spirv: add SPV_KHR_shader_draw_parameters support

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Reviewed-by: Anuj Phogat <anuj.phogat@gmail.com>

src/compiler/spirv/nir_spirv.h

@@ -48,6 +48,7 @@ struct nir_spirv_supported_extensions {
    bool float64;
    bool image_ms_array;
    bool tessellation;
+   bool draw_parameters;
 };
 
 nir_function *spirv_to_nir(const uint32_t *words, size_t word_count,

src/compiler/spirv/spirv_to_nir.c

@@ -2683,6 +2683,10 @@ vtn_handle_preamble_instruction(struct vtn_builder *b, SpvOp opcode,
          spv_check_supported(tessellation, cap);
          break;
 
+      case SpvCapabilityDrawParameters:
+         spv_check_supported(draw_parameters, cap);
+         break;
+
       default:
          unreachable("Unhandled capability");
       }

src/compiler/spirv/vtn_variables.c

@@ -1010,6 +1010,18 @@ vtn_get_builtin_location(struct vtn_builder *b,
       *location = SYSTEM_VALUE_GLOBAL_INVOCATION_ID;
       set_mode_system_value(mode);
       break;
+   case SpvBuiltInBaseVertex:
+      *location = SYSTEM_VALUE_BASE_VERTEX;
+      set_mode_system_value(mode);
+      break;
+   case SpvBuiltInBaseInstance:
+      *location = SYSTEM_VALUE_BASE_INSTANCE;
+      set_mode_system_value(mode);
+      break;
+   case SpvBuiltInDrawIndex:
+      *location = SYSTEM_VALUE_DRAW_ID;
+      set_mode_system_value(mode);
+      break;
    case SpvBuiltInHelperInvocation:
    default:
       unreachable("unsupported builtin");