blob: 72d43c38626c9ab6f57025157852c4a9c9871f29 [file] [log] [blame]
// Copyright 2016 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 "src/compiler/operation-typer.h"
#include "src/compiler/common-operator.h"
#include "src/compiler/js-heap-broker.h"
#include "src/compiler/type-cache.h"
#include "src/compiler/types.h"
#include "src/execution/isolate.h"
#include "src/heap/factory.h"
#include "src/objects/objects-inl.h"
namespace v8 {
namespace internal {
namespace compiler {
OperationTyper::OperationTyper(JSHeapBroker* broker, Zone* zone)
: zone_(zone), cache_(TypeCache::Get()) {
Factory* factory = broker->isolate()->factory();
infinity_ = Type::Constant(V8_INFINITY, zone);
minus_infinity_ = Type::Constant(-V8_INFINITY, zone);
Type truncating_to_zero = Type::MinusZeroOrNaN();
DCHECK(!truncating_to_zero.Maybe(Type::Integral32()));
singleton_empty_string_ =
Type::Constant(broker, factory->empty_string(), zone);
singleton_NaN_string_ = Type::Constant(broker, factory->NaN_string(), zone);
singleton_zero_string_ = Type::Constant(broker, factory->zero_string(), zone);
singleton_false_ = Type::Constant(broker, factory->false_value(), zone);
singleton_true_ = Type::Constant(broker, factory->true_value(), zone);
singleton_the_hole_ = Type::Hole();
signed32ish_ = Type::Union(Type::Signed32(), truncating_to_zero, zone);
unsigned32ish_ = Type::Union(Type::Unsigned32(), truncating_to_zero, zone);
falsish_ = Type::Union(
Type::Undetectable(),
Type::Union(Type::Union(singleton_false_, cache_->kZeroish, zone),
Type::Union(singleton_empty_string_, Type::Hole(), zone),
zone),
zone);
truish_ = Type::Union(
singleton_true_,
Type::Union(Type::DetectableReceiver(), Type::Symbol(), zone), zone);
}
Type OperationTyper::Merge(Type left, Type right) {
return Type::Union(left, right, zone());
}
Type OperationTyper::WeakenRange(Type previous_range, Type current_range) {
static const double kWeakenMinLimits[] = {0.0,
-1073741824.0,
-2147483648.0,
-4294967296.0,
-8589934592.0,
-17179869184.0,
-34359738368.0,
-68719476736.0,
-137438953472.0,
-274877906944.0,
-549755813888.0,
-1099511627776.0,
-2199023255552.0,
-4398046511104.0,
-8796093022208.0,
-17592186044416.0,
-35184372088832.0,
-70368744177664.0,
-140737488355328.0,
-281474976710656.0,
-562949953421312.0};
static const double kWeakenMaxLimits[] = {0.0,
1073741823.0,
2147483647.0,
4294967295.0,
8589934591.0,
17179869183.0,
34359738367.0,
68719476735.0,
137438953471.0,
274877906943.0,
549755813887.0,
1099511627775.0,
2199023255551.0,
4398046511103.0,
8796093022207.0,
17592186044415.0,
35184372088831.0,
70368744177663.0,
140737488355327.0,
281474976710655.0,
562949953421311.0};
STATIC_ASSERT(arraysize(kWeakenMinLimits) == arraysize(kWeakenMaxLimits));
double current_min = current_range.Min();
double new_min = current_min;
// Find the closest lower entry in the list of allowed
// minima (or negative infinity if there is no such entry).
if (current_min != previous_range.Min()) {
new_min = -V8_INFINITY;
for (double const min : kWeakenMinLimits) {
if (min <= current_min) {
new_min = min;
break;
}
}
}
double current_max = current_range.Max();
double new_max = current_max;
// Find the closest greater entry in the list of allowed
// maxima (or infinity if there is no such entry).
if (current_max != previous_range.Max()) {
new_max = V8_INFINITY;
for (double const max : kWeakenMaxLimits) {
if (max >= current_max) {
new_max = max;
break;
}
}
}
return Type::Range(new_min, new_max, zone());
}
Type OperationTyper::Rangify(Type type) {
if (type.IsRange()) return type; // Shortcut.
if (!type.Is(cache_->kInteger)) {
return type; // Give up on non-integer types.
}
return Type::Range(type.Min(), type.Max(), zone());
}
namespace {
// Returns the array's least element, ignoring NaN.
// There must be at least one non-NaN element.
// Any -0 is converted to 0.
double array_min(double a[], size_t n) {
DCHECK_NE(0, n);
double x = +V8_INFINITY;
for (size_t i = 0; i < n; ++i) {
if (!std::isnan(a[i])) {
x = std::min(a[i], x);
}
}
DCHECK(!std::isnan(x));
return x == 0 ? 0 : x; // -0 -> 0
}
// Returns the array's greatest element, ignoring NaN.
// There must be at least one non-NaN element.
// Any -0 is converted to 0.
double array_max(double a[], size_t n) {
DCHECK_NE(0, n);
double x = -V8_INFINITY;
for (size_t i = 0; i < n; ++i) {
if (!std::isnan(a[i])) {
x = std::max(a[i], x);
}
}
DCHECK(!std::isnan(x));
return x == 0 ? 0 : x; // -0 -> 0
}
} // namespace
Type OperationTyper::AddRanger(double lhs_min, double lhs_max, double rhs_min,
double rhs_max) {
double results[4];
results[0] = lhs_min + rhs_min;
results[1] = lhs_min + rhs_max;
results[2] = lhs_max + rhs_min;
results[3] = lhs_max + rhs_max;
// Since none of the inputs can be -0, the result cannot be -0 either.
// However, it can be nan (the sum of two infinities of opposite sign).
// On the other hand, if none of the "results" above is nan, then the
// actual result cannot be nan either.
int nans = 0;
for (int i = 0; i < 4; ++i) {
if (std::isnan(results[i])) ++nans;
}
if (nans == 4) return Type::NaN();
Type type = Type::Range(array_min(results, 4), array_max(results, 4), zone());
if (nans > 0) type = Type::Union(type, Type::NaN(), zone());
// Examples:
// [-inf, -inf] + [+inf, +inf] = NaN
// [-inf, -inf] + [n, +inf] = [-inf, -inf] \/ NaN
// [-inf, +inf] + [n, +inf] = [-inf, +inf] \/ NaN
// [-inf, m] + [n, +inf] = [-inf, +inf] \/ NaN
return type;
}
Type OperationTyper::SubtractRanger(double lhs_min, double lhs_max,
double rhs_min, double rhs_max) {
double results[4];
results[0] = lhs_min - rhs_min;
results[1] = lhs_min - rhs_max;
results[2] = lhs_max - rhs_min;
results[3] = lhs_max - rhs_max;
// Since none of the inputs can be -0, the result cannot be -0.
// However, it can be nan (the subtraction of two infinities of same sign).
// On the other hand, if none of the "results" above is nan, then the actual
// result cannot be nan either.
int nans = 0;
for (int i = 0; i < 4; ++i) {
if (std::isnan(results[i])) ++nans;
}
if (nans == 4) return Type::NaN(); // [inf..inf] - [inf..inf] (all same sign)
Type type = Type::Range(array_min(results, 4), array_max(results, 4), zone());
return nans == 0 ? type : Type::Union(type, Type::NaN(), zone());
// Examples:
// [-inf, +inf] - [-inf, +inf] = [-inf, +inf] \/ NaN
// [-inf, -inf] - [-inf, -inf] = NaN
// [-inf, -inf] - [n, +inf] = [-inf, -inf] \/ NaN
// [m, +inf] - [-inf, n] = [-inf, +inf] \/ NaN
}
Type OperationTyper::MultiplyRanger(double lhs_min, double lhs_max,
double rhs_min, double rhs_max) {
double results[4];
results[0] = lhs_min * rhs_min;
results[1] = lhs_min * rhs_max;
results[2] = lhs_max * rhs_min;
results[3] = lhs_max * rhs_max;
// If the result may be nan, we give up on calculating a precise type,
// because the discontinuity makes it too complicated. Note that even if
// none of the "results" above is nan, the actual result may still be, so we
// have to do a different check:
for (int i = 0; i < 4; ++i) {
if (std::isnan(results[i])) {
return cache_->kIntegerOrMinusZeroOrNaN;
}
}
double min = array_min(results, 4);
double max = array_max(results, 4);
Type type = Type::Range(min, max, zone());
if (min <= 0.0 && 0.0 <= max && (lhs_min < 0.0 || rhs_min < 0.0)) {
type = Type::Union(type, Type::MinusZero(), zone());
}
// 0 * V8_INFINITY is NaN, regardless of sign
if (((lhs_min == -V8_INFINITY || lhs_max == V8_INFINITY) &&
(rhs_min <= 0.0 && 0.0 <= rhs_max)) ||
((rhs_min == -V8_INFINITY || rhs_max == V8_INFINITY) &&
(lhs_min <= 0.0 && 0.0 <= lhs_max))) {
type = Type::Union(type, Type::NaN(), zone());
}
return type;
}
Type OperationTyper::ConvertReceiver(Type type) {
if (type.Is(Type::Receiver())) return type;
bool const maybe_primitive = type.Maybe(Type::Primitive());
type = Type::Intersect(type, Type::Receiver(), zone());
if (maybe_primitive) {
// ConvertReceiver maps null and undefined to the JSGlobalProxy of the
// target function, and all other primitives are wrapped into a
// JSPrimitiveWrapper.
type = Type::Union(type, Type::OtherObject(), zone());
}
return type;
}
Type OperationTyper::ToNumber(Type type) {
if (type.Is(Type::Number())) return type;
// If {type} includes any receivers, we cannot tell what kind of
// Number their callbacks might produce. Similarly in the case
// where {type} includes String, it's not possible at this point
// to tell which exact numbers are going to be produced.
if (type.Maybe(Type::StringOrReceiver())) return Type::Number();
// Both Symbol and BigInt primitives will cause exceptions
// to be thrown from ToNumber conversions, so they don't
// contribute to the resulting type anyways.
type = Type::Intersect(type, Type::PlainPrimitive(), zone());
// This leaves us with Number\/Oddball, so deal with the individual
// Oddball primitives below.
DCHECK(type.Is(Type::NumberOrOddball()));
if (type.Maybe(Type::Null())) {
// ToNumber(null) => +0
type = Type::Union(type, cache_->kSingletonZero, zone());
}
if (type.Maybe(Type::Undefined())) {
// ToNumber(undefined) => NaN
type = Type::Union(type, Type::NaN(), zone());
}
if (type.Maybe(singleton_false_)) {
// ToNumber(false) => +0
type = Type::Union(type, cache_->kSingletonZero, zone());
}
if (type.Maybe(singleton_true_)) {
// ToNumber(true) => +1
type = Type::Union(type, cache_->kSingletonOne, zone());
}
return Type::Intersect(type, Type::Number(), zone());
}
Type OperationTyper::ToNumberConvertBigInt(Type type) {
// If the {type} includes any receivers, then the callbacks
// might actually produce BigInt primitive values here.
bool maybe_bigint =
type.Maybe(Type::BigInt()) || type.Maybe(Type::Receiver());
type = ToNumber(Type::Intersect(type, Type::NonBigInt(), zone()));
// Any BigInt is rounded to an integer Number in the range [-inf, inf].
return maybe_bigint ? Type::Union(type, cache_->kInteger, zone()) : type;
}
Type OperationTyper::ToNumeric(Type type) {
// If the {type} includes any receivers, then the callbacks
// might actually produce BigInt primitive values here.
if (type.Maybe(Type::Receiver())) {
type = Type::Union(type, Type::BigInt(), zone());
}
return Type::Union(ToNumber(Type::Intersect(type, Type::NonBigInt(), zone())),
Type::Intersect(type, Type::BigInt(), zone()), zone());
}
Type OperationTyper::NumberAbs(Type type) {
DCHECK(type.Is(Type::Number()));
if (type.IsNone()) return type;
bool const maybe_nan = type.Maybe(Type::NaN());
bool const maybe_minuszero = type.Maybe(Type::MinusZero());
type = Type::Intersect(type, Type::PlainNumber(), zone());
if (!type.IsNone()) {
double const max = type.Max();
double const min = type.Min();
if (min < 0) {
if (type.Is(cache_->kInteger)) {
type =
Type::Range(0.0, std::max(std::fabs(min), std::fabs(max)), zone());
} else {
type = Type::PlainNumber();
}
}
}
if (maybe_minuszero) {
type = Type::Union(type, cache_->kSingletonZero, zone());
}
if (maybe_nan) {
type = Type::Union(type, Type::NaN(), zone());
}
return type;
}
Type OperationTyper::NumberAcos(Type type) {
DCHECK(type.Is(Type::Number()));
return Type::Number();
}
Type OperationTyper::NumberAcosh(Type type) {
DCHECK(type.Is(Type::Number()));
return Type::Number();
}
Type OperationTyper::NumberAsin(Type type) {
DCHECK(type.Is(Type::Number()));
return Type::Number();
}
Type OperationTyper::NumberAsinh(Type type) {
DCHECK(type.Is(Type::Number()));
return Type::Number();
}
Type OperationTyper::NumberAtan(Type type) {
DCHECK(type.Is(Type::Number()));
return Type::Number();
}
Type OperationTyper::NumberAtanh(Type type) {
DCHECK(type.Is(Type::Number()));
return Type::Number();
}
Type OperationTyper::NumberCbrt(Type type) {
DCHECK(type.Is(Type::Number()));
return Type::Number();
}
Type OperationTyper::NumberCeil(Type type) {
DCHECK(type.Is(Type::Number()));
if (type.Is(cache_->kIntegerOrMinusZeroOrNaN)) return type;
type = Type::Intersect(type, Type::NaN(), zone());
type = Type::Union(type, cache_->kIntegerOrMinusZero, zone());
return type;
}
Type OperationTyper::NumberClz32(Type type) {
DCHECK(type.Is(Type::Number()));
return cache_->kZeroToThirtyTwo;
}
Type OperationTyper::NumberCos(Type type) {
DCHECK(type.Is(Type::Number()));
return Type::Number();
}
Type OperationTyper::NumberCosh(Type type) {
DCHECK(type.Is(Type::Number()));
return Type::Number();
}
Type OperationTyper::NumberExp(Type type) {
DCHECK(type.Is(Type::Number()));
return Type::Union(Type::PlainNumber(), Type::NaN(), zone());
}
Type OperationTyper::NumberExpm1(Type type) {
DCHECK(type.Is(Type::Number()));
return Type::Number();
}
Type OperationTyper::NumberFloor(Type type) {
DCHECK(type.Is(Type::Number()));
if (type.Is(cache_->kIntegerOrMinusZeroOrNaN)) return type;
type = Type::Intersect(type, Type::MinusZeroOrNaN(), zone());
type = Type::Union(type, cache_->kInteger, zone());
return type;
}
Type OperationTyper::NumberFround(Type type) {
DCHECK(type.Is(Type::Number()));
return Type::Number();
}
Type OperationTyper::NumberLog(Type type) {
DCHECK(type.Is(Type::Number()));
return Type::Number();
}
Type OperationTyper::NumberLog1p(Type type) {
DCHECK(type.Is(Type::Number()));
return Type::Number();
}
Type OperationTyper::NumberLog2(Type type) {
DCHECK(type.Is(Type::Number()));
return Type::Number();
}
Type OperationTyper::NumberLog10(Type type) {
DCHECK(type.Is(Type::Number()));
return Type::Number();
}
Type OperationTyper::NumberRound(Type type) {
DCHECK(type.Is(Type::Number()));
if (type.Is(cache_->kIntegerOrMinusZeroOrNaN)) return type;
type = Type::Intersect(type, Type::NaN(), zone());
type = Type::Union(type, cache_->kIntegerOrMinusZero, zone());
return type;
}
Type OperationTyper::NumberSign(Type type) {
DCHECK(type.Is(Type::Number()));
if (type.Is(cache_->kZeroish)) return type;
bool maybe_minuszero = type.Maybe(Type::MinusZero());
bool maybe_nan = type.Maybe(Type::NaN());
type = Type::Intersect(type, Type::PlainNumber(), zone());
if (type.IsNone()) {
// Do nothing.
} else if (type.Max() < 0.0) {
type = cache_->kSingletonMinusOne;
} else if (type.Max() <= 0.0) {
type = cache_->kMinusOneOrZero;
} else if (type.Min() > 0.0) {
type = cache_->kSingletonOne;
} else if (type.Min() >= 0.0) {
type = cache_->kZeroOrOne;
} else {
type = Type::Range(-1.0, 1.0, zone());
}
if (maybe_minuszero) type = Type::Union(type, Type::MinusZero(), zone());
if (maybe_nan) type = Type::Union(type, Type::NaN(), zone());
DCHECK(!type.IsNone());
return type;
}
Type OperationTyper::NumberSin(Type type) {
DCHECK(type.Is(Type::Number()));
return Type::Number();
}
Type OperationTyper::NumberSinh(Type type) {
DCHECK(type.Is(Type::Number()));
return Type::Number();
}
Type OperationTyper::NumberSqrt(Type type) {
DCHECK(type.Is(Type::Number()));
return Type::Number();
}
Type OperationTyper::NumberTan(Type type) {
DCHECK(type.Is(Type::Number()));
return Type::Number();
}
Type OperationTyper::NumberTanh(Type type) {
DCHECK(type.Is(Type::Number()));
return Type::Number();
}
Type OperationTyper::NumberTrunc(Type type) {
DCHECK(type.Is(Type::Number()));
if (type.Is(cache_->kIntegerOrMinusZeroOrNaN)) return type;
type = Type::Intersect(type, Type::NaN(), zone());
type = Type::Union(type, cache_->kIntegerOrMinusZero, zone());
return type;
}
Type OperationTyper::NumberToBoolean(Type type) {
DCHECK(type.Is(Type::Number()));
if (type.IsNone()) return type;
if (type.Is(cache_->kZeroish)) return singleton_false_;
if (type.Is(Type::PlainNumber()) && (type.Max() < 0 || 0 < type.Min())) {
return singleton_true_; // Ruled out nan, -0 and +0.
}
return Type::Boolean();
}
Type OperationTyper::NumberToInt32(Type type) {
DCHECK(type.Is(Type::Number()));
if (type.Is(Type::Signed32())) return type;
if (type.Is(cache_->kZeroish)) return cache_->kSingletonZero;
if (type.Is(signed32ish_)) {
return Type::Intersect(Type::Union(type, cache_->kSingletonZero, zone()),
Type::Signed32(), zone());
}
return Type::Signed32();
}
Type OperationTyper::NumberToString(Type type) {
DCHECK(type.Is(Type::Number()));
if (type.IsNone()) return type;
if (type.Is(Type::NaN())) return singleton_NaN_string_;
if (type.Is(cache_->kZeroOrMinusZero)) return singleton_zero_string_;
return Type::String();
}
Type OperationTyper::NumberToUint32(Type type) {
DCHECK(type.Is(Type::Number()));
if (type.Is(Type::Unsigned32())) return type;
if (type.Is(cache_->kZeroish)) return cache_->kSingletonZero;
if (type.Is(unsigned32ish_)) {
return Type::Intersect(Type::Union(type, cache_->kSingletonZero, zone()),
Type::Unsigned32(), zone());
}
return Type::Unsigned32();
}
Type OperationTyper::NumberToUint8Clamped(Type type) {
DCHECK(type.Is(Type::Number()));
if (type.Is(cache_->kUint8)) return type;
return cache_->kUint8;
}
Type OperationTyper::NumberSilenceNaN(Type type) {
DCHECK(type.Is(Type::Number()));
// TODO(jarin): This is a terrible hack; we definitely need a dedicated type
// for the hole (tagged and/or double). Otherwise if the input is the hole
// NaN constant, we'd just eliminate this node in JSTypedLowering.
if (type.Maybe(Type::NaN())) return Type::Number();
return type;
}
Type OperationTyper::BigIntAsUintN(Type type) {
DCHECK(type.Is(Type::BigInt()));
return Type::BigInt();
}
Type OperationTyper::CheckBigInt(Type type) { return Type::BigInt(); }
Type OperationTyper::NumberAdd(Type lhs, Type rhs) {
DCHECK(lhs.Is(Type::Number()));
DCHECK(rhs.Is(Type::Number()));
if (lhs.IsNone() || rhs.IsNone()) return Type::None();
// Addition can return NaN if either input can be NaN or we try to compute
// the sum of two infinities of opposite sign.
bool maybe_nan = lhs.Maybe(Type::NaN()) || rhs.Maybe(Type::NaN());
// Addition can yield minus zero only if both inputs can be minus zero.
bool maybe_minuszero = true;
if (lhs.Maybe(Type::MinusZero())) {
lhs = Type::Union(lhs, cache_->kSingletonZero, zone());
} else {
maybe_minuszero = false;
}
if (rhs.Maybe(Type::MinusZero())) {
rhs = Type::Union(rhs, cache_->kSingletonZero, zone());
} else {
maybe_minuszero = false;
}
// We can give more precise types for integers.
Type type = Type::None();
lhs = Type::Intersect(lhs, Type::PlainNumber(), zone());
rhs = Type::Intersect(rhs, Type::PlainNumber(), zone());
if (!lhs.IsNone() && !rhs.IsNone()) {
if (lhs.Is(cache_->kInteger) && rhs.Is(cache_->kInteger)) {
type = AddRanger(lhs.Min(), lhs.Max(), rhs.Min(), rhs.Max());
} else {
if ((lhs.Maybe(minus_infinity_) && rhs.Maybe(infinity_)) ||
(rhs.Maybe(minus_infinity_) && lhs.Maybe(infinity_))) {
maybe_nan = true;
}
type = Type::PlainNumber();
}
}
// Take into account the -0 and NaN information computed earlier.
if (maybe_minuszero) type = Type::Union(type, Type::MinusZero(), zone());
if (maybe_nan) type = Type::Union(type, Type::NaN(), zone());
return type;
}
Type OperationTyper::NumberSubtract(Type lhs, Type rhs) {
DCHECK(lhs.Is(Type::Number()));
DCHECK(rhs.Is(Type::Number()));
if (lhs.IsNone() || rhs.IsNone()) return Type::None();
// Subtraction can return NaN if either input can be NaN or we try to
// compute the sum of two infinities of opposite sign.
bool maybe_nan = lhs.Maybe(Type::NaN()) || rhs.Maybe(Type::NaN());
// Subtraction can yield minus zero if {lhs} can be minus zero and {rhs}
// can be zero.
bool maybe_minuszero = false;
if (lhs.Maybe(Type::MinusZero())) {
lhs = Type::Union(lhs, cache_->kSingletonZero, zone());
maybe_minuszero = rhs.Maybe(cache_->kSingletonZero);
}
if (rhs.Maybe(Type::MinusZero())) {
rhs = Type::Union(rhs, cache_->kSingletonZero, zone());
}
// We can give more precise types for integers.
Type type = Type::None();
lhs = Type::Intersect(lhs, Type::PlainNumber(), zone());
rhs = Type::Intersect(rhs, Type::PlainNumber(), zone());
if (!lhs.IsNone() && !rhs.IsNone()) {
if (lhs.Is(cache_->kInteger) && rhs.Is(cache_->kInteger)) {
type = SubtractRanger(lhs.Min(), lhs.Max(), rhs.Min(), rhs.Max());
} else {
if ((lhs.Maybe(infinity_) && rhs.Maybe(infinity_)) ||
(rhs.Maybe(minus_infinity_) && lhs.Maybe(minus_infinity_))) {
maybe_nan = true;
}
type = Type::PlainNumber();
}
}
// Take into account the -0 and NaN information computed earlier.
if (maybe_minuszero) type = Type::Union(type, Type::MinusZero(), zone());
if (maybe_nan) type = Type::Union(type, Type::NaN(), zone());
return type;
}
Type OperationTyper::SpeculativeSafeIntegerAdd(Type lhs, Type rhs) {
Type result = SpeculativeNumberAdd(lhs, rhs);
// If we have a Smi or Int32 feedback, the representation selection will
// either truncate or it will check the inputs (i.e., deopt if not int32).
// In either case the result will be in the safe integer range, so we
// can bake in the type here. This needs to be in sync with
// SimplifiedLowering::VisitSpeculativeAdditiveOp.
return Type::Intersect(result, cache_->kSafeIntegerOrMinusZero, zone());
}
Type OperationTyper::SpeculativeSafeIntegerSubtract(Type lhs, Type rhs) {
Type result = SpeculativeNumberSubtract(lhs, rhs);
// If we have a Smi or Int32 feedback, the representation selection will
// either truncate or it will check the inputs (i.e., deopt if not int32).
// In either case the result will be in the safe integer range, so we
// can bake in the type here. This needs to be in sync with
// SimplifiedLowering::VisitSpeculativeAdditiveOp.
return Type::Intersect(result, cache_->kSafeIntegerOrMinusZero, zone());
}
Type OperationTyper::NumberMultiply(Type lhs, Type rhs) {
DCHECK(lhs.Is(Type::Number()));
DCHECK(rhs.Is(Type::Number()));
if (lhs.IsNone() || rhs.IsNone()) return Type::None();
if (lhs.Is(Type::NaN()) || rhs.Is(Type::NaN())) return Type::NaN();
// Multiplication propagates NaN:
// NaN * x = NaN (regardless of sign of x)
// 0 * Infinity = NaN (regardless of signs)
bool maybe_nan = lhs.Maybe(Type::NaN()) || rhs.Maybe(Type::NaN()) ||
(lhs.Maybe(cache_->kZeroish) &&
(rhs.Min() == -V8_INFINITY || rhs.Max() == V8_INFINITY)) ||
(rhs.Maybe(cache_->kZeroish) &&
(lhs.Min() == -V8_INFINITY || lhs.Max() == V8_INFINITY));
lhs = Type::Intersect(lhs, Type::OrderedNumber(), zone());
DCHECK(!lhs.IsNone());
rhs = Type::Intersect(rhs, Type::OrderedNumber(), zone());
DCHECK(!rhs.IsNone());
// Try to rule out -0.
bool maybe_minuszero = lhs.Maybe(Type::MinusZero()) ||
rhs.Maybe(Type::MinusZero()) ||
(lhs.Maybe(cache_->kZeroish) && rhs.Min() < 0.0) ||
(rhs.Maybe(cache_->kZeroish) && lhs.Min() < 0.0);
if (lhs.Maybe(Type::MinusZero())) {
lhs = Type::Union(lhs, cache_->kSingletonZero, zone());
lhs = Type::Intersect(lhs, Type::PlainNumber(), zone());
}
if (rhs.Maybe(Type::MinusZero())) {
rhs = Type::Union(rhs, cache_->kSingletonZero, zone());
rhs = Type::Intersect(rhs, Type::PlainNumber(), zone());
}
// Compute the effective type, utilizing range information if possible.
Type type = (lhs.Is(cache_->kInteger) && rhs.Is(cache_->kInteger))
? MultiplyRanger(lhs.Min(), lhs.Max(), rhs.Min(), rhs.Max())
: Type::OrderedNumber();
// Take into account the -0 and NaN information computed earlier.
if (maybe_minuszero) type = Type::Union(type, Type::MinusZero(), zone());
if (maybe_nan) type = Type::Union(type, Type::NaN(), zone());
return type;
}
Type OperationTyper::NumberDivide(Type lhs, Type rhs) {
DCHECK(lhs.Is(Type::Number()));
DCHECK(rhs.Is(Type::Number()));
if (lhs.IsNone() || rhs.IsNone()) return Type::None();
if (lhs.Is(Type::NaN()) || rhs.Is(Type::NaN())) return Type::NaN();
// Division is tricky, so all we do is try ruling out -0 and NaN.
bool maybe_nan = lhs.Maybe(Type::NaN()) || rhs.Maybe(cache_->kZeroish) ||
((lhs.Min() == -V8_INFINITY || lhs.Max() == +V8_INFINITY) &&
(rhs.Min() == -V8_INFINITY || rhs.Max() == +V8_INFINITY));
lhs = Type::Intersect(lhs, Type::OrderedNumber(), zone());
DCHECK(!lhs.IsNone());
rhs = Type::Intersect(rhs, Type::OrderedNumber(), zone());
DCHECK(!rhs.IsNone());
// Try to rule out -0.
bool maybe_minuszero =
!lhs.Is(cache_->kInteger) ||
(lhs.Maybe(cache_->kZeroish) && rhs.Min() < 0.0) ||
(rhs.Min() == -V8_INFINITY || rhs.Max() == +V8_INFINITY);
// Take into account the -0 and NaN information computed earlier.
Type type = Type::PlainNumber();
if (maybe_minuszero) type = Type::Union(type, Type::MinusZero(), zone());
if (maybe_nan) type = Type::Union(type, Type::NaN(), zone());
return type;
}
Type OperationTyper::NumberModulus(Type lhs, Type rhs) {
DCHECK(lhs.Is(Type::Number()));
DCHECK(rhs.Is(Type::Number()));
if (lhs.IsNone() || rhs.IsNone()) return Type::None();
// Modulus can yield NaN if either {lhs} or {rhs} are NaN, or
// {lhs} is not finite, or the {rhs} is a zero value.
bool maybe_nan = lhs.Maybe(Type::NaN()) || rhs.Maybe(cache_->kZeroish) ||
lhs.Min() == -V8_INFINITY || lhs.Max() == +V8_INFINITY;
// Deal with -0 inputs, only the signbit of {lhs} matters for the result.
bool maybe_minuszero = false;
if (lhs.Maybe(Type::MinusZero())) {
maybe_minuszero = true;
lhs = Type::Union(lhs, cache_->kSingletonZero, zone());
}
if (rhs.Maybe(Type::MinusZero())) {
rhs = Type::Union(rhs, cache_->kSingletonZero, zone());
}
// Rule out NaN and -0, and check what we can do with the remaining type info.
Type type = Type::None();
lhs = Type::Intersect(lhs, Type::PlainNumber(), zone());
rhs = Type::Intersect(rhs, Type::PlainNumber(), zone());
// We can only derive a meaningful type if both {lhs} and {rhs} are inhabited,
// and the {rhs} is not 0, otherwise the result is NaN independent of {lhs}.
if (!lhs.IsNone() && !rhs.Is(cache_->kSingletonZero)) {
// Determine the bounds of {lhs} and {rhs}.
double const lmin = lhs.Min();
double const lmax = lhs.Max();
double const rmin = rhs.Min();
double const rmax = rhs.Max();
// The sign of the result is the sign of the {lhs}.
if (lmin < 0.0) maybe_minuszero = true;
// For integer inputs {lhs} and {rhs} we can infer a precise type.
if (lhs.Is(cache_->kInteger) && rhs.Is(cache_->kInteger)) {
double labs = std::max(std::abs(lmin), std::abs(lmax));
double rabs = std::max(std::abs(rmin), std::abs(rmax)) - 1;
double abs = std::min(labs, rabs);
double min = 0.0, max = 0.0;
if (lmin >= 0.0) {
// {lhs} positive.
min = 0.0;
max = abs;
} else if (lmax <= 0.0) {
// {lhs} negative.
min = 0.0 - abs;
max = 0.0;
} else {
// {lhs} positive or negative.
min = 0.0 - abs;
max = abs;
}
type = Type::Range(min, max, zone());
} else {
type = Type::PlainNumber();
}
}
// Take into account the -0 and NaN information computed earlier.
if (maybe_minuszero) type = Type::Union(type, Type::MinusZero(), zone());
if (maybe_nan) type = Type::Union(type, Type::NaN(), zone());
return type;
}
Type OperationTyper::NumberBitwiseOr(Type lhs, Type rhs) {
DCHECK(lhs.Is(Type::Number()));
DCHECK(rhs.Is(Type::Number()));
lhs = NumberToInt32(lhs);
rhs = NumberToInt32(rhs);
if (lhs.IsNone() || rhs.IsNone()) return Type::None();
double lmin = lhs.Min();
double rmin = rhs.Min();
double lmax = lhs.Max();
double rmax = rhs.Max();
// Or-ing any two values results in a value no smaller than their minimum.
// Even no smaller than their maximum if both values are non-negative.
double min =
lmin >= 0 && rmin >= 0 ? std::max(lmin, rmin) : std::min(lmin, rmin);
double max = kMaxInt;
// Or-ing with 0 is essentially a conversion to int32.
if (rmin == 0 && rmax == 0) {
min = lmin;
max = lmax;
}
if (lmin == 0 && lmax == 0) {
min = rmin;
max = rmax;
}
if (lmax < 0 || rmax < 0) {
// Or-ing two values of which at least one is negative results in a negative
// value.
max = std::min(max, -1.0);
}
return Type::Range(min, max, zone());
}
Type OperationTyper::NumberBitwiseAnd(Type lhs, Type rhs) {
DCHECK(lhs.Is(Type::Number()));
DCHECK(rhs.Is(Type::Number()));
lhs = NumberToInt32(lhs);
rhs = NumberToInt32(rhs);
if (lhs.IsNone() || rhs.IsNone()) return Type::None();
double lmin = lhs.Min();
double rmin = rhs.Min();
double lmax = lhs.Max();
double rmax = rhs.Max();
double min = kMinInt;
// And-ing any two values results in a value no larger than their maximum.
// Even no larger than their minimum if both values are non-negative.
double max =
lmin >= 0 && rmin >= 0 ? std::min(lmax, rmax) : std::max(lmax, rmax);
// And-ing with a non-negative value x causes the result to be between
// zero and x.
if (lmin >= 0) {
min = 0;
max = std::min(max, lmax);
}
if (rmin >= 0) {
min = 0;
max = std::min(max, rmax);
}
return Type::Range(min, max, zone());
}
Type OperationTyper::NumberBitwiseXor(Type lhs, Type rhs) {
DCHECK(lhs.Is(Type::Number()));
DCHECK(rhs.Is(Type::Number()));
lhs = NumberToInt32(lhs);
rhs = NumberToInt32(rhs);
if (lhs.IsNone() || rhs.IsNone()) return Type::None();
double lmin = lhs.Min();
double rmin = rhs.Min();
double lmax = lhs.Max();
double rmax = rhs.Max();
if ((lmin >= 0 && rmin >= 0) || (lmax < 0 && rmax < 0)) {
// Xor-ing negative or non-negative values results in a non-negative value.
return Type::Unsigned31();
}
if ((lmax < 0 && rmin >= 0) || (lmin >= 0 && rmax < 0)) {
// Xor-ing a negative and a non-negative value results in a negative value.
// TODO(jarin) Use a range here.
return Type::Negative32();
}
return Type::Signed32();
}
Type OperationTyper::NumberShiftLeft(Type lhs, Type rhs) {
DCHECK(lhs.Is(Type::Number()));
DCHECK(rhs.Is(Type::Number()));
lhs = NumberToInt32(lhs);
rhs = NumberToUint32(rhs);
if (lhs.IsNone() || rhs.IsNone()) return Type::None();
int32_t min_lhs = lhs.Min();
int32_t max_lhs = lhs.Max();
uint32_t min_rhs = rhs.Min();
uint32_t max_rhs = rhs.Max();
if (max_rhs > 31) {
// rhs can be larger than the bitmask
max_rhs = 31;
min_rhs = 0;
}
if (max_lhs > (kMaxInt >> max_rhs) || min_lhs < (kMinInt >> max_rhs)) {
// overflow possible
return Type::Signed32();
}
double min =
std::min(static_cast<int32_t>(static_cast<uint32_t>(min_lhs) << min_rhs),
static_cast<int32_t>(static_cast<uint32_t>(min_lhs) << max_rhs));
double max =
std::max(static_cast<int32_t>(static_cast<uint32_t>(max_lhs) << min_rhs),
static_cast<int32_t>(static_cast<uint32_t>(max_lhs) << max_rhs));
if (max == kMaxInt && min == kMinInt) return Type::Signed32();
return Type::Range(min, max, zone());
}
Type OperationTyper::NumberShiftRight(Type lhs, Type rhs) {
DCHECK(lhs.Is(Type::Number()));
DCHECK(rhs.Is(Type::Number()));
lhs = NumberToInt32(lhs);
rhs = NumberToUint32(rhs);
if (lhs.IsNone() || rhs.IsNone()) return Type::None();
int32_t min_lhs = lhs.Min();
int32_t max_lhs = lhs.Max();
uint32_t min_rhs = rhs.Min();
uint32_t max_rhs = rhs.Max();
if (max_rhs > 31) {
// rhs can be larger than the bitmask
max_rhs = 31;
min_rhs = 0;
}
double min = std::min(min_lhs >> min_rhs, min_lhs >> max_rhs);
double max = std::max(max_lhs >> min_rhs, max_lhs >> max_rhs);
if (max == kMaxInt && min == kMinInt) return Type::Signed32();
return Type::Range(min, max, zone());
}
Type OperationTyper::NumberShiftRightLogical(Type lhs, Type rhs) {
DCHECK(lhs.Is(Type::Number()));
DCHECK(rhs.Is(Type::Number()));
lhs = NumberToUint32(lhs);
rhs = NumberToUint32(rhs);
if (lhs.IsNone() || rhs.IsNone()) return Type::None();
uint32_t min_lhs = lhs.Min();
uint32_t max_lhs = lhs.Max();
uint32_t min_rhs = rhs.Min();
uint32_t max_rhs = rhs.Max();
if (max_rhs > 31) {
// rhs can be larger than the bitmask
max_rhs = 31;
min_rhs = 0;
}
double min = min_lhs >> max_rhs;
double max = max_lhs >> min_rhs;
DCHECK_LE(0, min);
DCHECK_LE(max, kMaxUInt32);
if (min == 0 && max == kMaxInt) return Type::Unsigned31();
if (min == 0 && max == kMaxUInt32) return Type::Unsigned32();
return Type::Range(min, max, zone());
}
Type OperationTyper::NumberAtan2(Type lhs, Type rhs) {
DCHECK(lhs.Is(Type::Number()));
DCHECK(rhs.Is(Type::Number()));
return Type::Number();
}
Type OperationTyper::NumberImul(Type lhs, Type rhs) {
DCHECK(lhs.Is(Type::Number()));
DCHECK(rhs.Is(Type::Number()));
// TODO(turbofan): We should be able to do better here.
return Type::Signed32();
}
Type OperationTyper::NumberMax(Type lhs, Type rhs) {
DCHECK(lhs.Is(Type::Number()));
DCHECK(rhs.Is(Type::Number()));
if (lhs.IsNone() || rhs.IsNone()) return Type::None();
if (lhs.Is(Type::NaN()) || rhs.Is(Type::NaN())) return Type::NaN();
Type type = Type::None();
if (lhs.Maybe(Type::NaN()) || rhs.Maybe(Type::NaN())) {
type = Type::Union(type, Type::NaN(), zone());
}
if (!lhs.Is(cache_->kIntegerOrMinusZeroOrNaN) ||
!rhs.Is(cache_->kIntegerOrMinusZeroOrNaN)) {
return Type::Union(type, Type::Union(lhs, rhs, zone()), zone());
}
bool const lhs_maybe_minus_zero = lhs.Maybe(Type::MinusZero());
bool const rhs_maybe_minus_zero = rhs.Maybe(Type::MinusZero());
lhs = Type::Intersect(lhs, cache_->kInteger, zone());
rhs = Type::Intersect(rhs, cache_->kInteger, zone());
bool maybe_minus_zero = lhs_maybe_minus_zero || rhs_maybe_minus_zero;
if (!lhs.IsNone() || !rhs.IsNone()) {
double min = std::max(lhs.IsNone() ? -V8_INFINITY : lhs.Min(),
rhs.IsNone() ? -V8_INFINITY : rhs.Min());
double max = std::max(lhs.IsNone() ? -V8_INFINITY : lhs.Max(),
rhs.IsNone() ? -V8_INFINITY : rhs.Max());
type = Type::Union(type, Type::Range(min, max, zone()), zone());
maybe_minus_zero =
maybe_minus_zero && (min < 0.0 || (min == 0.0 && lhs_maybe_minus_zero &&
rhs_maybe_minus_zero));
}
if (maybe_minus_zero) {
type = Type::Union(type, Type::MinusZero(), zone());
}
return type;
}
Type OperationTyper::NumberMin(Type lhs, Type rhs) {
DCHECK(lhs.Is(Type::Number()));
DCHECK(rhs.Is(Type::Number()));
if (lhs.IsNone() || rhs.IsNone()) return Type::None();
if (lhs.Is(Type::NaN()) || rhs.Is(Type::NaN())) return Type::NaN();
Type type = Type::None();
if (lhs.Maybe(Type::NaN()) || rhs.Maybe(Type::NaN())) {
type = Type::Union(type, Type::NaN(), zone());
}
if (!lhs.Is(cache_->kIntegerOrMinusZeroOrNaN) ||
!rhs.Is(cache_->kIntegerOrMinusZeroOrNaN)) {
return Type::Union(type, Type::Union(lhs, rhs, zone()), zone());
}
bool maybe_minus_zero =
lhs.Maybe(Type::MinusZero()) || rhs.Maybe(Type::MinusZero());
lhs = Type::Intersect(lhs, cache_->kInteger, zone());
rhs = Type::Intersect(rhs, cache_->kInteger, zone());
if (!lhs.IsNone() || !rhs.IsNone()) {
double min = std::min(lhs.IsNone() ? +V8_INFINITY : lhs.Min(),
rhs.IsNone() ? +V8_INFINITY : rhs.Min());
double max = std::min(lhs.IsNone() ? +V8_INFINITY : lhs.Max(),
rhs.IsNone() ? +V8_INFINITY : rhs.Max());
type = Type::Union(type, Type::Range(min, max, zone()), zone());
maybe_minus_zero = maybe_minus_zero && max >= 0.0;
}
if (maybe_minus_zero) {
type = Type::Union(type, Type::MinusZero(), zone());
}
return type;
}
Type OperationTyper::NumberPow(Type lhs, Type rhs) {
DCHECK(lhs.Is(Type::Number()));
DCHECK(rhs.Is(Type::Number()));
// TODO(turbofan): We should be able to do better here.
return Type::Number();
}
#define SPECULATIVE_NUMBER_BINOP(Name) \
Type OperationTyper::Speculative##Name(Type lhs, Type rhs) { \
lhs = SpeculativeToNumber(lhs); \
rhs = SpeculativeToNumber(rhs); \
return Name(lhs, rhs); \
}
SPECULATIVE_NUMBER_BINOP(NumberAdd)
SPECULATIVE_NUMBER_BINOP(NumberSubtract)
SPECULATIVE_NUMBER_BINOP(NumberMultiply)
SPECULATIVE_NUMBER_BINOP(NumberDivide)
SPECULATIVE_NUMBER_BINOP(NumberModulus)
SPECULATIVE_NUMBER_BINOP(NumberBitwiseOr)
SPECULATIVE_NUMBER_BINOP(NumberBitwiseAnd)
SPECULATIVE_NUMBER_BINOP(NumberBitwiseXor)
SPECULATIVE_NUMBER_BINOP(NumberShiftLeft)
SPECULATIVE_NUMBER_BINOP(NumberShiftRight)
SPECULATIVE_NUMBER_BINOP(NumberShiftRightLogical)
#undef SPECULATIVE_NUMBER_BINOP
Type OperationTyper::BigIntAdd(Type lhs, Type rhs) {
if (lhs.IsNone() || rhs.IsNone()) return Type::None();
return Type::BigInt();
}
Type OperationTyper::BigIntSubtract(Type lhs, Type rhs) {
if (lhs.IsNone() || rhs.IsNone()) return Type::None();
return Type::BigInt();
}
Type OperationTyper::BigIntNegate(Type type) {
if (type.IsNone()) return type;
return Type::BigInt();
}
Type OperationTyper::SpeculativeBigIntAdd(Type lhs, Type rhs) {
if (lhs.IsNone() || rhs.IsNone()) return Type::None();
return Type::BigInt();
}
Type OperationTyper::SpeculativeBigIntSubtract(Type lhs, Type rhs) {
if (lhs.IsNone() || rhs.IsNone()) return Type::None();
return Type::BigInt();
}
Type OperationTyper::SpeculativeBigIntNegate(Type type) {
if (type.IsNone()) return type;
return Type::BigInt();
}
Type OperationTyper::SpeculativeToNumber(Type type) {
return ToNumber(Type::Intersect(type, Type::NumberOrOddball(), zone()));
}
Type OperationTyper::ToPrimitive(Type type) {
if (type.Is(Type::Primitive())) {
return type;
}
return Type::Primitive();
}
Type OperationTyper::Invert(Type type) {
DCHECK(type.Is(Type::Boolean()));
CHECK(!type.IsNone());
if (type.Is(singleton_false())) return singleton_true();
if (type.Is(singleton_true())) return singleton_false();
return type;
}
OperationTyper::ComparisonOutcome OperationTyper::Invert(
ComparisonOutcome outcome) {
ComparisonOutcome result(0);
if ((outcome & kComparisonUndefined) != 0) result |= kComparisonUndefined;
if ((outcome & kComparisonTrue) != 0) result |= kComparisonFalse;
if ((outcome & kComparisonFalse) != 0) result |= kComparisonTrue;
return result;
}
Type OperationTyper::FalsifyUndefined(ComparisonOutcome outcome) {
if ((outcome & kComparisonFalse) != 0 ||
(outcome & kComparisonUndefined) != 0) {
return (outcome & kComparisonTrue) != 0 ? Type::Boolean()
: singleton_false();
}
// Type should be non empty, so we know it should be true.
DCHECK_NE(0, outcome & kComparisonTrue);
return singleton_true();
}
namespace {
Type JSType(Type type) {
if (type.Is(Type::Boolean())) return Type::Boolean();
if (type.Is(Type::String())) return Type::String();
if (type.Is(Type::Number())) return Type::Number();
if (type.Is(Type::BigInt())) return Type::BigInt();
if (type.Is(Type::Undefined())) return Type::Undefined();
if (type.Is(Type::Null())) return Type::Null();
if (type.Is(Type::Symbol())) return Type::Symbol();
if (type.Is(Type::Receiver())) return Type::Receiver(); // JS "Object"
return Type::Any();
}
} // namespace
Type OperationTyper::SameValue(Type lhs, Type rhs) {
if (!JSType(lhs).Maybe(JSType(rhs))) return singleton_false();
if (lhs.Is(Type::NaN())) {
if (rhs.Is(Type::NaN())) return singleton_true();
if (!rhs.Maybe(Type::NaN())) return singleton_false();
} else if (rhs.Is(Type::NaN())) {
if (!lhs.Maybe(Type::NaN())) return singleton_false();
}
if (lhs.Is(Type::MinusZero())) {
if (rhs.Is(Type::MinusZero())) return singleton_true();
if (!rhs.Maybe(Type::MinusZero())) return singleton_false();
} else if (rhs.Is(Type::MinusZero())) {
if (!lhs.Maybe(Type::MinusZero())) return singleton_false();
}
if (lhs.Is(Type::OrderedNumber()) && rhs.Is(Type::OrderedNumber()) &&
(lhs.Max() < rhs.Min() || lhs.Min() > rhs.Max())) {
return singleton_false();
}
return Type::Boolean();
}
Type OperationTyper::SameValueNumbersOnly(Type lhs, Type rhs) {
// SameValue and SamevalueNumbersOnly only differ in treatment of
// strings and biginits. Since the SameValue typer does not do anything
// special about strings or bigints, we can just use it here.
return SameValue(lhs, rhs);
}
Type OperationTyper::StrictEqual(Type lhs, Type rhs) {
CHECK(!lhs.IsNone());
CHECK(!rhs.IsNone());
if (!JSType(lhs).Maybe(JSType(rhs))) return singleton_false();
if (lhs.Is(Type::NaN()) || rhs.Is(Type::NaN())) return singleton_false();
if (lhs.Is(Type::Number()) && rhs.Is(Type::Number()) &&
(lhs.Max() < rhs.Min() || lhs.Min() > rhs.Max())) {
return singleton_false();
}
if (lhs.IsSingleton() && rhs.Is(lhs)) {
// Types are equal and are inhabited only by a single semantic value,
// which is not nan due to the earlier check.
DCHECK(lhs.Is(rhs));
DCHECK(lhs.Is(Type::NonInternal()) || lhs.Is(Type::Hole()));
return singleton_true();
}
if ((lhs.Is(Type::Unique()) || rhs.Is(Type::Unique())) && !lhs.Maybe(rhs)) {
// One of the inputs has a canonical representation but types don't overlap.
return singleton_false();
}
return Type::Boolean();
}
Type OperationTyper::CheckBounds(Type index, Type length) {
DCHECK(length.Is(cache_->kPositiveSafeInteger));
if (length.Is(cache_->kSingletonZero)) return Type::None();
Type mask = Type::Range(0.0, length.Max() - 1, zone());
if (index.Maybe(Type::MinusZero())) {
index = Type::Union(index, cache_->kSingletonZero, zone());
}
if (index.Maybe(Type::String())) {
index = Type::Union(index, cache_->kIntPtr, zone());
}
return Type::Intersect(index, mask, zone());
}
Type OperationTyper::CheckFloat64Hole(Type type) {
if (type.Maybe(Type::Hole())) {
// Turn "the hole" into undefined.
type = Type::Intersect(type, Type::Number(), zone());
type = Type::Union(type, Type::Undefined(), zone());
}
return type;
}
Type OperationTyper::CheckNumber(Type type) {
return Type::Intersect(type, Type::Number(), zone());
}
Type OperationTyper::TypeTypeGuard(const Operator* sigma_op, Type input) {
return Type::Intersect(input, TypeGuardTypeOf(sigma_op), zone());
}
Type OperationTyper::ConvertTaggedHoleToUndefined(Type input) {
if (input.Maybe(Type::Hole())) {
// Turn "the hole" into undefined.
Type type = Type::Intersect(input, Type::NonInternal(), zone());
return Type::Union(type, Type::Undefined(), zone());
}
return input;
}
Type OperationTyper::ToBoolean(Type type) {
if (type.Is(Type::Boolean())) return type;
if (type.Is(falsish_)) return singleton_false_;
if (type.Is(truish_)) return singleton_true_;
if (type.Is(Type::Number())) {
return NumberToBoolean(type);
}
return Type::Boolean();
}
} // namespace compiler
} // namespace internal
} // namespace v8