[turbofan] First version of loop peeling.

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-marker.h"
 #include "src/compiler/node-matchers.h"
@@ skipping 438 matching lines @@
     if (live > 1 && live == node->InputCount()) return node;  // nothing to do.
 
     TRACE(("ReduceMerge: #%d:%s (%d live)\n", node->id(),
            node->op()->mnemonic(), live));
 
     if (live == 0) return dead();  // no remaining inputs.
 
     // Gather phis and effect phis to be edited.
     ZoneVector<Node*> phis(zone_);
     for (Node* const use : node->uses()) {
-      if (use->opcode() == IrOpcode::kPhi ||
-          use->opcode() == IrOpcode::kEffectPhi) {
-        phis.push_back(use);
-      }
+      if (IrOpcode::IsPhiOpcode(use->opcode())) phis.push_back(use);
     }
 
     if (live == 1) {
       // All phis are redundant. Replace them with their live input.
       for (Node* const phi : phis) ReplaceNode(phi, phi->InputAt(live_index));
       // The merge itself is redundant.
       return node->InputAt(live_index);
     }
 
     // Edit phis in place, removing dead inputs and revisiting them.
@@ skipping 114 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