cxx/test/hexfloat.h
Howard Hinnant e80c36e27b Correction to hexfloat hack.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@131340 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-14 14:33:56 +00:00

39 lines
1.0 KiB
C++

//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// Define a hexfloat literal emulator since we can't depend on being able to
// for hexfloat literals
// 0x10.F5p-10 == hexfloat<double>(0x10, 0xF5, -10)
#ifndef HEXFLOAT_H
#define HEXFLOAT_H
#include <algorithm>
#include <cmath>
#include <climits>
template <class T>
class hexfloat
{
T value_;
public:
hexfloat(long long m1, unsigned long long m0, int exp)
{
const std::size_t n = sizeof(unsigned long long) * CHAR_BIT;
int s = m1 < 0 ? -1 : 1;
value_ = std::ldexp(m1 + s * std::ldexp(T(m0), -static_cast<int>(n -
std::__clz(m0)/4*4)), exp);
}
operator T() const {return value_;}
};
#endif