Decrease byte-code's register pressure during preparation of long arguments list

jerry-core/parser/js/opcodes-dumper.cpp

@@ -755,6 +755,41 @@ dumper_finish_scope (void)
   STACK_DROP (temp_names, 1);
 }
 
+/**
+ * Handle start of argument preparation instruction sequence generation
+ *
+ * Note:
+ *      Values of registers, allocated for the code sequence, are not used outside of the sequence,
+ *      so they can be reused, reducing register pressure.
+ *
+ *      To reuse the registers, counter of register allocator is saved, and restored then,
+ *      after finishing generation of the code sequence, using dumper_finish_varg_code_sequence.
+ *
+ * FIXME:
+ *       Implement general register allocation mechanism
+ *
+ * See also:
+ *          dumper_finish_varg_code_sequence
+ */
+void
+dumper_start_varg_code_sequence (void)
+{
+  STACK_PUSH (temp_names, temp_name);
+} /* dumper_start_varg_code_sequence */
+
+/**
+ * Handle finish of argument preparation instruction sequence generation
+ *
+ * See also:
+ *          dumper_start_varg_code_sequence
+ */
+void
+dumper_finish_varg_code_sequence (void)
+{
+  temp_name = STACK_TOP (temp_names);
+  STACK_DROP (temp_names, 1);
+} /* dumper_finish_varg_code_sequence */
+
 /**
  * Check that byte-code operand refers to 'eval' string
  *

jerry-core/parser/js/opcodes-dumper.h

@@ -58,6 +58,8 @@ void dumper_free (void);
 void dumper_new_statement (void);
 void dumper_new_scope (void);
 void dumper_finish_scope (void);
+void dumper_start_varg_code_sequence (void);
+void dumper_finish_varg_code_sequence (void);
 
 extern bool dumper_is_eval_literal (operand);
 

jerry-core/parser/js/parser.cpp

@@ -521,62 +521,61 @@ parse_argument_list (varg_list_type vlt, operand obj, uint8_t *args_count, opera
   skip_newlines ();
   while (!token_is (close_tt))
   {
+    dumper_start_varg_code_sequence ();
+
     operand op;
-    switch (vlt)
+
+    if (vlt == VARG_FUNC_DECL
+        || vlt == VARG_FUNC_EXPR)
     {
-      case VARG_FUNC_DECL:
-      case VARG_FUNC_EXPR:
-      {
-        current_token_must_be (TOK_NAME);
-        op = literal_operand (token_data_as_lit_cp ());
-        syntax_add_varg (op);
-        syntax_check_for_eval_and_arguments_in_strict_mode (op, is_strict_mode (), tok.loc);
-        break;
-      }
-      case VARG_ARRAY_DECL:
-      {
-        if (token_is (TOK_COMMA))
-        {
-          op = dump_undefined_assignment_res ();
-          dump_varg (op);
-          args_num++;
-          skip_newlines ();
-          continue;
-        }
-        /* FALLTHRU  */
-      }
-      case VARG_CONSTRUCT_EXPR:
+      current_token_must_be (TOK_NAME);
+      op = literal_operand (token_data_as_lit_cp ());
+      syntax_add_varg (op);
+      syntax_check_for_eval_and_arguments_in_strict_mode (op, is_strict_mode (), tok.loc);
+      dump_varg (op);
+      skip_newlines ();
+    }
+    else if (vlt == VARG_CONSTRUCT_EXPR
+             || vlt == VARG_CALL_EXPR)
+    {
+      op = parse_assignment_expression (true);
+      dump_varg (op);
+      skip_newlines ();
+    }
+    else if (vlt == VARG_ARRAY_DECL)
+    {
+      if (token_is (TOK_COMMA))
       {
-        op = parse_assignment_expression (true);
-        break;
+        op = dump_undefined_assignment_res ();
+        dump_varg (op);
       }
-      case VARG_CALL_EXPR:
+      else
       {
         op = parse_assignment_expression (true);
-        break;
-      }
-      case VARG_OBJ_DECL:
-      {
-        parse_property_assignment ();
-        break;
+        dump_varg (op);
+        skip_newlines ();
       }
     }
-
-    /* In case of obj_decl prop is already dumped.  */
-    if (vlt != VARG_OBJ_DECL)
+    else
     {
-      dump_varg (op);
+      JERRY_ASSERT (vlt == VARG_OBJ_DECL);
+
+      parse_property_assignment ();
+      skip_newlines ();
     }
-    args_num++;
 
-    skip_newlines ();
-    if (!token_is (TOK_COMMA))
+    if (token_is (TOK_COMMA))
+    {
+      skip_newlines ();
+    }
+    else
     {
       current_token_must_be (close_tt);
-      break;
     }
 
-    skip_newlines ();
+    args_num++;
+
+    dumper_finish_varg_code_sequence ();
   }
 
   if (args_count != NULL)