spirv,nir: add support for SpvBuiltInFullyCoveredEXT

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Timur Kristóf <timur.kristof@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/21497>

src/compiler/nir/nir.c

@@ -2501,6 +2501,8 @@ nir_intrinsic_from_system_value(gl_system_value val)
       return nir_intrinsic_load_mesh_view_count;
    case SYSTEM_VALUE_FRAG_SHADING_RATE:
       return nir_intrinsic_load_frag_shading_rate;
+   case SYSTEM_VALUE_FULLY_COVERED:
+      return nir_intrinsic_load_fully_covered;
    default:
       unreachable("system value does not directly correspond to intrinsic");
    }
@@ -2648,6 +2650,8 @@ nir_system_value_from_intrinsic(nir_intrinsic_op intrin)
       return SYSTEM_VALUE_FRAG_SHADING_RATE;
    case nir_intrinsic_load_mesh_view_count:
       return SYSTEM_VALUE_MESH_VIEW_COUNT;
+   case nir_intrinsic_load_fully_covered:
+      return SYSTEM_VALUE_FULLY_COVERED;
    default:
       unreachable("intrinsic doesn't produce a system value");
    }

src/compiler/nir/nir_divergence_analysis.c

@@ -471,6 +471,7 @@ visit_intrinsic(nir_shader *shader, nir_intrinsic_instr *instr)
    case nir_intrinsic_load_point_coord:
    case nir_intrinsic_load_line_coord:
    case nir_intrinsic_load_frag_coord:
+   case nir_intrinsic_load_fully_covered:
    case nir_intrinsic_load_sample_pos:
    case nir_intrinsic_load_sample_pos_or_center:
    case nir_intrinsic_load_vertex_id_zero_base:

src/compiler/nir/nir_gather_info.c

@@ -709,6 +709,7 @@ gather_intrinsic_info(nir_intrinsic_instr *instr, nir_shader *shader,
    case nir_intrinsic_load_invocation_id:
    case nir_intrinsic_load_frag_coord:
    case nir_intrinsic_load_frag_shading_rate:
+   case nir_intrinsic_load_fully_covered:
    case nir_intrinsic_load_point_coord:
    case nir_intrinsic_load_line_coord:
    case nir_intrinsic_load_front_face:

src/compiler/nir/nir_intrinsics.py

@@ -1109,6 +1109,9 @@ intrinsic("store_stack", [0],
 intrinsic("load_frag_shading_rate", dest_comp=1, bit_sizes=[32],
           flags=[CAN_ELIMINATE, CAN_REORDER])
 
+# Whether the rasterized fragment is fully covered by the generating primitive.
+system_value("fully_covered", dest_comp=1, bit_sizes=[1])
+
 # OpenCL printf instruction
 # First source is a deref to the format string
 # Second source is a deref to a struct containing the args

src/compiler/shader_enums.c

@@ -338,6 +338,7 @@ gl_system_value_name(gl_system_value sysval)
      ENUM(SYSTEM_VALUE_TCS_HEADER_IR3),
      ENUM(SYSTEM_VALUE_REL_PATCH_ID_IR3),
      ENUM(SYSTEM_VALUE_FRAG_SHADING_RATE),
+     ENUM(SYSTEM_VALUE_FULLY_COVERED),
    };
    STATIC_ASSERT(ARRAY_SIZE(names) == SYSTEM_VALUE_MAX);
    return NAME(sysval);

src/compiler/shader_enums.h

@@ -869,6 +869,12 @@ typedef enum
     */
    SYSTEM_VALUE_FRAG_SHADING_RATE,
 
+   /*
+    * Rasterized fragment is fully covered by the generating primitive
+    * (SPV_EXT_fragment_fully_covered).
+    */
+   SYSTEM_VALUE_FULLY_COVERED,
+
    SYSTEM_VALUE_MAX             /**< Number of values */
 } gl_system_value;
 

src/compiler/spirv/vtn_variables.c

@@ -1174,6 +1174,11 @@ vtn_get_builtin_location(struct vtn_builder *b,
    case SpvBuiltInCullPrimitiveEXT:
       *location = VARYING_SLOT_CULL_PRIMITIVE;
       break;
+   case SpvBuiltInFullyCoveredEXT:
+      *location = SYSTEM_VALUE_FULLY_COVERED;
+      set_mode_system_value(b, mode);
+      break;
+
    default:
       vtn_fail("Unsupported builtin: %s (%u)",
                spirv_builtin_to_string(builtin), builtin);