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| //===--- Integral.h - Wrapper for numeric types for the VM ------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// Defines the VM types and helpers operating on types.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_AST_INTERP_INTEGRAL_H
#define LLVM_CLANG_AST_INTERP_INTEGRAL_H
#include "clang/AST/ComparisonCategories.h"
#include "clang/AST/APValue.h"
#include "llvm/ADT/APSInt.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"
#include <cstddef>
#include <cstdint>
namespace clang {
namespace interp {
using APInt = llvm::APInt;
using APSInt = llvm::APSInt;
/// Helper to compare two comparable types.
template <typename T>
ComparisonCategoryResult Compare(const T &X, const T &Y) {
if (X < Y)
return ComparisonCategoryResult::Less;
if (X > Y)
return ComparisonCategoryResult::Greater;
return ComparisonCategoryResult::Equal;
}
// Helper structure to select the representation.
template <unsigned Bits, bool Signed> struct Repr;
template <> struct Repr<8, false> { using Type = uint8_t; };
template <> struct Repr<16, false> { using Type = uint16_t; };
template <> struct Repr<32, false> { using Type = uint32_t; };
template <> struct Repr<64, false> { using Type = uint64_t; };
template <> struct Repr<8, true> { using Type = int8_t; };
template <> struct Repr<16, true> { using Type = int16_t; };
template <> struct Repr<32, true> { using Type = int32_t; };
template <> struct Repr<64, true> { using Type = int64_t; };
/// Wrapper around numeric types.
///
/// These wrappers are required to shared an interface between APSint and
/// builtin primitive numeral types, while optimising for storage and
/// allowing methods operating on primitive type to compile to fast code.
template <unsigned Bits, bool Signed> class Integral {
private:
template <unsigned OtherBits, bool OtherSigned> friend class Integral;
// The primitive representing the integral.
using T = typename Repr<Bits, Signed>::Type;
T V;
/// Primitive representing limits.
static const auto Min = std::numeric_limits<T>::min();
static const auto Max = std::numeric_limits<T>::max();
/// Construct an integral from anything that is convertible to storage.
template <typename T> explicit Integral(T V) : V(V) {}
public:
/// Zero-initializes an integral.
Integral() : V(0) {}
/// Constructs an integral from another integral.
template <unsigned SrcBits, bool SrcSign>
explicit Integral(Integral<SrcBits, SrcSign> V) : V(V.V) {}
/// Construct an integral from a value based on signedness.
explicit Integral(const APSInt &V)
: V(V.isSigned() ? V.getSExtValue() : V.getZExtValue()) {}
bool operator<(Integral RHS) const { return V < RHS.V; }
bool operator>(Integral RHS) const { return V > RHS.V; }
bool operator<=(Integral RHS) const { return V <= RHS.V; }
bool operator>=(Integral RHS) const { return V >= RHS.V; }
bool operator==(Integral RHS) const { return V == RHS.V; }
bool operator!=(Integral RHS) const { return V != RHS.V; }
bool operator>(unsigned RHS) const {
return V >= 0 && static_cast<unsigned>(V) > RHS;
}
Integral operator-() const { return Integral(-V); }
Integral operator~() const { return Integral(~V); }
template <unsigned DstBits, bool DstSign>
explicit operator Integral<DstBits, DstSign>() const {
return Integral<DstBits, DstSign>(V);
}
explicit operator unsigned() const { return V; }
explicit operator int64_t() const { return V; }
explicit operator uint64_t() const { return V; }
APSInt toAPSInt() const {
return APSInt(APInt(Bits, static_cast<uint64_t>(V), Signed), !Signed);
}
APSInt toAPSInt(unsigned NumBits) const {
if (Signed)
return APSInt(toAPSInt().sextOrTrunc(NumBits), !Signed);
else
return APSInt(toAPSInt().zextOrTrunc(NumBits), !Signed);
}
APValue toAPValue() const { return APValue(toAPSInt()); }
Integral<Bits, false> toUnsigned() const {
return Integral<Bits, false>(*this);
}
constexpr static unsigned bitWidth() { return Bits; }
bool isZero() const { return !V; }
bool isMin() const { return *this == min(bitWidth()); }
bool isMinusOne() const { return Signed && V == T(-1); }
constexpr static bool isSigned() { return Signed; }
bool isNegative() const { return V < T(0); }
bool isPositive() const { return !isNegative(); }
ComparisonCategoryResult compare(const Integral &RHS) const {
return Compare(V, RHS.V);
}
unsigned countLeadingZeros() const { return llvm::countLeadingZeros<T>(V); }
Integral truncate(unsigned TruncBits) const {
if (TruncBits >= Bits)
return *this;
const T BitMask = (T(1) << T(TruncBits)) - 1;
const T SignBit = T(1) << (TruncBits - 1);
const T ExtMask = ~BitMask;
return Integral((V & BitMask) | (Signed && (V & SignBit) ? ExtMask : 0));
}
void print(llvm::raw_ostream &OS) const { OS << V; }
static Integral min(unsigned NumBits) {
return Integral(Min);
}
static Integral max(unsigned NumBits) {
return Integral(Max);
}
template <typename T>
static typename std::enable_if<std::is_integral<T>::value, Integral>::type
from(T Value) {
return Integral(Value);
}
template <unsigned SrcBits, bool SrcSign>
static typename std::enable_if<SrcBits != 0, Integral>::type
from(Integral<SrcBits, SrcSign> Value) {
return Integral(Value.V);
}
template <bool SrcSign> static Integral from(Integral<0, SrcSign> Value) {
if (SrcSign)
return Integral(Value.V.getSExtValue());
else
return Integral(Value.V.getZExtValue());
}
static Integral zero() { return from(0); }
template <typename T> static Integral from(T Value, unsigned NumBits) {
return Integral(Value);
}
static bool inRange(int64_t Value, unsigned NumBits) {
return CheckRange<T, Min, Max>(Value);
}
static bool increment(Integral A, Integral *R) {
return add(A, Integral(T(1)), A.bitWidth(), R);
}
static bool decrement(Integral A, Integral *R) {
return sub(A, Integral(T(1)), A.bitWidth(), R);
}
static bool add(Integral A, Integral B, unsigned OpBits, Integral *R) {
return CheckAddUB(A.V, B.V, R->V);
}
static bool sub(Integral A, Integral B, unsigned OpBits, Integral *R) {
return CheckSubUB(A.V, B.V, R->V);
}
static bool mul(Integral A, Integral B, unsigned OpBits, Integral *R) {
return CheckMulUB(A.V, B.V, R->V);
}
private:
template <typename T>
static typename std::enable_if<std::is_signed<T>::value, bool>::type
CheckAddUB(T A, T B, T &R) {
return llvm::AddOverflow<T>(A, B, R);
}
template <typename T>
static typename std::enable_if<std::is_unsigned<T>::value, bool>::type
CheckAddUB(T A, T B, T &R) {
R = A + B;
return false;
}
template <typename T>
static typename std::enable_if<std::is_signed<T>::value, bool>::type
CheckSubUB(T A, T B, T &R) {
return llvm::SubOverflow<T>(A, B, R);
}
template <typename T>
static typename std::enable_if<std::is_unsigned<T>::value, bool>::type
CheckSubUB(T A, T B, T &R) {
R = A - B;
return false;
}
template <typename T>
static typename std::enable_if<std::is_signed<T>::value, bool>::type
CheckMulUB(T A, T B, T &R) {
return llvm::MulOverflow<T>(A, B, R);
}
template <typename T>
static typename std::enable_if<std::is_unsigned<T>::value, bool>::type
CheckMulUB(T A, T B, T &R) {
R = A * B;
return false;
}
template <typename T, T Min, T Max>
static typename std::enable_if<std::is_signed<T>::value, bool>::type
CheckRange(int64_t V) {
return Min <= V && V <= Max;
}
template <typename T, T Min, T Max>
static typename std::enable_if<std::is_unsigned<T>::value, bool>::type
CheckRange(int64_t V) {
return V >= 0 && static_cast<uint64_t>(V) <= Max;
}
};
template <unsigned Bits, bool Signed>
llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, Integral<Bits, Signed> I) {
I.print(OS);
return OS;
}
} // namespace interp
} // namespace clang
#endif
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