[turbofan] Change End to take a variable number of inputs.

src/compiler/osr.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.h"
 #include "src/compiler/all-nodes.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/control-reducer.h"
 #include "src/compiler/frame.h"
 #include "src/compiler/graph.h"
@@ skipping 210 matching lines @@
   // Kill the outer loops in the original graph.
   TRACE("Killing outer loop headers...\n");
   for (LoopTree::Loop* outer = osr_loop->parent(); outer;
        outer = outer->parent()) {
     Node* loop_header = loop_tree->HeaderNode(outer);
     loop_header->ReplaceUses(dead);
     TRACE(" ---- #%d:%s\n", loop_header->id(), loop_header->op()->mnemonic());
   }
 
   // Merge the ends of the graph copies.
-  Node* end = graph->end();
-  tmp_inputs.clear();
-  for (int i = -1; i < static_cast<int>(copies.size()); i++) {
-    Node* input = end->InputAt(0);
-    if (i >= 0) input = copies[i]->at(input->id());
-    if (input->opcode() == IrOpcode::kMerge) {
-      for (Node* node : input->inputs()) tmp_inputs.push_back(node);
-    } else {
-      tmp_inputs.push_back(input);
+  Node* const end = graph->end();
+  int const input_count = end->InputCount();
+  for (int i = 0; i < input_count; ++i) {
+    NodeId const id = end->InputAt(i)->id();
+    for (NodeVector* const copy : copies) {
+      end->AppendInput(graph->zone(), copy->at(id));
+      end->set_op(common->End(end->InputCount()));
     }
   }
-  int count = static_cast<int>(tmp_inputs.size());
-  Node* merge = graph->NewNode(common->Merge(count), count, &tmp_inputs[0]);
-  end->ReplaceInput(0, merge);
 
   if (FLAG_trace_turbo_graph) {  // Simple textual RPO.
     OFStream os(stdout);
     os << "-- Graph after OSR duplication -- " << std::endl;
     os << AsRPO(*graph);
   }
 }
 
 
 static void TransferOsrValueTypesFromLoopPhis(Zone* zone, Node* osr_loop_entry,
@@ skipping 98 matching lines @@
   // the first spill slots.
   frame->ReserveSpillSlots(UnoptimizedFrameSlots());
   // The frame needs to be adjusted by the number of unoptimized frame slots.
   frame->SetOsrStackSlotCount(static_cast<int>(UnoptimizedFrameSlots()));
 }
 
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8