Merge bleeding edge up to 8774 into the GC branch.

src/hydrogen.cc

 // Copyright 2011 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 718 matching lines @@
          order->Contains(block->end()->SecondSuccessor()) ||
          block->end()->SecondSuccessor()->IsLoopHeader());
   order->Add(block);
 }
 
 
 void HGraph::AssignDominators() {
   HPhase phase("Assign dominators", this);
   for (int i = 0; i < blocks_.length(); ++i) {
     if (blocks_[i]->IsLoopHeader()) {
+      // Only the first predecessor of a loop header is from outside the loop.
+      // All others are back edges, and thus cannot dominate the loop header.
       blocks_[i]->AssignCommonDominator(blocks_[i]->predecessors()->first());
     } else {
       for (int j = 0; j < blocks_[i]->predecessors()->length(); ++j) {
         blocks_[i]->AssignCommonDominator(blocks_[i]->predecessors()->at(j));
       }
     }
   }
+}
 
-  // Propagate flag marking blocks containing unconditional deoptimize.
+// Mark all blocks that are dominated by an unconditional soft deoptimize to
+// prevent code motion across those blocks.
+void HGraph::PropagateDeoptimizingMark() {
+  HPhase phase("Propagate deoptimizing mark", this);
   MarkAsDeoptimizingRecursively(entry_block());
 }
 
-
-// Mark all blocks that are dominated by an unconditional deoptimize.
 void HGraph::MarkAsDeoptimizingRecursively(HBasicBlock* block) {
   for (int i = 0; i < block->dominated_blocks()->length(); ++i) {
     HBasicBlock* dominated = block->dominated_blocks()->at(i);
     if (block->IsDeoptimizing()) dominated->MarkAsDeoptimizing();
     MarkAsDeoptimizingRecursively(dominated);
   }
 }
 
 void HGraph::EliminateRedundantPhis() {
   HPhase phase("Redundant phi elimination", this);
@@ skipping 66 matching lines @@
     HPhi* phi = phi_list[i];
     if (!phi->is_live()) {
       HBasicBlock* block = phi->block();
       block->RemovePhi(phi);
       block->RecordDeletedPhi(phi->merged_index());
     }
   }
 }
 
 
+bool HGraph::CheckPhis() {
+  int block_count = blocks_.length();
+  for (int i = 0; i < block_count; ++i) {
+    for (int j = 0; j < blocks_[i]->phis()->length(); ++j) {
+      HPhi* phi = blocks_[i]->phis()->at(j);
+      // We don't support phi uses of arguments for now.
+      if (phi->CheckFlag(HValue::kIsArguments)) return false;
+    }
+  }
+  return true;
+}
+
+
 bool HGraph::CollectPhis() {
   int block_count = blocks_.length();
   phi_list_ = new ZoneList<HPhi*>(block_count);
   for (int i = 0; i < block_count; ++i) {
     for (int j = 0; j < blocks_[i]->phis()->length(); ++j) {
       HPhi* phi = blocks_[i]->phis()->at(j);
       phi_list_->Add(phi);
-      // We don't support phi uses of arguments for now.
-      if (phi->CheckFlag(HValue::kIsArguments)) return false;
       // Check for the hole value (from an uninitialized const).
       for (int k = 0; k < phi->OperandCount(); k++) {
         if (phi->OperandAt(k) == GetConstantHole()) return false;
       }
     }
   }
   return true;
 }
 
 
@@ skipping 801 matching lines @@
   // indirectly through a transitive closure of the def-use relation.
   bool change = true;
   while (change) {
     change = false;
     for (int i = 0; i < phi_count; ++i) {
       HPhi* phi = phi_list->at(i);
       for (HUseIterator it(phi->uses()); !it.Done(); it.Advance()) {
         HValue* use = it.value();
         if (use->IsPhi()) {
           int id = HPhi::cast(use)->phi_id();
-          change = change ||
-              connected_phis[i]->UnionIsChanged(*connected_phis[id]);
+          if (connected_phis[i]->UnionIsChanged(*connected_phis[id]))
+            change = true;
         }
       }
     }
   }
 
   // (3) Sum up the non-phi use counts of all connected phis.  Don't include
   // the non-phi uses of the phi itself.
   for (int i = 0; i < phi_count; ++i) {
     HPhi* phi = phi_list->at(i);
     for (BitVector::Iterator it(connected_phis.at(i));
@@ skipping 470 matching lines @@
   // We expect the graph to be in edge-split form: there is no edge that
   // connects a branch node to a join node.  We conservatively ensure that
   // property by always adding an empty block on the outgoing edges of this
   // branch.
   HGraphBuilder* builder = owner();
   if (value != NULL && value->CheckFlag(HValue::kIsArguments)) {
     builder->Bailout("arguments object value in a test context");
   }
   HBasicBlock* empty_true = builder->graph()->CreateBasicBlock();
   HBasicBlock* empty_false = builder->graph()->CreateBasicBlock();
-  HBranch* test = new(zone()) HBranch(value, empty_true, empty_false);
+  unsigned test_id = condition()->test_id();
+  ToBooleanStub::Types expected(builder->oracle()->ToBooleanTypes(test_id));
+  HBranch* test = new(zone()) HBranch(value, empty_true, empty_false, expected);
   builder->current_block()->Finish(test);
 
   empty_true->Goto(if_true());
   empty_false->Goto(if_false());
   builder->set_current_block(NULL);
 }
 
 
 // HGraphBuilder infrastructure for bailing out and checking bailouts.
 #define CHECK_BAILOUT(call)                     \
@@ skipping 114 matching lines @@
 
     if (current_block() != NULL) {
       HReturn* instr = new(zone()) HReturn(graph()->GetConstantUndefined());
       current_block()->FinishExit(instr);
       set_current_block(NULL);
     }
   }
 
   graph()->OrderBlocks();
   graph()->AssignDominators();
+  graph()->PropagateDeoptimizingMark();
+  if (!graph()->CheckPhis()) {
+    Bailout("Unsupported phi use of arguments object");
+    return NULL;
+  }
   graph()->EliminateRedundantPhis();
   if (FLAG_eliminate_dead_phis) graph()->EliminateUnreachablePhis();
   if (!graph()->CollectPhis()) {
-    Bailout("Unsupported phi-use");
+    Bailout("Unsupported phi use of uninitialized constant");
     return NULL;
   }
 
   HInferRepresentation rep(graph());
   rep.Analyze();
 
   if (FLAG_use_range) {
     HRangeAnalysis rangeAnalysis(graph());
     rangeAnalysis.Analyze();
   }
@@ skipping 957 matching lines @@
     // If the subexpression is a literal or a simple materialized literal it
     // is already set in the cloned array.
     if (CompileTimeValue::IsCompileTimeValue(subexpr)) continue;
 
     CHECK_ALIVE(VisitForValue(subexpr));
     HValue* value = Pop();
     if (!Smi::IsValid(i)) return Bailout("Non-smi key in array literal");
 
     // Load the elements array before the first store.
     if (elements == NULL)  {
-     elements = new(zone()) HLoadElements(literal);
-     AddInstruction(elements);
+      elements = new(zone()) HLoadElements(literal);
+      AddInstruction(elements);
     }
 
     HValue* key = AddInstruction(
         new(zone()) HConstant(Handle<Object>(Smi::FromInt(i)),
                               Representation::Integer32()));
     AddInstruction(new(zone()) HStoreKeyedFastElement(elements, key, value));
     AddSimulate(expr->GetIdForElement(i));
   }
   return ast_context()->ReturnValue(Pop());
 }
@@ skipping 605 matching lines @@
 }
 
 
 HInstruction* HGraphBuilder::BuildMonomorphicElementAccess(HValue* object,
                                                            HValue* key,
                                                            HValue* val,
                                                            Expression* expr,
                                                            bool is_store) {
   ASSERT(expr->IsMonomorphic());
   Handle<Map> map = expr->GetMonomorphicReceiverType();
-  if (!map->has_fast_elements() && !map->has_external_array_elements()) {
+  if (!map->has_fast_elements() &&
+      !map->has_fast_double_elements() &&
+      !map->has_external_array_elements()) {
     return is_store ? BuildStoreKeyedGeneric(object, key, val)
                     : BuildLoadKeyedGeneric(object, key);
   }
   AddInstruction(new(zone()) HCheckNonSmi(object));
-  AddInstruction(new(zone()) HCheckMap(object, map));
-  HInstruction* elements = new(zone()) HLoadElements(object);
+  HInstruction* mapcheck = AddInstruction(new(zone()) HCheckMap(object, map));
+  HInstruction* elements = AddInstruction(new(zone()) HLoadElements(object));
+  bool fast_double_elements = map->has_fast_double_elements();
+  if (is_store && map->has_fast_elements()) {
+    AddInstruction(new(zone()) HCheckMap(
+        elements, isolate()->factory()->fixed_array_map()));
+  }
   HInstruction* length = NULL;
   HInstruction* checked_key = NULL;
   if (map->has_external_array_elements()) {
-    AddInstruction(elements);
     length = AddInstruction(new(zone()) HExternalArrayLength(elements));
     checked_key = AddInstruction(new(zone()) HBoundsCheck(key, length));
     HLoadExternalArrayPointer* external_elements =
         new(zone()) HLoadExternalArrayPointer(elements);
     AddInstruction(external_elements);
     return BuildExternalArrayElementAccess(external_elements, checked_key,
                                            val, map->elements_kind(), is_store);
   }
-  ASSERT(map->has_fast_elements());
+  ASSERT(map->has_fast_elements() || fast_double_elements);
   if (map->instance_type() == JS_ARRAY_TYPE) {
-    length = AddInstruction(new(zone()) HJSArrayLength(object));
-    checked_key = AddInstruction(new(zone()) HBoundsCheck(key, length));
-    AddInstruction(elements);
+    length = AddInstruction(new(zone()) HJSArrayLength(object, mapcheck));
   } else {
-    AddInstruction(elements);
     length = AddInstruction(new(zone()) HFixedArrayLength(elements));
-    checked_key = AddInstruction(new(zone()) HBoundsCheck(key, length));
   }
+  checked_key = AddInstruction(new(zone()) HBoundsCheck(key, length));
   if (is_store) {
-    return new(zone()) HStoreKeyedFastElement(elements, checked_key, val);
+    if (fast_double_elements) {
+      return new(zone()) HStoreKeyedFastDoubleElement(elements,
+                                                      checked_key,
+                                                      val);
+    } else {
+      return new(zone()) HStoreKeyedFastElement(elements, checked_key, val);
+    }
   } else {
-    return new(zone()) HLoadKeyedFastElement(elements, checked_key);
+    if (fast_double_elements) {
+      return new(zone()) HLoadKeyedFastDoubleElement(elements, checked_key);
+    } else {
+      return new(zone()) HLoadKeyedFastElement(elements, checked_key);
+    }
   }
 }
 
 
 HValue* HGraphBuilder::HandlePolymorphicElementAccess(HValue* object,
                                                       HValue* key,
                                                       HValue* val,
                                                       Expression* prop,
                                                       int ast_id,
                                                       int position,
@@ skipping 12 matching lines @@
   }
 
   for (int i = 0; i < maps->length(); ++i) {
     ASSERT(maps->at(i)->IsMap());
     type_todo[maps->at(i)->elements_kind()] = true;
     if (maps->at(i)->elements_kind()
         >= JSObject::FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND) {
       todo_external_array = true;
     }
   }
-  // Support for FAST_DOUBLE_ELEMENTS isn't implemented yet, so we deopt.
-  type_todo[JSObject::FAST_DOUBLE_ELEMENTS] = false;
 
   HBasicBlock* join = graph()->CreateBasicBlock();
 
   HInstruction* elements_kind_instr =
       AddInstruction(new(zone()) HElementsKind(object));
-  HInstruction* elements = NULL;
+  HCompareConstantEqAndBranch* elements_kind_branch = NULL;
+  HInstruction* elements = AddInstruction(new(zone()) HLoadElements(object));
   HLoadExternalArrayPointer* external_elements = NULL;
   HInstruction* checked_key = NULL;
 
   // FAST_ELEMENTS is assumed to be the first case.
   STATIC_ASSERT(JSObject::FAST_ELEMENTS == 0);
 
   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 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
-      // the current loop-invariant-code-motion algorithm isn't clever enough
-      // to deal with them properly.
-      // There's some performance to be gained by developing a smarter
-      // solution for this.
-      elements->ClearFlag(HValue::kUseGVN);
       HInstruction* length =
           AddInstruction(new(zone()) HExternalArrayLength(elements));
       checked_key = AddInstruction(new(zone()) HBoundsCheck(key, length));
       external_elements = new(zone()) HLoadExternalArrayPointer(elements);
       AddInstruction(external_elements);
     }
     if (type_todo[elements_kind]) {
       HBasicBlock* if_true = graph()->CreateBasicBlock();
       HBasicBlock* if_false = graph()->CreateBasicBlock();
-      HCompareConstantEqAndBranch* compare =
-          new(zone()) HCompareConstantEqAndBranch(elements_kind_instr,
-                                                  elements_kind,
-                                                  Token::EQ_STRICT);
-      compare->SetSuccessorAt(0, if_true);
-      compare->SetSuccessorAt(1, if_false);
-      current_block()->Finish(compare);
+      elements_kind_branch = new(zone()) HCompareConstantEqAndBranch(
+          elements_kind_instr, elements_kind, Token::EQ_STRICT);
+      elements_kind_branch->SetSuccessorAt(0, if_true);
+      elements_kind_branch->SetSuccessorAt(1, if_false);
+      current_block()->Finish(elements_kind_branch);
 
       set_current_block(if_true);
       HInstruction* access;
-      if (elements_kind == JSObject::FAST_ELEMENTS) {
+      if (elements_kind == JSObject::FAST_ELEMENTS ||
+          elements_kind == JSObject::FAST_DOUBLE_ELEMENTS) {
+        bool fast_double_elements =
+            elements_kind == JSObject::FAST_DOUBLE_ELEMENTS;
+        if (is_store && elements_kind == JSObject::FAST_ELEMENTS) {
+          AddInstruction(new(zone()) HCheckMap(
+              elements, isolate()->factory()->fixed_array_map(),
+              elements_kind_branch));
+        }
         HBasicBlock* if_jsarray = graph()->CreateBasicBlock();
         HBasicBlock* if_fastobject = graph()->CreateBasicBlock();
         HHasInstanceTypeAndBranch* typecheck =
             new(zone()) HHasInstanceTypeAndBranch(object, JS_ARRAY_TYPE);
         typecheck->SetSuccessorAt(0, if_jsarray);
         typecheck->SetSuccessorAt(1, if_fastobject);
         current_block()->Finish(typecheck);
 
         set_current_block(if_jsarray);
-        HInstruction* length = new(zone()) HJSArrayLength(object);
+        HInstruction* length = new(zone()) HJSArrayLength(object, typecheck);
         AddInstruction(length);
-        length->ClearFlag(HValue::kUseGVN);
         checked_key = AddInstruction(new(zone()) HBoundsCheck(key, length));
-        elements = AddInstruction(new(zone()) HLoadElements(object));
-        elements->ClearFlag(HValue::kUseGVN);
         if (is_store) {
-          access = AddInstruction(
-              new(zone()) HStoreKeyedFastElement(elements, checked_key, val));
+          if (fast_double_elements) {
+            access = AddInstruction(
+                new(zone()) HStoreKeyedFastDoubleElement(elements,
+                                                         checked_key,
+                                                         val));
+          } else {
+            access = AddInstruction(
+                new(zone()) HStoreKeyedFastElement(elements, checked_key, val));
+          }
         } else {
-          access = AddInstruction(
-              new(zone()) HLoadKeyedFastElement(elements, checked_key));
+          if (fast_double_elements) {
+            access = AddInstruction(
+                new(zone()) HLoadKeyedFastDoubleElement(elements, checked_key));
+          } else {
+            access = AddInstruction(
+                new(zone()) HLoadKeyedFastElement(elements, checked_key));
+          }
           Push(access);
         }
         *has_side_effects |= access->HasSideEffects();
         if (position != -1) {
           access->set_position(position);
         }
         if_jsarray->Goto(join);
 
         set_current_block(if_fastobject);
-        elements = AddInstruction(new(zone()) HLoadElements(object));
-        elements->ClearFlag(HValue::kUseGVN);
         length = AddInstruction(new(zone()) HFixedArrayLength(elements));
         checked_key = AddInstruction(new(zone()) HBoundsCheck(key, length));
         if (is_store) {
-          access = AddInstruction(
-              new(zone()) HStoreKeyedFastElement(elements, checked_key, val));
+          if (fast_double_elements) {
+            access = AddInstruction(
+                new(zone()) HStoreKeyedFastDoubleElement(elements,
+                                                         checked_key,
+                                                         val));
+          } else {
+            access = AddInstruction(
+                new(zone()) HStoreKeyedFastElement(elements, checked_key, val));
+          }
         } else {
-          access = AddInstruction(
-              new(zone()) HLoadKeyedFastElement(elements, checked_key));
+          if (fast_double_elements) {
+            access = AddInstruction(
+                new(zone()) HLoadKeyedFastDoubleElement(elements, checked_key));
+          } else {
+            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));
@@ skipping 104 matching lines @@
   expr->RecordTypeFeedback(oracle());
 
   if (TryArgumentsAccess(expr)) return;
 
   CHECK_ALIVE(VisitForValue(expr->obj()));
 
   HInstruction* instr = NULL;
   if (expr->IsArrayLength()) {
     HValue* array = Pop();
     AddInstruction(new(zone()) HCheckNonSmi(array));
-    AddInstruction(HCheckInstanceType::NewIsJSArray(array));
-    instr = new(zone()) HJSArrayLength(array);
+    HInstruction* mapcheck =
+        AddInstruction(HCheckInstanceType::NewIsJSArray(array));
+    instr = new(zone()) HJSArrayLength(array, mapcheck);
 
   } else if (expr->IsStringLength()) {
     HValue* string = Pop();
     AddInstruction(new(zone()) HCheckNonSmi(string));
     AddInstruction(HCheckInstanceType::NewIsString(string));
     instr = new(zone()) HStringLength(string);
   } else if (expr->IsStringAccess()) {
     CHECK_ALIVE(VisitForValue(expr->key()));
     HValue* index = Pop();
     HValue* string = Pop();
@@ skipping 1271 matching lines @@
       Visit(expr->right());
     }
 
   } else if (ast_context()->IsValue()) {
     CHECK_ALIVE(VisitForValue(expr->left()));
     ASSERT(current_block() != NULL);
 
     // We need an extra block to maintain edge-split form.
     HBasicBlock* empty_block = graph()->CreateBasicBlock();
     HBasicBlock* eval_right = graph()->CreateBasicBlock();
+    unsigned test_id = expr->left()->test_id();
+    ToBooleanStub::Types expected(oracle()->ToBooleanTypes(test_id));
     HBranch* test = is_logical_and
-      ? new(zone()) HBranch(Top(), eval_right, empty_block)
-      : new(zone()) HBranch(Top(), empty_block, eval_right);
+      ? new(zone()) HBranch(Top(), eval_right, empty_block, expected)
+      : new(zone()) HBranch(Top(), empty_block, eval_right, expected);
     current_block()->Finish(test);
 
     set_current_block(eval_right);
     Drop(1);  // Value of the left subexpression.
     CHECK_BAILOUT(VisitForValue(expr->right()));
 
     HBasicBlock* join_block =
       CreateJoin(empty_block, current_block(), expr->id());
     set_current_block(join_block);
     return ast_context()->ReturnValue(Pop());
@@ skipping 1202 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify();
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal