Hydrogen: fix keyed loads with string keys

Keyed loads should not unconditionally be compiled to element loads. Update KeyedLoadICs to keep track of the key type, so that Hydrogen can emit ICs for string-keyed loads it doesn't have inline support for.

BUG=v8:3167
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/755513003

Cr-Commit-Position: refs/heads/master@{#25817}

src/ast.h

@@ -1748,8 +1748,7 @@ class Property FINAL : public Expression {
   SmallMapList* GetReceiverTypes() OVERRIDE { return &receiver_types_; }
   KeyedAccessStoreMode GetStoreMode() const OVERRIDE { return STANDARD_STORE; }
   IcCheckType GetKeyType() const OVERRIDE {
-    // PROPERTY key types currently aren't implemented for KeyedLoadICs.
-    return ELEMENT;
+    return KeyTypeField::decode(bit_field_);
   }
   bool IsUninitialized() const {
     return !is_for_call() && HasNoTypeInformation();
@@ -1763,6 +1762,9 @@ class Property FINAL : public Expression {
   void set_is_string_access(bool b) {
     bit_field_ = IsStringAccessField::update(bit_field_, b);
   }
+  void set_key_type(IcCheckType key_type) {
+    bit_field_ = KeyTypeField::update(bit_field_, key_type);
+  }
   void mark_for_call() {
     bit_field_ = IsForCallField::update(bit_field_, true);
   }
@@ -1805,6 +1807,7 @@ class Property FINAL : public Expression {
   class IsForCallField : public BitField8<bool, 0, 1> {};
   class IsUninitializedField : public BitField8<bool, 1, 1> {};
   class IsStringAccessField : public BitField8<bool, 2, 1> {};
+  class KeyTypeField : public BitField8<IcCheckType, 3, 1> {};
   uint8_t bit_field_;
   FeedbackVectorICSlot property_feedback_slot_;
   Expression* obj_;

src/hydrogen.cc

@@ -7215,7 +7215,7 @@ HValue* HOptimizedGraphBuilder::HandleKeyedElementAccess(
   bool monomorphic = ComputeReceiverTypes(expr, obj, &types, zone());
 
   bool force_generic = false;
-  if (access_type == STORE && expr->GetKeyType() == PROPERTY) {
+  if (expr->GetKeyType() == PROPERTY) {
     // Non-Generic accesses assume that elements are being accessed, and will
     // deopt for non-index keys, which the IC knows will occur.
     // TODO(jkummerow): Consider adding proper support for property accesses.

src/ic/ic-compiler.cc

@@ -63,6 +63,9 @@ Handle<Code> PropertyICCompiler::ComputeMonomorphic(
         KeyedStoreIC::IcCheckTypeField::update(extra_ic_state, PROPERTY);
     DCHECK(STANDARD_STORE ==
            KeyedStoreIC::GetKeyedAccessStoreMode(extra_ic_state));
+  } else if (kind == Code::KEYED_LOAD_IC) {
+    extra_ic_state = KeyedLoadIC::IcCheckTypeField::update(extra_ic_state,
+                                                           PROPERTY);
   }
 
   Handle<Code> ic;
@@ -86,6 +89,7 @@ Handle<Code> PropertyICCompiler::ComputeMonomorphic(
 Handle<Code> PropertyICCompiler::ComputeKeyedLoadMonomorphic(
     Handle<Map> receiver_map) {
   Isolate* isolate = receiver_map->GetIsolate();
+  DCHECK(KeyedLoadIC::GetKeyType(kNoExtraICState) == ELEMENT);
   Code::Flags flags = Code::ComputeMonomorphicFlags(Code::KEYED_LOAD_IC);
   Handle<Name> name = isolate->factory()->KeyedLoadMonomorphic_string();
 
@@ -255,6 +259,7 @@ Handle<Code> PropertyICCompiler::ComputeCompareNil(Handle<Map> receiver_map,
 Handle<Code> PropertyICCompiler::ComputeKeyedLoadPolymorphic(
     MapHandleList* receiver_maps) {
   Isolate* isolate = receiver_maps->at(0)->GetIsolate();
+  DCHECK(KeyedLoadIC::GetKeyType(kNoExtraICState) == ELEMENT);
   Code::Flags flags = Code::ComputeFlags(Code::KEYED_LOAD_IC, POLYMORPHIC);
   Handle<PolymorphicCodeCache> cache =
       isolate->factory()->polymorphic_code_cache();

src/ic/ic.h

@@ -459,6 +459,19 @@ class LoadIC : public IC {
 
 class KeyedLoadIC : public LoadIC {
  public:
+  // ExtraICState bits (building on IC)
+  class IcCheckTypeField : public BitField<IcCheckType, 1, 1> {};
+
+  static ExtraICState ComputeExtraICState(ContextualMode contextual_mode,
+                                          IcCheckType key_type) {
+    return LoadICState(contextual_mode).GetExtraICState() |
+           IcCheckTypeField::encode(key_type);
+  }
+
+  static IcCheckType GetKeyType(ExtraICState extra_state) {
+    return IcCheckTypeField::decode(extra_state);
+  }
+
   KeyedLoadIC(FrameDepth depth, Isolate* isolate,
               KeyedLoadICNexus* nexus = NULL)
       : LoadIC(depth, isolate, nexus) {

src/type-info.cc

@@ -156,6 +156,21 @@ void TypeFeedbackOracle::GetStoreModeAndKeyType(
 }
 
 
+void TypeFeedbackOracle::GetLoadKeyType(
+    TypeFeedbackId ast_id, IcCheckType* key_type) {
+  Handle<Object> maybe_code = GetInfo(ast_id);
+  if (maybe_code->IsCode()) {
+    Handle<Code> code = Handle<Code>::cast(maybe_code);
+    if (code->kind() == Code::KEYED_LOAD_IC) {
+      ExtraICState extra_ic_state = code->extra_ic_state();
+      *key_type = KeyedLoadIC::GetKeyType(extra_ic_state);
+      return;
+    }
+  }
+  *key_type = ELEMENT;
+}
+
+
 Handle<JSFunction> TypeFeedbackOracle::GetCallTarget(
     FeedbackVectorICSlot slot) {
   Handle<Object> info = GetInfo(slot);
@@ -305,10 +320,14 @@ bool TypeFeedbackOracle::HasOnlyStringMaps(SmallMapList* receiver_types) {
 
 
 void TypeFeedbackOracle::KeyedPropertyReceiverTypes(
-    TypeFeedbackId id, SmallMapList* receiver_types, bool* is_string) {
+    TypeFeedbackId id,
+    SmallMapList* receiver_types,
+    bool* is_string,
+    IcCheckType* key_type) {
   receiver_types->Clear();
   CollectReceiverTypes(id, receiver_types);
   *is_string = HasOnlyStringMaps(receiver_types);
+  GetLoadKeyType(id, key_type);
 }
 
 

src/type-info.h

@@ -40,6 +40,7 @@ class TypeFeedbackOracle: public ZoneObject {
   void GetStoreModeAndKeyType(TypeFeedbackId id,
                               KeyedAccessStoreMode* store_mode,
                               IcCheckType* key_type);
+  void GetLoadKeyType(TypeFeedbackId id, IcCheckType* key_type);
 
   void PropertyReceiverTypes(TypeFeedbackId id, Handle<String> name,
                              SmallMapList* receiver_types);
@@ -47,7 +48,8 @@ class TypeFeedbackOracle: public ZoneObject {
                              SmallMapList* receiver_types);
   void KeyedPropertyReceiverTypes(TypeFeedbackId id,
                                   SmallMapList* receiver_types,
-                                  bool* is_string);
+                                  bool* is_string,
+                                  IcCheckType* key_type);
   void KeyedPropertyReceiverTypes(FeedbackVectorICSlot slot,
                                   SmallMapList* receiver_types,
                                   bool* is_string);

src/typing.cc

@@ -507,14 +507,17 @@ void AstTyper::VisitProperty(Property* expr) {
       }
     } else {
       bool is_string;
+      IcCheckType key_type;
       if (FLAG_vector_ics) {
         oracle()->KeyedPropertyReceiverTypes(slot, expr->GetReceiverTypes(),
                                              &is_string);
+        key_type = ELEMENT;
       } else {
         oracle()->KeyedPropertyReceiverTypes(id, expr->GetReceiverTypes(),
-                                             &is_string);
+                                             &is_string, &key_type);
       }
       expr->set_is_string_access(is_string);
+      expr->set_key_type(key_type);
     }
   }
 

test/mjsunit/keyed-load-with-string-key.js

+// Copyright 2014 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
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Flags: --allow-natives-syntax
+
+
+var o = {
+  "foo": "bar",
+}
+
+function get(obj, key) {
+  return obj[key];
+}
+
+get(o, "foo");
+get(o, "foo");
+get(o, "foo");
+
+%OptimizeFunctionOnNextCall(get);
+get(o, "foo");
+
+assertOptimized(get);