Support StringLength in hydrogen (similar to ArrayLength).

src/x64/stub-cache-x64.cc

 // Copyright 2010 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 289 matching lines @@
   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* miss,
+                                            bool support_wrappers) {
   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);
+  GenerateStringCheck(masm, receiver, scratch1, miss,
+                      support_wrappers ? &check_wrapper : miss);
 
   // Load length directly from the string.
   __ movq(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);
+  if (support_wrappers) {
+    // 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.
-  __ movq(scratch2, FieldOperand(receiver, JSValue::kValueOffset));
-  GenerateStringCheck(masm, scratch2, scratch1, miss, miss);
-  __ movq(rax, FieldOperand(scratch2, String::kLengthOffset));
-  __ ret(0);
+    // Check if the wrapped value is a string and load the length
+    // directly if it is.
+    __ movq(scratch2, FieldOperand(receiver, JSValue::kValueOffset));
+    GenerateStringCheck(masm, scratch2, scratch1, miss, miss);
+    __ movq(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)) __ movq(rax, result);
@@ skipping 2584 matching lines @@
   //  -- rsp[0] : return address
   // -----------------------------------
   Label miss;
 
   __ IncrementCounter(&Counters::keyed_load_string_length, 1);
 
   // Check that the name has not changed.
   __ Cmp(rax, Handle<String>(name));
   __ j(not_equal, &miss);
 
-  GenerateLoadStringLength(masm(), rdx, rcx, rbx, &miss);
+  GenerateLoadStringLength(masm(), rdx, rcx, rbx, &miss, true);
   __ bind(&miss);
   __ DecrementCounter(&Counters::keyed_load_string_length, 1);
   GenerateLoadMiss(masm(), Code::KEYED_LOAD_IC);
 
   // Return the generated code.
   return GetCode(CALLBACKS, name);
 }
 
 
 MaybeObject* KeyedLoadStubCompiler::CompileLoadFunctionPrototype(String* name) {
@@ skipping 495 matching lines @@
   __ TailCallRuntime(Runtime::kSetProperty, 3, 1);
 
   return GetCode(flags);
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64