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Diffstat (limited to 'deps/v8/src/compiler/types.cc')
| -rw-r--r-- | deps/v8/src/compiler/types.cc | 961 |
1 files changed, 961 insertions, 0 deletions
diff --git a/deps/v8/src/compiler/types.cc b/deps/v8/src/compiler/types.cc new file mode 100644 index 0000000000..43d2f80483 --- /dev/null +++ b/deps/v8/src/compiler/types.cc @@ -0,0 +1,961 @@ +// 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/compiler/types.h" + +#include "src/handles-inl.h" +#include "src/ostreams.h" + +namespace v8 { +namespace internal { +namespace compiler { + +// 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->Is(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->Is(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() | + type->AsUnion()->Get(1)->BitsetGlb(); // Shortcut. + } else if (type->IsRange()) { + bitset glb = + BitsetType::Glb(type->AsRange()->Min(), type->AsRange()->Max()); + return glb; + } else { + return kNone; + } +} + +// 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 |= 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; + } + case HEAP_NUMBER_TYPE: + return kNumber; + 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_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_STRING_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: + case MODULE_TYPE: + return kOtherInternal; + + // Remaining instance types are unsupported for now. If any of them do + // require bit set types, they should get kOtherInternal. + 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 PROMISE_CONTAINER_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()); + } + 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 & 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 & boundaries[i].internal) bits |= 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 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 & ~(kOtherNumber); +} + +double BitsetType::Min(bitset bits) { + DisallowHeapAllocation no_allocation; + DCHECK(Is(bits, kNumber)); + const Boundary* mins = Boundaries(); + bool mz = bits & kMinusZero; + for (size_t i = 0; i < BoundariesSize(); ++i) { + if (Is(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(bits, kNumber)); + const Boundary* mins = Boundaries(); + bool mz = bits & kMinusZero; + if (BitsetType::Is(mins[BoundariesSize() - 1].internal, bits)) { + return +V8_INFINITY; + } + for (size_t i = BoundariesSize() - 1; i-- > 0;) { + if (Is(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; +} + +// 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()); + } + + // (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)->Is(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->Is(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; + + if (!BitsetType::IsInhabited(this->BitsetLub() & that->BitsetLub())) + return false; + + // (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)->Maybe(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->Maybe(that->AsUnion()->Get(i))) return true; + } + 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->Maybe(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 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)->Is(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. + + // Semantic subtyping check - this is needed for consistency with the + // semi-fast case above. + if (type1->Is(type2)) { + type2 = Any(); + } else if (type2->Is(type1)) { + type1 = Any(); + } + + bitset bits = type1->BitsetGlb() & type2->BitsetGlb(); + 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, 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)->Is(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::IsInhabited(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 = 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, 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; + + // 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 = 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, 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); + } + 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->Is(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 && bits == BitsetType::kNone) { + if (unioned->Get(1)->IsRange()) { + return RangeType::New(unioned->Get(1)->AsRange()->Min(), + unioned->Get(1)->AsRange()->Max(), zone); + } + } + unioned->Shrink(size); + SLOW_DCHECK(unioned->Wellformed()); + return union_type; +} + +// ----------------------------------------------------------------------------- +// 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; + } +} + +// ----------------------------------------------------------------------------- +// Printing. + +const char* BitsetType::Name(bitset bits) { + switch (bits) { +#define RETURN_NAMED_TYPE(type, value) \ + case k##type: \ + return #type; + PROPER_BITSET_TYPE_LIST(RETURN_NAMED_TYPE) + INTERNAL_BITSET_TYPE_LIST(RETURN_NAMED_TYPE) +#undef RETURN_NAMED_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) k##type, + INTERNAL_BITSET_TYPE_LIST(BITSET_CONSTANT) + PROPER_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) { + DisallowHeapAllocation no_allocation; + if (this->IsBitset()) { + BitsetType::Print(os, 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); + } + 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); + } + os << ">"; + } else { + UNREACHABLE(); + } +} + +#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; +} + +} // namespace compiler +} // namespace internal +} // namespace v8 |