[turbofan] put src/types.[h/cc] into src/compiler/types.[h/cc]

src/types.cc

Index: src/types.cc
diff --git a/src/types.cc b/src/types.cc
deleted file mode 100644
index d2b5e2b8e13cc2b75ecacf28d1bfbe76b0f470c9..0000000000000000000000000000000000000000
--- a/src/types.cc
+++ /dev/null
@@ -1,1139 +0,0 @@
-// 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 <iomanip>
-
-#include "src/types.h"
-
-#include "src/handles-inl.h"
-#include "src/ostreams.h"
-
-namespace v8 {
-namespace internal {
-
-
-// NOTE: If code is marked as being a "shortcut", this means that removing
-// the code won't affect the semantics of the surrounding function definition.
-
-// static
-bool Type::IsInteger(i::Object* x) {
-  return x->IsNumber() && Type::IsInteger(x->Number());
-}
-
-// -----------------------------------------------------------------------------
-// Range-related helper functions.
-
-bool RangeType::Limits::IsEmpty() { return this->min > this->max; }
-
-RangeType::Limits RangeType::Limits::Intersect(Limits lhs, Limits rhs) {
-  DisallowHeapAllocation no_allocation;
-  Limits result(lhs);
-  if (lhs.min < rhs.min) result.min = rhs.min;
-  if (lhs.max > rhs.max) result.max = rhs.max;
-  return result;
-}
-
-RangeType::Limits RangeType::Limits::Union(Limits lhs, Limits rhs) {
-  DisallowHeapAllocation no_allocation;
-  if (lhs.IsEmpty()) return rhs;
-  if (rhs.IsEmpty()) return lhs;
-  Limits result(lhs);
-  if (lhs.min > rhs.min) result.min = rhs.min;
-  if (lhs.max < rhs.max) result.max = rhs.max;
-  return result;
-}
-
-bool Type::Overlap(RangeType* lhs, RangeType* rhs) {
-  DisallowHeapAllocation no_allocation;
-  return !RangeType::Limits::Intersect(RangeType::Limits(lhs),
-                                       RangeType::Limits(rhs))
-              .IsEmpty();
-}
-
-bool Type::Contains(RangeType* lhs, RangeType* rhs) {
-  DisallowHeapAllocation no_allocation;
-  return lhs->Min() <= rhs->Min() && rhs->Max() <= lhs->Max();
-}
-
-bool Type::Contains(RangeType* lhs, ConstantType* rhs) {
-  DisallowHeapAllocation no_allocation;
-  return IsInteger(*rhs->Value()) &&
-         lhs->Min() <= rhs->Value()->Number() &&
-         rhs->Value()->Number() <= lhs->Max();
-}
-
-bool Type::Contains(RangeType* range, i::Object* val) {
-  DisallowHeapAllocation no_allocation;
-  return IsInteger(val) &&
-         range->Min() <= val->Number() && val->Number() <= range->Max();
-}
-
-
-// -----------------------------------------------------------------------------
-// Min and Max computation.
-
-double Type::Min() {
-  DCHECK(this->SemanticIs(Number()));
-  if (this->IsBitset()) return BitsetType::Min(this->AsBitset());
-  if (this->IsUnion()) {
-    double min = +V8_INFINITY;
-    for (int i = 0, n = this->AsUnion()->Length(); i < n; ++i) {
-      min = std::min(min, this->AsUnion()->Get(i)->Min());
-    }
-    return min;
-  }
-  if (this->IsRange()) return this->AsRange()->Min();
-  if (this->IsConstant()) return this->AsConstant()->Value()->Number();
-  UNREACHABLE();
-  return 0;
-}
-
-double Type::Max() {
-  DCHECK(this->SemanticIs(Number()));
-  if (this->IsBitset()) return BitsetType::Max(this->AsBitset());
-  if (this->IsUnion()) {
-    double max = -V8_INFINITY;
-    for (int i = 0, n = this->AsUnion()->Length(); i < n; ++i) {
-      max = std::max(max, this->AsUnion()->Get(i)->Max());
-    }
-    return max;
-  }
-  if (this->IsRange()) return this->AsRange()->Max();
-  if (this->IsConstant()) return this->AsConstant()->Value()->Number();
-  UNREACHABLE();
-  return 0;
-}
-
-
-// -----------------------------------------------------------------------------
-// Glb and lub computation.
-
-
-// The largest bitset subsumed by this type.
-Type::bitset BitsetType::Glb(Type* type) {
-  DisallowHeapAllocation no_allocation;
-  // Fast case.
-  if (IsBitset(type)) {
-    return type->AsBitset();
-  } else if (type->IsUnion()) {
-    SLOW_DCHECK(type->AsUnion()->Wellformed());
-    return type->AsUnion()->Get(0)->BitsetGlb() |
-           SEMANTIC(type->AsUnion()->Get(1)->BitsetGlb());  // Shortcut.
-  } else if (type->IsRange()) {
-    bitset glb = SEMANTIC(
-        BitsetType::Glb(type->AsRange()->Min(), type->AsRange()->Max()));
-    return glb | REPRESENTATION(type->BitsetLub());
-  } else {
-    return type->Representation();
-  }
-}
-
-
-// The smallest bitset subsuming this type, possibly not a proper one.
-Type::bitset BitsetType::Lub(Type* type) {
-  DisallowHeapAllocation no_allocation;
-  if (IsBitset(type)) return type->AsBitset();
-  if (type->IsUnion()) {
-    // Take the representation from the first element, which is always
-    // a bitset.
-    int bitset = type->AsUnion()->Get(0)->BitsetLub();
-    for (int i = 0, n = type->AsUnion()->Length(); i < n; ++i) {
-      // Other elements only contribute their semantic part.
-      bitset |= SEMANTIC(type->AsUnion()->Get(i)->BitsetLub());
-    }
-    return bitset;
-  }
-  if (type->IsConstant()) return type->AsConstant()->Lub();
-  if (type->IsRange()) return type->AsRange()->Lub();
-  if (type->IsTuple()) return kOtherInternal;
-  UNREACHABLE();
-  return kNone;
-}
-
-Type::bitset BitsetType::Lub(i::Map* map) {
-  DisallowHeapAllocation no_allocation;
-  switch (map->instance_type()) {
-    case STRING_TYPE:
-    case ONE_BYTE_STRING_TYPE:
-    case CONS_STRING_TYPE:
-    case CONS_ONE_BYTE_STRING_TYPE:
-    case SLICED_STRING_TYPE:
-    case SLICED_ONE_BYTE_STRING_TYPE:
-    case EXTERNAL_STRING_TYPE:
-    case EXTERNAL_ONE_BYTE_STRING_TYPE:
-    case EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE:
-    case SHORT_EXTERNAL_STRING_TYPE:
-    case SHORT_EXTERNAL_ONE_BYTE_STRING_TYPE:
-    case SHORT_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE:
-      return kOtherString;
-    case INTERNALIZED_STRING_TYPE:
-    case ONE_BYTE_INTERNALIZED_STRING_TYPE:
-    case EXTERNAL_INTERNALIZED_STRING_TYPE:
-    case EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE:
-    case EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE:
-    case SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE:
-    case SHORT_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE:
-    case SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE:
-      return kInternalizedString;
-    case SYMBOL_TYPE:
-      return kSymbol;
-    case ODDBALL_TYPE: {
-      Heap* heap = map->GetHeap();
-      if (map == heap->undefined_map()) return kUndefined;
-      if (map == heap->null_map()) return kNull;
-      if (map == heap->boolean_map()) return kBoolean;
-      if (map == heap->the_hole_map()) return kHole;
-      DCHECK(map == heap->uninitialized_map() ||
-             map == heap->no_interceptor_result_sentinel_map() ||
-             map == heap->termination_exception_map() ||
-             map == heap->arguments_marker_map() ||
-             map == heap->optimized_out_map() ||
-             map == heap->stale_register_map());
-      return kOtherInternal & kTaggedPointer;
-    }
-    case HEAP_NUMBER_TYPE:
-      return kNumber & kTaggedPointer;
-    case SIMD128_VALUE_TYPE:
-      return kSimd;
-    case JS_OBJECT_TYPE:
-    case JS_ARGUMENTS_TYPE:
-    case JS_ERROR_TYPE:
-    case JS_GLOBAL_OBJECT_TYPE:
-    case JS_GLOBAL_PROXY_TYPE:
-    case JS_API_OBJECT_TYPE:
-    case JS_SPECIAL_API_OBJECT_TYPE:
-      if (map->is_undetectable()) return kOtherUndetectable;
-      return kOtherObject;
-    case JS_VALUE_TYPE:
-    case JS_MESSAGE_OBJECT_TYPE:
-    case JS_DATE_TYPE:
-    case JS_CONTEXT_EXTENSION_OBJECT_TYPE:
-    case JS_GENERATOR_OBJECT_TYPE:
-    case JS_MODULE_TYPE:
-    case JS_ARRAY_BUFFER_TYPE:
-    case JS_ARRAY_TYPE:
-    case JS_REGEXP_TYPE:  // TODO(rossberg): there should be a RegExp type.
-    case JS_TYPED_ARRAY_TYPE:
-    case JS_DATA_VIEW_TYPE:
-    case JS_SET_TYPE:
-    case JS_MAP_TYPE:
-    case JS_SET_ITERATOR_TYPE:
-    case JS_MAP_ITERATOR_TYPE:
-    case JS_WEAK_MAP_TYPE:
-    case JS_WEAK_SET_TYPE:
-    case JS_PROMISE_TYPE:
-    case JS_BOUND_FUNCTION_TYPE:
-      DCHECK(!map->is_undetectable());
-      return kOtherObject;
-    case JS_FUNCTION_TYPE:
-      DCHECK(!map->is_undetectable());
-      return kFunction;
-    case JS_PROXY_TYPE:
-      DCHECK(!map->is_undetectable());
-      return kProxy;
-    case MAP_TYPE:
-    case ALLOCATION_SITE_TYPE:
-    case ACCESSOR_INFO_TYPE:
-    case SHARED_FUNCTION_INFO_TYPE:
-    case ACCESSOR_PAIR_TYPE:
-    case FIXED_ARRAY_TYPE:
-    case FIXED_DOUBLE_ARRAY_TYPE:
-    case BYTE_ARRAY_TYPE:
-    case BYTECODE_ARRAY_TYPE:
-    case TRANSITION_ARRAY_TYPE:
-    case FOREIGN_TYPE:
-    case SCRIPT_TYPE:
-    case CODE_TYPE:
-    case PROPERTY_CELL_TYPE:
-      return kOtherInternal & kTaggedPointer;
-
-    // Remaining instance types are unsupported for now. If any of them do
-    // require bit set types, they should get kOtherInternal & kTaggedPointer.
-    case MUTABLE_HEAP_NUMBER_TYPE:
-    case FREE_SPACE_TYPE:
-#define FIXED_TYPED_ARRAY_CASE(Type, type, TYPE, ctype, size) \
-  case FIXED_##TYPE##_ARRAY_TYPE:
-
-      TYPED_ARRAYS(FIXED_TYPED_ARRAY_CASE)
-#undef FIXED_TYPED_ARRAY_CASE
-    case FILLER_TYPE:
-    case ACCESS_CHECK_INFO_TYPE:
-    case INTERCEPTOR_INFO_TYPE:
-    case CALL_HANDLER_INFO_TYPE:
-    case FUNCTION_TEMPLATE_INFO_TYPE:
-    case OBJECT_TEMPLATE_INFO_TYPE:
-    case SIGNATURE_INFO_TYPE:
-    case TYPE_SWITCH_INFO_TYPE:
-    case ALLOCATION_MEMENTO_TYPE:
-    case TYPE_FEEDBACK_INFO_TYPE:
-    case ALIASED_ARGUMENTS_ENTRY_TYPE:
-    case BOX_TYPE:
-    case DEBUG_INFO_TYPE:
-    case BREAK_POINT_INFO_TYPE:
-    case CELL_TYPE:
-    case WEAK_CELL_TYPE:
-    case PROTOTYPE_INFO_TYPE:
-    case CONTEXT_EXTENSION_TYPE:
-      UNREACHABLE();
-      return kNone;
-  }
-  UNREACHABLE();
-  return kNone;
-}
-
-Type::bitset BitsetType::Lub(i::Object* value) {
-  DisallowHeapAllocation no_allocation;
-  if (value->IsNumber()) {
-    return Lub(value->Number()) &
-        (value->IsSmi() ? kTaggedSigned : kTaggedPointer);
-  }
-  return Lub(i::HeapObject::cast(value)->map());
-}
-
-Type::bitset BitsetType::Lub(double value) {
-  DisallowHeapAllocation no_allocation;
-  if (i::IsMinusZero(value)) return kMinusZero;
-  if (std::isnan(value)) return kNaN;
-  if (IsUint32Double(value) || IsInt32Double(value)) return Lub(value, value);
-  return kOtherNumber;
-}
-
-
-// Minimum values of plain numeric bitsets.
-const BitsetType::Boundary BitsetType::BoundariesArray[] = {
-    {kOtherNumber, kPlainNumber, -V8_INFINITY},
-    {kOtherSigned32, kNegative32, kMinInt},
-    {kNegative31, kNegative31, -0x40000000},
-    {kUnsigned30, kUnsigned30, 0},
-    {kOtherUnsigned31, kUnsigned31, 0x40000000},
-    {kOtherUnsigned32, kUnsigned32, 0x80000000},
-    {kOtherNumber, kPlainNumber, static_cast<double>(kMaxUInt32) + 1}};
-
-const BitsetType::Boundary* BitsetType::Boundaries() { return BoundariesArray; }
-
-size_t BitsetType::BoundariesSize() {
-  // Windows doesn't like arraysize here.
-  // return arraysize(BoundariesArray);
-  return 7;
-}
-
-Type::bitset BitsetType::ExpandInternals(Type::bitset bits) {
-  DisallowHeapAllocation no_allocation;
-  if (!(bits & SEMANTIC(kPlainNumber))) return bits;  // Shortcut.
-  const Boundary* boundaries = Boundaries();
-  for (size_t i = 0; i < BoundariesSize(); ++i) {
-    DCHECK(BitsetType::Is(boundaries[i].internal, boundaries[i].external));
-    if (bits & SEMANTIC(boundaries[i].internal))
-      bits |= SEMANTIC(boundaries[i].external);
-  }
-  return bits;
-}
-
-Type::bitset BitsetType::Lub(double min, double max) {
-  DisallowHeapAllocation no_allocation;
-  int lub = kNone;
-  const Boundary* mins = Boundaries();
-
-  for (size_t i = 1; i < BoundariesSize(); ++i) {
-    if (min < mins[i].min) {
-      lub |= mins[i-1].internal;
-      if (max < mins[i].min) return lub;
-    }
-  }
-  return lub | mins[BoundariesSize() - 1].internal;
-}
-
-Type::bitset BitsetType::NumberBits(bitset bits) {
-  return SEMANTIC(bits & kPlainNumber);
-}
-
-Type::bitset BitsetType::Glb(double min, double max) {
-  DisallowHeapAllocation no_allocation;
-  int glb = kNone;
-  const Boundary* mins = Boundaries();
-
-  // If the range does not touch 0, the bound is empty.
-  if (max < -1 || min > 0) return glb;
-
-  for (size_t i = 1; i + 1 < BoundariesSize(); ++i) {
-    if (min <= mins[i].min) {
-      if (max + 1 < mins[i + 1].min) break;
-      glb |= mins[i].external;
-    }
-  }
-  // OtherNumber also contains float numbers, so it can never be
-  // in the greatest lower bound.
-  return glb & ~(SEMANTIC(kOtherNumber));
-}
-
-double BitsetType::Min(bitset bits) {
-  DisallowHeapAllocation no_allocation;
-  DCHECK(Is(SEMANTIC(bits), kNumber));
-  const Boundary* mins = Boundaries();
-  bool mz = SEMANTIC(bits & kMinusZero);
-  for (size_t i = 0; i < BoundariesSize(); ++i) {
-    if (Is(SEMANTIC(mins[i].internal), bits)) {
-      return mz ? std::min(0.0, mins[i].min) : mins[i].min;
-    }
-  }
-  if (mz) return 0;
-  return std::numeric_limits<double>::quiet_NaN();
-}
-
-double BitsetType::Max(bitset bits) {
-  DisallowHeapAllocation no_allocation;
-  DCHECK(Is(SEMANTIC(bits), kNumber));
-  const Boundary* mins = Boundaries();
-  bool mz = SEMANTIC(bits & kMinusZero);
-  if (BitsetType::Is(SEMANTIC(mins[BoundariesSize() - 1].internal), bits)) {
-    return +V8_INFINITY;
-  }
-  for (size_t i = BoundariesSize() - 1; i-- > 0;) {
-    if (Is(SEMANTIC(mins[i].internal), bits)) {
-      return mz ?
-          std::max(0.0, mins[i+1].min - 1) : mins[i+1].min - 1;
-    }
-  }
-  if (mz) return 0;
-  return std::numeric_limits<double>::quiet_NaN();
-}
-
-
-// -----------------------------------------------------------------------------
-// Predicates.
-
-bool Type::SimplyEquals(Type* that) {
-  DisallowHeapAllocation no_allocation;
-  if (this->IsConstant()) {
-    return that->IsConstant()
-        && *this->AsConstant()->Value() == *that->AsConstant()->Value();
-  }
-  if (this->IsTuple()) {
-    if (!that->IsTuple()) return false;
-    TupleType* this_tuple = this->AsTuple();
-    TupleType* that_tuple = that->AsTuple();
-    if (this_tuple->Arity() != that_tuple->Arity()) {
-      return false;
-    }
-    for (int i = 0, n = this_tuple->Arity(); i < n; ++i) {
-      if (!this_tuple->Element(i)->Equals(that_tuple->Element(i))) return false;
-    }
-    return true;
-  }
-  UNREACHABLE();
-  return false;
-}
-
-Type::bitset Type::Representation() {
-  return REPRESENTATION(this->BitsetLub());
-}
-
-
-// Check if [this] <= [that].
-bool Type::SlowIs(Type* that) {
-  DisallowHeapAllocation no_allocation;
-
-  // Fast bitset cases
-  if (that->IsBitset()) {
-    return BitsetType::Is(this->BitsetLub(), that->AsBitset());
-  }
-
-  if (this->IsBitset()) {
-    return BitsetType::Is(this->AsBitset(), that->BitsetGlb());
-  }
-
-  // Check the representations.
-  if (!BitsetType::Is(Representation(), that->Representation())) {
-    return false;
-  }
-
-  // Check the semantic part.
-  return SemanticIs(that);
-}
-
-
-// Check if SEMANTIC([this]) <= SEMANTIC([that]). The result of the method
-// should be independent of the representation axis of the types.
-bool Type::SemanticIs(Type* that) {
-  DisallowHeapAllocation no_allocation;
-
-  if (this == that) return true;
-
-  if (that->IsBitset()) {
-    return BitsetType::Is(SEMANTIC(this->BitsetLub()), that->AsBitset());
-  }
-  if (this->IsBitset()) {
-    return BitsetType::Is(SEMANTIC(this->AsBitset()), that->BitsetGlb());
-  }
-
-  // (T1 \/ ... \/ Tn) <= T  if  (T1 <= T) /\ ... /\ (Tn <= T)
-  if (this->IsUnion()) {
-    for (int i = 0, n = this->AsUnion()->Length(); i < n; ++i) {
-      if (!this->AsUnion()->Get(i)->SemanticIs(that)) return false;
-    }
-    return true;
-  }
-
-  // T <= (T1 \/ ... \/ Tn)  if  (T <= T1) \/ ... \/ (T <= Tn)
-  if (that->IsUnion()) {
-    for (int i = 0, n = that->AsUnion()->Length(); i < n; ++i) {
-      if (this->SemanticIs(that->AsUnion()->Get(i))) return true;
-      if (i > 1 && this->IsRange()) return false;  // Shortcut.
-    }
-    return false;
-  }
-
-  if (that->IsRange()) {
-    return (this->IsRange() && Contains(that->AsRange(), this->AsRange())) ||
-           (this->IsConstant() &&
-            Contains(that->AsRange(), this->AsConstant()));
-  }
-  if (this->IsRange()) return false;
-
-  return this->SimplyEquals(that);
-}
-
-
-// Check if [this] and [that] overlap.
-bool Type::Maybe(Type* that) {
-  DisallowHeapAllocation no_allocation;
-
-  // Take care of the representation part (and also approximate
-  // the semantic part).
-  if (!BitsetType::IsInhabited(this->BitsetLub() & that->BitsetLub()))
-    return false;
-
-  return SemanticMaybe(that);
-}
-
-bool Type::SemanticMaybe(Type* that) {
-  DisallowHeapAllocation no_allocation;
-
-  // (T1 \/ ... \/ Tn) overlaps T  if  (T1 overlaps T) \/ ... \/ (Tn overlaps T)
-  if (this->IsUnion()) {
-    for (int i = 0, n = this->AsUnion()->Length(); i < n; ++i) {
-      if (this->AsUnion()->Get(i)->SemanticMaybe(that)) return true;
-    }
-    return false;
-  }
-
-  // T overlaps (T1 \/ ... \/ Tn)  if  (T overlaps T1) \/ ... \/ (T overlaps Tn)
-  if (that->IsUnion()) {
-    for (int i = 0, n = that->AsUnion()->Length(); i < n; ++i) {
-      if (this->SemanticMaybe(that->AsUnion()->Get(i))) return true;
-    }
-    return false;
-  }
-
-  if (!BitsetType::SemanticIsInhabited(this->BitsetLub() & that->BitsetLub()))
-    return false;
-
-  if (this->IsBitset() && that->IsBitset()) return true;
-
-  if (this->IsRange()) {
-    if (that->IsConstant()) {
-      return Contains(this->AsRange(), that->AsConstant());
-    }
-    if (that->IsRange()) {
-      return Overlap(this->AsRange(), that->AsRange());
-    }
-    if (that->IsBitset()) {
-      bitset number_bits = BitsetType::NumberBits(that->AsBitset());
-      if (number_bits == BitsetType::kNone) {
-        return false;
-      }
-      double min = std::max(BitsetType::Min(number_bits), this->Min());
-      double max = std::min(BitsetType::Max(number_bits), this->Max());
-      return min <= max;
-    }
-  }
-  if (that->IsRange()) {
-    return that->SemanticMaybe(this);  // This case is handled above.
-  }
-
-  if (this->IsBitset() || that->IsBitset()) return true;
-
-  return this->SimplyEquals(that);
-}
-
-
-// Return the range in [this], or [NULL].
-Type* Type::GetRange() {
-  DisallowHeapAllocation no_allocation;
-  if (this->IsRange()) return this;
-  if (this->IsUnion() && this->AsUnion()->Get(1)->IsRange()) {
-    return this->AsUnion()->Get(1);
-  }
-  return NULL;
-}
-
-bool Type::Contains(i::Object* value) {
-  DisallowHeapAllocation no_allocation;
-  for (Iterator<i::Object> it = this->Constants(); !it.Done(); it.Advance()) {
-    if (*it.Current() == value) return true;
-  }
-  if (IsInteger(value)) {
-    Type* range = this->GetRange();
-    if (range != NULL && Contains(range->AsRange(), value)) return true;
-  }
-  return BitsetType::New(BitsetType::Lub(value))->Is(this);
-}
-
-bool UnionType::Wellformed() {
-  DisallowHeapAllocation no_allocation;
-  // This checks the invariants of the union representation:
-  // 1. There are at least two elements.
-  // 2. The first element is a bitset, no other element is a bitset.
-  // 3. At most one element is a range, and it must be the second one.
-  // 4. No element is itself a union.
-  // 5. No element (except the bitset) is a subtype of any other.
-  // 6. If there is a range, then the bitset type does not contain
-  //    plain number bits.
-  DCHECK(this->Length() >= 2);  // (1)
-  DCHECK(this->Get(0)->IsBitset());  // (2a)
-
-  for (int i = 0; i < this->Length(); ++i) {
-    if (i != 0) DCHECK(!this->Get(i)->IsBitset());  // (2b)
-    if (i != 1) DCHECK(!this->Get(i)->IsRange());   // (3)
-    DCHECK(!this->Get(i)->IsUnion());               // (4)
-    for (int j = 0; j < this->Length(); ++j) {
-      if (i != j && i != 0)
-        DCHECK(!this->Get(i)->SemanticIs(this->Get(j)));  // (5)
-    }
-  }
-  DCHECK(!this->Get(1)->IsRange() ||
-         (BitsetType::NumberBits(this->Get(0)->AsBitset()) ==
-          BitsetType::kNone));  // (6)
-  return true;
-}
-
-
-// -----------------------------------------------------------------------------
-// Union and intersection
-
-
-static bool AddIsSafe(int x, int y) {
-  return x >= 0 ?
-      y <= std::numeric_limits<int>::max() - x :
-      y >= std::numeric_limits<int>::min() - x;
-}
-
-Type* Type::Intersect(Type* type1, Type* type2, Zone* zone) {
-  // Fast case: bit sets.
-  if (type1->IsBitset() && type2->IsBitset()) {
-    return BitsetType::New(type1->AsBitset() & type2->AsBitset());
-  }
-
-  // Fast case: top or bottom types.
-  if (type1->IsNone() || type2->IsAny()) return type1;  // Shortcut.
-  if (type2->IsNone() || type1->IsAny()) return type2;  // Shortcut.
-
-  // Semi-fast case.
-  if (type1->Is(type2)) return type1;
-  if (type2->Is(type1)) return type2;
-
-  // Slow case: create union.
-
-  // Figure out the representation of the result first.
-  // The rest of the method should not change this representation and
-  // it should not make any decisions based on representations (i.e.,
-  // it should only use the semantic part of types).
-  const bitset representation =
-      type1->Representation() & type2->Representation();
-
-  // Semantic subtyping check - this is needed for consistency with the
-  // semi-fast case above - we should behave the same way regardless of
-  // representations. Intersection with a universal bitset should only update
-  // the representations.
-  if (type1->SemanticIs(type2)) {
-    type2 = Any();
-  } else if (type2->SemanticIs(type1)) {
-    type1 = Any();
-  }
-
-  bitset bits =
-      SEMANTIC(type1->BitsetGlb() & type2->BitsetGlb()) | representation;
-  int size1 = type1->IsUnion() ? type1->AsUnion()->Length() : 1;
-  int size2 = type2->IsUnion() ? type2->AsUnion()->Length() : 1;
-  if (!AddIsSafe(size1, size2)) return Any();
-  int size = size1 + size2;
-  if (!AddIsSafe(size, 2)) return Any();
-  size += 2;
-  Type* result_type = UnionType::New(size, zone);
-  UnionType* result = result_type->AsUnion();
-  size = 0;
-
-  // Deal with bitsets.
-  result->Set(size++, BitsetType::New(bits));
-
-  RangeType::Limits lims = RangeType::Limits::Empty();
-  size = IntersectAux(type1, type2, result, size, &lims, zone);
-
-  // If the range is not empty, then insert it into the union and
-  // remove the number bits from the bitset.
-  if (!lims.IsEmpty()) {
-    size = UpdateRange(RangeType::New(lims, representation, zone), result, size,
-                       zone);
-
-    // Remove the number bits.
-    bitset number_bits = BitsetType::NumberBits(bits);
-    bits &= ~number_bits;
-    result->Set(0, BitsetType::New(bits));
-  }
-  return NormalizeUnion(result_type, size, zone);
-}
-
-int Type::UpdateRange(Type* range, UnionType* result, int size, Zone* zone) {
-  if (size == 1) {
-    result->Set(size++, range);
-  } else {
-    // Make space for the range.
-    result->Set(size++, result->Get(1));
-    result->Set(1, range);
-  }
-
-  // Remove any components that just got subsumed.
-  for (int i = 2; i < size; ) {
-    if (result->Get(i)->SemanticIs(range)) {
-      result->Set(i, result->Get(--size));
-    } else {
-      ++i;
-    }
-  }
-  return size;
-}
-
-RangeType::Limits Type::ToLimits(bitset bits, Zone* zone) {
-  bitset number_bits = BitsetType::NumberBits(bits);
-
-  if (number_bits == BitsetType::kNone) {
-    return RangeType::Limits::Empty();
-  }
-
-  return RangeType::Limits(BitsetType::Min(number_bits),
-                           BitsetType::Max(number_bits));
-}
-
-RangeType::Limits Type::IntersectRangeAndBitset(Type* range, Type* bitset,
-                                                Zone* zone) {
-  RangeType::Limits range_lims(range->AsRange());
-  RangeType::Limits bitset_lims = ToLimits(bitset->AsBitset(), zone);
-  return RangeType::Limits::Intersect(range_lims, bitset_lims);
-}
-
-int Type::IntersectAux(Type* lhs, Type* rhs, UnionType* result, int size,
-                       RangeType::Limits* lims, Zone* zone) {
-  if (lhs->IsUnion()) {
-    for (int i = 0, n = lhs->AsUnion()->Length(); i < n; ++i) {
-      size =
-          IntersectAux(lhs->AsUnion()->Get(i), rhs, result, size, lims, zone);
-    }
-    return size;
-  }
-  if (rhs->IsUnion()) {
-    for (int i = 0, n = rhs->AsUnion()->Length(); i < n; ++i) {
-      size =
-          IntersectAux(lhs, rhs->AsUnion()->Get(i), result, size, lims, zone);
-    }
-    return size;
-  }
-
-  if (!BitsetType::SemanticIsInhabited(lhs->BitsetLub() & rhs->BitsetLub())) {
-    return size;
-  }
-
-  if (lhs->IsRange()) {
-    if (rhs->IsBitset()) {
-      RangeType::Limits lim = IntersectRangeAndBitset(lhs, rhs, zone);
-
-      if (!lim.IsEmpty()) {
-        *lims = RangeType::Limits::Union(lim, *lims);
-      }
-      return size;
-    }
-    if (rhs->IsConstant() && Contains(lhs->AsRange(), rhs->AsConstant())) {
-      return AddToUnion(rhs, result, size, zone);
-    }
-    if (rhs->IsRange()) {
-      RangeType::Limits lim = RangeType::Limits::Intersect(
-          RangeType::Limits(lhs->AsRange()), RangeType::Limits(rhs->AsRange()));
-      if (!lim.IsEmpty()) {
-        *lims = RangeType::Limits::Union(lim, *lims);
-      }
-    }
-    return size;
-  }
-  if (rhs->IsRange()) {
-    // This case is handled symmetrically above.
-    return IntersectAux(rhs, lhs, result, size, lims, zone);
-  }
-  if (lhs->IsBitset() || rhs->IsBitset()) {
-    return AddToUnion(lhs->IsBitset() ? rhs : lhs, result, size, zone);
-  }
-  if (lhs->SimplyEquals(rhs)) {
-    return AddToUnion(lhs, result, size, zone);
-  }
-  return size;
-}
-
-
-// Make sure that we produce a well-formed range and bitset:
-// If the range is non-empty, the number bits in the bitset should be
-// clear. Moreover, if we have a canonical range (such as Signed32),
-// we want to produce a bitset rather than a range.
-Type* Type::NormalizeRangeAndBitset(Type* range, bitset* bits, Zone* zone) {
-  // Fast path: If the bitset does not mention numbers, we can just keep the
-  // range.
-  bitset number_bits = BitsetType::NumberBits(*bits);
-  if (number_bits == 0) {
-    return range;
-  }
-
-  // If the range is semantically contained within the bitset, return None and
-  // leave the bitset untouched.
-  bitset range_lub = SEMANTIC(range->BitsetLub());
-  if (BitsetType::Is(range_lub, *bits)) {
-    return None();
-  }
-
-  // Slow path: reconcile the bitset range and the range.
-  double bitset_min = BitsetType::Min(number_bits);
-  double bitset_max = BitsetType::Max(number_bits);
-
-  double range_min = range->Min();
-  double range_max = range->Max();
-
-  // Remove the number bits from the bitset, they would just confuse us now.
-  // NOTE: bits contains OtherNumber iff bits contains PlainNumber, in which
-  // case we already returned after the subtype check above.
-  *bits &= ~number_bits;
-
-  if (range_min <= bitset_min && range_max >= bitset_max) {
-    // Bitset is contained within the range, just return the range.
-    return range;
-  }
-
-  if (bitset_min < range_min) {
-    range_min = bitset_min;
-  }
-  if (bitset_max > range_max) {
-    range_max = bitset_max;
-  }
-  return RangeType::New(range_min, range_max, BitsetType::kNone, zone);
-}
-
-Type* Type::Union(Type* type1, Type* type2, Zone* zone) {
-  // Fast case: bit sets.
-  if (type1->IsBitset() && type2->IsBitset()) {
-    return BitsetType::New(type1->AsBitset() | type2->AsBitset());
-  }
-
-  // Fast case: top or bottom types.
-  if (type1->IsAny() || type2->IsNone()) return type1;
-  if (type2->IsAny() || type1->IsNone()) return type2;
-
-  // Semi-fast case.
-  if (type1->Is(type2)) return type2;
-  if (type2->Is(type1)) return type1;
-
-  // Figure out the representation of the result.
-  // The rest of the method should not change this representation and
-  // it should not make any decisions based on representations (i.e.,
-  // it should only use the semantic part of types).
-  const bitset representation =
-      type1->Representation() | type2->Representation();
-
-  // Slow case: create union.
-  int size1 = type1->IsUnion() ? type1->AsUnion()->Length() : 1;
-  int size2 = type2->IsUnion() ? type2->AsUnion()->Length() : 1;
-  if (!AddIsSafe(size1, size2)) return Any();
-  int size = size1 + size2;
-  if (!AddIsSafe(size, 2)) return Any();
-  size += 2;
-  Type* result_type = UnionType::New(size, zone);
-  UnionType* result = result_type->AsUnion();
-  size = 0;
-
-  // Compute the new bitset.
-  bitset new_bitset = SEMANTIC(type1->BitsetGlb() | type2->BitsetGlb());
-
-  // Deal with ranges.
-  Type* range = None();
-  Type* range1 = type1->GetRange();
-  Type* range2 = type2->GetRange();
-  if (range1 != NULL && range2 != NULL) {
-    RangeType::Limits lims =
-        RangeType::Limits::Union(RangeType::Limits(range1->AsRange()),
-                                 RangeType::Limits(range2->AsRange()));
-    Type* union_range = RangeType::New(lims, representation, zone);
-    range = NormalizeRangeAndBitset(union_range, &new_bitset, zone);
-  } else if (range1 != NULL) {
-    range = NormalizeRangeAndBitset(range1, &new_bitset, zone);
-  } else if (range2 != NULL) {
-    range = NormalizeRangeAndBitset(range2, &new_bitset, zone);
-  }
-  new_bitset = SEMANTIC(new_bitset) | representation;
-  Type* bits = BitsetType::New(new_bitset);
-  result->Set(size++, bits);
-  if (!range->IsNone()) result->Set(size++, range);
-
-  size = AddToUnion(type1, result, size, zone);
-  size = AddToUnion(type2, result, size, zone);
-  return NormalizeUnion(result_type, size, zone);
-}
-
-
-// Add [type] to [result] unless [type] is bitset, range, or already subsumed.
-// Return new size of [result].
-int Type::AddToUnion(Type* type, UnionType* result, int size, Zone* zone) {
-  if (type->IsBitset() || type->IsRange()) return size;
-  if (type->IsUnion()) {
-    for (int i = 0, n = type->AsUnion()->Length(); i < n; ++i) {
-      size = AddToUnion(type->AsUnion()->Get(i), result, size, zone);
-    }
-    return size;
-  }
-  for (int i = 0; i < size; ++i) {
-    if (type->SemanticIs(result->Get(i))) return size;
-  }
-  result->Set(size++, type);
-  return size;
-}
-
-Type* Type::NormalizeUnion(Type* union_type, int size, Zone* zone) {
-  UnionType* unioned = union_type->AsUnion();
-  DCHECK(size >= 1);
-  DCHECK(unioned->Get(0)->IsBitset());
-  // If the union has just one element, return it.
-  if (size == 1) {
-    return unioned->Get(0);
-  }
-  bitset bits = unioned->Get(0)->AsBitset();
-  // If the union only consists of a range, we can get rid of the union.
-  if (size == 2 && SEMANTIC(bits) == BitsetType::kNone) {
-    bitset representation = REPRESENTATION(bits);
-    if (representation == unioned->Get(1)->Representation()) {
-      return unioned->Get(1);
-    }
-    if (unioned->Get(1)->IsRange()) {
-      return RangeType::New(unioned->Get(1)->AsRange()->Min(),
-                            unioned->Get(1)->AsRange()->Max(),
-                            unioned->Get(0)->AsBitset(), zone);
-    }
-  }
-  unioned->Shrink(size);
-  SLOW_DCHECK(unioned->Wellformed());
-  return union_type;
-}
-
-
-// -----------------------------------------------------------------------------
-// Component extraction
-
-// static
-Type* Type::Representation(Type* t, Zone* zone) {
-  return BitsetType::New(t->Representation());
-}
-
-
-// static
-Type* Type::Semantic(Type* t, Zone* zone) {
-  return Intersect(t, BitsetType::New(BitsetType::kSemantic), zone);
-}
-
-
-// -----------------------------------------------------------------------------
-// Iteration.
-
-int Type::NumConstants() {
-  DisallowHeapAllocation no_allocation;
-  if (this->IsConstant()) {
-    return 1;
-  } else if (this->IsUnion()) {
-    int result = 0;
-    for (int i = 0, n = this->AsUnion()->Length(); i < n; ++i) {
-      if (this->AsUnion()->Get(i)->IsConstant()) ++result;
-    }
-    return result;
-  } else {
-    return 0;
-  }
-}
-
-template <class T>
-Type* Type::Iterator<T>::get_type() {
-  DCHECK(!Done());
-  return type_->IsUnion() ? type_->AsUnion()->Get(index_) : type_;
-}
-
-
-// C++ cannot specialise nested templates, so we have to go through this
-// contortion with an auxiliary template to simulate it.
-template <class T>
-struct TypeImplIteratorAux {
-  static bool matches(Type* type);
-  static i::Handle<T> current(Type* type);
-};
-
-template <>
-struct TypeImplIteratorAux<i::Object> {
-  static bool matches(Type* type) { return type->IsConstant(); }
-  static i::Handle<i::Object> current(Type* type) {
-    return type->AsConstant()->Value();
-  }
-};
-
-template <class T>
-bool Type::Iterator<T>::matches(Type* type) {
-  return TypeImplIteratorAux<T>::matches(type);
-}
-
-template <class T>
-i::Handle<T> Type::Iterator<T>::Current() {
-  return TypeImplIteratorAux<T>::current(get_type());
-}
-
-template <class T>
-void Type::Iterator<T>::Advance() {
-  DisallowHeapAllocation no_allocation;
-  ++index_;
-  if (type_->IsUnion()) {
-    for (int n = type_->AsUnion()->Length(); index_ < n; ++index_) {
-      if (matches(type_->AsUnion()->Get(index_))) return;
-    }
-  } else if (index_ == 0 && matches(type_)) {
-    return;
-  }
-  index_ = -1;
-}
-
-
-// -----------------------------------------------------------------------------
-// Printing.
-
-const char* BitsetType::Name(bitset bits) {
-  switch (bits) {
-    case REPRESENTATION(kAny): return "Any";
-    #define RETURN_NAMED_REPRESENTATION_TYPE(type, value) \
-    case REPRESENTATION(k##type): return #type;
-    REPRESENTATION_BITSET_TYPE_LIST(RETURN_NAMED_REPRESENTATION_TYPE)
-    #undef RETURN_NAMED_REPRESENTATION_TYPE
-
-    #define RETURN_NAMED_SEMANTIC_TYPE(type, value) \
-    case SEMANTIC(k##type): return #type;
-    SEMANTIC_BITSET_TYPE_LIST(RETURN_NAMED_SEMANTIC_TYPE)
-    INTERNAL_BITSET_TYPE_LIST(RETURN_NAMED_SEMANTIC_TYPE)
-    #undef RETURN_NAMED_SEMANTIC_TYPE
-
-    default:
-      return NULL;
-  }
-}
-
-void BitsetType::Print(std::ostream& os,  // NOLINT
-                       bitset bits) {
-  DisallowHeapAllocation no_allocation;
-  const char* name = Name(bits);
-  if (name != NULL) {
-    os << name;
-    return;
-  }
-
-  // clang-format off
-  static const bitset named_bitsets[] = {
-#define BITSET_CONSTANT(type, value) REPRESENTATION(k##type),
-    REPRESENTATION_BITSET_TYPE_LIST(BITSET_CONSTANT)
-#undef BITSET_CONSTANT
-
-#define BITSET_CONSTANT(type, value) SEMANTIC(k##type),
-    INTERNAL_BITSET_TYPE_LIST(BITSET_CONSTANT)
-    SEMANTIC_BITSET_TYPE_LIST(BITSET_CONSTANT)
-#undef BITSET_CONSTANT
-  };
-  // clang-format on
-
-  bool is_first = true;
-  os << "(";
-  for (int i(arraysize(named_bitsets) - 1); bits != 0 && i >= 0; --i) {
-    bitset subset = named_bitsets[i];
-    if ((bits & subset) == subset) {
-      if (!is_first) os << " | ";
-      is_first = false;
-      os << Name(subset);
-      bits -= subset;
-    }
-  }
-  DCHECK(bits == 0);
-  os << ")";
-}
-
-void Type::PrintTo(std::ostream& os, PrintDimension dim) {
-  DisallowHeapAllocation no_allocation;
-  if (dim != REPRESENTATION_DIM) {
-    if (this->IsBitset()) {
-      BitsetType::Print(os, SEMANTIC(this->AsBitset()));
-    } else if (this->IsConstant()) {
-      os << "Constant(" << Brief(*this->AsConstant()->Value()) << ")";
-    } else if (this->IsRange()) {
-      std::ostream::fmtflags saved_flags = os.setf(std::ios::fixed);
-      std::streamsize saved_precision = os.precision(0);
-      os << "Range(" << this->AsRange()->Min() << ", " << this->AsRange()->Max()
-         << ")";
-      os.flags(saved_flags);
-      os.precision(saved_precision);
-    } else if (this->IsUnion()) {
-      os << "(";
-      for (int i = 0, n = this->AsUnion()->Length(); i < n; ++i) {
-        Type* type_i = this->AsUnion()->Get(i);
-        if (i > 0) os << " | ";
-        type_i->PrintTo(os, dim);
-      }
-      os << ")";
-    } else if (this->IsTuple()) {
-      os << "<";
-      for (int i = 0, n = this->AsTuple()->Arity(); i < n; ++i) {
-        Type* type_i = this->AsTuple()->Element(i);
-        if (i > 0) os << ", ";
-        type_i->PrintTo(os, dim);
-      }
-      os << ">";
-    } else {
-      UNREACHABLE();
-    }
-  }
-  if (dim == BOTH_DIMS) os << "/";
-  if (dim != SEMANTIC_DIM) {
-    BitsetType::Print(os, REPRESENTATION(this->BitsetLub()));
-  }
-}
-
-
-#ifdef DEBUG
-void Type::Print() {
-  OFStream os(stdout);
-  PrintTo(os);
-  os << std::endl;
-}
-void BitsetType::Print(bitset bits) {
-  OFStream os(stdout);
-  Print(os, bits);
-  os << std::endl;
-}
-#endif
-
-BitsetType::bitset BitsetType::SignedSmall() {
-  return i::SmiValuesAre31Bits() ? kSigned31 : kSigned32;
-}
-
-BitsetType::bitset BitsetType::UnsignedSmall() {
-  return i::SmiValuesAre31Bits() ? kUnsigned30 : kUnsigned31;
-}
-
-// -----------------------------------------------------------------------------
-// Instantiations.
-
-template class Type::Iterator<i::Object>;
-
-}  // namespace internal
-}  // namespace v8