external/bsd/libc++/dist/libcxx/test/support/hexfloat.h

   1 //===----------------------------------------------------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is dual licensed under the MIT and the University of Illinois Open
   6 // Source Licenses. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 // Define a hexfloat literal emulator since we can't depend on being able to
  11 //   for hexfloat literals
  12
  13 // 0x10.F5p-10 == hexfloat<double>(0x10, 0xF5, -10)
  14
  15 #ifndef HEXFLOAT_H
  16 #define HEXFLOAT_H
  17
  18 #include <algorithm>
  19 #include <cmath>
  20 #include <climits>
  21
  22 template <class T>
  23 class hexfloat
  24 {
  25     T value_;
  26 public:
  27     hexfloat(long long m1, unsigned long long m0, int exp)
  28     {
  29         const std::size_t n = sizeof(unsigned long long) * CHAR_BIT;
  30         int s = m1 < 0 ? -1 : 1;
  31         value_ = std::ldexp(m1 + s * std::ldexp(T(m0), -static_cast<int>(n -
  32                                                      std::__clz(m0)/4*4)), exp);
  33     }
  34
  35     operator T() const {return value_;}
  36 };
  37
  38 #endif