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v8/src/types.cc
franzih e9a93a9c2b Refactor Object.prototype.toString() to use the instance type instead of class_name(). 
Now we can turn it into a turbofan stub.

Create new instance types JS_ARGUMENTS_TYPE and JS_ERROR_TYPE.

Review-Url: https://codereview.chromium.org/2080243003
Cr-Commit-Position: refs/heads/master@{#37219}
2016-06-23 14:40:47 +00:00

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// 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->IsClass()) return type->AsClass()->Lub();
if (type->IsConstant()) return type->AsConstant()->Lub();
if (type->IsRange()) return type->AsRange()->Lub();
if (type->IsContext()) return kInternal & kTaggedPointer;
if (type->IsArray()) return kOtherObject;
if (type->IsFunction()) return kFunction;
if (type->IsTuple()) return kInternal;
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;
DCHECK(map == heap->the_hole_map() ||
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 kInternal & 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 kInternal & kTaggedPointer;
// Remaining instance types are unsupported for now. If any of them do
// require bit set types, they should get kInternal & 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 SLOPPY_BLOCK_WITH_EVAL_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->IsClass()) {
return that->IsClass()
&& *this->AsClass()->Map() == *that->AsClass()->Map();
}
if (this->IsConstant()) {
return that->IsConstant()
&& *this->AsConstant()->Value() == *that->AsConstant()->Value();
}
if (this->IsContext()) {
return that->IsContext()
&& this->AsContext()->Outer()->Equals(that->AsContext()->Outer());
}
if (this->IsArray()) {
return that->IsArray()
&& this->AsArray()->Element()->Equals(that->AsArray()->Element());
}
if (this->IsFunction()) {
if (!that->IsFunction()) return false;
FunctionType* this_fun = this->AsFunction();
FunctionType* that_fun = that->AsFunction();
if (this_fun->Arity() != that_fun->Arity() ||
!this_fun->Result()->Equals(that_fun->Result()) ||
!this_fun->Receiver()->Equals(that_fun->Receiver())) {
return false;
}
for (int i = 0, n = this_fun->Arity(); i < n; ++i) {
if (!this_fun->Parameter(i)->Equals(that_fun->Parameter(i))) return false;
}
return true;
}
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);
}
// Most precise _current_ type of a value (usually its class).
Type* Type::NowOf(i::Object* value, Zone* zone) {
if (value->IsSmi() ||
i::HeapObject::cast(value)->map()->instance_type() == HEAP_NUMBER_TYPE) {
return Of(value, zone);
}
return Class(i::handle(i::HeapObject::cast(value)->map()), zone);
}
bool Type::NowContains(i::Object* value) {
DisallowHeapAllocation no_allocation;
if (this->IsAny()) return true;
if (value->IsHeapObject()) {
i::Map* map = i::HeapObject::cast(value)->map();
for (Iterator<i::Map> it = this->Classes(); !it.Done(); it.Advance()) {
if (*it.Current() == map) return true;
}
}
return this->Contains(value);
}
bool Type::NowIs(Type* that) {
DisallowHeapAllocation no_allocation;
// TODO(rossberg): this is incorrect for
// Union(Constant(V), T)->NowIs(Class(M))
// but fuzzing does not cover that!
if (this->IsConstant()) {
i::Object* object = *this->AsConstant()->Value();
if (object->IsHeapObject()) {
i::Map* map = i::HeapObject::cast(object)->map();
for (Iterator<i::Map> it = that->Classes(); !it.Done(); it.Advance()) {
if (*it.Current() == map) return true;
}
}
}
return this->Is(that);
}
// Check if [this] contains only (currently) stable classes.
bool Type::NowStable() {
DisallowHeapAllocation no_allocation;
return !this->IsClass() || this->AsClass()->Map()->is_stable();
}
// 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->IsClass() != that->IsClass()) 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->IsClass()) {
*lims =
RangeType::Limits::Union(RangeType::Limits(lhs->AsRange()), *lims);
}
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->IsClass() != rhs->IsClass()) {
return AddToUnion(lhs->IsClass() ? 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::NumClasses() {
DisallowHeapAllocation no_allocation;
if (this->IsClass()) {
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)->IsClass()) ++result;
}
return result;
} else {
return 0;
}
}
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::Map> {
static bool matches(Type* type) { return type->IsClass(); }
static i::Handle<i::Map> current(Type* type) {
return type->AsClass()->Map();
}
};
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->IsClass()) {
os << "Class(" << static_cast<void*>(*this->AsClass()->Map()) << " < ";
BitsetType::New(BitsetType::Lub(this))->PrintTo(os, dim);
os << ")";
} 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->IsContext()) {
os << "Context(";
this->AsContext()->Outer()->PrintTo(os, dim);
os << ")";
} 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->IsArray()) {
os << "Array(";
AsArray()->Element()->PrintTo(os, dim);
os << ")";
} else if (this->IsFunction()) {
if (!this->AsFunction()->Receiver()->IsAny()) {
this->AsFunction()->Receiver()->PrintTo(os, dim);
os << ".";
}
os << "(";
for (int i = 0; i < this->AsFunction()->Arity(); ++i) {
if (i > 0) os << ", ";
this->AsFunction()->Parameter(i)->PrintTo(os, dim);
}
os << ")->";
this->AsFunction()->Result()->PrintTo(os, dim);
} 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;
}
#define CONSTRUCT_SIMD_TYPE(NAME, Name, name, lane_count, lane_type) \
Type* Type::Name(Isolate* isolate, Zone* zone) { \
return Class(i::handle(isolate->heap()->name##_map()), zone); \
}
SIMD128_TYPES(CONSTRUCT_SIMD_TYPE)
#undef CONSTRUCT_SIMD_TYPE
// -----------------------------------------------------------------------------
// Instantiations.
template class Type::Iterator<i::Map>;
template class Type::Iterator<i::Object>;
} // namespace internal
} // namespace v8
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