blob: 34fe1d8ce42b22377b83b156e0701e326d6c471f [file] [log] [blame]
// 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/objects-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* 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->IsOtherNumberConstant())
return this->AsOtherNumberConstant()->Value();
UNREACHABLE();
}
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->IsOtherNumberConstant())
return this->AsOtherNumberConstant()->Value();
UNREACHABLE();
}
// -----------------------------------------------------------------------------
// 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->IsHeapConstant()) return type->AsHeapConstant()->Lub();
if (type->IsOtherNumberConstant())
return type->AsOtherNumberConstant()->Lub();
if (type->IsRange()) return type->AsRange()->Lub();
if (type->IsTuple()) return kOtherInternal;
UNREACHABLE();
}
Type::bitset BitsetType::Lub(i::Map* map) {
DisallowHeapAllocation no_allocation;
switch (map->instance_type()) {
case CONS_STRING_TYPE:
case CONS_ONE_BYTE_STRING_TYPE:
case THIN_STRING_TYPE:
case THIN_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 kOtherNonSeqString;
case STRING_TYPE:
case ONE_BYTE_STRING_TYPE:
return kOtherSeqString;
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 kInternalizedNonSeqString;
case INTERNALIZED_STRING_TYPE:
case ONE_BYTE_INTERNALIZED_STRING_TYPE:
return kInternalizedSeqString;
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->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 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()) {
// Currently we assume that every undetectable receiver is also
// callable, which is what we need to support document.all. We
// could add another Type bit to support other use cases in the
// future if necessary.
DCHECK(map->is_callable());
return kOtherUndetectable;
}
if (map->is_callable()) {
return kOtherCallable;
}
return kOtherObject;
case JS_ARRAY_TYPE:
return kArray;
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_ASYNC_GENERATOR_OBJECT_TYPE:
case JS_MODULE_NAMESPACE_TYPE:
case JS_ARRAY_BUFFER_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_ASYNC_FROM_SYNC_ITERATOR_TYPE:
case JS_TYPED_ARRAY_KEY_ITERATOR_TYPE:
case JS_FAST_ARRAY_KEY_ITERATOR_TYPE:
case JS_GENERIC_ARRAY_KEY_ITERATOR_TYPE:
case JS_UINT8_ARRAY_KEY_VALUE_ITERATOR_TYPE:
case JS_INT8_ARRAY_KEY_VALUE_ITERATOR_TYPE:
case JS_UINT16_ARRAY_KEY_VALUE_ITERATOR_TYPE:
case JS_INT16_ARRAY_KEY_VALUE_ITERATOR_TYPE:
case JS_UINT32_ARRAY_KEY_VALUE_ITERATOR_TYPE:
case JS_INT32_ARRAY_KEY_VALUE_ITERATOR_TYPE:
case JS_FLOAT32_ARRAY_KEY_VALUE_ITERATOR_TYPE:
case JS_FLOAT64_ARRAY_KEY_VALUE_ITERATOR_TYPE:
case JS_UINT8_CLAMPED_ARRAY_KEY_VALUE_ITERATOR_TYPE:
case JS_FAST_SMI_ARRAY_KEY_VALUE_ITERATOR_TYPE:
case JS_FAST_HOLEY_SMI_ARRAY_KEY_VALUE_ITERATOR_TYPE:
case JS_FAST_ARRAY_KEY_VALUE_ITERATOR_TYPE:
case JS_FAST_HOLEY_ARRAY_KEY_VALUE_ITERATOR_TYPE:
case JS_FAST_DOUBLE_ARRAY_KEY_VALUE_ITERATOR_TYPE:
case JS_FAST_HOLEY_DOUBLE_ARRAY_KEY_VALUE_ITERATOR_TYPE:
case JS_GENERIC_ARRAY_KEY_VALUE_ITERATOR_TYPE:
case JS_UINT8_ARRAY_VALUE_ITERATOR_TYPE:
case JS_INT8_ARRAY_VALUE_ITERATOR_TYPE:
case JS_UINT16_ARRAY_VALUE_ITERATOR_TYPE:
case JS_INT16_ARRAY_VALUE_ITERATOR_TYPE:
case JS_UINT32_ARRAY_VALUE_ITERATOR_TYPE:
case JS_INT32_ARRAY_VALUE_ITERATOR_TYPE:
case JS_FLOAT32_ARRAY_VALUE_ITERATOR_TYPE:
case JS_FLOAT64_ARRAY_VALUE_ITERATOR_TYPE:
case JS_UINT8_CLAMPED_ARRAY_VALUE_ITERATOR_TYPE:
case JS_FAST_SMI_ARRAY_VALUE_ITERATOR_TYPE:
case JS_FAST_HOLEY_SMI_ARRAY_VALUE_ITERATOR_TYPE:
case JS_FAST_ARRAY_VALUE_ITERATOR_TYPE:
case JS_FAST_HOLEY_ARRAY_VALUE_ITERATOR_TYPE:
case JS_FAST_DOUBLE_ARRAY_VALUE_ITERATOR_TYPE:
case JS_FAST_HOLEY_DOUBLE_ARRAY_VALUE_ITERATOR_TYPE:
case JS_GENERIC_ARRAY_VALUE_ITERATOR_TYPE:
case JS_WEAK_MAP_TYPE:
case JS_WEAK_SET_TYPE:
case JS_PROMISE_CAPABILITY_TYPE:
case JS_PROMISE_TYPE:
DCHECK(!map->is_callable());
DCHECK(!map->is_undetectable());
return kOtherObject;
case JS_BOUND_FUNCTION_TYPE:
DCHECK(!map->is_undetectable());
return kBoundFunction;
case JS_FUNCTION_TYPE:
DCHECK(!map->is_undetectable());
return kFunction;
case JS_PROXY_TYPE:
DCHECK(!map->is_undetectable());
if (map->is_callable()) return kCallableProxy;
return kOtherProxy;
case MAP_TYPE:
case ALLOCATION_SITE_TYPE:
case ACCESSOR_INFO_TYPE:
case SHARED_FUNCTION_INFO_TYPE:
case FUNCTION_TEMPLATE_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:
case MODULE_INFO_ENTRY_TYPE:
case CELL_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 OBJECT_TEMPLATE_INFO_TYPE:
case ALLOCATION_MEMENTO_TYPE:
case ALIASED_ARGUMENTS_ENTRY_TYPE:
case PROMISE_RESOLVE_THENABLE_JOB_INFO_TYPE:
case PROMISE_REACTION_JOB_INFO_TYPE:
case DEBUG_INFO_TYPE:
case STACK_FRAME_INFO_TYPE:
case WEAK_CELL_TYPE:
case SMALL_ORDERED_HASH_SET_TYPE:
case PROTOTYPE_INFO_TYPE:
case TUPLE2_TYPE:
case TUPLE3_TYPE:
case CONTEXT_EXTENSION_TYPE:
case ASYNC_GENERATOR_REQUEST_TYPE:
case PADDING_TYPE_1:
case PADDING_TYPE_2:
case PADDING_TYPE_3:
case PADDING_TYPE_4:
UNREACHABLE();
}
UNREACHABLE();
}
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();
}
// static
bool OtherNumberConstantType::IsOtherNumberConstant(double value) {
// Not an integer, not NaN, and not -0.
return !std::isnan(value) && !Type::IsInteger(value) &&
!i::IsMinusZero(value);
}
// static
bool OtherNumberConstantType::IsOtherNumberConstant(Object* value) {
return value->IsHeapNumber() &&
IsOtherNumberConstant(HeapNumber::cast(value)->value());
}
HeapConstantType::HeapConstantType(BitsetType::bitset bitset,
i::Handle<i::HeapObject> object)
: TypeBase(kHeapConstant), bitset_(bitset), object_(object) {
DCHECK(!object->IsHeapNumber());
DCHECK_IMPLIES(object->IsString(), object->IsInternalizedString());
}
// -----------------------------------------------------------------------------
// Predicates.
bool Type::SimplyEquals(Type* that) {
DisallowHeapAllocation no_allocation;
if (this->IsHeapConstant()) {
return that->IsHeapConstant() &&
this->AsHeapConstant()->Value().address() ==
that->AsHeapConstant()->Value().address();
}
if (this->IsOtherNumberConstant()) {
return that->IsOtherNumberConstant() &&
this->AsOtherNumberConstant()->Value() ==
that->AsOtherNumberConstant()->Value();
}
if (this->IsRange()) {
if (that->IsHeapConstant() || that->IsOtherNumberConstant()) return false;
}
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();
}
// 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()));
}
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->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->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::NewConstant(double value, Zone* zone) {
if (IsInteger(value)) {
return Range(value, value, zone);
} else if (i::IsMinusZero(value)) {
return Type::MinusZero();
} else if (std::isnan(value)) {
return Type::NaN();
}
DCHECK(OtherNumberConstantType::IsOtherNumberConstant(value));
return OtherNumberConstant(value, zone);
}
Type* Type::NewConstant(i::Handle<i::Object> value, Zone* zone) {
if (IsInteger(*value)) {
double v = value->Number();
return Range(v, v, zone);
} else if (value->IsHeapNumber()) {
return NewConstant(value->Number(), zone);
} else if (value->IsString() && !value->IsInternalizedString()) {
return Type::OtherString();
}
return HeapConstant(i::Handle<i::HeapObject>::cast(value), 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;
}
int Type::NumConstants() {
DisallowHeapAllocation no_allocation;
if (this->IsHeapConstant() || this->IsOtherNumberConstant()) {
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)->IsHeapConstant()) ++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->IsHeapConstant()) {
os << "HeapConstant(" << Brief(*this->AsHeapConstant()->Value()) << ")";
} else if (this->IsOtherNumberConstant()) {
os << "OtherNumberConstant(" << this->AsOtherNumberConstant()->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