Polymorphism support for load IC.

src/arm/stub-cache-arm.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 1056 matching lines @@
 
 
 Register StubCompiler::CheckPrototypes(Handle<JSObject> object,
                                        Register object_reg,
                                        Handle<JSObject> holder,
                                        Register holder_reg,
                                        Register scratch1,
                                        Register scratch2,
                                        Handle<String> name,
                                        int save_at_depth,
-                                       Label* miss) {
+                                       Label* miss,
+                                       PrototypeCheckType check) {
+  Handle<JSObject> first = object;
   // 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)
          && !scratch2.is(scratch1));
 
   // Keep track of the current object in register reg.
   Register reg = object_reg;
   int depth = 0;
 
   if (save_at_depth == depth) {
@@ skipping 21 matching lines @@
              StringDictionary::kNotFound);
 
       GenerateDictionaryNegativeLookup(masm(), miss, reg, name,
                                        scratch1, scratch2);
 
       __ ldr(scratch1, FieldMemOperand(reg, HeapObject::kMapOffset));
       reg = holder_reg;  // From now on the object will be in holder_reg.
       __ ldr(reg, FieldMemOperand(scratch1, Map::kPrototypeOffset));
     } else {
       Handle<Map> current_map(current->map());
-      __ CheckMap(reg, scratch1, current_map, miss, DONT_DO_SMI_CHECK,
-                  ALLOW_ELEMENT_TRANSITION_MAPS);
+      if (!current.is_identical_to(first) || check == CHECK_ALL_MAPS) {
+        __ CheckMap(reg, scratch1, current_map, miss, DONT_DO_SMI_CHECK,
+                    ALLOW_ELEMENT_TRANSITION_MAPS);
+      }
 
       // Check access rights to the global object.  This has to happen after
       // the map check so that we know that the object is actually a global
       // object.
       if (current->IsJSGlobalProxy()) {
         __ CheckAccessGlobalProxy(reg, scratch2, miss);
       }
       reg = holder_reg;  // From now on the object will be in holder_reg.
 
       if (heap()->InNewSpace(*prototype)) {
@@ skipping 10 matching lines @@
       __ str(reg, MemOperand(sp));
     }
 
     // Go to the next object in the prototype chain.
     current = prototype;
   }
 
   // Log the check depth.
   LOG(masm()->isolate(), IntEvent("check-maps-depth", depth + 1));
 
-  // Check the holder map.
-  __ CheckMap(reg, scratch1, Handle<Map>(current->map()), miss,
-              DONT_DO_SMI_CHECK, ALLOW_ELEMENT_TRANSITION_MAPS);
+  Handle<Map> current_map(current->map());
+  if (!current.is_identical_to(first) || check == CHECK_ALL_MAPS) {
+    // Check the holder map.
+    __ CheckMap(reg, scratch1, Handle<Map>(current->map()), miss,
+                DONT_DO_SMI_CHECK, ALLOW_ELEMENT_TRANSITION_MAPS);
+  }
 
   // Perform security check for access to the global object.
   ASSERT(holder->IsJSGlobalProxy() || !holder->IsAccessCheckNeeded());
   if (holder->IsJSGlobalProxy()) {
     __ CheckAccessGlobalProxy(reg, scratch1, miss);
   }
 
   // If we've skipped any global objects, it's not enough to verify that
   // their maps haven't changed.  We also need to check that the property
   // cell for the property is still empty.
@@ skipping 1811 matching lines @@
   }
 
   Handle<Code> ic = isolate()->builtins()->KeyedLoadIC_Miss();
   __ Jump(ic, RelocInfo::CODE_TARGET);
 
   // Return the generated code.
   return GetCode(Code::NORMAL, factory()->empty_string());
 }
 
 
-Handle<Code> KeyedLoadStubCompiler::CompileLoadPolymorphic(
+Handle<Code> BaseLoadStubCompiler::CompilePolymorphicIC(
     MapHandleList* receiver_maps,
-    CodeHandleList* handler_ics) {
-  // ----------- S t a t e -------------
-  //  -- lr    : return address
-  //  -- r0    : key
-  //  -- r1    : receiver
-  // -----------------------------------
+    CodeHandleList* handlers,
+    Handle<String> name) {
   Label miss;
-  __ JumpIfSmi(r1, &miss);
+  __ JumpIfSmi(receiver(), &miss);
 
   int receiver_count = receiver_maps->length();
-  __ ldr(r2, FieldMemOperand(r1, HeapObject::kMapOffset));
+  __ ldr(scratch1(), FieldMemOperand(receiver(), HeapObject::kMapOffset));
   for (int current = 0; current < receiver_count; ++current) {
     __ mov(ip, Operand(receiver_maps->at(current)));
-    __ cmp(r2, ip);
-    __ Jump(handler_ics->at(current), RelocInfo::CODE_TARGET, eq);
+    __ cmp(scratch1(), ip);
+    __ Jump(handlers->at(current), RelocInfo::CODE_TARGET, eq);
   }
 
   __ bind(&miss);
-  Handle<Code> miss_ic = isolate()->builtins()->KeyedLoadIC_Miss();
-  __ Jump(miss_ic, RelocInfo::CODE_TARGET, al);
+  GenerateLoadMiss(masm(), kind());
 
   // Return the generated code.
-  return GetCode(Code::NORMAL, factory()->empty_string(), POLYMORPHIC);
+  InlineCacheState state =
+      receiver_maps->length() > 1 ? POLYMORPHIC : MONOMORPHIC;
+  return GetCode(type, name, state);
 }
 
 
 Handle<Code> KeyedStoreStubCompiler::CompileStoreField(Handle<JSObject> object,
                                                        int index,
                                                        Handle<Map> transition,
                                                        Handle<String> name) {
   // ----------- S t a t e -------------
   //  -- r0    : value
   //  -- r1    : name
@@ skipping 1034 matching lines @@
     __ Jump(ic_slow, RelocInfo::CODE_TARGET);
   }
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM