mesa: implement system values in program interpreter
diff --git a/src/mesa/program/prog_execute.c b/src/mesa/program/prog_execute.c
index 1d97a07..c20347f 100644
--- a/src/mesa/program/prog_execute.c
+++ b/src/mesa/program/prog_execute.c
@@ -159,6 +159,10 @@
          return ZeroVec;
       return prog->Parameters->ParameterValues[reg];
 
+   case PROGRAM_SYSTEM_VALUE:
+      assert(reg < Elements(machine->SystemValues));
+      return machine->SystemValues[reg];
+
    default:
       _mesa_problem(NULL,
          "Invalid src register file %d in get_src_register_pointer()",