Support StringLength in hydrogen (similar to ArrayLength).

src/arm/stub-cache-arm.cc

 // Copyright 2006-2009 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 352 matching lines @@
 
 
 // Generate code to load the length from a string object and return the length.
 // If the receiver object is not a string or a wrapped string object the
 // execution continues at the miss label. The register containing the
 // receiver is potentially clobbered.
 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
   // scratch1 register.
-  GenerateStringCheck(masm, receiver, scratch1, scratch2, miss, &check_wrapper);
+  GenerateStringCheck(masm, receiver, scratch1, scratch2, miss,
+                      support_wrappers ? &check_wrapper : miss);
 
   // Load length directly from the string.
   __ ldr(r0, FieldMemOperand(receiver, String::kLengthOffset));
   __ Ret();
 
-  // Check if the object is a JSValue wrapper.
-  __ bind(&check_wrapper);
-  __ cmp(scratch1, Operand(JS_VALUE_TYPE));
-  __ b(ne, miss);
+  if (support_wrappers) {
+    // Check if the object is a JSValue wrapper.
+    __ bind(&check_wrapper);
+    __ cmp(scratch1, Operand(JS_VALUE_TYPE));
+    __ b(ne, miss);
 
-  // Unwrap the value and check if the wrapped value is a string.
-  __ ldr(scratch1, FieldMemOperand(receiver, JSValue::kValueOffset));
-  GenerateStringCheck(masm, scratch1, scratch2, scratch2, miss, miss);
-  __ ldr(r0, FieldMemOperand(scratch1, String::kLengthOffset));
-  __ Ret();
+    // Unwrap the value and check if the wrapped value is a string.
+    __ ldr(scratch1, FieldMemOperand(receiver, JSValue::kValueOffset));
+    GenerateStringCheck(masm, scratch1, scratch2, scratch2, miss, miss);
+    __ ldr(r0, FieldMemOperand(scratch1, String::kLengthOffset));
+    __ Ret();
+  }
 }
 
 
 void StubCompiler::GenerateLoadFunctionPrototype(MacroAssembler* masm,
                                                  Register receiver,
                                                  Register scratch1,
                                                  Register scratch2,
                                                  Label* miss_label) {
   __ TryGetFunctionPrototype(receiver, scratch1, scratch2, miss_label);
   __ mov(r0, scratch1);
@@ skipping 2584 matching lines @@
   //  -- r0    : key
   //  -- r1    : receiver
   // -----------------------------------
   Label miss;
   __ IncrementCounter(&Counters::keyed_load_string_length, 1, r2, r3);
 
   // Check the key is the cached one.
   __ cmp(r0, Operand(Handle<String>(name)));
   __ b(ne, &miss);
 
-  GenerateLoadStringLength(masm(), r1, r2, r3, &miss);
+  GenerateLoadStringLength(masm(), r1, r2, r3, &miss, true);
   __ bind(&miss);
   __ DecrementCounter(&Counters::keyed_load_string_length, 1, r2, r3);
 
   GenerateLoadMiss(masm(), Code::KEYED_LOAD_IC);
 
   return GetCode(CALLBACKS, name);
 }
 
 
 MaybeObject* KeyedLoadStubCompiler::CompileLoadFunctionPrototype(String* name) {
@@ skipping 915 matching lines @@
 
   return GetCode(flags);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM