libcruft-util/float.cpp

98 lines
2.6 KiB
C++

#include "float.hpp"
#include <cmath>
using namespace std;
/* Constructors */
template <unsigned int E, unsigned int S>
ieee_float<E, S>::ieee_float (void)
{ ; }
template <unsigned int E, unsigned int S>
ieee_float<E, S>::ieee_float (floating_t _floating):
m_floating (_floating)
{ ; }
template <unsigned int E, unsigned int S>
ieee_float<E, S>::ieee_float (const ieee_float &rhs):
m_bits (rhs.m_bits)
{ ; }
/* Classifiers */
template <unsigned int E, unsigned int S>
bool
ieee_float<E, S>::is_zero (void) const {
return m_components.exponent == 0 &&
m_components.significand == 0;
}
template <unsigned int E, unsigned int S>
bool
ieee_float<E, S>::is_subnormal (void) const {
return m_components.exponent == 0 &&
m_components.significand != 0;
}
template <unsigned int E, unsigned int S>
bool
ieee_float<E, S>::is_inifinity (void) const {
return m_components.exponent == (1 << EXPONENT_BITS) - 1 &&
m_components.significand == 0;
}
template <unsigned int E, unsigned int S>
bool
ieee_float<E, S>::is_nan (void) const {
return m_components.exponent == (1 << EXPONENT_BITS) - 1 &&
m_components.significand != 0;
}
template <unsigned int E, unsigned int S>
bool
ieee_float<E, S>::operator==(floating_t _floating) const {
// TODO: This method really shouldn't be generated if there's no
// representative native floating point type. But I'm sick of
// C++'s template bullshit for tonight.
CHECK_HARD (bits_type<TOTAL_BITS>::has_floating);
union {
floating_t _floating;
uint_t _uint;
} convertor;
convertor._floating = _floating;
return m_bits == convertor._uint;
}
#include <iostream>
template <unsigned int E, unsigned int S>
bool
ieee_float<E, S>::almost_equal (floating_t a,
floating_t b) {
// Static cast to avoid integer casting warnings when using uint16_t for half
static const floating_t epsilon = static_cast<floating_t> (0.001);
const floating_t diff = static_cast<floating_t> (std::fabs (a - b));
// * Use an exact equality first so that infinities are not indirectly compared. This would generate NaNs in the diff.
// * Do not use gte or lte. This stops an infinite from making infinities on both sides of the inequality.
return exactly_equal (a, b) ||
diff < epsilon * std::fabs (a) ||
diff < epsilon * std::fabs (b);
}
template class ieee_float< 5, 10>; // ieee_half
template class ieee_float< 8, 23>; // ieee_single;
template class ieee_float<11, 52>; // ieee_double;