libcruft-util/float.hpp

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/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Copyright 2011 Danny Robson <danny@nerdcruft.net>
*/
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#ifndef __FLOAT_HPP
#define __FLOAT_HPP
#include "types/bits.hpp"
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///////////////////////////////////////////////////////////////////////////////
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template <unsigned int EXPONENT, unsigned int SIGNIFICAND>
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class ieee_float
{
public:
static const unsigned int EXPONENT_BITS = EXPONENT;
static const unsigned int SIGNIFICAND_BITS = SIGNIFICAND;
static const unsigned int TOTAL_BITS = 1 + EXPONENT + SIGNIFICAND;
static const unsigned int BIAS = (1 << (EXPONENT - 1)) - 1;
typedef typename bits_type<TOTAL_BITS>::sint sint_t;
typedef typename bits_type<TOTAL_BITS>::uint uint_t;
typedef typename bits_type<TOTAL_BITS>::floating floating_t;
protected:
union {
uint_t m_bits;
floating_t m_floating;
struct {
uint_t sign : 1;
uint_t exponent : EXPONENT;
uint_t significand : SIGNIFICAND;
} m_components;
};
public:
ieee_float (void);
ieee_float (floating_t _floating);
ieee_float (const ieee_float &rhs);
static unsigned int bias (void)
{ return BIAS; }
void set_bits (uint_t _bits) { m_bits = _bits; }
uint_t bits (void) const { return m_bits; }
bool negative (void) const { return m_components.sign; }
void negate (void) { m_components.sign ^= m_components.sign; }
bool is_zero (void) const;
bool is_subnormal (void) const;
bool is_inifinity (void) const;
bool is_nan (void) const;
bool operator== (floating_t) const;
static bool almost_equal (floating_t, floating_t);
static bool almost_equal (floating_t, floating_t, unsigned ulps);
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};
typedef ieee_float< 5, 10> ieee_half;
typedef ieee_float< 8, 23> ieee_single;
typedef ieee_float<11, 52> ieee_double;
static_assert (sizeof(ieee_half ) == 2, "ieee_half must be 2 bytes");
static_assert (sizeof(ieee_single ) == 4, "ieee_single must be 4 bytes");
static_assert (sizeof(ieee_double ) == 8, "ieee_double must be 8 bytes");
#endif // __FLOAT_HPP