From 39b06d8850d18460284f0c4ce4a72a91fafb88eb Mon Sep 17 00:00:00 2001
From: "jkummerow@chromium.org"
 <jkummerow@chromium.org@ce2b1a6d-e550-0410-aec6-3dcde31c8c00>
Date: Thu, 30 Jun 2011 08:40:31 +0000
Subject: [PATCH] Add support for dictionary elements to polymorphic crankshaft
 code.

Review URL: http://codereview.chromium.org/7285001

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8479 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
---
 src/hydrogen.cc   | 17 ++++++++++++-----
 src/ic.cc         |  3 ++-
 src/objects.h     |  4 ++++
 src/stub-cache.cc |  4 ++++
 4 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index d700fd2e34..602344ec4d 100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -3917,8 +3917,6 @@ HValue* HGraphBuilder::HandlePolymorphicElementAccess(HValue* object,
       todo_external_array = true;
     }
   }
-  // We can't treat dictionary elements here (need to deopt instead).
-  type_todo[JSObject::DICTIONARY_ELEMENTS] = false;
   // Support for FAST_DOUBLE_ELEMENTS isn't implemented yet, so we deopt.
   type_todo[JSObject::FAST_DOUBLE_ELEMENTS] = false;
 
@@ -3936,9 +3934,12 @@ HValue* HGraphBuilder::HandlePolymorphicElementAccess(HValue* object,
   for (JSObject::ElementsKind elements_kind = JSObject::FAST_ELEMENTS;
        elements_kind <= JSObject::LAST_ELEMENTS_KIND;
        elements_kind = JSObject::ElementsKind(elements_kind + 1)) {
-    // After having handled FAST_ELEMENTS in the first run of the loop, we
-    // need to add some code that's executed for all other cases.
-    if (elements_kind == 1 && todo_external_array) {
+    // After having handled FAST_ELEMENTS and DICTIONARY_ELEMENTS, we
+    // need to add some code that's executed for all external array cases.
+    STATIC_ASSERT(JSObject::LAST_EXTERNAL_ARRAY_ELEMENTS_KIND ==
+                  JSObject::LAST_ELEMENTS_KIND);
+    if (elements_kind == JSObject::FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND
+        && todo_external_array) {
       elements = AddInstruction(new(zone()) HLoadElements(object));
       // We need to forcibly prevent some ElementsKind-dependent instructions
       // from being hoisted out of any loops they might occur in, because
@@ -4007,6 +4008,12 @@ HValue* HGraphBuilder::HandlePolymorphicElementAccess(HValue* object,
           access = AddInstruction(
               new(zone()) HLoadKeyedFastElement(elements, checked_key));
         }
+      } else if (elements_kind == JSObject::DICTIONARY_ELEMENTS) {
+        if (is_store) {
+          access = AddInstruction(BuildStoreKeyedGeneric(object, key, val));
+        } else {
+          access = AddInstruction(BuildLoadKeyedGeneric(object, key));
+        }
       } else {  // External array elements.
         access = AddInstruction(BuildExternalArrayElementAccess(
             external_elements, checked_key, val, elements_kind, is_store));
diff --git a/src/ic.cc b/src/ic.cc
index efa8f2db95..fd8c27045d 100644
--- a/src/ic.cc
+++ b/src/ic.cc
@@ -1745,7 +1745,8 @@ MaybeObject* KeyedIC::ComputeMonomorphicStub(JSObject* receiver,
                                              Code* generic_stub) {
   Code* result = NULL;
   if (receiver->HasFastElements() ||
-      receiver->HasExternalArrayElements()) {
+      receiver->HasExternalArrayElements() ||
+      receiver->HasDictionaryElements()) {
     MaybeObject* maybe_stub =
         isolate()->stub_cache()->ComputeKeyedLoadOrStoreElement(
             receiver, is_store, strict_mode);
diff --git a/src/objects.h b/src/objects.h
index e49bbefa30..b2b1a77c6b 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -3946,6 +3946,10 @@ class Map: public HeapObject {
         kind <= JSObject::LAST_EXTERNAL_ARRAY_ELEMENTS_KIND;
   }
 
+  inline bool has_dictionary_elements() {
+    return elements_kind() == JSObject::DICTIONARY_ELEMENTS;
+  }
+
   // Tells whether the map is attached to SharedFunctionInfo
   // (for inobject slack tracking).
   inline void set_attached_to_shared_function_info(bool value);
diff --git a/src/stub-cache.cc b/src/stub-cache.cc
index d5392d95bf..eb813814d4 100644
--- a/src/stub-cache.cc
+++ b/src/stub-cache.cc
@@ -1694,6 +1694,8 @@ MaybeObject* KeyedLoadStubCompiler::ComputeSharedKeyedLoadElementStub(
   } else if (receiver_map->has_external_array_elements()) {
     JSObject::ElementsKind elements_kind = receiver_map->elements_kind();
     maybe_stub = KeyedLoadExternalArrayStub(elements_kind).TryGetCode();
+  } else if (receiver_map->has_dictionary_elements()) {
+    maybe_stub = isolate()->builtins()->builtin(Builtins::kKeyedLoadIC_Slow);
   } else {
     UNREACHABLE();
   }
@@ -1746,6 +1748,8 @@ MaybeObject* KeyedStoreStubCompiler::ComputeSharedKeyedStoreElementStub(
   } else if (receiver_map->has_external_array_elements()) {
     JSObject::ElementsKind elements_kind = receiver_map->elements_kind();
     maybe_stub = KeyedStoreExternalArrayStub(elements_kind).TryGetCode();
+  } else if (receiver_map->has_dictionary_elements()) {
+    maybe_stub = isolate()->builtins()->builtin(Builtins::kKeyedStoreIC_Slow);
   } else {
     UNREACHABLE();
   }