text: // 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/v8.h"
  #include "test/cctest/cctest.h"
  #include "test/cctest/compiler/graph-builder-tester.h"
  #include "test/cctest/compiler/value-helper.h"
  
  #include "src/compiler/node-matchers.h"
  #include "src/compiler/representation-change.h"
  
  using namespace v8::internal;
  using namespace v8::internal::compiler;
  
  namespace v8 {  // for friendiness.
  namespace internal {
  namespace compiler {
  
  class RepresentationChangerTester : public HandleAndZoneScope,
                                      public GraphAndBuilders {
   public:
    explicit RepresentationChangerTester(int num_parameters = 0)
        : GraphAndBuilders(main_zone()),
          javascript_(main_zone()),
          jsgraph_(main_graph_, &main_common_, &javascript_, &main_machine_),
          changer_(&jsgraph_, &main_simplified_, main_isolate()) {
      Node* s = graph()->NewNode(common()->Start(num_parameters));
      graph()->SetStart(s);
    }
  
    JSOperatorBuilder javascript_;
    JSGraph jsgraph_;
    RepresentationChanger changer_;
  
    Isolate* isolate() { return main_isolate(); }
    Graph* graph() { return main_graph_; }
    CommonOperatorBuilder* common() { return &main_common_; }
    JSGraph* jsgraph() { return &jsgraph_; }
    RepresentationChanger* changer() { return &changer_; }
  
    // TODO(titzer): use ValueChecker / ValueUtil
    void CheckInt32Constant(Node* n, int32_t expected) {
      Int32Matcher m(n);
      CHECK(m.HasValue());
      CHECK_EQ(expected, m.Value());
    }
  
    void CheckUint32Constant(Node* n, uint32_t expected) {
      Uint32Matcher m(n);
      CHECK(m.HasValue());
      CHECK_EQ(static_cast<int>(expected), static_cast<int>(m.Value()));
    }
  
    void CheckFloat64Constant(Node* n, double expected) {
      Float64Matcher m(n);
      CHECK(m.HasValue());
      CHECK_EQ(expected, m.Value());
    }
  
    void CheckFloat32Constant(Node* n, float expected) {
      CHECK_EQ(IrOpcode::kFloat32Constant, n->opcode());
      float fval = OpParameter<float>(n->op());
      CHECK_EQ(expected, fval);
    }
  
    void CheckHeapConstant(Node* n, HeapObject* expected) {
      HeapObjectMatcher<HeapObject> m(n);
      CHECK(m.HasValue());
      CHECK_EQ(expected, *m.Value().handle());
    }
  
    void CheckNumberConstant(Node* n, double expected) {
      NumberMatcher m(n);
      CHECK_EQ(IrOpcode::kNumberConstant, n->opcode());
      CHECK(m.HasValue());
      CHECK_EQ(expected, m.Value());
    }
  
    Node* Parameter(int index = 0) {
      return graph()->NewNode(common()->Parameter(index), graph()->start());
    }
  
    void CheckTypeError(MachineTypeUnion from, MachineTypeUnion to) {
      changer()->testing_type_errors_ = true;
      changer()->type_error_ = false;
      Node* n = Parameter(0);
      Node* c = changer()->GetRepresentationFor(n, from, to);
      CHECK(changer()->type_error_);
      CHECK_EQ(n, c);
    }
  
    void CheckNop(MachineTypeUnion from, MachineTypeUnion to) {
      Node* n = Parameter(0);
      Node* c = changer()->GetRepresentationFor(n, from, to);
      CHECK_EQ(n, c);
    }
  };
  }
  }
  }  // namespace v8::internal::compiler
  
  
  static const MachineType all_reps[] = {kRepBit,     kRepWord32,  kRepWord64,
                                         kRepFloat32, kRepFloat64, kRepTagged};
  
  
  TEST(BoolToBit_constant) {
    RepresentationChangerTester r;
  
    Node* true_node = r.jsgraph()->TrueConstant();
    Node* true_bit =
        r.changer()->GetRepresentationFor(true_node, kRepTagged, kRepBit);
    r.CheckInt32Constant(true_bit, 1);
  
    Node* false_node = r.jsgraph()->FalseConstant();
    Node* false_bit =
        r.changer()->GetRepresentationFor(false_node, kRepTagged, kRepBit);
    r.CheckInt32Constant(false_bit, 0);
  }
  
  
  TEST(BitToBool_constant) {
    RepresentationChangerTester r;
  
    for (int i = -5; i < 5; i++) {
      Node* node = r.jsgraph()->Int32Constant(i);
      Node* val = r.changer()->GetRepresentationFor(node, kRepBit, kRepTagged);
      r.CheckHeapConstant(val, i == 0 ? r.isolate()->heap()->false_value()
                                      : r.isolate()->heap()->true_value());
    }
  }
  
  
  TEST(ToTagged_constant) {
    RepresentationChangerTester r;
  
    {
      FOR_FLOAT64_INPUTS(i) {
        Node* n = r.jsgraph()->Float64Constant(*i);
        Node* c = r.changer()->GetRepresentationFor(n, kRepFloat64, kRepTagged);
        r.CheckNumberConstant(c, *i);
      }
    }
  
    {
      FOR_FLOAT64_INPUTS(i) {
        Node* n = r.jsgraph()->Constant(*i);
        Node* c = r.changer()->GetRepresentationFor(n, kRepFloat64, kRepTagged);
        r.CheckNumberConstant(c, *i);
      }
    }
  
    {
      FOR_FLOAT32_INPUTS(i) {
        Node* n = r.jsgraph()->Float32Constant(*i);
        Node* c = r.changer()->GetRepresentationFor(n, kRepFloat32, kRepTagged);
        r.CheckNumberConstant(c, *i);
      }
    }
  
    {
      FOR_INT32_INPUTS(i) {
        Node* n = r.jsgraph()->Int32Constant(*i);
        Node* c = r.changer()->GetRepresentationFor(n, kRepWord32 | kTypeInt32,
                                                    kRepTagged);
        r.CheckNumberConstant(c, *i);
      }
    }
  
    {
      FOR_UINT32_INPUTS(i) {
        Node* n = r.jsgraph()->Int32Constant(*i);
        Node* c = r.changer()->GetRepresentationFor(n, kRepWord32 | kTypeUint32,
                                                    kRepTagged);
        r.CheckNumberConstant(c, *i);
      }
    }
  }
  
  
  TEST(ToFloat64_constant) {
    RepresentationChangerTester r;
  
    {
      FOR_FLOAT64_INPUTS(i) {
        Node* n = r.jsgraph()->Float64Constant(*i);
        Node* c = r.changer()->GetRepresentationFor(n, kRepFloat64, kRepFloat64);
        CHECK_EQ(n, c);
      }
    }
  
    {
      FOR_FLOAT64_INPUTS(i) {
        Node* n = r.jsgraph()->Constant(*i);
        Node* c = r.changer()->GetRepresentationFor(n, kRepTagged, kRepFloat64);
        r.CheckFloat64Constant(c, *i);
      }
    }
  
    {
      FOR_FLOAT32_INPUTS(i) {
        Node* n = r.jsgraph()->Float32Constant(*i);
        Node* c = r.changer()->GetRepresentationFor(n, kRepFloat32, kRepFloat64);
        r.CheckFloat64Constant(c, *i);
      }
    }
  
    {
      FOR_INT32_INPUTS(i) {
        Node* n = r.jsgraph()->Int32Constant(*i);
        Node* c = r.changer()->GetRepresentationFor(n, kRepWord32 | kTypeInt32,
                                                    kRepFloat64);
        r.CheckFloat64Constant(c, *i);
      }
    }
  
    {
      FOR_UINT32_INPUTS(i) {
        Node* n = r.jsgraph()->Int32Constant(*i);
        Node* c = r.changer()->GetRepresentationFor(n, kRepWord32 | kTypeUint32,
                                                    kRepFloat64);
        r.CheckFloat64Constant(c, *i);
      }
    }
  }
  
  
  static bool IsFloat32Int32(int32_t val) {
    return val >= -(1 << 23) && val <= (1 << 23);
  }
  
  
  static bool IsFloat32Uint32(uint32_t val) { return val <= (1 << 23); }
  
  
  TEST(ToFloat32_constant) {
    RepresentationChangerTester r;
  
    {
      FOR_FLOAT32_INPUTS(i) {
        Node* n = r.jsgraph()->Float32Constant(*i);
        Node* c = r.changer()->GetRepresentationFor(n, kRepFloat32, kRepFloat32);
        CHECK_EQ(n, c);
      }
    }
  
    {
      FOR_FLOAT32_INPUTS(i) {
        Node* n = r.jsgraph()->Constant(*i);
        Node* c = r.changer()->GetRepresentationFor(n, kRepTagged, kRepFloat32);
        r.CheckFloat32Constant(c, *i);
      }
    }
  
    {
      FOR_FLOAT32_INPUTS(i) {
        Node* n = r.jsgraph()->Float64Constant(*i);
        Node* c = r.changer()->GetRepresentationFor(n, kRepFloat64, kRepFloat32);
        r.CheckFloat32Constant(c, *i);
      }
    }
  
    {
      FOR_INT32_INPUTS(i) {
        if (!IsFloat32Int32(*i)) continue;
        Node* n = r.jsgraph()->Int32Constant(*i);
        Node* c = r.changer()->GetRepresentationFor(n, kRepWord32 | kTypeInt32,
                                                    kRepFloat32);
        r.CheckFloat32Constant(c, static_cast<float>(*i));
      }
    }
  
    {
      FOR_UINT32_INPUTS(i) {
        if (!IsFloat32Uint32(*i)) continue;
        Node* n = r.jsgraph()->Int32Constant(*i);
        Node* c = r.changer()->GetRepresentationFor(n, kRepWord32 | kTypeUint32,
                                                    kRepFloat32);
        r.CheckFloat32Constant(c, static_cast<float>(*i));
      }
    }
  }
  
  
  TEST(ToInt32_constant) {
    RepresentationChangerTester r;
  
    {
      FOR_INT32_INPUTS(i) {
        Node* n = r.jsgraph()->Int32Constant(*i);
        Node* c = r.changer()->GetRepresentationFor(n, kRepWord32 | kTypeInt32,
                                                    kRepWord32);
        r.CheckInt32Constant(c, *i);
      }
    }
  
    {
      FOR_INT32_INPUTS(i) {
        if (!IsFloat32Int32(*i)) continue;
        Node* n = r.jsgraph()->Float32Constant(static_cast<float>(*i));
        Node* c = r.changer()->GetRepresentationFor(n, kRepFloat32 | kTypeInt32,
                                                    kRepWord32);
        r.CheckInt32Constant(c, *i);
      }
    }
  
    {
      FOR_INT32_INPUTS(i) {
        Node* n = r.jsgraph()->Float64Constant(*i);
        Node* c = r.changer()->GetRepresentationFor(n, kRepFloat64 | kTypeInt32,
                                                    kRepWord32);
        r.CheckInt32Constant(c, *i);
      }
    }
  
    {
      FOR_INT32_INPUTS(i) {
        Node* n = r.jsgraph()->Constant(*i);
        Node* c = r.changer()->GetRepresentationFor(n, kRepTagged | kTypeInt32,
                                                    kRepWord32);
        r.CheckInt32Constant(c, *i);
      }
    }
  }
  
  
  TEST(ToUint32_constant) {
    RepresentationChangerTester r;
  
    {
      FOR_UINT32_INPUTS(i) {
        Node* n = r.jsgraph()->Int32Constant(*i);
        Node* c = r.changer()->GetRepresentationFor(n, kRepWord32 | kTypeUint32,
                                                    kRepWord32);
        r.CheckUint32Constant(c, *i);
      }
    }
  
    {
      FOR_UINT32_INPUTS(i) {
        if (!IsFloat32Uint32(*i)) continue;
        Node* n = r.jsgraph()->Float32Constant(static_cast<float>(*i));
        Node* c = r.changer()->GetRepresentationFor(n, kRepFloat32 | kTypeUint32,
                                                    kRepWord32);
        r.CheckUint32Constant(c, *i);
      }
    }
  
    {
      FOR_UINT32_INPUTS(i) {
        Node* n = r.jsgraph()->Float64Constant(*i);
        Node* c = r.changer()->GetRepresentationFor(n, kRepFloat64 | kTypeUint32,
                                                    kRepWord32);
        r.CheckUint32Constant(c, *i);
      }
    }
  
    {
      FOR_UINT32_INPUTS(i) {
        Node* n = r.jsgraph()->Constant(static_cast<double>(*i));
        Node* c = r.changer()->GetRepresentationFor(n, kRepTagged | kTypeUint32,
                                                    kRepWord32);
        r.CheckUint32Constant(c, *i);
      }
    }
  }
  
  
  static void CheckChange(IrOpcode::Value expected, MachineTypeUnion from,
                          MachineTypeUnion to) {
    RepresentationChangerTester r;
  
    Node* n = r.Parameter();
    Node* c = r.changer()->GetRepresentationFor(n, from, to);
  
    CHECK_NE(c, n);
    CHECK_EQ(expected, c->opcode());
    CHECK_EQ(n, c->InputAt(0));
  }
  
  
  static void CheckTwoChanges(IrOpcode::Value expected2,
                              IrOpcode::Value expected1, MachineTypeUnion from,
                              MachineTypeUnion to) {
    RepresentationChangerTester r;
  
    Node* n = r.Parameter();
    Node* c1 = r.changer()->GetRepresentationFor(n, from, to);
  
    CHECK_NE(c1, n);
    CHECK_EQ(expected1, c1->opcode());
    Node* c2 = c1->InputAt(0);
    CHECK_NE(c2, n);
    CHECK_EQ(expected2, c2->opcode());
    CHECK_EQ(n, c2->InputAt(0));
  }
  
  
  TEST(SingleChanges) {
    CheckChange(IrOpcode::kChangeBoolToBit, kRepTagged, kRepBit);
    CheckChange(IrOpcode::kChangeBitToBool, kRepBit, kRepTagged);
  
    CheckChange(IrOpcode::kChangeInt32ToTagged, kRepWord32 | kTypeInt32,
                kRepTagged);
    CheckChange(IrOpcode::kChangeUint32ToTagged, kRepWord32 | kTypeUint32,
                kRepTagged);
    CheckChange(IrOpcode::kChangeFloat64ToTagged, kRepFloat64, kRepTagged);
  
    CheckChange(IrOpcode::kChangeTaggedToInt32, kRepTagged | kTypeInt32,
                kRepWord32);
    CheckChange(IrOpcode::kChangeTaggedToUint32, kRepTagged | kTypeUint32,
                kRepWord32);
    CheckChange(IrOpcode::kChangeTaggedToFloat64, kRepTagged, kRepFloat64);
  
    // Int32,Uint32 <-> Float64 are actually machine conversions.
    CheckChange(IrOpcode::kChangeInt32ToFloat64, kRepWord32 | kTypeInt32,
                kRepFloat64);
    CheckChange(IrOpcode::kChangeUint32ToFloat64, kRepWord32 | kTypeUint32,
                kRepFloat64);
    CheckChange(IrOpcode::kChangeFloat64ToInt32, kRepFloat64 | kTypeInt32,
                kRepWord32);
    CheckChange(IrOpcode::kChangeFloat64ToUint32, kRepFloat64 | kTypeUint32,
                kRepWord32);
  
    CheckChange(IrOpcode::kTruncateFloat64ToFloat32, kRepFloat64, kRepFloat32);
  
    // Int32,Uint32 <-> Float32 require two changes.
    CheckTwoChanges(IrOpcode::kChangeInt32ToFloat64,
                    IrOpcode::kTruncateFloat64ToFloat32, kRepWord32 | kTypeInt32,
                    kRepFloat32);
    CheckTwoChanges(IrOpcode::kChangeUint32ToFloat64,
                    IrOpcode::kTruncateFloat64ToFloat32, kRepWord32 | kTypeUint32,
                    kRepFloat32);
    CheckTwoChanges(IrOpcode::kChangeFloat32ToFloat64,
                    IrOpcode::kChangeFloat64ToInt32, kRepFloat32 | kTypeInt32,
                    kRepWord32);
    CheckTwoChanges(IrOpcode::kChangeFloat32ToFloat64,
                    IrOpcode::kChangeFloat64ToUint32, kRepFloat32 | kTypeUint32,
                    kRepWord32);
  
    // Float32 <-> Tagged require two changes.
    CheckTwoChanges(IrOpcode::kChangeFloat32ToFloat64,
                    IrOpcode::kChangeFloat64ToTagged, kRepFloat32, kRepTagged);
    CheckTwoChanges(IrOpcode::kChangeTaggedToFloat64,
                    IrOpcode::kTruncateFloat64ToFloat32, kRepTagged, kRepFloat32);
  }
  
  
  TEST(SignednessInWord32) {
    RepresentationChangerTester r;
  
    // TODO(titzer): assume that uses of a word32 without a sign mean kTypeInt32.
    CheckChange(IrOpcode::kChangeTaggedToInt32, kRepTagged,
                kRepWord32 | kTypeInt32);
    CheckChange(IrOpcode::kChangeTaggedToUint32, kRepTagged,
                kRepWord32 | kTypeUint32);
    CheckChange(IrOpcode::kChangeInt32ToFloat64, kRepWord32, kRepFloat64);
    CheckChange(IrOpcode::kChangeFloat64ToInt32, kRepFloat64, kRepWord32);
  
    CheckTwoChanges(IrOpcode::kChangeInt32ToFloat64,
                    IrOpcode::kTruncateFloat64ToFloat32, kRepWord32, kRepFloat32);
    CheckTwoChanges(IrOpcode::kChangeFloat32ToFloat64,
                    IrOpcode::kChangeFloat64ToInt32, kRepFloat32, kRepWord32);
  }
  
  
  TEST(Nops) {
    RepresentationChangerTester r;
  
    // X -> X is always a nop for any single representation X.
    for (size_t i = 0; i < arraysize(all_reps); i++) {
      r.CheckNop(all_reps[i], all_reps[i]);
    }
  
    // 32-bit floats.
    r.CheckNop(kRepFloat32, kRepFloat32);
    r.CheckNop(kRepFloat32 | kTypeNumber, kRepFloat32);
    r.CheckNop(kRepFloat32, kRepFloat32 | kTypeNumber);
  
    // 32-bit or 64-bit words can be used as branch conditions (kRepBit).
    r.CheckNop(kRepWord32, kRepBit);
    r.CheckNop(kRepWord32, kRepBit | kTypeBool);
    r.CheckNop(kRepWord64, kRepBit);
    r.CheckNop(kRepWord64, kRepBit | kTypeBool);
  
    // 32-bit words can be used as smaller word sizes and vice versa, because
    // loads from memory implicitly sign or zero extend the value to the
    // full machine word size, and stores implicitly truncate.
    r.CheckNop(kRepWord32, kRepWord8);
    r.CheckNop(kRepWord32, kRepWord16);
    r.CheckNop(kRepWord32, kRepWord32);
    r.CheckNop(kRepWord8, kRepWord32);
    r.CheckNop(kRepWord16, kRepWord32);
  
    // kRepBit (result of comparison) is implicitly a wordish thing.
    r.CheckNop(kRepBit, kRepWord8);
    r.CheckNop(kRepBit | kTypeBool, kRepWord8);
    r.CheckNop(kRepBit, kRepWord16);
    r.CheckNop(kRepBit | kTypeBool, kRepWord16);
    r.CheckNop(kRepBit, kRepWord32);
    r.CheckNop(kRepBit | kTypeBool, kRepWord32);
    r.CheckNop(kRepBit, kRepWord64);
    r.CheckNop(kRepBit | kTypeBool, kRepWord64);
  }
  
  
  TEST(TypeErrors) {
    RepresentationChangerTester r;
  
    // Floats cannot be implicitly converted to/from comparison conditions.
    r.CheckTypeError(kRepFloat64, kRepBit);
    r.CheckTypeError(kRepFloat64, kRepBit | kTypeBool);
    r.CheckTypeError(kRepBit, kRepFloat64);
    r.CheckTypeError(kRepBit | kTypeBool, kRepFloat64);
  
    // Floats cannot be implicitly converted to/from comparison conditions.
    r.CheckTypeError(kRepFloat32, kRepBit);
    r.CheckTypeError(kRepFloat32, kRepBit | kTypeBool);
    r.CheckTypeError(kRepBit, kRepFloat32);
    r.CheckTypeError(kRepBit | kTypeBool, kRepFloat32);
  
    // Word64 is internal and shouldn't be implicitly converted.
    r.CheckTypeError(kRepWord64, kRepTagged | kTypeBool);
    r.CheckTypeError(kRepWord64, kRepTagged);
    r.CheckTypeError(kRepWord64, kRepTagged | kTypeBool);
    r.CheckTypeError(kRepTagged, kRepWord64);
    r.CheckTypeError(kRepTagged | kTypeBool, kRepWord64);
  
    // Word64 / Word32 shouldn't be implicitly converted.
    r.CheckTypeError(kRepWord64, kRepWord32);
    r.CheckTypeError(kRepWord32, kRepWord64);
    r.CheckTypeError(kRepWord64, kRepWord32 | kTypeInt32);
    r.CheckTypeError(kRepWord32 | kTypeInt32, kRepWord64);
    r.CheckTypeError(kRepWord64, kRepWord32 | kTypeUint32);
    r.CheckTypeError(kRepWord32 | kTypeUint32, kRepWord64);
  
    for (size_t i = 0; i < arraysize(all_reps); i++) {
      for (size_t j = 0; j < arraysize(all_reps); j++) {
        if (i == j) continue;
        // Only a single from representation is allowed.
        r.CheckTypeError(all_reps[i] | all_reps[j], kRepTagged);
      }
    }
  }
  