#ifndef HEXFLOAT_H
#define HEXFLOAT_H
-#include <algorithm>
#include <cmath>
#include <climits>
class hexfloat
{
T value_;
+
+ static int CountLeadingZeros(unsigned long long n) {
+ const std::size_t Digits = sizeof(unsigned long long) * CHAR_BIT;
+ const unsigned long long TopBit = 1ull << (Digits - 1);
+ if (n == 0) return Digits;
+ int LeadingZeros = 0;
+ while ((n & TopBit) == 0) {
+ ++LeadingZeros;
+ n <<= 1;
+ }
+ return LeadingZeros;
+ }
+
public:
hexfloat(long long m1, unsigned long long m0, int exp)
{
- const std::size_t n = sizeof(unsigned long long) * CHAR_BIT;
+ const std::size_t Digits = 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);
+ int exp2 = -static_cast<int>(Digits - CountLeadingZeros(m0)/4*4);
+ value_ = std::ldexp(m1 + s * std::ldexp(T(m0), exp2), exp);
}
operator T() const {return value_;}