Add new ARM macro assembler function CompareRoot left out of previous commit.

Review URL: http://codereview.chromium.org/6614015

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7042 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/macro-assembler-arm.cc

@@ -1537,6 +1537,14 @@ void MacroAssembler::CompareInstanceType(Register map,
 }
 
 
+void MacroAssembler::CompareRoot(Register obj,
+                                 Heap::RootListIndex index) {
+  ASSERT(!obj.is(ip));
+  LoadRoot(ip, index);
+  cmp(obj, ip);
+}
+
+
 void MacroAssembler::CheckMap(Register obj,
                               Register scratch,
                               Handle<Map> map,
@@ -2342,9 +2350,7 @@ void MacroAssembler::AbortIfNotString(Register object) {
 void MacroAssembler::AbortIfNotRootValue(Register src,
                                          Heap::RootListIndex root_value_index,
                                          const char* message) {
-  ASSERT(!src.is(ip));
-  LoadRoot(ip, root_value_index);
-  cmp(src, ip);
+  CompareRoot(src, root_value_index);
   Assert(eq, message);
 }
 

src/arm/macro-assembler-arm.h

@@ -577,6 +577,11 @@ class MacroAssembler: public Assembler {
                 bool is_heap_object);
 
 
+  // Compare the object in a register to a value from the root list.
+  // Uses the ip register as scratch.
+  void CompareRoot(Register obj, Heap::RootListIndex index);
+
+
   // Load and check the instance type of an object for being a string.
   // Loads the type into the second argument register.
   // Returns a condition that will be enabled if the object was a string.