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 310 matching lines @@
 
 
 // Load a fast property out of a holder object (src). In-object properties
 // are loaded directly otherwise the property is loaded from the properties
 // fixed array.
 void StubCompiler::GenerateFastPropertyLoad(MacroAssembler* masm,
                                             Register dst,
                                             Register src,
                                             Handle<JSObject> holder,
                                             PropertyIndex index) {
-  if (index.is_header_index()) {
-    int offset = index.header_index() * kPointerSize;
-    __ ldr(dst, FieldMemOperand(src, offset));
-  } else {
-    // Adjust for the number of properties stored in the holder.
-    int slot = index.field_index() - holder->map()->inobject_properties();
-    if (slot < 0) {
-      // Get the property straight out of the holder.
-      int offset = holder->map()->instance_size() + (slot * kPointerSize);
-      __ ldr(dst, FieldMemOperand(src, offset));
-    } else {
-      // Calculate the offset into the properties array.
-      int offset = slot * kPointerSize + FixedArray::kHeaderSize;
-      __ ldr(dst, FieldMemOperand(src, JSObject::kPropertiesOffset));
-      __ ldr(dst, FieldMemOperand(dst, offset));
-    }
-  }
+  DoGenerateFastPropertyLoad(
+      masm, dst, src, index.is_inobject(holder), index.translate(holder));
 }
 
 
+void StubCompiler::DoGenerateFastPropertyLoad(MacroAssembler* masm,
+                                              Register dst,
+                                              Register src,
+                                              bool inobject,
+                                              int index) {
+  int offset = index * kPointerSize;
+  if (!inobject) {
+    // Calculate the offset into the properties array.
+    offset = offset + FixedArray::kHeaderSize;
+    __ ldr(dst, FieldMemOperand(src, JSObject::kPropertiesOffset));
+    src = dst;
+  }
+  __ ldr(dst, FieldMemOperand(src, offset));
+}
+
+
 void StubCompiler::GenerateLoadArrayLength(MacroAssembler* masm,
                                            Register receiver,
                                            Register scratch,
                                            Label* miss_label) {
   // Check that the receiver isn't a smi.
   __ JumpIfSmi(receiver, miss_label);
 
   // Check that the object is a JS array.
   __ CompareObjectType(receiver, scratch, scratch, JS_ARRAY_TYPE);
   __ b(ne, miss_label);
@@ skipping 698 matching lines @@
     __ bind(&done);
     __ str(fval, MemOperand(dst, wordoffset, LSL, 2));
   }
 }
 
 
 #undef __
 #define __ ACCESS_MASM(masm())
 
 
+void StubCompiler::GenerateTailCall(Handle<Code> code) {
+  __ Jump(code, RelocInfo::CODE_TARGET);
+}
+
+
 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 20 matching lines @@
       ASSERT(current->property_dictionary()->FindEntry(*name) ==
              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);
+      Register map_reg = scratch1;
+      if (!current.is_identical_to(first) || check == CHECK_ALL_MAPS) {
+        Handle<Map> current_map(current->map());
+        // CheckMap implicitly loads the map of |reg| into |map_reg|.
+        __ CheckMap(reg, map_reg, current_map, miss, DONT_DO_SMI_CHECK,
+                    ALLOW_ELEMENT_TRANSITION_MAPS);
+      } else {
+        __ ldr(map_reg, FieldMemOperand(reg, HeapObject::kMapOffset));
+      }
 
       // 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)) {
         // The prototype is in new space; we cannot store a reference to it
         // in the code.  Load it from the map.
-        __ ldr(reg, FieldMemOperand(scratch1, Map::kPrototypeOffset));
+        __ ldr(reg, FieldMemOperand(map_reg, Map::kPrototypeOffset));
       } else {
         // The prototype is in old space; load it directly.
         __ mov(reg, Operand(prototype));
       }
     }
 
     if (save_at_depth == depth) {
       __ 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);
+  if (!holder.is_identical_to(first) || check == CHECK_ALL_MAPS) {
+    // Check the holder map.
+    __ CheckMap(reg, scratch1, Handle<Map>(holder->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.
   GenerateCheckPropertyCells(masm(), object, holder, name, scratch1, miss);
 
   // Return the register containing the holder.
   return reg;
 }
 
 
 void BaseLoadStubCompiler::HandlerFrontendFooter(Label* success,
                                                  Label* miss) {
-  __ b(success);
-  __ bind(miss);
-  GenerateLoadMiss(masm(), kind());
+  if (!miss->is_unused()) {
+    __ b(success);
+    __ bind(miss);
+    GenerateLoadMiss(masm(), kind());
+  }
 }
 
 
 Register BaseLoadStubCompiler::CallbackHandlerFrontend(
     Handle<JSObject> object,
     Register object_reg,
     Handle<JSObject> holder,
     Handle<String> name,
     Label* success,
-    FrontendCheckType check,
     Handle<ExecutableAccessorInfo> callback) {
   Label miss;
 
-  Register reg = HandlerFrontendHeader(
-      object, object_reg, holder, name, &miss, check);
+  Register reg = HandlerFrontendHeader(object, object_reg, holder, name, &miss);
 
   if (!holder->HasFastProperties() && !holder->IsJSGlobalObject()) {
     ASSERT(!reg.is(scratch2()));
     ASSERT(!reg.is(scratch3()));
     ASSERT(!reg.is(scratch4()));
 
     // Load the properties dictionary.
     Register dictionary = scratch4();
     __ ldr(dictionary, FieldMemOperand(reg, JSObject::kPropertiesOffset));
 
@@ skipping 25 matching lines @@
 
 
 void BaseLoadStubCompiler::NonexistentHandlerFrontend(
     Handle<JSObject> object,
     Handle<JSObject> last,
     Handle<String> name,
     Label* success,
     Handle<GlobalObject> global) {
   Label miss;
 
-  Register reg = HandlerFrontendHeader(
-      object, receiver(), last, name, &miss, PERFORM_INITIAL_CHECKS);
+  Register reg = HandlerFrontendHeader(object, receiver(), last, name, &miss);
 
   // If the last object in the prototype chain is a global object,
   // check that the global property cell is empty.
   if (!global.is_null()) {
     GenerateCheckPropertyCell(masm(), global, name, scratch2(), &miss);
   }
 
   if (!last->HasFastProperties()) {
     __ ldr(scratch2(), FieldMemOperand(reg, HeapObject::kMapOffset));
     __ ldr(scratch2(), FieldMemOperand(scratch2(), Map::kPrototypeOffset));
@@ skipping 1607 matching lines @@
 
   NonexistentHandlerFrontend(object, last, name, &success, global);
 
   __ bind(&success);
   // Return undefined if maps of the full prototype chain are still the
   // same and no global property with this name contains a value.
   __ LoadRoot(r0, Heap::kUndefinedValueRootIndex);
   __ Ret();
 
   // Return the generated code.
-  return GetCode(Code::NONEXISTENT, factory()->empty_string());
+  return GetCode(Code::HANDLER_FRAGMENT, Code::NONEXISTENT, name);
 }
 
 
 Register* LoadStubCompiler::registers() {
   // receiver, name, scratch1, scratch2, scratch3, scratch4.
   static Register registers[] = { r0, r2, r3, r1, r4, r5 };
   return registers;
 }
 
 
@@ skipping 50 matching lines @@
 
 
 Handle<Code> LoadStubCompiler::CompileLoadGlobal(
     Handle<JSObject> object,
     Handle<GlobalObject> global,
     Handle<JSGlobalPropertyCell> cell,
     Handle<String> name,
     bool is_dont_delete) {
   Label success, miss;
 
-  HandlerFrontendHeader(object, receiver(), Handle<JSObject>::cast(global),
-                        name, &miss, PERFORM_INITIAL_CHECKS);
+  __ CheckMap(
+      receiver(), scratch1(), Handle<Map>(object->map()), &miss, DO_SMI_CHECK);
+  HandlerFrontendHeader(
+      object, receiver(), Handle<JSObject>::cast(global), name, &miss);
 
   // Get the value from the cell.
   __ mov(r3, Operand(cell));
   __ ldr(r4, FieldMemOperand(r3, JSGlobalPropertyCell::kValueOffset));
 
   // Check for deleted property if property can actually be deleted.
   if (!is_dont_delete) {
     __ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
     __ cmp(r4, ip);
     __ b(eq, &miss);
   }
 
   HandlerFrontendFooter(&success, &miss);
   __ bind(&success);
 
   Counters* counters = masm()->isolate()->counters();
   __ IncrementCounter(counters->named_load_global_stub(), 1, r1, r3);
   __ mov(r0, r4);
   __ Ret();
 
   // Return the generated code.
-  return GetCode(Code::NORMAL, name);
+  return GetCode(Code::IC_FRAGMENT, Code::NORMAL, name);
 }
 
 
 Handle<Code> KeyedLoadStubCompiler::CompileLoadElement(
     Handle<Map> receiver_map) {
   // ----------- S t a t e -------------
   //  -- lr    : return address
   //  -- r0    : key
   //  -- r1    : receiver
   // -----------------------------------
   ElementsKind elements_kind = receiver_map->elements_kind();
   if (receiver_map->has_fast_elements() ||
       receiver_map->has_external_array_elements()) {
     Handle<Code> stub = KeyedLoadFastElementStub(
         receiver_map->instance_type() == JS_ARRAY_TYPE,
         elements_kind).GetCode(isolate());
     __ DispatchMap(r1, r2, receiver_map, stub, DO_SMI_CHECK);
   } else {
     Handle<Code> stub =
         KeyedLoadDictionaryElementStub().GetCode(isolate());
     __ DispatchMap(r1, r2, receiver_map, stub, DO_SMI_CHECK);
   }
 
   Handle<Code> ic = isolate()->builtins()->KeyedLoadIC_Miss();
   __ Jump(ic, RelocInfo::CODE_TARGET);
 
   // Return the generated code.
-  return GetCode(Code::NORMAL, factory()->empty_string());
+  return GetCode(Code::IC_FRAGMENT, 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,
+    Code::StubType type,
+    IcCheckType check) {
   Label miss;
-  __ JumpIfSmi(r1, &miss);
+
+  if (check == PROPERTY) {
+    GenerateNameCheck(name, this->name(), &miss);
+  }
+
+  __ JumpIfSmi(receiver(), &miss);
+  Register map_reg = scratch1();
 
   int receiver_count = receiver_maps->length();
-  __ ldr(r2, FieldMemOperand(r1, HeapObject::kMapOffset));
+  __ ldr(map_reg, 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(map_reg, 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(Code::IC_FRAGMENT, 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