+          *                              //   pair of 32-bit unsigned integers
+          *  any sampler type(uvec2)     // Converts a pair of 32-bit unsigned integers to
+          *                              //   a sampler type
+          *  uvec2(any image type)       // Converts an image type to a
+          *                              //   pair of 32-bit unsigned integers
+          *  any image type(uvec2)       // Converts a pair of 32-bit unsigned integers to
+          *                              //   an image type
+          */
+         if (ir->type->is_sampler() || ir->type->is_image()) {
+            /* Convert a sampler/image type to a pair of 32-bit unsigned
+             * integers as defined by ARB_bindless_texture.
+             */
+            if (constructor_type != glsl_type::uvec2_type) {
+               _mesa_glsl_error(&loc, state, "sampler and image types can only "
+                                "be converted to a pair of 32-bit unsigned "
+                                "integers");
+            }
+            desired_type = glsl_type::uvec2_type;
+         } else if (constructor_type->is_sampler() ||
+                    constructor_type->is_image()) {
+            /* Convert a pair of 32-bit unsigned integers to a sampler or image
+             * type as defined by ARB_bindless_texture.
+             */
+            if (ir->type != glsl_type::uvec2_type) {
+               _mesa_glsl_error(&loc, state, "sampler and image types can only "
+                                "be converted from a pair of 32-bit unsigned "
+                                "integers");
+            }
+            desired_type = constructor_type;
+         } else {
+            desired_type =
+               glsl_type::get_instance(constructor_type->base_type,
+                                       ir->type->vector_elements,
+                                       ir->type->matrix_columns);
+         }
+
          ir_rvalue *result = convert_component(ir, desired_type);
 
          /* Attempt to convert the parameter to a constant valued expression.