ARM: Use ubfx and movw instructions to avoid a PC-relative load on

src/arm/stub-cache-arm.cc

Index: src/arm/stub-cache-arm.cc
===================================================================
--- src/arm/stub-cache-arm.cc	(revision 10578)
+++ src/arm/stub-cache-arm.cc	(working copy)
@@ -377,7 +377,8 @@
   Label exit;
 
   // Check that the map of the object hasn't changed.
-  __ CheckMap(receiver_reg, scratch, Handle<Map>(object->map()), miss_label,
+  __ CheckMap(receiver_reg, scratch, scratch,
+              Handle<Map>(object->map()), miss_label,
               DO_SMI_CHECK, ALLOW_ELEMENT_TRANSITION_MAPS);
 
   // Perform global security token check if needed.
@@ -973,7 +974,8 @@
                                        Register scratch2,
                                        Handle<String> name,
                                        int save_at_depth,
-                                       Label* miss) {
+                                       Label* miss,
+                                       bool fast_map_check) {
   // Make sure there's no overlap between holder and object registers.
   ASSERT(!scratch1.is(object_reg) && !scratch1.is(holder_reg));
   ASSERT(!scratch2.is(object_reg) && !scratch2.is(holder_reg)
@@ -1015,7 +1017,12 @@
       __ ldr(reg, FieldMemOperand(scratch1, Map::kPrototypeOffset));
     } else {
       Handle<Map> current_map(current->map());
-      __ CheckMap(reg, scratch1, current_map, miss, DONT_DO_SMI_CHECK,
+      __ CheckMap(reg,
+                  scratch1,
+                  fast_map_check ? scratch2 : no_reg,
+                  current_map,
+                  miss,
+                  DONT_DO_SMI_CHECK,
                   ALLOW_ELEMENT_TRANSITION_MAPS);
 
       // Check access rights to the global object.  This has to happen after
@@ -1048,7 +1055,7 @@
   LOG(masm()->isolate(), IntEvent("check-maps-depth", depth + 1));
 
   // Check the holder map.
-  __ CheckMap(reg, scratch1, Handle<Map>(current->map()), miss,
+  __ CheckMap(reg, scratch1, scratch1, Handle<Map>(current->map()), miss,
               DONT_DO_SMI_CHECK, ALLOW_ELEMENT_TRANSITION_MAPS);
 
   // Perform security check for access to the global object.
@@ -2471,7 +2478,7 @@
   Label miss;
 
   // Check that the map of the object hasn't changed.
-  __ CheckMap(r1, r3, Handle<Map>(object->map()), &miss,
+  __ CheckMap(r1, r3, r3, Handle<Map>(object->map()), &miss,
               DO_SMI_CHECK, ALLOW_ELEMENT_TRANSITION_MAPS);
 
   // Perform global security token check if needed.
@@ -2515,7 +2522,7 @@
   Label miss;
 
   // Check that the map of the object hasn't changed.
-  __ CheckMap(r1, r3, Handle<Map>(receiver->map()), &miss,
+  __ CheckMap(r1, r3, r3, Handle<Map>(receiver->map()), &miss,
               DO_SMI_CHECK, ALLOW_ELEMENT_TRANSITION_MAPS);
 
   // Perform global security token check if needed.