[turbofan] Reduce memory consumption of graph building

src/compiler/graph-builder.cc

 // Copyright 2013 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/graph-builder.h"
 
 #include "src/compiler.h"
 #include "src/compiler/generic-graph.h"
 #include "src/compiler/generic-node.h"
 #include "src/compiler/generic-node-inl.h"
 #include "src/compiler/graph-visualizer.h"
 #include "src/compiler/node-properties.h"
 #include "src/compiler/node-properties-inl.h"
 #include "src/compiler/operator-properties.h"
 #include "src/compiler/operator-properties-inl.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 
 StructuredGraphBuilder::StructuredGraphBuilder(Graph* graph,
                                                CommonOperatorBuilder* common)
     : GraphBuilder(graph),
       common_(common),
       environment_(NULL),
       local_zone_(isolate()),
+      input_buffer_size_(0),
+      input_buffer_(NULL),
       current_context_(NULL),
-      exit_control_(NULL) {}
+      exit_control_(NULL) {
+  EnsureInputBufferSize(kInputBufferSizeIncrement);
+}
+
+
+Node** StructuredGraphBuilder::EnsureInputBufferSize(int size) {
+  if (size > input_buffer_size_) {
+    size += kInputBufferSizeIncrement;
+    input_buffer_ = local_zone()->NewArray<Node*>(size);
+  }
+  return input_buffer_;
+}
 
 
 Node* StructuredGraphBuilder::MakeNode(const Operator* op,
                                        int value_input_count,
-                                       Node** value_inputs) {
+                                       Node** value_inputs, bool incomplete) {
   DCHECK(op->InputCount() == value_input_count);
 
   bool has_context = OperatorProperties::HasContextInput(op);
   bool has_framestate = OperatorProperties::HasFrameStateInput(op);
   bool has_control = OperatorProperties::GetControlInputCount(op) == 1;
   bool has_effect = OperatorProperties::GetEffectInputCount(op) == 1;
 
   DCHECK(OperatorProperties::GetControlInputCount(op) < 2);
   DCHECK(OperatorProperties::GetEffectInputCount(op) < 2);
 
   Node* result = NULL;
   if (!has_context && !has_framestate && !has_control && !has_effect) {
-    result = graph()->NewNode(op, value_input_count, value_inputs);
+    result = graph()->NewNode(op, value_input_count, value_inputs, incomplete);
   } else {
     int input_count_with_deps = value_input_count;
     if (has_context) ++input_count_with_deps;
     if (has_framestate) ++input_count_with_deps;
     if (has_control) ++input_count_with_deps;
     if (has_effect) ++input_count_with_deps;
-    Node** buffer = local_zone()->NewArray<Node*>(input_count_with_deps);
+    Node** buffer = EnsureInputBufferSize(input_count_with_deps);
     memcpy(buffer, value_inputs, kPointerSize * value_input_count);
     Node** current_input = buffer + value_input_count;
     if (has_context) {
       *current_input++ = current_context();
     }
     if (has_framestate) {
       // The frame state will be inserted later. Here we misuse
       // the dead_control node as a sentinel to be later overwritten
       // with the real frame state.
       *current_input++ = dead_control();
     }
     if (has_effect) {
       *current_input++ = environment_->GetEffectDependency();
     }
     if (has_control) {
       *current_input++ = environment_->GetControlDependency();
     }
-    result = graph()->NewNode(op, input_count_with_deps, buffer);
+    result = graph()->NewNode(op, input_count_with_deps, buffer, incomplete);
     if (has_effect) {
       environment_->UpdateEffectDependency(result);
     }
     if (OperatorProperties::HasControlOutput(result->op()) &&
         !environment()->IsMarkedAsUnreachable()) {
       environment_->UpdateControlDependency(result);
     }
   }
 
   return result;
@@ skipping 35 matching lines @@
 void StructuredGraphBuilder::Environment::Merge(Environment* other) {
   DCHECK(values_.size() == other->values_.size());
 
   // Nothing to do if the other environment is dead.
   if (other->IsMarkedAsUnreachable()) return;
 
   // Resurrect a dead environment by copying the contents of the other one and
   // placing a singleton merge as the new control dependency.
   if (this->IsMarkedAsUnreachable()) {
     Node* other_control = other->control_dependency_;
-    control_dependency_ = graph()->NewNode(common()->Merge(1), other_control);
+    Node* inputs[] = {other_control};
+    control_dependency_ =
+        graph()->NewNode(common()->Merge(1), arraysize(inputs), inputs, true);

[Michael Starzinger, 2014/10/27 09:34:19]

suggestion: Having the "incomplete" parameter (with default value) on the
one-operand NewNode method might slightly increase readability.

     effect_dependency_ = other->effect_dependency_;
     values_ = other->values_;
     return;
   }
 
   // Create a merge of the control dependencies of both environments and update
   // the current environment's control dependency accordingly.
   Node* control = builder_->MergeControl(this->GetControlDependency(),
                                          other->GetControlDependency());
   UpdateControlDependency(control);
@@ skipping 18 matching lines @@
     Node* phi = builder_->NewPhi(1, values()->at(i), control);
     values()->at(i) = phi;
   }
   Node* effect = builder_->NewEffectPhi(1, GetEffectDependency(), control);
   UpdateEffectDependency(effect);
 }
 
 
 Node* StructuredGraphBuilder::NewPhi(int count, Node* input, Node* control) {
   const Operator* phi_op = common()->Phi(kMachAnyTagged, count);
-  Node** buffer = local_zone()->NewArray<Node*>(count + 1);
+  Node** buffer = EnsureInputBufferSize(count + 1);
   MemsetPointer(buffer, input, count);
   buffer[count] = control;
   return graph()->NewNode(phi_op, count + 1, buffer, true);
 }
 
 
 // TODO(mstarzinger): Revisit this once we have proper effect states.
 Node* StructuredGraphBuilder::NewEffectPhi(int count, Node* input,
                                            Node* control) {
   const Operator* phi_op = common()->EffectPhi(count);
-  Node** buffer = local_zone()->NewArray<Node*>(count + 1);
+  Node** buffer = EnsureInputBufferSize(count + 1);
   MemsetPointer(buffer, input, count);
   buffer[count] = control;
   return graph()->NewNode(phi_op, count + 1, buffer, true);
 }
 
 
 Node* StructuredGraphBuilder::MergeControl(Node* control, Node* other) {
   int inputs = OperatorProperties::GetControlInputCount(control->op()) + 1;
   if (control->opcode() == IrOpcode::kLoop) {
     // Control node for loop exists, add input.
     const Operator* op = common()->Loop(inputs);
     control->AppendInput(graph_zone(), other);
     control->set_op(op);
   } else if (control->opcode() == IrOpcode::kMerge) {
     // Control node for merge exists, add input.
     const Operator* op = common()->Merge(inputs);
     control->AppendInput(graph_zone(), other);
     control->set_op(op);
   } else {
     // Control node is a singleton, introduce a merge.
     const Operator* op = common()->Merge(inputs);
-    control = graph()->NewNode(op, control, other);
+    Node* inputs[] = {control, other};
+    control = graph()->NewNode(op, arraysize(inputs), inputs, true);

[Michael Starzinger, 2014/10/27 09:34:19]

suggestion: Having the "incomplete" parameter (with default value) on the
two-operand NewNode method might slightly increase readability.

   }
   return control;
 }
 
 
 Node* StructuredGraphBuilder::MergeEffect(Node* value, Node* other,
                                           Node* control) {
   int inputs = OperatorProperties::GetControlInputCount(control->op());
   if (value->opcode() == IrOpcode::kEffectPhi &&
       NodeProperties::GetControlInput(value) == control) {
@@ skipping 30 matching lines @@
   if (!dead_control_.is_set()) {
     Node* dead_node = graph()->NewNode(common_->Dead());
     dead_control_.set(dead_node);
     return dead_node;
   }
   return dead_control_.get();
 }
 }
 }
 }  // namespace v8::internal::compiler