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test/cctest/compiler/test-graph-reducer.cc

Index: test/cctest/compiler/test-graph-reducer.cc
diff --git a/test/cctest/compiler/test-graph-reducer.cc b/test/cctest/compiler/test-graph-reducer.cc
new file mode 100644
index 0000000000000000000000000000000000000000..445162f13700d8f5697fca5bd945b228e73f22ee
--- /dev/null
+++ b/test/cctest/compiler/test-graph-reducer.cc
@@ -0,0 +1,668 @@
+// 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/v8.h"
+
+#include "graph-tester.h"
+#include "src/compiler/generic-node-inl.h"
+#include "src/compiler/graph-reducer.h"
+
+using namespace v8::internal;
+using namespace v8::internal::compiler;
+
+const uint8_t OPCODE_A0 = 10;
+const uint8_t OPCODE_A1 = 11;
+const uint8_t OPCODE_A2 = 12;
+const uint8_t OPCODE_B0 = 20;
+const uint8_t OPCODE_B1 = 21;
+const uint8_t OPCODE_B2 = 22;
+const uint8_t OPCODE_C0 = 30;
+const uint8_t OPCODE_C1 = 31;
+const uint8_t OPCODE_C2 = 32;
+
+static SimpleOperator OPA0(OPCODE_A0, Operator::kNoWrite, 0, 0, "opa0");
+static SimpleOperator OPA1(OPCODE_A1, Operator::kNoWrite, 1, 0, "opa1");
+static SimpleOperator OPA2(OPCODE_A2, Operator::kNoWrite, 2, 0, "opa2");
+static SimpleOperator OPB0(OPCODE_B0, Operator::kNoWrite, 0, 0, "opa0");
+static SimpleOperator OPB1(OPCODE_B1, Operator::kNoWrite, 1, 0, "opa1");
+static SimpleOperator OPB2(OPCODE_B2, Operator::kNoWrite, 2, 0, "opa2");
+static SimpleOperator OPC0(OPCODE_C0, Operator::kNoWrite, 0, 0, "opc0");
+static SimpleOperator OPC1(OPCODE_C1, Operator::kNoWrite, 1, 0, "opc1");
+static SimpleOperator OPC2(OPCODE_C2, Operator::kNoWrite, 2, 0, "opc2");
+
+
+// Replaces all "A" operators with "B" operators without creating new nodes.
+class InPlaceABReducer : public Reducer {
+ public:
+  virtual Reduction Reduce(Node* node) {
+    switch (node->op()->opcode()) {
+      case OPCODE_A0:
+        CHECK_EQ(0, node->InputCount());
+        node->set_op(&OPB0);
+        return Replace(node);
+      case OPCODE_A1:
+        CHECK_EQ(1, node->InputCount());
+        node->set_op(&OPB1);
+        return Replace(node);
+      case OPCODE_A2:
+        CHECK_EQ(2, node->InputCount());
+        node->set_op(&OPB2);
+        return Replace(node);
+    }
+    return NoChange();
+  }
+};
+
+
+// Replaces all "A" operators with "B" operators by allocating new nodes.
+class NewABReducer : public Reducer {
+ public:
+  explicit NewABReducer(Graph* graph) : graph_(graph) { }
+  virtual Reduction Reduce(Node* node) {
+    switch (node->op()->opcode()) {
+      case OPCODE_A0:
+        CHECK_EQ(0, node->InputCount());
+        return Replace(graph_->NewNode(&OPB0));
+      case OPCODE_A1:
+        CHECK_EQ(1, node->InputCount());
+        return Replace(graph_->NewNode(&OPB1, node->InputAt(0)));
+      case OPCODE_A2:
+        CHECK_EQ(2, node->InputCount());
+        return Replace(graph_->NewNode(&OPB2, node->InputAt(0),
+                                       node->InputAt(1)));
+    }
+    return NoChange();
+  }
+  Graph* graph_;
+};
+
+
+// Replaces all "B" operators with "C" operators without creating new nodes.
+class InPlaceBCReducer : public Reducer {
+ public:
+  virtual Reduction Reduce(Node* node) {
+    switch (node->op()->opcode()) {
+      case OPCODE_B0:
+        CHECK_EQ(0, node->InputCount());
+        node->set_op(&OPC0);
+        return Replace(node);
+      case OPCODE_B1:
+        CHECK_EQ(1, node->InputCount());
+        node->set_op(&OPC1);
+        return Replace(node);
+      case OPCODE_B2:
+        CHECK_EQ(2, node->InputCount());
+        node->set_op(&OPC2);
+        return Replace(node);
+    }
+    return NoChange();
+  }
+};
+
+
+// Wraps all "OPA0" nodes in "OPB1" operators by allocating new nodes.
+class A0Wrapper V8_FINAL : public Reducer {
+ public:
+  explicit A0Wrapper(Graph* graph) : graph_(graph) {}
+  virtual Reduction Reduce(Node* node) V8_OVERRIDE {
+    switch (node->op()->opcode()) {
+      case OPCODE_A0:
+        CHECK_EQ(0, node->InputCount());
+        return Replace(graph_->NewNode(&OPB1, node));
+    }
+    return NoChange();
+  }
+  Graph* graph_;
+};
+
+
+// Wraps all "OPB0" nodes in two "OPC1" operators by allocating new nodes.
+class B0Wrapper V8_FINAL : public Reducer {
+ public:
+  explicit B0Wrapper(Graph* graph) : graph_(graph) {}
+  virtual Reduction Reduce(Node* node) V8_OVERRIDE {
+    switch (node->op()->opcode()) {
+      case OPCODE_B0:
+        CHECK_EQ(0, node->InputCount());
+        return Replace(graph_->NewNode(&OPC1, graph_->NewNode(&OPC1, node)));
+    }
+    return NoChange();
+  }
+  Graph* graph_;
+};
+
+
+// Replaces all "OPA1" nodes with the first input.
+class A1Forwarder : public Reducer {
+  virtual Reduction Reduce(Node* node) {
+    switch (node->op()->opcode()) {
+      case OPCODE_A1:
+        CHECK_EQ(1, node->InputCount());
+        return Replace(node->InputAt(0));
+    }
+    return NoChange();
+  }
+};
+
+
+// Replaces all "OPB1" nodes with the first input.
+class B1Forwarder : public Reducer {
+  virtual Reduction Reduce(Node* node) {
+    switch (node->op()->opcode()) {
+      case OPCODE_B1:
+        CHECK_EQ(1, node->InputCount());
+        return Replace(node->InputAt(0));
+    }
+    return NoChange();
+  }
+};
+
+
+// Swaps the inputs to "OP2A" and "OP2B" nodes based on ids.
+class AB2Sorter : public Reducer {
+  virtual Reduction Reduce(Node* node) {
+    switch (node->op()->opcode()) {
+      case OPCODE_A2:
+      case OPCODE_B2:
+        CHECK_EQ(2, node->InputCount());
+        Node* x = node->InputAt(0);
+        Node* y = node->InputAt(1);
+        if (x->id() > y->id()) {
+          node->ReplaceInput(0, y);
+          node->ReplaceInput(1, x);
+          return Replace(node);
+        }
+    }
+    return NoChange();
+  }
+};
+
+
+// Simply records the nodes visited.
+class ReducerRecorder : public Reducer {
+ public:
+  explicit ReducerRecorder(Zone* zone)
+    : set(NodeSet::key_compare(), NodeSet::allocator_type(zone)) {
+  }
+  virtual Reduction Reduce(Node* node) {
+    set.insert(node);
+    return NoChange();
+  }
+  void CheckContains(Node* node) {
+    CHECK_EQ(1, set.count(node));
+  }
+  NodeSet set;
+};
+
+
+TEST(ReduceGraphFromEnd1) {
+  GraphTester graph;
+
+  Node* n1 = graph.NewNode(&OPA0);
+  Node* end = graph.NewNode(&OPA1, n1);
+  graph.SetEnd(end);
+
+  GraphReducer reducer(&graph);
+  ReducerRecorder recorder(graph.zone());
+  reducer.AddReducer(&recorder);
+  reducer.ReduceGraph();
+  recorder.CheckContains(n1);
+  recorder.CheckContains(end);
+}
+
+
+TEST(ReduceGraphFromEnd2) {
+  GraphTester graph;
+
+  Node* n1 = graph.NewNode(&OPA0);
+  Node* n2 = graph.NewNode(&OPA1, n1);
+  Node* n3 = graph.NewNode(&OPA1, n1);
+  Node* end = graph.NewNode(&OPA2, n2, n3);
+  graph.SetEnd(end);
+
+  GraphReducer reducer(&graph);
+  ReducerRecorder recorder(graph.zone());
+  reducer.AddReducer(&recorder);
+  reducer.ReduceGraph();
+  recorder.CheckContains(n1);
+  recorder.CheckContains(n2);
+  recorder.CheckContains(n3);
+  recorder.CheckContains(end);
+}
+
+
+TEST(ReduceInPlace1) {
+  GraphTester graph;
+
+  Node* n1 = graph.NewNode(&OPA0);
+  Node* end = graph.NewNode(&OPA1, n1);
+  graph.SetEnd(end);
+
+  GraphReducer reducer(&graph);
+  InPlaceABReducer r;
+  reducer.AddReducer(&r);
+
+  // Tests A* => B* with in-place updates.
+  for (int i = 0; i < 3; i++) {
+    int before = graph.NodeCount();
+    reducer.ReduceGraph();
+    CHECK_EQ(before, graph.NodeCount());
+    CHECK_EQ(&OPB0, n1->op());
+    CHECK_EQ(&OPB1, end->op());
+    CHECK_EQ(n1, end->InputAt(0));
+  }
+}
+
+
+TEST(ReduceInPlace2) {
+  GraphTester graph;
+
+  Node* n1 = graph.NewNode(&OPA0);
+  Node* n2 = graph.NewNode(&OPA1, n1);
+  Node* n3 = graph.NewNode(&OPA1, n1);
+  Node* end = graph.NewNode(&OPA2, n2, n3);
+  graph.SetEnd(end);
+
+  GraphReducer reducer(&graph);
+  InPlaceABReducer r;
+  reducer.AddReducer(&r);
+
+  // Tests A* => B* with in-place updates.
+  for (int i = 0; i < 3; i++) {
+    int before = graph.NodeCount();
+    reducer.ReduceGraph();
+    CHECK_EQ(before, graph.NodeCount());
+    CHECK_EQ(&OPB0, n1->op());
+    CHECK_EQ(&OPB1, n2->op());
+    CHECK_EQ(n1, n2->InputAt(0));
+    CHECK_EQ(&OPB1, n3->op());
+    CHECK_EQ(n1, n3->InputAt(0));
+    CHECK_EQ(&OPB2, end->op());
+    CHECK_EQ(n2, end->InputAt(0));
+    CHECK_EQ(n3, end->InputAt(1));
+  }
+}
+
+
+TEST(ReduceNew1) {
+  GraphTester graph;
+
+  Node* n1 = graph.NewNode(&OPA0);
+  Node* n2 = graph.NewNode(&OPA1, n1);
+  Node* n3 = graph.NewNode(&OPA1, n1);
+  Node* end = graph.NewNode(&OPA2, n2, n3);
+  graph.SetEnd(end);
+
+  GraphReducer reducer(&graph);
+  NewABReducer r(&graph);
+  reducer.AddReducer(&r);
+
+  // Tests A* => B* while creating new nodes.
+  for (int i = 0; i < 3; i++) {
+    int before = graph.NodeCount();
+    reducer.ReduceGraph();
+    if (i == 0) {
+      CHECK_NE(before, graph.NodeCount());
+    } else {
+      CHECK_EQ(before, graph.NodeCount());
+    }
+    Node* nend = graph.end();
+    CHECK_NE(end, nend);  // end() should be updated too.
+
+    Node* nn2 = nend->InputAt(0);
+    Node* nn3 = nend->InputAt(1);
+    Node* nn1 = nn2->InputAt(0);
+
+    CHECK_EQ(nn1, nn3->InputAt(0));
+
+    CHECK_EQ(&OPB0, nn1->op());
+    CHECK_EQ(&OPB1, nn2->op());
+    CHECK_EQ(&OPB1, nn3->op());
+    CHECK_EQ(&OPB2, nend->op());
+  }
+}
+
+
+TEST(Wrapping1) {
+  GraphTester graph;
+
+  Node* end = graph.NewNode(&OPA0);
+  graph.SetEnd(end);
+  CHECK_EQ(1, graph.NodeCount());
+
+  GraphReducer reducer(&graph);
+  A0Wrapper r(&graph);
+  reducer.AddReducer(&r);
+
+  reducer.ReduceGraph();
+  CHECK_EQ(2, graph.NodeCount());
+
+  Node* nend = graph.end();
+  CHECK_NE(end, nend);
+  CHECK_EQ(&OPB1, nend->op());
+  CHECK_EQ(1, nend->InputCount());
+  CHECK_EQ(end, nend->InputAt(0));
+}
+
+
+TEST(Wrapping2) {
+  GraphTester graph;
+
+  Node* end = graph.NewNode(&OPB0);
+  graph.SetEnd(end);
+  CHECK_EQ(1, graph.NodeCount());
+
+  GraphReducer reducer(&graph);
+  B0Wrapper r(&graph);
+  reducer.AddReducer(&r);
+
+  reducer.ReduceGraph();
+  CHECK_EQ(3, graph.NodeCount());
+
+  Node* nend = graph.end();
+  CHECK_NE(end, nend);
+  CHECK_EQ(&OPC1, nend->op());
+  CHECK_EQ(1, nend->InputCount());
+
+  Node* n1 = nend->InputAt(0);
+  CHECK_NE(end, n1);
+  CHECK_EQ(&OPC1, n1->op());
+  CHECK_EQ(1, n1->InputCount());
+  CHECK_EQ(end, n1->InputAt(0));
+}
+
+
+TEST(Forwarding1) {
+  GraphTester graph;
+
+  Node* n1 = graph.NewNode(&OPA0);
+  Node* end = graph.NewNode(&OPA1, n1);
+  graph.SetEnd(end);
+
+  GraphReducer reducer(&graph);
+  A1Forwarder r;
+  reducer.AddReducer(&r);
+
+  // Tests A1(x) => x
+  for (int i = 0; i < 3; i++) {
+    int before = graph.NodeCount();
+    reducer.ReduceGraph();
+    CHECK_EQ(before, graph.NodeCount());
+    CHECK_EQ(&OPA0, n1->op());
+    CHECK_EQ(n1, graph.end());
+  }
+}
+
+
+TEST(Forwarding2) {
+  GraphTester graph;
+
+  Node* n1 = graph.NewNode(&OPA0);
+  Node* n2 = graph.NewNode(&OPA1, n1);
+  Node* n3 = graph.NewNode(&OPA1, n1);
+  Node* end = graph.NewNode(&OPA2, n2, n3);
+  graph.SetEnd(end);
+
+  GraphReducer reducer(&graph);
+  A1Forwarder r;
+  reducer.AddReducer(&r);
+
+  // Tests reducing A2(A1(x), A1(y)) => A2(x, y).
+  for (int i = 0; i < 3; i++) {
+    int before = graph.NodeCount();
+    reducer.ReduceGraph();
+    CHECK_EQ(before, graph.NodeCount());
+    CHECK_EQ(&OPA0, n1->op());
+    CHECK_EQ(n1, end->InputAt(0));
+    CHECK_EQ(n1, end->InputAt(1));
+    CHECK_EQ(&OPA2, end->op());
+    CHECK_EQ(0, n2->UseCount());
+    CHECK_EQ(0, n3->UseCount());
+  }
+}
+
+
+TEST(Forwarding3) {
+  // Tests reducing a chain of A1(A1(A1(A1(x)))) => x.
+  for (int i = 0; i < 8; i++) {
+    GraphTester graph;
+
+    Node* n1 = graph.NewNode(&OPA0);
+    Node* end = n1;
+    for (int j = 0; j < i; j++) {
+      end = graph.NewNode(&OPA1, end);
+    }
+    graph.SetEnd(end);
+
+    GraphReducer reducer(&graph);
+    A1Forwarder r;
+    reducer.AddReducer(&r);
+
+    for (int i = 0; i < 3; i++) {
+      int before = graph.NodeCount();
+      reducer.ReduceGraph();
+      CHECK_EQ(before, graph.NodeCount());
+      CHECK_EQ(&OPA0, n1->op());
+      CHECK_EQ(n1, graph.end());
+    }
+  }
+}
+
+
+TEST(ReduceForward1) {
+  GraphTester graph;
+
+  Node* n1 = graph.NewNode(&OPA0);
+  Node* n2 = graph.NewNode(&OPA1, n1);
+  Node* n3 = graph.NewNode(&OPA1, n1);
+  Node* end = graph.NewNode(&OPA2, n2, n3);
+  graph.SetEnd(end);
+
+  GraphReducer reducer(&graph);
+  InPlaceABReducer r;
+  B1Forwarder f;
+  reducer.AddReducer(&r);
+  reducer.AddReducer(&f);
+
+  // Tests first reducing A => B, then B1(x) => x.
+  for (int i = 0; i < 3; i++) {
+    int before = graph.NodeCount();
+    reducer.ReduceGraph();
+    CHECK_EQ(before, graph.NodeCount());
+    CHECK_EQ(&OPB0, n1->op());
+    CHECK_EQ(&OPB1, n2->op());
+    CHECK_EQ(n1, end->InputAt(0));
+    CHECK_EQ(&OPB1, n3->op());
+    CHECK_EQ(n1, end->InputAt(0));
+    CHECK_EQ(&OPB2, end->op());
+    CHECK_EQ(0, n2->UseCount());
+    CHECK_EQ(0, n3->UseCount());
+  }
+}
+
+
+TEST(Sorter1) {
+  HandleAndZoneScope scope;
+  AB2Sorter r;
+  for (int i = 0; i < 6; i++) {
+    GraphTester graph;
+
+    Node* n1 = graph.NewNode(&OPA0);
+    Node* n2 = graph.NewNode(&OPA1, n1);
+    Node* n3 = graph.NewNode(&OPA1, n1);
+    Node* end;
+
+    if (i == 0) end = graph.NewNode(&OPA2, n2, n3);
+    if (i == 1) end = graph.NewNode(&OPA2, n3, n2);
+    if (i == 2) end = graph.NewNode(&OPA2, n2, n1);
+    if (i == 3) end = graph.NewNode(&OPA2, n1, n2);
+    if (i == 4) end = graph.NewNode(&OPA2, n3, n1);
+    if (i == 5) end = graph.NewNode(&OPA2, n1, n3);
+
+    graph.SetEnd(end);
+
+    GraphReducer reducer(&graph);
+    reducer.AddReducer(&r);
+
+    int before = graph.NodeCount();
+    reducer.ReduceGraph();
+    CHECK_EQ(before, graph.NodeCount());
+    CHECK_EQ(&OPA0, n1->op());
+    CHECK_EQ(&OPA1, n2->op());
+    CHECK_EQ(&OPA1, n3->op());
+    CHECK_EQ(&OPA2, end->op());
+    CHECK_EQ(end, graph.end());
+    CHECK(end->InputAt(0)->id() <= end->InputAt(1)->id());
+  }
+}
+
+
+// Generate a node graph with the given permutations.
+void GenDAG(Graph* graph, int* p3, int* p2, int* p1) {
+  Node* level4 = graph->NewNode(&OPA0);
+  Node* level3[] = {
+    graph->NewNode(&OPA1, level4),
+    graph->NewNode(&OPA1, level4)
+  };
+
+  Node* level2[] = {
+    graph->NewNode(&OPA1, level3[p3[0]]),
+    graph->NewNode(&OPA1, level3[p3[1]]),
+    graph->NewNode(&OPA1, level3[p3[0]]),
+    graph->NewNode(&OPA1, level3[p3[1]])
+  };
+
+  Node* level1[] = {
+    graph->NewNode(&OPA2, level2[p2[0]], level2[p2[1]]),
+    graph->NewNode(&OPA2, level2[p2[2]], level2[p2[3]])
+  };
+
+  Node* end = graph->NewNode(&OPA2, level1[p1[0]], level1[p1[1]]);
+  graph->SetEnd(end);
+}
+
+
+TEST(SortForwardReduce) {
+  GraphTester graph;
+
+  // Tests combined reductions on a series of DAGs.
+  for (int j = 0; j < 2; j++) {
+    int p3[] = { j, 1 - j };
+    for (int m = 0; m < 2; m++) {
+      int p1[] = { m, 1 - m };
+      for (int k = 0; k < 24; k++) {  // All permutations of 0, 1, 2, 3
+        int p2[] = { -1, -1, -1, -1 };
+        int n = k;
+        for (int d = 4; d >= 1; d--) {  // Construct permutation.
+          int p = n % d;
+          for (int z = 0; z < 4; z++) {
+            if (p2[z] == -1) {
+              if (p == 0) p2[z] = d - 1;
+              p--;
+            }
+          }
+          n = n / d;
+        }
+
+        GenDAG(&graph, p3, p2, p1);
+
+        GraphReducer reducer(&graph);
+        AB2Sorter r1;
+        A1Forwarder r2;
+        InPlaceABReducer r3;
+        reducer.AddReducer(&r1);
+        reducer.AddReducer(&r2);
+        reducer.AddReducer(&r3);
+
+        reducer.ReduceGraph();
+
+        Node* end = graph.end();
+        CHECK_EQ(&OPB2, end->op());
+        Node* n1 = end->InputAt(0);
+        Node* n2 = end->InputAt(1);
+        CHECK_NE(n1, n2);
+        CHECK(n1->id() < n2->id());
+        CHECK_EQ(&OPB2, n1->op());
+        CHECK_EQ(&OPB2, n2->op());
+        Node* n4 = n1->InputAt(0);
+        CHECK_EQ(&OPB0, n4->op());
+        CHECK_EQ(n4, n1->InputAt(1));
+        CHECK_EQ(n4, n2->InputAt(0));
+        CHECK_EQ(n4, n2->InputAt(1));
+      }
+    }
+  }
+}
+
+
+TEST(Order) {
+  // Test that the order of reducers doesn't matter, as they should be
+  // rerun for changed nodes.
+  for (int i = 0; i < 2; i++) {
+    GraphTester graph;
+
+    Node* n1 = graph.NewNode(&OPA0);
+    Node* end = graph.NewNode(&OPA1, n1);
+    graph.SetEnd(end);
+
+    GraphReducer reducer(&graph);
+    InPlaceABReducer abr;
+    InPlaceBCReducer bcr;
+    if (i == 0) {
+      reducer.AddReducer(&abr);
+      reducer.AddReducer(&bcr);
+    } else {
+      reducer.AddReducer(&bcr);
+      reducer.AddReducer(&abr);
+    }
+
+    // Tests A* => C* with in-place updates.
+    for (int i = 0; i < 3; i++) {
+      int before = graph.NodeCount();
+      reducer.ReduceGraph();
+      CHECK_EQ(before, graph.NodeCount());
+      CHECK_EQ(&OPC0, n1->op());
+      CHECK_EQ(&OPC1, end->op());
+      CHECK_EQ(n1, end->InputAt(0));
+    }
+  }
+}
+
+
+// Tests that a reducer is only applied once.
+class OneTimeReducer : public Reducer {
+ public:
+  OneTimeReducer(Reducer* reducer, Zone* zone)
+    : reducer_(reducer),
+      nodes_(NodeSet::key_compare(), NodeSet::allocator_type(zone)) { }
+  virtual Reduction Reduce(Node* node) {
+    CHECK_EQ(0, nodes_.count(node));
+    nodes_.insert(node);
+    return reducer_->Reduce(node);
+  }
+  Reducer* reducer_;
+  NodeSet nodes_;
+};
+
+
+TEST(OneTimeReduce1) {
+  GraphTester graph;
+
+  Node* n1 = graph.NewNode(&OPA0);
+  Node* end = graph.NewNode(&OPA1, n1);
+  graph.SetEnd(end);
+
+  GraphReducer reducer(&graph);
+  InPlaceABReducer r;
+  OneTimeReducer once(&r, graph.zone());
+  reducer.AddReducer(&once);
+
+  // Tests A* => B* with in-place updates. Should only be applied once.
+  int before = graph.NodeCount();
+  reducer.ReduceGraph();
+  CHECK_EQ(before, graph.NodeCount());
+  CHECK_EQ(&OPB0, n1->op());
+  CHECK_EQ(&OPB1, end->op());
+  CHECK_EQ(n1, end->InputAt(0));
+}