Add copy support in inliner.

src/compiler/js-inlining.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/ast-graph-builder.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/generic-node-inl.h"
 #include "src/compiler/graph-inl.h"
 #include "src/compiler/graph-visualizer.h"
 #include "src/compiler/js-inlining.h"
@@ skipping 49 matching lines @@
   CHECK(Scope::Analyze(info));
   CHECK_NE(NULL, info->scope());
   Handle<ScopeInfo> scope_info = ScopeInfo::Create(info->scope(), info->zone());
   info->shared_info()->set_scope_info(*scope_info);
 }
 
 
 // A facade on a JSFunction's graph to facilitate inlining. It assumes the
 // that the function graph has only one return statement, and provides
 // {UnifyReturn} to convert a function graph to that end.
 // InlineAtCall will create some new nodes using {graph}'s builders (and hence

[Michael Starzinger, 2014/09/09 11:52:15]

nit: The last sentence of the comment is slightly out of date, let's adapt it.

[sigurds, 2014/09/15 10:29:09]

Done.

 // those nodes will live in {graph}'s zone.
 class Inlinee {
  public:
-  explicit Inlinee(JSGraph* graph) : jsgraph_(graph) {}
-
-  Graph* graph() { return jsgraph_->graph(); }
-  JSGraph* jsgraph() { return jsgraph_; }
+  Inlinee(Node* start, Node* end) : start_(start), end_(end) {}
 
   // Returns the last regular control node, that is
   // the last control node before the end node.
   Node* end_block() { return NodeProperties::GetControlInput(unique_return()); }
 
   // Return the effect output of the graph,
   // that is the effect input of the return statement of the inlinee.
   Node* effect_output() {
     return NodeProperties::GetEffectInput(unique_return());
   }
   // Return the value output of the graph,
   // that is the value input of the return statement of the inlinee.
   Node* value_output() {
     return NodeProperties::GetValueInput(unique_return(), 0);
   }
   // Return the unique return statement of the graph.
   Node* unique_return() {
-    Node* unique_return =
-        NodeProperties::GetControlInput(jsgraph_->graph()->end());
+    Node* unique_return = NodeProperties::GetControlInput(end_);
     DCHECK_EQ(IrOpcode::kReturn, unique_return->opcode());
     return unique_return;
   }
   // Inline this graph at {call}, use {jsgraph} and its zone to create
   // any new nodes.
   void InlineAtCall(JSGraph* jsgraph, Node* call);
+
   // Ensure that only a single return reaches the end node.
-  void UnifyReturn();
+  static void UnifyReturn(JSGraph* jsgraph);
 
  private:
-  JSGraph* jsgraph_;
+  Node* start_;
+  Node* end_;
 };
 
 
-void Inlinee::UnifyReturn() {
-  Graph* graph = jsgraph_->graph();
+void Inlinee::UnifyReturn(JSGraph* jsgraph) {
+  Graph* graph = jsgraph->graph();
 
   Node* final_merge = NodeProperties::GetControlInput(graph->end(), 0);
   if (final_merge->opcode() == IrOpcode::kReturn) {
     // nothing to do
     return;
   }
   DCHECK_EQ(IrOpcode::kMerge, final_merge->opcode());
 
   int predecessors =
       OperatorProperties::GetControlInputCount(final_merge->op());
-  Operator* op_phi = jsgraph_->common()->Phi(kMachAnyTagged, predecessors);
-  Operator* op_ephi = jsgraph_->common()->EffectPhi(predecessors);
+  Operator* op_phi = jsgraph->common()->Phi(kMachAnyTagged, predecessors);
+  Operator* op_ephi = jsgraph->common()->EffectPhi(predecessors);
 
-  NodeVector values(jsgraph_->zone());
-  NodeVector effects(jsgraph_->zone());
+  NodeVector values(jsgraph->zone());
+  NodeVector effects(jsgraph->zone());
   // Iterate over all control flow predecessors,
   // which must be return statements.
   InputIter iter = final_merge->inputs().begin();
   while (iter != final_merge->inputs().end()) {
     Node* input = *iter;
     switch (input->opcode()) {
       case IrOpcode::kReturn:
         values.push_back(NodeProperties::GetValueInput(input, 0));
         effects.push_back(NodeProperties::GetEffectInput(input));
         iter.UpdateToAndIncrement(NodeProperties::GetControlInput(input));
         input->RemoveAllInputs();
         break;
       default:
         UNREACHABLE();
         ++iter;
         break;
     }
   }
   values.push_back(final_merge);
   effects.push_back(final_merge);
   Node* phi =
       graph->NewNode(op_phi, static_cast<int>(values.size()), &values.front());
   Node* ephi = graph->NewNode(op_ephi, static_cast<int>(effects.size()),
                               &effects.front());
   Node* new_return =
-      graph->NewNode(jsgraph_->common()->Return(), phi, ephi, final_merge);
+      graph->NewNode(jsgraph->common()->Return(), phi, ephi, final_merge);
   graph->end()->ReplaceInput(0, new_return);
 }
 
 
+class CopyVisitor : public NullNodeVisitor {
+ public:
+  CopyVisitor(Graph* source_graph, JSGraph* target_graph, Zone* temp_zone)
+      : copies_(source_graph->NodeCount(), NULL, temp_zone),
+        sentinels_(source_graph->NodeCount(), NULL, temp_zone),
+        source_graph_(source_graph),
+        target_graph_(target_graph),
+        temp_zone_(temp_zone) {}
+
+  GenericGraphVisit::Control Post(Node* original) {
+    NodeVector inputs(temp_zone_);
+    for (InputIter it = original->inputs().begin();
+         it != original->inputs().end(); ++it) {
+      inputs.push_back(GetCopy(*it));
+    }
+
+    // Reuse the operator in the copy. This assumes that op lives in a zone
+    // that lives longer than graph()'s zone.
+    Node* copy = target_graph_->graph()->NewNode(original->op(), inputs.size(),
+                                                 &inputs.front());
+    copies_[original->id()] = copy;
+    return GenericGraphVisit::CONTINUE;
+  }
+
+  Node* GetCopy(Node* original) {
+    Node* copy = copies_[original->id()];
+    if (copy == NULL) {
+      copy = GetSentinel(original);
+    }
+    return copy;
+  }
+
+  void CopyGraph() {
+    source_graph_->VisitNodeInputsFromEnd(this);
+    ReplaceSentinels();
+  }
+
+  const NodeVector& copies() { return copies_; }
+
+ private:
+  void ReplaceSentinels() {
+    for (int id = 0; id < source_graph_->NodeCount(); ++id) {
+      Node* sentinel = sentinels_[id];
+      if (sentinel == NULL) continue;
+      Node* copy = copies_[id];
+      DCHECK_NE(NULL, copy);
+      sentinel->ReplaceUses(copy);
+    }
+  }
+
+  Node* GetSentinel(Node* original) {
+    Node* sentinel = sentinels_[original->id()];
+    if (sentinel == NULL) {
+      // Create a dummy node we can replace later.
+      sentinel = target_graph_->graph()->NewNode(
+          target_graph_->common()->Int32Constant(0));
+    }
+    return sentinel;
+  }
+
+  NodeVector copies_;
+  NodeVector sentinels_;
+  Graph* source_graph_;
+  JSGraph* target_graph_;

[Michael Starzinger, 2014/09/09 11:52:15]

I think the target_graph_ should be of type "Graph*" as well. The only place
where we need the original type graph is to create the operator for the
sentinel. Could we either just use NULL as the operator of the sentinel or pass
in one constant sentinel operator from the outside?

[sigurds, 2014/09/15 10:29:09]

Done.

+  Zone* temp_zone_;
+};
+
+
 void Inlinee::InlineAtCall(JSGraph* jsgraph, Node* call) {
-  MachineOperatorBuilder machine(jsgraph->zone());
-
   // The scheduler is smart enough to place our code; we just ensure {control}
   // becomes the control input of the start of the inlinee.
   Node* control = NodeProperties::GetControlInput(call);
 
   // The inlinee uses the context from the JSFunction object. This will
   // also be the effect dependency for the inlinee as it produces an effect.
   // TODO(sigurds) Use simplified load once it is ready.
   Node* context = jsgraph->graph()->NewNode(
-      machine.Load(kMachAnyTagged), NodeProperties::GetValueInput(call, 0),
+      jsgraph->machine()->Load(kMachAnyTagged),
+      NodeProperties::GetValueInput(call, 0),
       jsgraph->Int32Constant(JSFunction::kContextOffset - kHeapObjectTag),
       NodeProperties::GetEffectInput(call));
 
   // {inlinee_inputs} counts JSFunction, Receiver, arguments, context,
   // but not effect, control.
-  int inlinee_inputs = graph()->start()->op()->OutputCount();
+  int inlinee_inputs = start_->op()->OutputCount();
   // Context is last argument.
   int inlinee_context_index = inlinee_inputs - 1;
   // {inliner_inputs} counts JSFunction, Receiver, arguments, but not
   // context, effect, control.
   int inliner_inputs = OperatorProperties::GetValueInputCount(call->op());
   // Iterate over all uses of the start node.
-  UseIter iter = graph()->start()->uses().begin();
-  while (iter != graph()->start()->uses().end()) {
+  UseIter iter = start_->uses().begin();
+  while (iter != start_->uses().end()) {
     Node* use = *iter;
     switch (use->opcode()) {
       case IrOpcode::kParameter: {
         int index = 1 + OpParameter<int>(use->op());
         if (index < inliner_inputs && index < inlinee_context_index) {
           // There is an input from the call, and the index is a value
           // projection but not the context, so rewire the input.
           NodeProperties::ReplaceWithValue(*iter, call->InputAt(index));
         } else if (index == inlinee_context_index) {
           // This is the context projection, rewire it to the context from the
@@ skipping 33 matching lines @@
       iter.UpdateToAndIncrement(value_output());
     }
   }
   call->RemoveAllInputs();
   DCHECK_EQ(0, call->UseCount());
   // TODO(sigurds) Remove this once we copy.
   unique_return()->RemoveAllInputs();
 }
 
 
-void JSInliner::TryInlineCall(Node* node) {
-  DCHECK_EQ(IrOpcode::kJSCallFunction, node->opcode());
+void JSInliner::TryInlineCall(Node* call) {
+  DCHECK_EQ(IrOpcode::kJSCallFunction, call->opcode());
 
-  HeapObjectMatcher<JSFunction> match(node->InputAt(0));
+  HeapObjectMatcher<JSFunction> match(call->InputAt(0));
   if (!match.HasValue()) {
     return;
   }
 
   Handle<JSFunction> function = match.Value().handle();
 
   if (function->shared()->native()) {
     if (FLAG_trace_turbo_inlining) {
       SmartArrayPointer<char> name =
           function->shared()->DebugName()->ToCString();
@@ skipping 17 matching lines @@
     }
     return;
   }
 
   if (FLAG_trace_turbo_inlining) {
     SmartArrayPointer<char> name = function->shared()->DebugName()->ToCString();
     PrintF("Inlining %s into %s\n", name.get(),
            info_->shared_info()->DebugName()->ToCString().get());
   }
 
-  Graph graph(info_->zone());
-  graph.SetNextNodeId(jsgraph_->graph()->NextNodeID());
-
-  Typer typer(info_->zone());
-  CommonOperatorBuilder common(info_->zone());
-  JSGraph jsgraph(&graph, &common, &typer);
+  Graph graph(info.zone());
+  Typer typer(info.zone());
+  JSGraph jsgraph(&graph, jsgraph_->common(), jsgraph_->javascript(), &typer,
+                  jsgraph_->machine());
 
   AstGraphBuilder graph_builder(&info, &jsgraph);
   graph_builder.CreateGraph();
+  Inlinee::UnifyReturn(&jsgraph);
 
-  Inlinee inlinee(&jsgraph);
-  inlinee.UnifyReturn();
-  inlinee.InlineAtCall(jsgraph_, node);
+  CopyVisitor visitor(&graph, jsgraph_, jsgraph_->zone());
+  visitor.CopyGraph();
 
-  jsgraph_->graph()->SetNextNodeId(inlinee.graph()->NextNodeID());
+  Inlinee inlinee(visitor.GetCopy(graph.start()), visitor.GetCopy(graph.end()));
+  inlinee.InlineAtCall(jsgraph_, call);
 }
 }
 }
 }  // namespace v8::internal::compiler