complex.h

//===-- include/flang/Evaluate/complex.h ------------------------*- 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
//
//===----------------------------------------------------------------------===//
 
#ifndef FORTRAN_EVALUATE_COMPLEX_H_
#define FORTRAN_EVALUATE_COMPLEX_H_
 
#include "formatting.h"
#include "real.h"
#include <string>
 
namespace llvm {
class raw_ostream;
}
 
namespace Fortran::evaluate::value {
 
template <typename REAL_TYPE> class Complex {
public:
  using Part = REAL_TYPE;
  static constexpr int bits{2 * Part::bits};
 
  constexpr Complex() {} // (+0.0, +0.0)
  constexpr Complex(const Complex &) = default;
  constexpr Complex(const Part &r, const Part &i) : re_{r}, im_{i} {}
  explicit constexpr Complex(const Part &r) : re_{r} {}
  constexpr Complex &operator=(const Complex &) = default;
  constexpr Complex &operator=(Complex &&) = default;
 
  constexpr bool operator==(const Complex &that) const {
    return re_ == that.re_ && im_ == that.im_;
  }
 
  constexpr const Part &REAL() const { return re_; }
  constexpr const Part &AIMAG() const { return im_; }
  constexpr Complex CONJG() const { return {re_, im_.Negate()}; }
  constexpr Complex Negate() const { return {re_.Negate(), im_.Negate()}; }
 
  constexpr bool Equals(const Complex &that) const {
    return re_.Compare(that.re_) == Relation::Equal &&
        im_.Compare(that.im_) == Relation::Equal;
  }
 
  constexpr bool IsZero() const { return re_.IsZero() && im_.IsZero(); }
 
  constexpr bool IsInfinite() const {
    return re_.IsInfinite() || im_.IsInfinite();
  }
 
  constexpr bool IsNotANumber() const {
    return re_.IsNotANumber() || im_.IsNotANumber();
  }
 
  constexpr bool IsSignalingNaN() const {
    return re_.IsSignalingNaN() || im_.IsSignalingNaN();
  }
 
  template <typename INT>
  static ValueWithRealFlags<Complex> FromInteger(const INT &n,
      bool isUnsigned = false,
      Rounding rounding = TargetCharacteristics::defaultRounding) {
    ValueWithRealFlags<Complex> result;
    result.value.re_ = Part::FromInteger(n, isUnsigned, rounding)
                           .AccumulateFlags(result.flags);
    return result;
  }
 
  ValueWithRealFlags<Complex> Add(const Complex &,
      Rounding rounding = TargetCharacteristics::defaultRounding) const;
  ValueWithRealFlags<Complex> Subtract(const Complex &,
      Rounding rounding = TargetCharacteristics::defaultRounding) const;
  ValueWithRealFlags<Complex> Multiply(const Complex &,
      Rounding rounding = TargetCharacteristics::defaultRounding) const;
  ValueWithRealFlags<Complex> Divide(const Complex &,
      Rounding rounding = TargetCharacteristics::defaultRounding) const;
  ValueWithRealFlags<Complex> KahanSummation(const Complex &,
      Complex &correction,
      Rounding rounding = TargetCharacteristics::defaultRounding) const;
 
  // ABS/CABS = HYPOT(re_, imag_) = SQRT(re_**2 + im_**2)
  ValueWithRealFlags<Part> ABS(
      Rounding rounding = TargetCharacteristics::defaultRounding) const {
    return re_.HYPOT(im_, rounding);
  }
 
  constexpr Complex FlushSubnormalToZero() const {
    return {re_.FlushSubnormalToZero(), im_.FlushSubnormalToZero()};
  }
 
  static constexpr Complex NotANumber() {
    return {Part::NotANumber(), Part::NotANumber()};
  }
 
  std::string DumpHexadecimal() const;
  llvm::raw_ostream &AsFortran(llvm::raw_ostream &, int kind) const;

  constexpr static std::size_t bytesStored() { return 2 * Part::bytesStored(); }

  static Complex FromRawBytes(
      const void *raw, [[maybe_unused]] std::size_t expectedSize) {
    CHECK(bytesStored() == expectedSize);
    const char *data{static_cast<const char *>(raw)};
    Part realPart{Part::FromRawBytes(data, Part::bytesStored())};
    Part imagPart{
        Part::FromRawBytes(data + Part::bytesStored(), Part::bytesStored())};
    return {realPart, imagPart};
  }

  void StoreRawBytes(void *dst, [[maybe_unused]] size_t expectedSize,
      bool *changed = nullptr) const {
    CHECK(expectedSize == bytesStored());
    re_.StoreRawBytes(dst, Part::bytesStored(), changed);
    im_.StoreRawBytes(static_cast<char *>(dst) + Part::bytesStored(),
        Part::bytesStored(), changed);
  }
 
  // TODO: unit testing
 
private:
  Part re_, im_;
};
 
extern template class Complex<Real<Integer<16>, 11>>;
extern template class Complex<Real<Integer<16>, 8>>;
extern template class Complex<Real<Integer<32>, 24>>;
extern template class Complex<Real<Integer<64>, 53>>;
extern template class Complex<Real<X87IntegerContainer, 64>>;
extern template class Complex<Real<Integer<128>, 113>>;
} // namespace Fortran::evaluate::value
#endif // FORTRAN_EVALUATE_COMPLEX_H_