[turbofan] Pull ResizeMergeOrPhi into CommonOperatorBuilder and use in ControlReducer.

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 491 matching lines @@
         ReplaceNode(use, (result == kTrue) ? dead() : control);
         control = NodeProperties::GetControlInput(node);  // Could change!
       }
     }
     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++) {
+    int live = 0;
+    for (int i = 0; i < merge->InputCount(); i++) {
       // skip dead inputs.
-      if (i < merge->InputCount() &&
-          merge->InputAt(i)->opcode() == IrOpcode::kDead)
-        continue;
+      if (merge->InputAt(i)->opcode() == IrOpcode::kDead) continue;
       // compact live inputs.
-      if (pos != i) node->ReplaceInput(pos, node->InputAt(i));
-      pos++;
+      if (live != i) node->ReplaceInput(live, node->InputAt(i));
+      live++;
     }
-    node->TrimInputCount(pos);
-    if (node->opcode() == IrOpcode::kPhi) {
-      node->set_op(common_->Phi(OpParameter<MachineType>(node->op()), pos - 1));
-    } else if (node->opcode() == IrOpcode::kEffectPhi) {
-      node->set_op(common_->EffectPhi(pos - 1));
-    } else if (node->opcode() == IrOpcode::kMerge) {
-      node->set_op(common_->Merge(pos));
-    } else if (node->opcode() == IrOpcode::kLoop) {
-      node->set_op(common_->Loop(pos));
-    } else {
-      UNREACHABLE();
+    // compact remaining inputs.
+    int total = live;
+    for (int i = merge->InputCount(); i < node->InputCount(); i++) {
+      if (total != i) node->ReplaceInput(total, node->InputAt(i));
+      total++;
     }
+    DCHECK_EQ(total, live + node->InputCount() - merge->InputCount());
+    DCHECK_NE(total, node->InputCount());
+    node->TrimInputCount(total);
+    node->set_op(common_->ResizeMergeOrPhi(node->op(), live));
   }
 
   // Replace uses of {node} with {replacement} and revisit the uses.
   void ReplaceNode(Node* node, Node* replacement) {
     if (node == replacement) return;
     TRACE(("  Replace: #%d:%s with #%d:%s\n", node->id(),
            node->op()->mnemonic(), replacement->id(),
            replacement->op()->mnemonic()));
     for (Node* const use : node->uses()) {
       // Don't revisit this node if it refers to itself.
@@ skipping 41 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