Remove of 'this_binding' opcode.

- introduce 'const' register type;
 - adding constant register for reading ThisBinding value of active interpreter context.

JerryScript-DCO-1.0-Signed-off-by: Ruben Ayrapetyan r.ayrapetyan@samsung.com

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

@@ -1182,18 +1182,10 @@ rewrite_function_end ()
   STACK_DROP (function_ends, 1);
 }
 
-void
-dump_this (jsp_operand_t op)
-{
-  dump_single_address (VM_OP_THIS_BINDING, op);
-}
-
 jsp_operand_t
 dump_this_res (void)
 {
-  const jsp_operand_t res = tmp_operand ();
-  dump_this (res);
-  return res;
+  return jsp_operand_t::make_reg_operand (VM_REG_SPECIAL_THIS_BINDING);
 }
 
 void

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

@@ -348,7 +348,6 @@ void dump_prop_setter (jsp_operand_t, jsp_operand_t, jsp_operand_t);
 void dump_function_end_for_rewrite (void);
 void rewrite_function_end ();
 
-void dump_this (jsp_operand_t);
 jsp_operand_t dump_this_res (void);
 
 void dump_post_increment (jsp_operand_t, jsp_operand_t);

jerry-core/parser/js/scopes-tree.cpp

@@ -350,7 +350,6 @@ generate_instr (linked_list instr_list, /**< instruction list */
     case VM_OP_FUNC_DECL_N:
     case VM_OP_ARRAY_DECL:
     case VM_OP_OBJ_DECL:
-    case VM_OP_THIS_BINDING:
     case VM_OP_WITH:
     case VM_OP_FOR_IN:
     case VM_OP_THROW_VALUE:
@@ -492,7 +491,6 @@ count_new_literals_in_instr (op_meta *om_p) /**< instruction */
     case VM_OP_FUNC_DECL_N:
     case VM_OP_ARRAY_DECL:
     case VM_OP_OBJ_DECL:
-    case VM_OP_THIS_BINDING:
     case VM_OP_WITH:
     case VM_OP_THROW_VALUE:
     case VM_OP_IS_TRUE_JMP_UP:

jerry-core/vm/opcodes-helpers-variables.cpp

@@ -55,7 +55,7 @@ do_strict_eval_arguments_check (ecma_object_t *ref_base_lex_env_p, /**< base of
 /**
  * Check if the variable is register variable.
  *
- * @return true - if var_idx is register variable in current interpreter context,
+ * @return true - if var_idx is a register variable,
  *         false - otherwise.
  */
 bool

jerry-core/vm/opcodes.cpp

@@ -1350,32 +1350,6 @@ opfunc_logical_not (vm_instr_t instr, /**< instruction */
   return ret_value;
 } /* opfunc_logical_not */
 
-/**
- * 'This' opcode handler.
- *
- * See also: ECMA-262 v5, 11.1.1
- *
- * @return completion value
- *         Returned value must be freed with ecma_free_completion_value
- */
-ecma_completion_value_t
-opfunc_this_binding (vm_instr_t instr, /**< instruction */
-                     vm_frame_ctx_t *frame_ctx_p) /**< interpreter context */
-{
-  const vm_idx_t dst_var_idx = instr.data.this_binding.lhs;
-  const vm_instr_counter_t lit_oc = frame_ctx_p->pos;
-
-  frame_ctx_p->pos++;
-
-  ecma_completion_value_t ret_value;
-
-  ret_value = set_variable_value (frame_ctx_p, lit_oc,
-                                  dst_var_idx,
-                                  frame_ctx_p->this_binding);
-
-  return ret_value;
-} /* opfunc_this_binding */
-
 /**
  * 'With' opcode handler.
  *

jerry-core/vm/opcodes.h

@@ -90,8 +90,9 @@ typedef enum : vm_idx_t
   VM_REG_SPECIAL_EVAL_RET = VM_REG_SPECIAL_FIRST, /**< eval return value */
   VM_REG_SPECIAL_FOR_IN_PROPERTY_NAME, /**< variable, containing property name,
                                         *   at start of for-in loop body */
+  VM_REG_SPECIAL_THIS_BINDING, /**< value of ThisBinding */
 
-  VM_REG_SPECIAL_LAST = VM_REG_SPECIAL_FOR_IN_PROPERTY_NAME, /**< last special register */
+  VM_REG_SPECIAL_LAST = VM_REG_SPECIAL_THIS_BINDING, /**< last special register */
 
   VM_REG_GENERAL_FIRST, /** first non-special register */
   VM_REG_GENERAL_LAST = VM_IDX_REG_LAST /** last non-special register */
@@ -205,7 +206,6 @@ typedef struct
 {
   const bytecode_data_header_t *bytecode_header_p; /**< currently executed byte-code data */
   vm_instr_counter_t pos; /**< current position instruction to execute */
-  ecma_value_t this_binding; /**< this binding for current context */
   ecma_object_t *lex_env_p; /**< current lexical environment */
   bool is_strict; /**< is current code execution mode strict? */
   bool is_eval_code; /**< is current code executed with eval */

jerry-core/vm/pretty-printer.cpp

@@ -227,7 +227,6 @@ pp_op_meta (const bytecode_data_header_t *bytecode_data_p,
     PP_OP (VM_OP_RET, "ret;");
     PP_OP (VM_OP_PROP_GETTER, "%s = %s[%s];");
     PP_OP (VM_OP_PROP_SETTER, "%s[%s] = %s;");
-    PP_OP (VM_OP_THIS_BINDING, "%s = this;");
     PP_OP (VM_OP_DELETE_VAR, "%s = delete %s;");
     PP_OP (VM_OP_DELETE_PROP, "%s = delete %s.%s;");
     PP_OP (VM_OP_TYPEOF, "%s = typeof %s;");

jerry-core/vm/vm-opcodes.inc.h

@@ -78,9 +78,6 @@ VM_OP_3 (prop_setter,           PROP_SETTER,
          prop,                  VM_OP_ARG_TYPE_VARIABLE,
          rhs,                   VM_OP_ARG_TYPE_VARIABLE)
 
-VM_OP_1 (this_binding,          THIS_BINDING,
-         lhs,                   VM_OP_ARG_TYPE_VARIABLE)
-
 VM_OP_2 (delete_var,            DELETE_VAR,
          lhs,                   VM_OP_ARG_TYPE_VARIABLE,
          name,                  VM_OP_ARG_TYPE_VARIABLE)

jerry-core/vm/vm.cpp

@@ -615,7 +615,6 @@ vm_run_from_pos (const bytecode_data_header_t *header_p, /**< byte-code data hea
   vm_frame_ctx_t frame_ctx;
   frame_ctx.bytecode_header_p = header_p;
   frame_ctx.pos = (vm_instr_counter_t) (start_pos + 1);
-  frame_ctx.this_binding = this_binding_value;
   frame_ctx.lex_env_p = lex_env_p;
   frame_ctx.is_strict = is_strict;
   frame_ctx.is_eval_code = is_eval_code;
@@ -623,6 +622,9 @@ vm_run_from_pos (const bytecode_data_header_t *header_p, /**< byte-code data hea
   frame_ctx.tmp_num_p = ecma_alloc_number ();
 
   vm_stack_add_frame (&frame_ctx.stack_frame, regs, regs_num, local_var_regs_num);
+  vm_stack_frame_set_reg_value (&frame_ctx.stack_frame,
+                                VM_REG_SPECIAL_THIS_BINDING,
+                                ecma_copy_value (this_binding_value, false));
 
   vm_frame_ctx_t *prev_context_p = vm_top_context_p;
   vm_top_context_p = &frame_ctx;
@@ -729,7 +731,9 @@ vm_get_this_binding (void)
 {
   JERRY_ASSERT (vm_top_context_p != NULL);
 
-  return ecma_copy_value (vm_top_context_p->this_binding, true);
+  return ecma_copy_value (vm_stack_frame_get_reg_value (&vm_top_context_p->stack_frame,
+                                                        VM_REG_SPECIAL_THIS_BINDING),
+                                                        true);
 } /* vm_get_this_binding */
 
 /**