vendor/clang/clang-trunk-r375505vendor/clang

1 files changed, 269 insertions, 0 deletions

diff --git a/lib/AST/Interp/Integral.h b/lib/AST/Interp/Integral.h
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+++ b/lib/AST/Interp/Integral.h
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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