tor-browser

TypePolicy.h (20321B)

---

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 tw=80:
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef jit_TypePolicy_h
#define jit_TypePolicy_h

#include "jit/IonTypes.h"
#include "js/ScalarType.h"  // js::Scalar::Type

namespace js {
namespace jit {

class MInstruction;
class MDefinition;
class TempAllocator;

extern MDefinition* BoxAt(TempAllocator& alloc, MInstruction* at,
                         MDefinition* operand);

// A type policy directs the type analysis phases, which insert conversion,
// boxing, unboxing, and type changes as necessary.
class TypePolicy {
public:
 // Analyze the inputs of the instruction and perform one of the following
 // actions for each input:
 //  * Nothing; the input already type-checks.
 //  * If untyped, optionally ask the input to try and specialize its value.
 //  * Replace the operand with a conversion instruction.
 //  * Insert an unconditional deoptimization (no conversion possible).
 [[nodiscard]] virtual bool adjustInputs(TempAllocator& alloc,
                                         MInstruction* def) const = 0;
};

struct TypeSpecializationData {
protected:
 // Specifies three levels of specialization:
 //  - < Value. This input is expected and required.
 //  - == None. This op should not be specialized.
 MIRType specialization_;

 MIRType thisTypeSpecialization() { return specialization_; }

public:
 MIRType specialization() const { return specialization_; }
};

#define EMPTY_DATA_                            \
 struct Data {                                \
   static const TypePolicy* thisTypePolicy(); \
 }

#define INHERIT_DATA_(DATA_TYPE)               \
 struct Data : public DATA_TYPE {             \
   static const TypePolicy* thisTypePolicy(); \
 }

#define SPECIALIZATION_DATA_ INHERIT_DATA_(TypeSpecializationData)

class NoTypePolicy {
public:
 struct Data {
   static const TypePolicy* thisTypePolicy() { return nullptr; }
 };
};

class BoxInputsPolicy final : public TypePolicy {
public:
 constexpr BoxInputsPolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] static bool staticAdjustInputs(TempAllocator& alloc,
                                              MInstruction* def);
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* def) const override {
   return staticAdjustInputs(alloc, def);
 }
};

class ArithPolicy final : public TypePolicy {
public:
 constexpr ArithPolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* def) const override;
};

class BigIntArithPolicy final : public TypePolicy {
public:
 constexpr BigIntArithPolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* def) const override;
};

class AllDoublePolicy final : public TypePolicy {
public:
 constexpr AllDoublePolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] static bool staticAdjustInputs(TempAllocator& alloc,
                                              MInstruction* def);
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* def) const override {
   return staticAdjustInputs(alloc, def);
 }
};

class BitwisePolicy final : public TypePolicy {
public:
 constexpr BitwisePolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* def) const override;
};

class ComparePolicy final : public TypePolicy {
public:
 constexpr ComparePolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* def) const override;
};

// Policy for MTest instructions.
class TestPolicy final : public TypePolicy {
public:
 constexpr TestPolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* ins) const override;
};

class CallPolicy final : public TypePolicy {
public:
 constexpr CallPolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* def) const override;
};

// Policy for MPow:
//
// * If return type is MIRType::Double, we need (Double, Double) or
//   (Double, Int32) operands.
// * If return type is MIRType::Int32, we need (Int32, Int32) operands.
class PowPolicy final : public TypePolicy {
public:
 constexpr PowPolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* ins) const override;
};

// Policy for MSign. Operand is either Double or Int32.
class SignPolicy final : public TypePolicy {
public:
 constexpr SignPolicy() = default;
 SPECIALIZATION_DATA_;
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* ins) const override;
};

// Expect a symbol for operand Op. If the input is a Value, it is unboxed.
template <unsigned Op>
class SymbolPolicy final : public TypePolicy {
public:
 constexpr SymbolPolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] static bool staticAdjustInputs(TempAllocator& alloc,
                                              MInstruction* def);
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* def) const override {
   return staticAdjustInputs(alloc, def);
 }
};

// Expect a boolean for operand Op. If the input is a Value, it is unboxed.
template <unsigned Op>
class BooleanPolicy final : public TypePolicy {
public:
 constexpr BooleanPolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] static bool staticAdjustInputs(TempAllocator& alloc,
                                              MInstruction* def);
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* def) const override {
   return staticAdjustInputs(alloc, def);
 }
};

// Expect a string for operand Op. If the input is a Value, it is unboxed.
template <unsigned Op>
class StringPolicy final : public TypePolicy {
public:
 constexpr StringPolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] static bool staticAdjustInputs(TempAllocator& alloc,
                                              MInstruction* def);
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* def) const override {
   return staticAdjustInputs(alloc, def);
 }
};

// Expect a string for operand Op. Else a ToString instruction is inserted.
template <unsigned Op>
class ConvertToStringPolicy final : public TypePolicy {
public:
 constexpr ConvertToStringPolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] static bool staticAdjustInputs(TempAllocator& alloc,
                                              MInstruction* def);
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* def) const override {
   return staticAdjustInputs(alloc, def);
 }
};

// Expect a BigInt for operand Op. If the input is a Value, it is unboxed.
template <unsigned Op>
class BigIntPolicy final : public TypePolicy {
public:
 constexpr BigIntPolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] static bool staticAdjustInputs(TempAllocator& alloc,
                                              MInstruction* def);
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* def) const override {
   return staticAdjustInputs(alloc, def);
 }
};

// Expects either an Int32 or a boxed Int32 for operand Op; may unbox if needed.
template <unsigned Op>
class UnboxedInt32Policy final : private TypePolicy {
public:
 constexpr UnboxedInt32Policy() = default;
 EMPTY_DATA_;
 [[nodiscard]] static bool staticAdjustInputs(TempAllocator& alloc,
                                              MInstruction* def);
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* def) const override {
   return staticAdjustInputs(alloc, def);
 }
};

// Expects either an Int32 or IntPtr for operand Op.
template <unsigned Op>
class Int32OrIntPtrPolicy final : private TypePolicy {
public:
 constexpr Int32OrIntPtrPolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] static bool staticAdjustInputs(TempAllocator& alloc,
                                              MInstruction* def);
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* def) const override {
   return staticAdjustInputs(alloc, def);
 }
};

// Expect an IntPtr for operand Op.
template <unsigned Op>
class IntPtrPolicy final : private TypePolicy {
public:
 constexpr IntPtrPolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] static bool staticAdjustInputs(TempAllocator& alloc,
                                              MInstruction* def);
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* def) const override {
   return staticAdjustInputs(alloc, def);
 }
};

// Expect an Int for operand Op. Else a ToInt32 instruction is inserted.
template <unsigned Op>
class ConvertToInt32Policy final : public TypePolicy {
public:
 constexpr ConvertToInt32Policy() = default;
 EMPTY_DATA_;
 [[nodiscard]] static bool staticAdjustInputs(TempAllocator& alloc,
                                              MInstruction* def);
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* def) const override {
   return staticAdjustInputs(alloc, def);
 }
};

// Expect either an Int32 or Int64 for operand Op. Else a TruncateToInt32 or
// ToInt64 instruction is inserted.
template <unsigned Op>
class TruncateToInt32OrToInt64Policy final : public TypePolicy {
public:
 constexpr TruncateToInt32OrToInt64Policy() = default;
 EMPTY_DATA_;
 [[nodiscard]] static bool staticAdjustInputs(TempAllocator& alloc,
                                              MInstruction* def);
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* def) const override {
   return staticAdjustInputs(alloc, def);
 }
};

// Expect a double for operand Op. If the input is a Value, it is unboxed.
template <unsigned Op>
class DoublePolicy final : public TypePolicy {
public:
 constexpr DoublePolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] static bool staticAdjustInputs(TempAllocator& alloc,
                                              MInstruction* def);
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* def) const override {
   return staticAdjustInputs(alloc, def);
 }
};

// Expect a float32 for operand Op. If the input is a Value, it is unboxed.
template <unsigned Op>
class Float32Policy final : public TypePolicy {
public:
 constexpr Float32Policy() = default;
 EMPTY_DATA_;
 [[nodiscard]] static bool staticAdjustInputs(TempAllocator& alloc,
                                              MInstruction* def);
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* def) const override {
   return staticAdjustInputs(alloc, def);
 }
};

// Expect a float32 OR a double for operand Op, but will prioritize Float32
// if the result type is set as such. If the input is a Value, it is unboxed.
template <unsigned Op>
class FloatingPointPolicy final : public TypePolicy {
public:
 constexpr FloatingPointPolicy() = default;
 SPECIALIZATION_DATA_;
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* def) const override;
};

template <unsigned Op>
class NoFloatPolicy final : public TypePolicy {
public:
 constexpr NoFloatPolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] static bool staticAdjustInputs(TempAllocator& alloc,
                                              MInstruction* def);
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* def) const override {
   return staticAdjustInputs(alloc, def);
 }
};

// Policy for guarding variadic instructions such as object / array state
// instructions.
template <unsigned FirstOp>
class NoFloatPolicyAfter final : public TypePolicy {
public:
 constexpr NoFloatPolicyAfter() = default;
 EMPTY_DATA_;
 [[nodiscard]] static bool staticAdjustInputs(TempAllocator& alloc,
                                              MInstruction* def);
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* ins) const override {
   return staticAdjustInputs(alloc, ins);
 }
};

// Box objects or strings as an input to a ToDouble instruction.
class ToDoublePolicy final : public TypePolicy {
public:
 constexpr ToDoublePolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] static bool staticAdjustInputs(TempAllocator& alloc,
                                              MInstruction* def);
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* def) const override {
   return staticAdjustInputs(alloc, def);
 }
};

// Box objects, strings and undefined as input to a ToInt32 instruction.
class ToInt32Policy final : public TypePolicy {
public:
 constexpr ToInt32Policy() = default;
 EMPTY_DATA_;
 [[nodiscard]] static bool staticAdjustInputs(TempAllocator& alloc,
                                              MInstruction* def);
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* def) const override {
   return staticAdjustInputs(alloc, def);
 }
};

// Box any non-BigInts as input to a ToBigInt instruction.
class ToBigIntPolicy final : public TypePolicy {
public:
 constexpr ToBigIntPolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] static bool staticAdjustInputs(TempAllocator& alloc,
                                              MInstruction* def);
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* def) const override {
   return staticAdjustInputs(alloc, def);
 }
};

// Box objects as input to a ToString instruction.
class ToStringPolicy final : public TypePolicy {
public:
 constexpr ToStringPolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] static bool staticAdjustInputs(TempAllocator& alloc,
                                              MInstruction* def);
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* def) const override {
   return staticAdjustInputs(alloc, def);
 }
};

// Box non-Boolean, non-String, non-BigInt as input to a ToInt64 instruction.
class ToInt64Policy final : public TypePolicy {
public:
 constexpr ToInt64Policy() = default;
 EMPTY_DATA_;
 [[nodiscard]] static bool staticAdjustInputs(TempAllocator& alloc,
                                              MInstruction* ins);
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* ins) const override {
   return staticAdjustInputs(alloc, ins);
 }
};

template <unsigned Op>
class ObjectPolicy final : public TypePolicy {
public:
 constexpr ObjectPolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] static bool staticAdjustInputs(TempAllocator& alloc,
                                              MInstruction* ins);
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* ins) const override {
   return staticAdjustInputs(alloc, ins);
 }
};

// Single-object input. If the input is a Value, it is unboxed. If it is
// a primitive, we use ValueToNonNullObject.
using SingleObjectPolicy = ObjectPolicy<0>;

template <unsigned Op>
class BoxPolicy final : public TypePolicy {
public:
 constexpr BoxPolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] static bool staticAdjustInputs(TempAllocator& alloc,
                                              MInstruction* ins);
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* ins) const override {
   return staticAdjustInputs(alloc, ins);
 }
};

// Boxes everything except inputs of type Type.
template <unsigned Op, MIRType Type>
class BoxExceptPolicy final : public TypePolicy {
public:
 constexpr BoxExceptPolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] static bool staticAdjustInputs(TempAllocator& alloc,
                                              MInstruction* ins);
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* ins) const override {
   return staticAdjustInputs(alloc, ins);
 }
};

// Box if not a typical property id (string, symbol, int32).
template <unsigned Op>
class CacheIdPolicy final : public TypePolicy {
public:
 EMPTY_DATA_;
 [[nodiscard]] static bool staticAdjustInputs(TempAllocator& alloc,
                                              MInstruction* ins);
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* ins) const override {
   return staticAdjustInputs(alloc, ins);
 }
};

// Combine multiple policies.
template <class... Policies>
class MixPolicy final : public TypePolicy {
public:
 constexpr MixPolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] static bool staticAdjustInputs(TempAllocator& alloc,
                                              MInstruction* ins) {
   return (Policies::staticAdjustInputs(alloc, ins) && ...);
 }
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* ins) const override {
   return staticAdjustInputs(alloc, ins);
 }
};

class MegamorphicSetElementPolicy final : public TypePolicy {
public:
 constexpr MegamorphicSetElementPolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* def) const override;
};

class StoreDataViewElementPolicy;
class StoreTypedArrayHolePolicy;

class StoreUnboxedScalarPolicy : public TypePolicy {
private:
 constexpr StoreUnboxedScalarPolicy() = default;
 [[nodiscard]] static bool adjustValueInput(TempAllocator& alloc,
                                            MInstruction* ins,
                                            Scalar::Type arrayType,
                                            MDefinition* value,
                                            int valueOperand);

 friend class StoreDataViewElementPolicy;
 friend class StoreTypedArrayHolePolicy;
 friend class TypedArrayFillPolicy;

public:
 EMPTY_DATA_;
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* ins) const override;
};

class StoreDataViewElementPolicy final : public StoreUnboxedScalarPolicy {
public:
 constexpr StoreDataViewElementPolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* ins) const override;
};

class StoreTypedArrayHolePolicy final : public StoreUnboxedScalarPolicy {
public:
 constexpr StoreTypedArrayHolePolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* ins) const override;
};

class TypedArrayFillPolicy final : public StoreUnboxedScalarPolicy {
public:
 constexpr TypedArrayFillPolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* ins) const override;
};

// Accepts integers and doubles. Everything else is boxed.
class ClampPolicy final : public TypePolicy {
public:
 constexpr ClampPolicy() = default;
 EMPTY_DATA_;
 [[nodiscard]] bool adjustInputs(TempAllocator& alloc,
                                 MInstruction* ins) const override;
};

#undef SPECIALIZATION_DATA_
#undef INHERIT_DATA_
#undef EMPTY_DATA_

}  // namespace jit
}  // namespace js

#endif /* jit_TypePolicy_h */