Implement tracking and optimizations of packed arrays.

src/code-stubs.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 245 matching lines @@
   Handle<FixedArray> handler_table =
       code->GetIsolate()->factory()->NewFixedArray(1, TENURED);
   handler_table->set(0, Smi::FromInt(handler_offset_));
   code->set_handler_table(*handler_table);
 }
 
 
 void KeyedLoadElementStub::Generate(MacroAssembler* masm) {
   switch (elements_kind_) {
     case FAST_ELEMENTS:
-    case FAST_SMI_ONLY_ELEMENTS:
+    case FAST_HOLEY_ELEMENTS:
+    case FAST_SMI_ELEMENTS:
+    case FAST_HOLEY_SMI_ELEMENTS:
       KeyedLoadStubCompiler::GenerateLoadFastElement(masm);
       break;
     case FAST_DOUBLE_ELEMENTS:
+    case FAST_HOLEY_DOUBLE_ELEMENTS:
       KeyedLoadStubCompiler::GenerateLoadFastDoubleElement(masm);
       break;
     case EXTERNAL_BYTE_ELEMENTS:
     case EXTERNAL_UNSIGNED_BYTE_ELEMENTS:
     case EXTERNAL_SHORT_ELEMENTS:
     case EXTERNAL_UNSIGNED_SHORT_ELEMENTS:
     case EXTERNAL_INT_ELEMENTS:
     case EXTERNAL_UNSIGNED_INT_ELEMENTS:
     case EXTERNAL_FLOAT_ELEMENTS:
     case EXTERNAL_DOUBLE_ELEMENTS:
     case EXTERNAL_PIXEL_ELEMENTS:
       KeyedLoadStubCompiler::GenerateLoadExternalArray(masm, elements_kind_);
       break;
     case DICTIONARY_ELEMENTS:
       KeyedLoadStubCompiler::GenerateLoadDictionaryElement(masm);
       break;
     case NON_STRICT_ARGUMENTS_ELEMENTS:
       UNREACHABLE();
       break;
   }
 }
 
 
 void KeyedStoreElementStub::Generate(MacroAssembler* masm) {
   switch (elements_kind_) {
     case FAST_ELEMENTS:
-    case FAST_SMI_ONLY_ELEMENTS: {
+    case FAST_HOLEY_ELEMENTS:
+    case FAST_SMI_ELEMENTS:
+    case FAST_HOLEY_SMI_ELEMENTS: {
       KeyedStoreStubCompiler::GenerateStoreFastElement(masm,
                                                        is_js_array_,
                                                        elements_kind_,
                                                        grow_mode_);
     }
       break;
     case FAST_DOUBLE_ELEMENTS:
+    case FAST_HOLEY_DOUBLE_ELEMENTS:
       KeyedStoreStubCompiler::GenerateStoreFastDoubleElement(masm,
                                                              is_js_array_,
                                                              grow_mode_);
       break;
     case EXTERNAL_BYTE_ELEMENTS:
     case EXTERNAL_UNSIGNED_BYTE_ELEMENTS:
     case EXTERNAL_SHORT_ELEMENTS:
     case EXTERNAL_UNSIGNED_SHORT_ELEMENTS:
     case EXTERNAL_INT_ELEMENTS:
     case EXTERNAL_UNSIGNED_INT_ELEMENTS:
@@ skipping 110 matching lines @@
 
 
 bool ToBooleanStub::Types::CanBeUndetectable() const {
   return Contains(ToBooleanStub::SPEC_OBJECT)
       || Contains(ToBooleanStub::STRING);
 }
 
 
 void ElementsTransitionAndStoreStub::Generate(MacroAssembler* masm) {
   Label fail;
+  ASSERT(!IsFastHoleyElementsKind(from_) || IsFastHoleyElementsKind(to_));
   if (!FLAG_trace_elements_transitions) {
-    if (to_ == FAST_ELEMENTS) {
-      if (from_ == FAST_SMI_ONLY_ELEMENTS) {
-        ElementsTransitionGenerator::GenerateSmiOnlyToObject(masm);
-      } else if (from_ == FAST_DOUBLE_ELEMENTS) {
+    if (IsFastSmiOrObjectElementsKind(to_)) {
+      if (IsFastSmiOrObjectElementsKind(from_)) {
+        ElementsTransitionGenerator::
+            GenerateMapChangeElementTransition(masm);
+      } else if (IsFastDoubleElementsKind(from_)) {
+        ASSERT(!IsFastSmiElementsKind(to_));
         ElementsTransitionGenerator::GenerateDoubleToObject(masm, &fail);
       } else {
         UNREACHABLE();
       }
       KeyedStoreStubCompiler::GenerateStoreFastElement(masm,
                                                        is_jsarray_,
-                                                       FAST_ELEMENTS,
+                                                       to_,
                                                        grow_mode_);
-    } else if (from_ == FAST_SMI_ONLY_ELEMENTS && to_ == FAST_DOUBLE_ELEMENTS) {
+    } else if (IsFastSmiElementsKind(from_) &&
+               IsFastDoubleElementsKind(to_)) {
       ElementsTransitionGenerator::GenerateSmiOnlyToDouble(masm, &fail);
       KeyedStoreStubCompiler::GenerateStoreFastDoubleElement(masm,
                                                              is_jsarray_,
                                                              grow_mode_);
+    } else if (IsFastDoubleElementsKind(from_)) {
+      ASSERT(to_ == FAST_HOLEY_DOUBLE_ELEMENTS);
+      ElementsTransitionGenerator::
+          GenerateMapChangeElementTransition(masm);
     } else {
       UNREACHABLE();
     }
   }
   masm->bind(&fail);
   KeyedStoreIC::GenerateRuntimeSetProperty(masm, strict_mode_);
 }
 
 } }  // namespace v8::internal