[turbofan] Nodes are killed by resetting all their inputs to zero.

src/compiler/value-numbering-reducer-unittest.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 <limits>
 
 #include "src/compiler/graph.h"
 #include "src/compiler/value-numbering-reducer.h"
 #include "src/test/test-utils.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 namespace {
 
 const SimpleOperator kOp0(0, Operator::kNoProperties, 0, 1, "op0");
+const SimpleOperator kOp1(1, Operator::kNoProperties, 1, 1, "op1");
 
 }  // namespace
 
 
 class ValueNumberingReducerTest : public TestWithZone {
  public:
   ValueNumberingReducerTest() : graph_(zone()), reducer_(zone()) {}
 
  protected:
   Reduction Reduce(Node* node) { return reducer_.Reduce(node); }
 
   Graph* graph() { return &graph_; }
 
  private:
   Graph graph_;
   ValueNumberingReducer reducer_;
 };
 
 
 TEST_F(ValueNumberingReducerTest, AllInputsAreChecked) {
   Node* na = graph()->NewNode(&kOp0);
   Node* nb = graph()->NewNode(&kOp0);
   Node* n1 = graph()->NewNode(&kOp0, na);
   Node* n2 = graph()->NewNode(&kOp0, nb);
   EXPECT_FALSE(Reduce(n1).Changed());
   EXPECT_FALSE(Reduce(n2).Changed());
 }
 
 
-TEST_F(ValueNumberingReducerTest, KilledNodesAreNeverReturned) {
-  Node* n1 = graph()->NewNode(&kOp0);
+TEST_F(ValueNumberingReducerTest, DeadNodesAreNeverReturned) {
+  Node* n0 = graph()->NewNode(&kOp0);
+  Node* n1 = graph()->NewNode(&kOp1, n0);
   EXPECT_FALSE(Reduce(n1).Changed());
   n1->Kill();
-  EXPECT_FALSE(Reduce(graph()->NewNode(&kOp0)).Changed());
+  EXPECT_FALSE(Reduce(graph()->NewNode(&kOp1, n0)).Changed());
 }
 
 
 TEST_F(ValueNumberingReducerTest, OperatorEqualityNotIdentity) {
   static const size_t kMaxInputCount = 16;
   Node* inputs[kMaxInputCount];
   for (size_t i = 0; i < arraysize(inputs); ++i) {
     Operator::Opcode opcode = static_cast<Operator::Opcode>(
         std::numeric_limits<Operator::Opcode>::max() - i);
     inputs[i] = graph()->NewNode(new (zone()) SimpleOperator(
@@ skipping 47 matching lines @@
 
 TEST_F(ValueNumberingReducerTest, WontReplaceNodeWithItself) {
   Node* n = graph()->NewNode(&kOp0);
   EXPECT_FALSE(Reduce(n).Changed());
   EXPECT_FALSE(Reduce(n).Changed());
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8