Turn StringLengthStub (used by string wrappers only) into a hydrogen stub.

src/x64/stub-cache-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 263 matching lines @@
   // Check that the object is a JS array.
   __ CmpObjectType(receiver, JS_ARRAY_TYPE, scratch);
   __ j(not_equal, miss_label);
 
   // Load length directly from the JS array.
   __ movp(rax, FieldOperand(receiver, JSArray::kLengthOffset));
   __ ret(0);
 }
 
 
-// Generate code to check if an object is a string.  If the object is
-// a string, the map's instance type is left in the scratch register.
-static void GenerateStringCheck(MacroAssembler* masm,
-                                Register receiver,
-                                Register scratch,
-                                Label* smi,
-                                Label* non_string_object) {
-  // Check that the object isn't a smi.
-  __ JumpIfSmi(receiver, smi);
-
-  // Check that the object is a string.
-  __ movp(scratch, FieldOperand(receiver, HeapObject::kMapOffset));
-  __ movzxbq(scratch, FieldOperand(scratch, Map::kInstanceTypeOffset));
-  STATIC_ASSERT(kNotStringTag != 0);
-  __ testl(scratch, Immediate(kNotStringTag));
-  __ j(not_zero, non_string_object);
-}
-
-
-void StubCompiler::GenerateLoadStringLength(MacroAssembler* masm,
-                                            Register receiver,
-                                            Register scratch1,
-                                            Register scratch2,
-                                            Label* miss) {
-  Label check_wrapper;
-
-  // Check if the object is a string leaving the instance type in the
-  // scratch register.
-  GenerateStringCheck(masm, receiver, scratch1, miss, &check_wrapper);
-
-  // Load length directly from the string.
-  __ movp(rax, FieldOperand(receiver, String::kLengthOffset));
-  __ ret(0);
-
-  // Check if the object is a JSValue wrapper.
-  __ bind(&check_wrapper);
-  __ cmpl(scratch1, Immediate(JS_VALUE_TYPE));
-  __ j(not_equal, miss);
-
-  // Check if the wrapped value is a string and load the length
-  // directly if it is.
-  __ movp(scratch2, FieldOperand(receiver, JSValue::kValueOffset));
-  GenerateStringCheck(masm, scratch2, scratch1, miss, miss);
-  __ movp(rax, FieldOperand(scratch2, String::kLengthOffset));
-  __ ret(0);
-}
-
-
 void StubCompiler::GenerateLoadFunctionPrototype(MacroAssembler* masm,
                                                  Register receiver,
                                                  Register result,
                                                  Register scratch,
                                                  Label* miss_label) {
   __ TryGetFunctionPrototype(receiver, result, miss_label);
   if (!result.is(rax)) __ movp(rax, result);
   __ ret(0);
 }
 
@@ skipping 1132 matching lines @@
   // -----------------------------------
   TailCallBuiltin(masm, Builtins::kKeyedLoadIC_Miss);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64