//===-- llvm/Constants.h - Constant class subclass definitions --*- C++ -*-===//

//

//                     The LLVM Compiler Infrastructure

//

// This file is distributed under the University of Illinois Open Source

// License. See LICENSE.TXT for details.

//

//===----------------------------------------------------------------------===//

//

/// @file

/// This file contains the declarations for the subclasses of Constant,

/// which represent the different flavors of constant values that live in LLVM.

/// Note that Constants are immutable (once created they never change) and are

/// fully shared by structural equivalence.  This means that two structurally

/// equivalent constants will always have the same address.  Constants are

/// created on demand as needed and never deleted: thus clients don't have to

/// worry about the lifetime of the objects.

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_IR_CONSTANTS_H

#define LLVM_IR_CONSTANTS_H

#include "llvh/ADT/APFloat.h"

#include "llvh/ADT/APInt.h"

#include "llvh/ADT/ArrayRef.h"

#include "llvh/ADT/None.h"

#include "llvh/ADT/Optional.h"

#include "llvh/ADT/STLExtras.h"

#include "llvh/ADT/StringRef.h"

#include "llvh/IR/Constant.h"

#include "llvh/IR/DerivedTypes.h"

#include "llvh/IR/OperandTraits.h"

#include "llvh/IR/User.h"

#include "llvh/IR/Value.h"

#include "llvh/Support/Casting.h"

#include "llvh/Support/Compiler.h"

#include "llvh/Support/ErrorHandling.h"

#include <cassert>

#include <cstddef>

#include <cstdint>

namespace llvh {

class ArrayType;

class IntegerType;

class PointerType;

class SequentialType;

class StructType;

class VectorType;

template <class ConstantClass> struct ConstantAggrKeyType;

/// Base class for constants with no operands.

///

/// These constants have no operands; they represent their data directly.

/// Since they can be in use by unrelated modules (and are never based on

/// GlobalValues), it never makes sense to RAUW them.

class ConstantData : public Constant {

  friend class Constant;

  Value *handleOperandChangeImpl(Value *From, Value *To) {

    llvm_unreachable("Constant data does not have operands!");

  }

protected:

  explicit ConstantData(Type *Ty, ValueTy VT) : Constant(Ty, VT, nullptr, 0) {}

  void *operator new(size_t s) { return User::operator new(s, 0); }

public:

  ConstantData(const ConstantData &) = delete;

  /// Methods to support type inquiry through isa, cast, and dyn_cast.

  static bool classof(const Value *V) {

    return V->getValueID() >= ConstantDataFirstVal &&

           V->getValueID() <= ConstantDataLastVal;

  }

};

//===----------------------------------------------------------------------===//

/// This is the shared class of boolean and integer constants. This class

/// represents both boolean and integral constants.

/// Class for constant integers.

class ConstantInt final : public ConstantData {

  friend class Constant;

  APInt Val;

  ConstantInt(IntegerType *Ty, const APInt& V);

  void destroyConstantImpl();

public:

  ConstantInt(const ConstantInt &) = delete;

  static ConstantInt *getTrue(LLVMContext &Context);

  static ConstantInt *getFalse(LLVMContext &Context);

  static Constant *getTrue(Type *Ty);

  static Constant *getFalse(Type *Ty);

  /// If Ty is a vector type, return a Constant with a splat of the given

  /// value. Otherwise return a ConstantInt for the given value.

  static Constant *get(Type *Ty, uint64_t V, bool isSigned = false);

  /// Return a ConstantInt with the specified integer value for the specified

  /// type. If the type is wider than 64 bits, the value will be zero-extended

  /// to fit the type, unless isSigned is true, in which case the value will

  /// be interpreted as a 64-bit signed integer and sign-extended to fit

  /// the type.

  /// Get a ConstantInt for a specific value.

  static ConstantInt *get(IntegerType *Ty, uint64_t V,

                          bool isSigned = false);

  /// Return a ConstantInt with the specified value for the specified type. The

  /// value V will be canonicalized to a an unsigned APInt. Accessing it with

  /// either getSExtValue() or getZExtValue() will yield a correctly sized and

  /// signed value for the type Ty.

  /// Get a ConstantInt for a specific signed value.

  static ConstantInt *getSigned(IntegerType *Ty, int64_t V);

  static Constant *getSigned(Type *Ty, int64_t V);

  /// Return a ConstantInt with the specified value and an implied Type. The

  /// type is the integer type that corresponds to the bit width of the value.

  static ConstantInt *get(LLVMContext &Context, const APInt &V);

  /// Return a ConstantInt constructed from the string strStart with the given

  /// radix.

  static ConstantInt *get(IntegerType *Ty, StringRef Str,

                          uint8_t radix);

  /// If Ty is a vector type, return a Constant with a splat of the given

  /// value. Otherwise return a ConstantInt for the given value.

  static Constant *get(Type* Ty, const APInt& V);

  /// Return the constant as an APInt value reference. This allows clients to

  /// obtain a full-precision copy of the value.

  /// Return the constant's value.

  inline const APInt &getValue() const {

    return Val;

  }

  /// getBitWidth - Return the bitwidth of this constant.

  unsigned getBitWidth() const { return Val.getBitWidth(); }

  /// Return the constant as a 64-bit unsigned integer value after it

  /// has been zero extended as appropriate for the type of this constant. Note

  /// that this method can assert if the value does not fit in 64 bits.

  /// Return the zero extended value.

  inline uint64_t getZExtValue() const {

    return Val.getZExtValue();

  }

  /// Return the constant as a 64-bit integer value after it has been sign

  /// extended as appropriate for the type of this constant. Note that

  /// this method can assert if the value does not fit in 64 bits.

  /// Return the sign extended value.

  inline int64_t getSExtValue() const {

    return Val.getSExtValue();

  }

  /// A helper method that can be used to determine if the constant contained

  /// within is equal to a constant.  This only works for very small values,

  /// because this is all that can be represented with all types.

  /// Determine if this constant's value is same as an unsigned char.

  bool equalsInt(uint64_t V) const {

    return Val == V;

  }

  /// getType - Specialize the getType() method to always return an IntegerType,

  /// which reduces the amount of casting needed in parts of the compiler.

  ///

  inline IntegerType *getType() const {

    return cast<IntegerType>(Value::getType());

  }

  /// This static method returns true if the type Ty is big enough to

  /// represent the value V. This can be used to avoid having the get method

  /// assert when V is larger than Ty can represent. Note that there are two

  /// versions of this method, one for unsigned and one for signed integers.

  /// Although ConstantInt canonicalizes everything to an unsigned integer,

  /// the signed version avoids callers having to convert a signed quantity

  /// to the appropriate unsigned type before calling the method.

  /// @returns true if V is a valid value for type Ty

  /// Determine if the value is in range for the given type.

  static bool isValueValidForType(Type *Ty, uint64_t V);

  static bool isValueValidForType(Type *Ty, int64_t V);

  bool isNegative() const { return Val.isNegative(); }

  /// This is just a convenience method to make client code smaller for a

  /// common code. It also correctly performs the comparison without the

  /// potential for an assertion from getZExtValue().

  bool isZero() const {

    return Val.isNullValue();

  }

  /// This is just a convenience method to make client code smaller for a

  /// common case. It also correctly performs the comparison without the

  /// potential for an assertion from getZExtValue().

  /// Determine if the value is one.

  bool isOne() const {

    return Val.isOneValue();

  }

  /// This function will return true iff every bit in this constant is set

  /// to true.

  /// @returns true iff this constant's bits are all set to true.

  /// Determine if the value is all ones.

  bool isMinusOne() const {

    return Val.isAllOnesValue();

  }

  /// This function will return true iff this constant represents the largest

  /// value that may be represented by the constant's type.

  /// @returns true iff this is the largest value that may be represented

  /// by this type.

  /// Determine if the value is maximal.

  bool isMaxValue(bool isSigned) const {

    if (isSigned)

      return Val.isMaxSignedValue();

    else

      return Val.isMaxValue();

  }

  /// This function will return true iff this constant represents the smallest

  /// value that may be represented by this constant's type.

  /// @returns true if this is the smallest value that may be represented by

  /// this type.

  /// Determine if the value is minimal.

  bool isMinValue(bool isSigned) const {

    if (isSigned)

      return Val.isMinSignedValue();

    else

      return Val.isMinValue();

  }

  /// This function will return true iff this constant represents a value with

  /// active bits bigger than 64 bits or a value greater than the given uint64_t

  /// value.

  /// @returns true iff this constant is greater or equal to the given number.

  /// Determine if the value is greater or equal to the given number.

  bool uge(uint64_t Num) const {

    return Val.uge(Num);

  }

  /// getLimitedValue - If the value is smaller than the specified limit,

  /// return it, otherwise return the limit value.  This causes the value

  /// to saturate to the limit.

  /// @returns the min of the value of the constant and the specified value

  /// Get the constant's value with a saturation limit

  uint64_t getLimitedValue(uint64_t Limit = ~0ULL) const {

    return Val.getLimitedValue(Limit);

  }

  /// Methods to support type inquiry through isa, cast, and dyn_cast.

  static bool classof(const Value *V) {

    return V->getValueID() == ConstantIntVal;

  }

};

//===----------------------------------------------------------------------===//

/// ConstantFP - Floating Point Values [float, double]

///

class ConstantFP final : public ConstantData {

  friend class Constant;

  APFloat Val;

  ConstantFP(Type *Ty, const APFloat& V);

  void destroyConstantImpl();

public:

  ConstantFP(const ConstantFP &) = delete;

  /// Floating point negation must be implemented with f(x) = -0.0 - x. This

  /// method returns the negative zero constant for floating point or vector

  /// floating point types; for all other types, it returns the null value.

  static Constant *getZeroValueForNegation(Type *Ty);

  /// This returns a ConstantFP, or a vector containing a splat of a ConstantFP,

  /// for the specified value in the specified type. This should only be used

  /// for simple constant values like 2.0/1.0 etc, that are known-valid both as

  /// host double and as the target format.

  static Constant *get(Type* Ty, double V);

  /// If Ty is a vector type, return a Constant with a splat of the given

  /// value. Otherwise return a ConstantFP for the given value.

  static Constant *get(Type *Ty, const APFloat &V);

  static Constant *get(Type* Ty, StringRef Str);

  static ConstantFP *get(LLVMContext &Context, const APFloat &V);

  static Constant *getNaN(Type *Ty, bool Negative = false, unsigned type = 0);

  static Constant *getNegativeZero(Type *Ty);

  static Constant *getInfinity(Type *Ty, bool Negative = false);

  /// Return true if Ty is big enough to represent V.

  static bool isValueValidForType(Type *Ty, const APFloat &V);

  inline const APFloat &getValueAPF() const { return Val; }

  /// Return true if the value is positive or negative zero.

  bool isZero() const { return Val.isZero(); }

  /// Return true if the sign bit is set.

  bool isNegative() const { return Val.isNegative(); }

  /// Return true if the value is infinity

  bool isInfinity() const { return Val.isInfinity(); }

  /// Return true if the value is a NaN.

  bool isNaN() const { return Val.isNaN(); }

  /// We don't rely on operator== working on double values, as it returns true

  /// for things that are clearly not equal, like -0.0 and 0.0.

  /// As such, this method can be used to do an exact bit-for-bit comparison of

  /// two floating point values.  The version with a double operand is retained

  /// because it's so convenient to write isExactlyValue(2.0), but please use

  /// it only for simple constants.

  bool isExactlyValue(const APFloat &V) const;

  bool isExactlyValue(double V) const {

    bool ignored;

    APFloat FV(V);

    FV.convert(Val.getSemantics(), APFloat::rmNearestTiesToEven, &ignored);

    return isExactlyValue(FV);

  }

  /// Methods for support type inquiry through isa, cast, and dyn_cast:

  static bool classof(const Value *V) {

    return V->getValueID() == ConstantFPVal;

  }

};

//===----------------------------------------------------------------------===//

/// All zero aggregate value

///

class ConstantAggregateZero final : public ConstantData {

  friend class Constant;

  explicit ConstantAggregateZero(Type *Ty)

      : ConstantData(Ty, ConstantAggregateZeroVal) {}

  void destroyConstantImpl();

public:

  ConstantAggregateZero(const ConstantAggregateZero &) = delete;

  static ConstantAggregateZero *get(Type *Ty);

  /// If this CAZ has array or vector type, return a zero with the right element

  /// type.

  Constant *getSequentialElement() const;

  /// If this CAZ has struct type, return a zero with the right element type for

  /// the specified element.

  Constant *getStructElement(unsigned Elt) const;

  /// Return a zero of the right value for the specified GEP index if we can,

  /// otherwise return null (e.g. if C is a ConstantExpr).

  Constant *getElementValue(Constant *C) const;

  /// Return a zero of the right value for the specified GEP index.

  Constant *getElementValue(unsigned Idx) const;

  /// Return the number of elements in the array, vector, or struct.

  unsigned getNumElements() const;

  /// Methods for support type inquiry through isa, cast, and dyn_cast:

  ///

  static bool classof(const Value *V) {

    return V->getValueID() == ConstantAggregateZeroVal;

  }

};

/// Base class for aggregate constants (with operands).

///

/// These constants are aggregates of other constants, which are stored as

/// operands.

///

/// Subclasses are \a ConstantStruct, \a ConstantArray, and \a

/// ConstantVector.

///

/// \note Some subclasses of \a ConstantData are semantically aggregates --

/// such as \a ConstantDataArray -- but are not subclasses of this because they

/// use operands.

class ConstantAggregate : public Constant {

protected:

  ConstantAggregate(CompositeType *T, ValueTy VT, ArrayRef<Constant *> V);

public:

  /// Transparently provide more efficient getOperand methods.

  DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);

  /// Methods for support type inquiry through isa, cast, and dyn_cast:

  static bool classof(const Value *V) {

    return V->getValueID() >= ConstantAggregateFirstVal &&

           V->getValueID() <= ConstantAggregateLastVal;

  }

};

template <>

struct OperandTraits<ConstantAggregate>

    : public VariadicOperandTraits<ConstantAggregate> {};

DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantAggregate, Constant)

//===----------------------------------------------------------------------===//

/// ConstantArray - Constant Array Declarations

///

class ConstantArray final : public ConstantAggregate {

  friend struct ConstantAggrKeyType<ConstantArray>;

  friend class Constant;

  ConstantArray(ArrayType *T, ArrayRef<Constant *> Val);

  void destroyConstantImpl();

  Value *handleOperandChangeImpl(Value *From, Value *To);

public:

  // ConstantArray accessors

  static Constant *get(ArrayType *T, ArrayRef<Constant*> V);

private:

  static Constant *getImpl(ArrayType *T, ArrayRef<Constant *> V);

public:

  /// Specialize the getType() method to always return an ArrayType,

  /// which reduces the amount of casting needed in parts of the compiler.

  inline ArrayType *getType() const {

    return cast<ArrayType>(Value::getType());

  }

  /// Methods for support type inquiry through isa, cast, and dyn_cast:

  static bool classof(const Value *V) {

    return V->getValueID() == ConstantArrayVal;

  }

};

//===----------------------------------------------------------------------===//

// Constant Struct Declarations

//

class ConstantStruct final : public ConstantAggregate {

  friend struct ConstantAggrKeyType<ConstantStruct>;

  friend class Constant;

  ConstantStruct(StructType *T, ArrayRef<Constant *> Val);

  void destroyConstantImpl();

  Value *handleOperandChangeImpl(Value *From, Value *To);

public:

  // ConstantStruct accessors

  static Constant *get(StructType *T, ArrayRef<Constant*> V);

  template <typename... Csts>

  static typename std::enable_if<are_base_of<Constant, Csts...>::value,

                                 Constant *>::type

  get(StructType *T, Csts *... Vs) {

    SmallVector<Constant *, 8> Values({Vs...});

    return get(T, Values);

  }

  /// Return an anonymous struct that has the specified elements.

  /// If the struct is possibly empty, then you must specify a context.

  static Constant *getAnon(ArrayRef<Constant*> V, bool Packed = false) {

    return get(getTypeForElements(V, Packed), V);

  }

  static Constant *getAnon(LLVMContext &Ctx,

                           ArrayRef<Constant*> V, bool Packed = false) {

    return get(getTypeForElements(Ctx, V, Packed), V);

  }

  /// Return an anonymous struct type to use for a constant with the specified

  /// set of elements. The list must not be empty.

  static StructType *getTypeForElements(ArrayRef<Constant*> V,

                                        bool Packed = false);

  /// This version of the method allows an empty list.

  static StructType *getTypeForElements(LLVMContext &Ctx,

                                        ArrayRef<Constant*> V,

                                        bool Packed = false);

  /// Specialization - reduce amount of casting.

  inline StructType *getType() const {

    return cast<StructType>(Value::getType());

  }

  /// Methods for support type inquiry through isa, cast, and dyn_cast:

  static bool classof(const Value *V) {

    return V->getValueID() == ConstantStructVal;

  }

};

//===----------------------------------------------------------------------===//

/// Constant Vector Declarations

///

class ConstantVector final : public ConstantAggregate {

  friend struct ConstantAggrKeyType<ConstantVector>;

  friend class Constant;

  ConstantVector(VectorType *T, ArrayRef<Constant *> Val);

  void destroyConstantImpl();

  Value *handleOperandChangeImpl(Value *From, Value *To);

public:

  // ConstantVector accessors

  static Constant *get(ArrayRef<Constant*> V);

private:

  static Constant *getImpl(ArrayRef<Constant *> V);

public:

  /// Return a ConstantVector with the specified constant in each element.

  static Constant *getSplat(unsigned NumElts, Constant *Elt);

  /// Specialize the getType() method to always return a VectorType,

  /// which reduces the amount of casting needed in parts of the compiler.

  inline VectorType *getType() const {

    return cast<VectorType>(Value::getType());

  }

  /// If this is a splat constant, meaning that all of the elements have the

  /// same value, return that value. Otherwise return NULL.

  Constant *getSplatValue() const;

  /// Methods for support type inquiry through isa, cast, and dyn_cast:

  static bool classof(const Value *V) {

    return V->getValueID() == ConstantVectorVal;

  }

};

//===----------------------------------------------------------------------===//

/// A constant pointer value that points to null

///

class ConstantPointerNull final : public ConstantData {

  friend class Constant;

  explicit ConstantPointerNull(PointerType *T)

      : ConstantData(T, Value::ConstantPointerNullVal) {}

  void destroyConstantImpl();

public:

  ConstantPointerNull(const ConstantPointerNull &) = delete;

  /// Static factory methods - Return objects of the specified value

  static ConstantPointerNull *get(PointerType *T);

  /// Specialize the getType() method to always return an PointerType,

  /// which reduces the amount of casting needed in parts of the compiler.

  inline PointerType *getType() const {

    return cast<PointerType>(Value::getType());

  }

  /// Methods for support type inquiry through isa, cast, and dyn_cast:

  static bool classof(const Value *V) {

    return V->getValueID() == ConstantPointerNullVal;

  }

};

//===----------------------------------------------------------------------===//

/// ConstantDataSequential - A vector or array constant whose element type is a

/// simple 1/2/4/8-byte integer or float/double, and whose elements are just

/// simple data values (i.e. ConstantInt/ConstantFP).  This Constant node has no

/// operands because it stores all of the elements of the constant as densely

/// packed data, instead of as Value*'s.

///

/// This is the common base class of ConstantDataArray and ConstantDataVector.

///

class ConstantDataSequential : public ConstantData {

  friend class LLVMContextImpl;

  friend class Constant;

  /// A pointer to the bytes underlying this constant (which is owned by the

  /// uniquing StringMap).

  const char *DataElements;

  /// This forms a link list of ConstantDataSequential nodes that have

  /// the same value but different type.  For example, 0,0,0,1 could be a 4

  /// element array of i8, or a 1-element array of i32.  They'll both end up in

  /// the same StringMap bucket, linked up.

  ConstantDataSequential *Next;

  void destroyConstantImpl();

protected:

  explicit ConstantDataSequential(Type *ty, ValueTy VT, const char *Data)

      : ConstantData(ty, VT), DataElements(Data), Next(nullptr) {}

  ~ConstantDataSequential() { delete Next; }

  static Constant *getImpl(StringRef Bytes, Type *Ty);

public:

  ConstantDataSequential(const ConstantDataSequential &) = delete;

  /// Return true if a ConstantDataSequential can be formed with a vector or

  /// array of the specified element type.

  /// ConstantDataArray only works with normal float and int types that are

  /// stored densely in memory, not with things like i42 or x86_f80.

  static bool isElementTypeCompatible(Type *Ty);

  /// If this is a sequential container of integers (of any size), return the

  /// specified element in the low bits of a uint64_t.

  uint64_t getElementAsInteger(unsigned i) const;

  /// If this is a sequential container of integers (of any size), return the

  /// specified element as an APInt.

  APInt getElementAsAPInt(unsigned i) const;

  /// If this is a sequential container of floating point type, return the

  /// specified element as an APFloat.

  APFloat getElementAsAPFloat(unsigned i) const;

  /// If this is an sequential container of floats, return the specified element

  /// as a float.

  float getElementAsFloat(unsigned i) const;

  /// If this is an sequential container of doubles, return the specified

  /// element as a double.

  double getElementAsDouble(unsigned i) const;

  /// Return a Constant for a specified index's element.

  /// Note that this has to compute a new constant to return, so it isn't as

  /// efficient as getElementAsInteger/Float/Double.

  Constant *getElementAsConstant(unsigned i) const;

  /// Specialize the getType() method to always return a SequentialType, which

  /// reduces the amount of casting needed in parts of the compiler.

  inline SequentialType *getType() const {

    return cast<SequentialType>(Value::getType());

  }

  /// Return the element type of the array/vector.

  Type *getElementType() const;

  /// Return the number of elements in the array or vector.

  unsigned getNumElements() const;

  /// Return the size (in bytes) of each element in the array/vector.

  /// The size of the elements is known to be a multiple of one byte.

  uint64_t getElementByteSize() const;

  /// This method returns true if this is an array of \p CharSize integers.

  bool isString(unsigned CharSize = 8) const;

  /// This method returns true if the array "isString", ends with a null byte,

  /// and does not contains any other null bytes.

  bool isCString() const;

  /// If this array is isString(), then this method returns the array as a

  /// StringRef. Otherwise, it asserts out.

  StringRef getAsString() const {

    assert(isString() && "Not a string");

    return getRawDataValues();

  }

  /// If this array is isCString(), then this method returns the array (without

  /// the trailing null byte) as a StringRef. Otherwise, it asserts out.

  StringRef getAsCString() const {

    assert(isCString() && "Isn't a C string");

    StringRef Str = getAsString();

    return Str.substr(0, Str.size()-1);

  }

  /// Return the raw, underlying, bytes of this data. Note that this is an

  /// extremely tricky thing to work with, as it exposes the host endianness of

  /// the data elements.

  StringRef getRawDataValues() const;

  /// Methods for support type inquiry through isa, cast, and dyn_cast:

  static bool classof(const Value *V) {

    return V->getValueID() == ConstantDataArrayVal ||

           V->getValueID() == ConstantDataVectorVal;

  }

private:

  const char *getElementPointer(unsigned Elt) const;

};

//===----------------------------------------------------------------------===//

/// An array constant whose element type is a simple 1/2/4/8-byte integer or

/// float/double, and whose elements are just simple data values

/// (i.e. ConstantInt/ConstantFP). This Constant node has no operands because it

/// stores all of the elements of the constant as densely packed data, instead

/// of as Value*'s.

class ConstantDataArray final : public ConstantDataSequential {

  friend class ConstantDataSequential;

  explicit ConstantDataArray(Type *ty, const char *Data)

      : ConstantDataSequential(ty, ConstantDataArrayVal, Data) {}

public:

  ConstantDataArray(const ConstantDataArray &) = delete;

  /// get() constructor - Return a constant with array type with an element

  /// count and element type matching the ArrayRef passed in.  Note that this

  /// can return a ConstantAggregateZero object.

  template <typename ElementTy>

  static Constant *get(LLVMContext &Context, ArrayRef<ElementTy> Elts) {

    const char *Data = reinterpret_cast<const char *>(Elts.data());

    return getRaw(StringRef(Data, Elts.size() * sizeof(ElementTy)), Elts.size(),

                  Type::getScalarTy<ElementTy>(Context));

  }

  /// get() constructor - ArrayTy needs to be compatible with

  /// ArrayRef<ElementTy>. Calls get(LLVMContext, ArrayRef<ElementTy>).

  template <typename ArrayTy>

  static Constant *get(LLVMContext &Context, ArrayTy &Elts) {

    return ConstantDataArray::get(Context, makeArrayRef(Elts));

  }

  /// get() constructor - Return a constant with array type with an element

  /// count and element type matching the NumElements and ElementTy parameters

  /// passed in. Note that this can return a ConstantAggregateZero object.

  /// ElementTy needs to be one of i8/i16/i32/i64/float/double. Data is the

  /// buffer containing the elements. Be careful to make sure Data uses the

  /// right endianness, the buffer will be used as-is.

  static Constant *getRaw(StringRef Data, uint64_t NumElements, Type *ElementTy) {

    Type *Ty = ArrayType::get(ElementTy, NumElements);

    return getImpl(Data, Ty);

  }

  /// getFP() constructors - Return a constant with array type with an element

  /// count and element type of float with precision matching the number of

  /// bits in the ArrayRef passed in. (i.e. half for 16bits, float for 32bits,

  /// double for 64bits) Note that this can return a ConstantAggregateZero

  /// object.

  static Constant *getFP(LLVMContext &Context, ArrayRef<uint16_t> Elts);

  static Constant *getFP(LLVMContext &Context, ArrayRef<uint32_t> Elts);

  static Constant *getFP(LLVMContext &Context, ArrayRef<uint64_t> Elts);

  /// This method constructs a CDS and initializes it with a text string.

  /// The default behavior (AddNull==true) causes a null terminator to

  /// be placed at the end of the array (increasing the length of the string by

  /// one more than the StringRef would normally indicate.  Pass AddNull=false

  /// to disable this behavior.

  static Constant *getString(LLVMContext &Context, StringRef Initializer,

                             bool AddNull = true);

  /// Specialize the getType() method to always return an ArrayType,

  /// which reduces the amount of casting needed in parts of the compiler.

  inline ArrayType *getType() const {

    return cast<ArrayType>(Value::getType());

  }

  /// Methods for support type inquiry through isa, cast, and dyn_cast:

  static bool classof(const Value *V) {

    return V->getValueID() == ConstantDataArrayVal;

  }

};

//===----------------------------------------------------------------------===//

/// A vector constant whose element type is a simple 1/2/4/8-byte integer or

/// float/double, and whose elements are just simple data values

/// (i.e. ConstantInt/ConstantFP). This Constant node has no operands because it

/// stores all of the elements of the constant as densely packed data, instead

/// of as Value*'s.

class ConstantDataVector final : public ConstantDataSequential {

  friend class ConstantDataSequential;

  explicit ConstantDataVector(Type *ty, const char *Data)

      : ConstantDataSequential(ty, ConstantDataVectorVal, Data) {}

public:

  ConstantDataVector(const ConstantDataVector &) = delete;

  /// get() constructors - Return a constant with vector type with an element

  /// count and element type matching the ArrayRef passed in.  Note that this

  /// can return a ConstantAggregateZero object.

  static Constant *get(LLVMContext &Context, ArrayRef<uint8_t> Elts);

  static Constant *get(LLVMContext &Context, ArrayRef<uint16_t> Elts);

  static Constant *get(LLVMContext &Context, ArrayRef<uint32_t> Elts);

  static Constant *get(LLVMContext &Context, ArrayRef<uint64_t> Elts);

  static Constant *get(LLVMContext &Context, ArrayRef<float> Elts);

  static Constant *get(LLVMContext &Context, ArrayRef<double> Elts);

  /// getFP() constructors - Return a constant with vector type with an element

  /// count and element type of float with the precision matching the number of

  /// bits in the ArrayRef passed in.  (i.e. half for 16bits, float for 32bits,

  /// double for 64bits) Note that this can return a ConstantAggregateZero

  /// object.

  static Constant *getFP(LLVMContext &Context, ArrayRef<uint16_t> Elts);

  static Constant *getFP(LLVMContext &Context, ArrayRef<uint32_t> Elts);

  static Constant *getFP(LLVMContext &Context, ArrayRef<uint64_t> Elts);

  /// Return a ConstantVector with the specified constant in each element.

  /// The specified constant has to be a of a compatible type (i8/i16/

  /// i32/i64/float/double) and must be a ConstantFP or ConstantInt.

  static Constant *getSplat(unsigned NumElts, Constant *Elt);

  /// Returns true if this is a splat constant, meaning that all elements have

  /// the same value.

  bool isSplat() const;

  /// If this is a splat constant, meaning that all of the elements have the

  /// same value, return that value. Otherwise return NULL.

  Constant *getSplatValue() const;

  /// Specialize the getType() method to always return a VectorType,

  /// which reduces the amount of casting needed in parts of the compiler.

  inline VectorType *getType() const {

    return cast<VectorType>(Value::getType());

  }

  /// Methods for support type inquiry through isa, cast, and dyn_cast:

  static bool classof(const Value *V) {

    return V->getValueID() == ConstantDataVectorVal;

  }

};

//===----------------------------------------------------------------------===//

/// A constant token which is empty

///

class ConstantTokenNone final : public ConstantData {

  friend class Constant;

  explicit ConstantTokenNone(LLVMContext &Context)

      : ConstantData(Type::getTokenTy(Context), ConstantTokenNoneVal) {}

  void destroyConstantImpl();

public:

  ConstantTokenNone(const ConstantTokenNone &) = delete;

  /// Return the ConstantTokenNone.

  static ConstantTokenNone *get(LLVMContext &Context);

  /// Methods to support type inquiry through isa, cast, and dyn_cast.

  static bool classof(const Value *V) {

    return V->getValueID() == ConstantTokenNoneVal;

  }

};

/// The address of a basic block.

///

class BlockAddress final : public Constant {

  friend class Constant;

  BlockAddress(Function *F, BasicBlock *BB);

  void *operator new(size_t s) { return User::operator new(s, 2); }

  void destroyConstantImpl();

  Value *handleOperandChangeImpl(Value *From, Value *To);

public:

  /// Return a BlockAddress for the specified function and basic block.

  static BlockAddress *get(Function *F, BasicBlock *BB);

  /// Return a BlockAddress for the specified basic block.  The basic

  /// block must be embedded into a function.

  static BlockAddress *get(BasicBlock *BB);

  /// Lookup an existing \c BlockAddress constant for the given BasicBlock.

  ///

  /// \returns 0 if \c !BB->hasAddressTaken(), otherwise the \c BlockAddress.

  static BlockAddress *lookup(const BasicBlock *BB);

  /// Transparently provide more efficient getOperand methods.

  DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);

  Function *getFunction() const { return (Function*)Op<0>().get(); }

  BasicBlock *getBasicBlock() const { return (BasicBlock*)Op<1>().get(); }

  /// Methods for support type inquiry through isa, cast, and dyn_cast:

  static bool classof(const Value *V) {

    return V->getValueID() == BlockAddressVal;

  }

};

template <>

struct OperandTraits<BlockAddress> :

  public FixedNumOperandTraits<BlockAddress, 2> {

};

DEFINE_TRANSPARENT_OPERAND_ACCESSORS(BlockAddress, Value)

//===----------------------------------------------------------------------===//

/// A constant value that is initialized with an expression using

/// other constant values.

///

/// This class uses the standard Instruction opcodes to define the various

/// constant expressions.  The Opcode field for the ConstantExpr class is

/// maintained in the Value::SubclassData field.

class ConstantExpr : public Constant {

  friend struct ConstantExprKeyType;

  friend class Constant;

  void destroyConstantImpl();

  Value *handleOperandChangeImpl(Value *From, Value *To);

protected:

  ConstantExpr(Type *ty, unsigned Opcode, Use *Ops, unsigned NumOps)

      : Constant(ty, ConstantExprVal, Ops, NumOps) {

    // Operation type (an Instruction opcode) is stored as the SubclassData.

    setValueSubclassData(Opcode);

  }

public:

  // Static methods to construct a ConstantExpr of different kinds.  Note that

  // these methods may return a object that is not an instance of the

  // ConstantExpr class, because they will attempt to fold the constant

  // expression into something simpler if possible.

  /// getAlignOf constant expr - computes the alignment of a type in a target

  /// independent way (Note: the return type is an i64).

  static Constant *getAlignOf(Type *Ty);

  /// getSizeOf constant expr - computes the (alloc) size of a type (in

  /// address-units, not bits) in a target independent way (Note: the return

  /// type is an i64).

  ///

  static Constant *getSizeOf(Type *Ty);

  /// getOffsetOf constant expr - computes the offset of a struct field in a

  /// target independent way (Note: the return type is an i64).

  ///

  static Constant *getOffsetOf(StructType *STy, unsigned FieldNo);

  /// getOffsetOf constant expr - This is a generalized form of getOffsetOf,

  /// which supports any aggregate type, and any Constant index.

  ///

  static Constant *getOffsetOf(Type *Ty, Constant *FieldNo);

  static Constant *getNeg(Constant *C, bool HasNUW = false, bool HasNSW =false);

  static Constant *getFNeg(Constant *C);

  static Constant *getNot(Constant *C);

  static Constant *getAdd(Constant *C1, Constant *C2,

                          bool HasNUW = false, bool HasNSW = false);

  static Constant *getFAdd(Constant *C1, Constant *C2);

  static Constant *getSub(Constant *C1, Constant *C2,

                          bool HasNUW = false, bool HasNSW = false);

  static Constant *getFSub(Constant *C1, Constant *C2);

  static Constant *getMul(Constant *C1, Constant *C2,

                          bool HasNUW = false, bool HasNSW = false);

  static Constant *getFMul(Constant *C1, Constant *C2);

  static Constant *getUDiv(Constant *C1, Constant *C2, bool isExact = false);

  static Constant *getSDiv(Constant *C1, Constant *C2, bool isExact = false);

  static Constant *getFDiv(Constant *C1, Constant *C2);

  static Constant *getURem(Constant *C1, Constant *C2);

  static Constant *getSRem(Constant *C1, Constant *C2);

  static Constant *getFRem(Constant *C1, Constant *C2);

  static Constant *getAnd(Constant *C1, Constant *C2);

  static Constant *getOr(Constant *C1, Constant *C2);

  static Constant *getXor(Constant *C1, Constant *C2);

  static Constant *getShl(Constant *C1, Constant *C2,

                          bool HasNUW = false, bool HasNSW = false);

  static Constant *getLShr(Constant *C1, Constant *C2, bool isExact = false);

  static Constant *getAShr(Constant *C1, Constant *C2, bool isExact = false);

  static Constant *getTrunc(Constant *C, Type *Ty, bool OnlyIfReduced = false);

  static Constant *getSExt(Constant *C, Type *Ty, bool OnlyIfReduced = false);

  static Constant *getZExt(Constant *C, Type *Ty, bool OnlyIfReduced = false);

  static Constant *getFPTrunc(Constant *C, Type *Ty,

                              bool OnlyIfReduced = false);

  static Constant *getFPExtend(Constant *C, Type *Ty,

                               bool OnlyIfReduced = false);

  static Constant *getUIToFP(Constant *C, Type *Ty, bool OnlyIfReduced = false);

  static Constant *getSIToFP(Constant *C, Type *Ty, bool OnlyIfReduced = false);

  static Constant *getFPToUI(Constant *C, Type *Ty, bool OnlyIfReduced = false);

  static Constant *getFPToSI(Constant *C, Type *Ty, bool OnlyIfReduced = false);

  static Constant *getPtrToInt(Constant *C, Type *Ty,

                               bool OnlyIfReduced = false);

  static Constant *getIntToPtr(Constant *C, Type *Ty,

                               bool OnlyIfReduced = false);

  static Constant *getBitCast(Constant *C, Type *Ty,

                              bool OnlyIfReduced = false);

  static Constant *getAddrSpaceCast(Constant *C, Type *Ty,

                                    bool OnlyIfReduced = false);

  static Constant *getNSWNeg(Constant *C) { return getNeg(C, false, true); }

  static Constant *getNUWNeg(Constant *C) { return getNeg(C, true, false); }

  static Constant *getNSWAdd(Constant *C1, Constant *C2) {

    return getAdd(C1, C2, false, true);

  }

  static Constant *getNUWAdd(Constant *C1, Constant *C2) {

    return getAdd(C1, C2, true, false);

  }

  static Constant *getNSWSub(Constant *C1, Constant *C2) {

    return getSub(C1, C2, false, true);

  }

  static Constant *getNUWSub(Constant *C1, Constant *C2) {

    return getSub(C1, C2, true, false);

  }

  static Constant *getNSWMul(Constant *C1, Constant *C2) {

    return getMul(C1, C2, false, true);

  }

  static Constant *getNUWMul(Constant *C1, Constant *C2) {

    return getMul(C1, C2, true, false);

  }

  static Constant *getNSWShl(Constant *C1, Constant *C2) {

    return getShl(C1, C2, false, true);

  }

  static Constant *getNUWShl(Constant *C1, Constant *C2) {

    return getShl(C1, C2, true, false);

  }

  static Constant *getExactSDiv(Constant *C1, Constant *C2) {

    return getSDiv(C1, C2, true);

  }

  static Constant *getExactUDiv(Constant *C1, Constant *C2) {

    return getUDiv(C1, C2, true);

  }

  static Constant *getExactAShr(Constant *C1, Constant *C2) {

    return getAShr(C1, C2, true);

  }

  static Constant *getExactLShr(Constant *C1, Constant *C2) {

    return getLShr(C1, C2, true);

  }

  /// Return the identity constant for a binary opcode.

  /// The identity constant C is defined as X op C = X and C op X = X for every

  /// X when the binary operation is commutative. If the binop is not

  /// commutative, callers can acquire the operand 1 identity constant by

  /// setting AllowRHSConstant to true. For example, any shift has a zero

  /// identity constant for operand 1: X shift 0 = X.

  /// Return nullptr if the operator does not have an identity constant.

  static Constant *getBinOpIdentity(unsigned Opcode, Type *Ty,

                                    bool AllowRHSConstant = false);

  /// Return the absorbing element for the given binary

  /// operation, i.e. a constant C such that X op C = C and C op X = C for

  /// every X.  For example, this returns zero for integer multiplication.

  /// It returns null if the operator doesn't have an absorbing element.

  static Constant *getBinOpAbsorber(unsigned Opcode, Type *Ty);

  /// Transparently provide more efficient getOperand methods.

  DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);

  /// Convenience function for getting a Cast operation.

  ///

  /// \param ops The opcode for the conversion

  /// \param C  The constant to be converted

  /// \param Ty The type to which the constant is converted

  /// \param OnlyIfReduced see \a getWithOperands() docs.

  static Constant *getCast(unsigned ops, Constant *C, Type *Ty,

                           bool OnlyIfReduced = false);

  // Create a ZExt or BitCast cast constant expression

  static Constant *getZExtOrBitCast(

    Constant *C,   ///< The constant to zext or bitcast

    Type *Ty ///< The type to zext or bitcast C to

  );

  // Create a SExt or BitCast cast constant expression

  static Constant *getSExtOrBitCast(

    Constant *C,   ///< The constant to sext or bitcast

    Type *Ty ///< The type to sext or bitcast C to

  );

  // Create a Trunc or BitCast cast constant expression

  static Constant *getTruncOrBitCast(

    Constant *C,   ///< The constant to trunc or bitcast

    Type *Ty ///< The type to trunc or bitcast C to

  );

  /// Create a BitCast, AddrSpaceCast, or a PtrToInt cast constant

  /// expression.

  static Constant *getPointerCast(

    Constant *C,   ///< The pointer value to be casted (operand 0)

    Type *Ty ///< The type to which cast should be made

  );

  /// Create a BitCast or AddrSpaceCast for a pointer type depending on

  /// the address space.

  static Constant *getPointerBitCastOrAddrSpaceCast(

    Constant *C,   ///< The constant to addrspacecast or bitcast

    Type *Ty ///< The type to bitcast or addrspacecast C to

  );

  /// Create a ZExt, Bitcast or Trunc for integer -> integer casts

  static Constant *getIntegerCast(

    Constant *C,    ///< The integer constant to be casted

    Type *Ty, ///< The integer type to cast to