Clean up node iteration

src/compiler/control-reducer.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/common-operator.h"
 #include "src/compiler/control-reducer.h"
 #include "src/compiler/graph.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties-inl.h"
@@ skipping 197 matching lines @@
 
     // Process cached nodes in the JSGraph too.
     jsgraph_->GetCachedNodes(&nodes);
     TrimNodes(nodes);
   }
 
   void TrimNodes(NodeVector& nodes) {
     // Remove dead->live edges.
     for (size_t j = 0; j < nodes.size(); j++) {
       Node* node = nodes[j];
-      for (UseIter i = node->uses().begin(); i != node->uses().end();) {
-        size_t id = static_cast<size_t>((*i)->id());
+      for (auto edge : node->use_edges()) {

[Michael Starzinger, 2014/11/28 13:55:46]

Can we pretty please with a cherry on top just write "Edge edge" instead of
"auto edge" here and everywhere else?

+        Node* use = edge.from();
+        size_t id = static_cast<size_t>(use->id());
         if (state_[id] != kVisited) {
-          TRACE(("DeadLink: #%d:%s(%d) -> #%d:%s\n", (*i)->id(),
-                 (*i)->op()->mnemonic(), i.index(), node->id(),
+          TRACE(("DeadLink: #%d:%s(%d) -> #%d:%s\n", use->id(),
+                 use->op()->mnemonic(), edge.index(), node->id(),
                  node->op()->mnemonic()));
-          i.UpdateToAndIncrement(NULL);
-        } else {
-          ++i;
+          edge.UpdateTo(NULL);
         }
       }
     }
 #if DEBUG
     // Verify that no inputs to live nodes are NULL.
     for (size_t j = 0; j < nodes.size(); j++) {
       Node* node = nodes[j];
       for (Node* const input : node->inputs()) {
         CHECK_NE(NULL, input);
       }
@@ skipping 209 matching lines @@
   // Reduce branches if they have constant inputs.
   Node* ReduceBranch(Node* node) {
     Decision result = DecideCondition(node->InputAt(0));
     if (result == kUnknown) return node;
 
     TRACE(("BranchReduce: #%d:%s = %s\n", node->id(), node->op()->mnemonic(),
            (result == kTrue) ? "true" : "false"));
 
     // Replace IfTrue and IfFalse projections from this branch.
     Node* control = NodeProperties::GetControlInput(node);
-    for (UseIter i = node->uses().begin(); i != node->uses().end();) {
-      Node* to = *i;
-      if (to->opcode() == IrOpcode::kIfTrue) {
-        TRACE(("  IfTrue: #%d:%s\n", to->id(), to->op()->mnemonic()));
-        i.UpdateToAndIncrement(NULL);
-        ReplaceNode(to, (result == kTrue) ? control : dead());
-      } else if (to->opcode() == IrOpcode::kIfFalse) {
-        TRACE(("  IfFalse: #%d:%s\n", to->id(), to->op()->mnemonic()));
-        i.UpdateToAndIncrement(NULL);
-        ReplaceNode(to, (result == kTrue) ? dead() : control);
-      } else {
-        ++i;
+    for (auto edge : node->use_edges()) {
+      Node* use = edge.from();
+      if (use->opcode() == IrOpcode::kIfTrue) {
+        TRACE(("  IfTrue: #%d:%s\n", use->id(), use->op()->mnemonic()));
+        edge.UpdateTo(NULL);
+        ReplaceNode(use, (result == kTrue) ? control : dead());
+      } else if (use->opcode() == IrOpcode::kIfFalse) {
+        TRACE(("  IfFalse: #%d:%s\n", use->id(), use->op()->mnemonic()));
+        edge.UpdateTo(NULL);
+        ReplaceNode(use, (result == kTrue) ? dead() : control);
       }
     }
     return control;
   }
 
   // Remove inputs to {node} corresponding to the dead inputs to {merge}
   // and compact the remaining inputs, updating the operator.
   void RemoveDeadInputs(Node* merge, Node* node) {
     int pos = 0;
     for (int i = 0; i < node->InputCount(); i++) {
@@ skipping 72 matching lines @@
 Node* ControlReducer::ReduceBranchForTesting(JSGraph* jsgraph,
                                              CommonOperatorBuilder* common,
                                              Node* node) {
   Zone zone(jsgraph->graph()->zone()->isolate());
   ControlReducerImpl impl(&zone, jsgraph, common);
   return impl.ReduceBranch(node);
 }
 }
 }
 }  // namespace v8::internal::compiler