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Diffstat (limited to 'src/systemc/ext/dt/fx/scfx_ieee.hh')
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diff --git a/src/systemc/ext/dt/fx/scfx_ieee.hh b/src/systemc/ext/dt/fx/scfx_ieee.hh new file mode 100644 index 000000000..a1c5ac6a8 --- /dev/null +++ b/src/systemc/ext/dt/fx/scfx_ieee.hh @@ -0,0 +1,613 @@ +/***************************************************************************** + + Licensed to Accellera Systems Initiative Inc. (Accellera) under one or + more contributor license agreements. See the NOTICE file distributed + with this work for additional information regarding copyright ownership. + Accellera licenses this file to you 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. + + *****************************************************************************/ + +/***************************************************************************** + + scfx_ieee.h - + + Original Author: Martin Janssen, Synopsys, Inc. + + *****************************************************************************/ + +/***************************************************************************** + + MODIFICATION LOG - modifiers, enter your name, affiliation, date and + changes you are making here. + + Name, Affiliation, Date: + Description of Modification: + + *****************************************************************************/ + +// $Log: scfx_ieee.h,v $ +// Revision 1.3 2011/08/24 22:05:43 acg +// Torsten Maehne: initialization changes to remove warnings. +// +// Revision 1.2 2011/08/07 18:55:24 acg +// Philipp A. Hartmann: added guard for __clang__ to get the clang platform +// working. +// +// Revision 1.1.1.1 2006/12/15 20:20:04 acg +// SystemC 2.3 +// +// Revision 1.3 2006/01/13 18:53:58 acg +// Andy Goodrich: added $Log command so that CVS comments are reproduced in +// the source. +// + +#ifndef __SYSTEMC_EXT_DT_FX_SCFX_IEEE_HH__ +#define __SYSTEMC_EXT_DT_FX_SCFX_IEEE_HH__ + +#include "../../utils/endian.hh" +#include "sc_fxdefs.hh" + +namespace sc_dt +{ + +// classes defined in this module +union ieee_double; +class scfx_ieee_double; +union ieee_float; +class scfx_ieee_float; + +#define SCFX_MASK_(Size) ((1u << (Size))-1u) + +// ---------------------------------------------------------------------------- +// UNION : ieee_double +// +// IEEE 754 double-precision format. +// ---------------------------------------------------------------------------- + +union ieee_double +{ + double d; + + struct + { +#if defined(SC_BOOST_BIG_ENDIAN) + unsigned negative:1; + unsigned exponent:11; + unsigned mantissa0:20; + unsigned mantissa1:32; +#elif defined(SC_BOOST_LITTLE_ENDIAN) + unsigned mantissa1:32; + unsigned mantissa0:20; + unsigned exponent:11; + unsigned negative:1; +#endif + } s; +}; + + +const unsigned int SCFX_IEEE_DOUBLE_BIAS = 1023U; + +const int SCFX_IEEE_DOUBLE_E_MAX = 1023; +const int SCFX_IEEE_DOUBLE_E_MIN = -1022; + +const unsigned int SCFX_IEEE_DOUBLE_M_SIZE = 52; +const unsigned int SCFX_IEEE_DOUBLE_M0_SIZE = 20; +const unsigned int SCFX_IEEE_DOUBLE_M1_SIZE = 32; +const unsigned int SCFX_IEEE_DOUBLE_E_SIZE = 11; + + +// ---------------------------------------------------------------------------- +// CLASS : scfx_ieee_double +// +// Convenient interface to union ieee_double. +// ---------------------------------------------------------------------------- + +class scfx_ieee_double +{ + ieee_double m_id; + public: + scfx_ieee_double(); + scfx_ieee_double(double); + scfx_ieee_double(const scfx_ieee_double &); + + scfx_ieee_double &operator = (double); + scfx_ieee_double &operator = (const scfx_ieee_double &); + + operator double() const; + + unsigned int negative() const; + void negative(unsigned int); + int exponent() const; + void exponent(int); + unsigned int mantissa0() const; + void mantissa0(unsigned int); + unsigned int mantissa1() const; + void mantissa1(unsigned int); + + bool is_zero() const; + bool is_subnormal() const; + bool is_normal() const; + bool is_inf() const; + bool is_nan() const; + + void set_inf(); + void set_nan(); + + int msb() const; // most significant non-zero bit + int lsb() const; // least significant non-zero bit + + static const scfx_ieee_double nan(); + static const scfx_ieee_double inf(int); +}; + + +// IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII + +inline scfx_ieee_double::scfx_ieee_double() : m_id() +{ + m_id.d = 0.0; +} + +inline scfx_ieee_double::scfx_ieee_double(double d) : m_id() +{ + m_id.d = d; +} + +inline scfx_ieee_double::scfx_ieee_double(const scfx_ieee_double &a) : + m_id(a.m_id) +{ + // m_id.d = a.m_id.d; +} + +inline scfx_ieee_double & +scfx_ieee_double::operator = (double d) +{ + m_id.d = d; + return *this; +} + +inline scfx_ieee_double & +scfx_ieee_double::operator = (const scfx_ieee_double &a) +{ + m_id.d = a.m_id.d; + return *this; +} + +inline scfx_ieee_double::operator double() const +{ + return m_id.d; +} + +inline unsigned int +scfx_ieee_double::negative() const +{ + return m_id.s.negative; +} + +inline void +scfx_ieee_double::negative(unsigned int a) +{ + m_id.s.negative = a & SCFX_MASK_(1); +} + +inline int +scfx_ieee_double::exponent() const +{ + return m_id.s.exponent - SCFX_IEEE_DOUBLE_BIAS; +} + +inline void +scfx_ieee_double::exponent(int a) +{ + m_id.s.exponent = (SCFX_IEEE_DOUBLE_BIAS + a) + & SCFX_MASK_(SCFX_IEEE_DOUBLE_E_SIZE); +} + +inline unsigned int +scfx_ieee_double::mantissa0() const +{ + return m_id.s.mantissa0; +} + +inline void +scfx_ieee_double::mantissa0(unsigned int a) +{ + m_id.s.mantissa0 = a & SCFX_MASK_(SCFX_IEEE_DOUBLE_M0_SIZE); +} + +inline unsigned int +scfx_ieee_double::mantissa1() const +{ + return m_id.s.mantissa1; +} + +inline void +scfx_ieee_double::mantissa1(unsigned int a) +{ + m_id.s.mantissa1 = a; // & SCFX_MASK_(SCFX_IEEE_DOUBLE_M1_SIZE); +} + +inline bool +scfx_ieee_double::is_zero() const +{ + return (exponent() == SCFX_IEEE_DOUBLE_E_MIN - 1 && + mantissa0() == 0U && mantissa1() == 0U); +} + +inline bool +scfx_ieee_double::is_subnormal() const +{ + return (exponent() == SCFX_IEEE_DOUBLE_E_MIN - 1 && + (mantissa0() != 0U || mantissa1() != 0U)); +} + +inline bool +scfx_ieee_double::is_normal() const +{ + return (exponent() >= SCFX_IEEE_DOUBLE_E_MIN && + exponent() <= SCFX_IEEE_DOUBLE_E_MAX); +} + +inline bool +scfx_ieee_double::is_inf() const +{ + return (exponent() == SCFX_IEEE_DOUBLE_E_MAX + 1 && + mantissa0() == 0U && mantissa1() == 0U); +} + +inline bool +scfx_ieee_double::is_nan() const +{ + return (exponent() == SCFX_IEEE_DOUBLE_E_MAX + 1 && + (mantissa0() != 0U || mantissa1() != 0U)); +} + +inline void +scfx_ieee_double::set_inf() +{ + exponent(SCFX_IEEE_DOUBLE_E_MAX + 1); + mantissa0(0U); + mantissa1(0U); +} + +inline void +scfx_ieee_double::set_nan() +{ + exponent(SCFX_IEEE_DOUBLE_E_MAX + 1); + mantissa0((unsigned int)-1); + mantissa1((unsigned int)-1); +} + +#define MSB_STATEMENT(x,n) if ( x >> n ) { x >>= n; i += n; } + +inline int +scfx_ieee_double::msb() const +{ + unsigned int m0 = mantissa0(); + unsigned int m1 = mantissa1(); + if (m0 != 0) { + int i = 0; + MSB_STATEMENT(m0, 16); + MSB_STATEMENT(m0, 8); + MSB_STATEMENT(m0, 4); + MSB_STATEMENT(m0, 2); + MSB_STATEMENT(m0, 1); + return (i - 20); + } else if (m1 != 0) { + int i = 0; + MSB_STATEMENT(m1, 16); + MSB_STATEMENT(m1, 8); + MSB_STATEMENT(m1, 4); + MSB_STATEMENT(m1, 2); + MSB_STATEMENT(m1, 1); + return (i - 52); + } else { + return 0; + } +} + +#undef MSB_STATEMENT + +#define LSB_STATEMENT(x,n) if ( x << n ) { x <<= n; i -= n; } + +inline int +scfx_ieee_double::lsb() const +{ + unsigned int m0 = mantissa0(); + unsigned int m1 = mantissa1(); + if (m1 != 0) { + int i = 31; + LSB_STATEMENT(m1, 16); + LSB_STATEMENT(m1, 8); + LSB_STATEMENT(m1, 4); + LSB_STATEMENT(m1, 2); + LSB_STATEMENT(m1, 1); + return (i - 52); + } else if (m0 != 0) { + int i = 31; + LSB_STATEMENT(m0, 16); + LSB_STATEMENT(m0, 8); + LSB_STATEMENT(m0, 4); + LSB_STATEMENT(m0, 2); + LSB_STATEMENT(m0, 1); + return (i - 20); + } else { + return 0; + } +} + +#undef LSB_STATEMENT + +inline const scfx_ieee_double +scfx_ieee_double::nan() +{ + scfx_ieee_double id; + id.set_nan(); + return id; +} + +inline const scfx_ieee_double +scfx_ieee_double::inf(int sign) +{ + scfx_ieee_double id(sign); + id.set_inf(); + return id; +} + + +// ---------------------------------------------------------------------------- +// UNION : ieee_float +// +// IEEE 754 single-precision format. +// ---------------------------------------------------------------------------- + +union ieee_float +{ + float f; + struct + { +#if defined(SC_BOOST_BIG_ENDIAN) + unsigned negative:1; + unsigned exponent:8; + unsigned mantissa:23; +#elif defined(SC_BOOST_LITTLE_ENDIAN) + unsigned mantissa:23; + unsigned exponent:8; + unsigned negative:1; +#endif + } s; +}; + + +const unsigned int SCFX_IEEE_FLOAT_BIAS = 127U; + +const int SCFX_IEEE_FLOAT_E_MAX = 127; +const int SCFX_IEEE_FLOAT_E_MIN = -126; + +const unsigned int SCFX_IEEE_FLOAT_M_SIZE = 23; +const unsigned int SCFX_IEEE_FLOAT_E_SIZE = 8; + + +// ---------------------------------------------------------------------------- +// CLASS : scfx_ieee_float +// +// Convenient wrapper to union ieee_float. +// ---------------------------------------------------------------------------- + +class scfx_ieee_float +{ + ieee_float m_if; + + public: + scfx_ieee_float(); + scfx_ieee_float(float); + scfx_ieee_float(const scfx_ieee_float &); + + scfx_ieee_float &operator = (float); + scfx_ieee_float &operator = (const scfx_ieee_float &); + + operator float() const; + + unsigned int negative() const; + void negative(unsigned int); + int exponent() const; + void exponent(int); + unsigned int mantissa() const; + void mantissa(unsigned int); + + bool is_zero() const; + bool is_subnormal() const; + bool is_normal() const; + bool is_inf() const; + bool is_nan() const; + + void set_inf(); + void set_nan(); +}; + + +// IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII + +inline scfx_ieee_float::scfx_ieee_float() : m_if() +{ + m_if.f = 0.0; +} + +inline scfx_ieee_float::scfx_ieee_float(float f) : m_if() +{ + m_if.f = f; +} + +inline scfx_ieee_float::scfx_ieee_float(const scfx_ieee_float &a) : + m_if(a.m_if) +{ + // m_if.f = a.m_if.f; +} + + +inline scfx_ieee_float & +scfx_ieee_float::operator = (float f) +{ + m_if.f = f; + return *this; +} + +inline scfx_ieee_float & +scfx_ieee_float::operator = (const scfx_ieee_float &a) +{ + m_if.f = a.m_if.f; + return *this; +} + +inline scfx_ieee_float::operator float() const +{ + return m_if.f; +} + +inline unsigned int +scfx_ieee_float::negative() const +{ + return m_if.s.negative; +} + +inline void +scfx_ieee_float::negative(unsigned int a) +{ + m_if.s.negative = a & SCFX_MASK_(1); +} + +inline int +scfx_ieee_float::exponent() const +{ + return m_if.s.exponent - SCFX_IEEE_FLOAT_BIAS; +} + +inline void +scfx_ieee_float::exponent(int a) +{ + m_if.s.exponent = (SCFX_IEEE_FLOAT_BIAS + a) & + SCFX_MASK_(SCFX_IEEE_FLOAT_E_SIZE); +} + +inline unsigned int +scfx_ieee_float::mantissa() const +{ + return m_if.s.mantissa; +} + +inline void +scfx_ieee_float::mantissa(unsigned int a) +{ + m_if.s.mantissa = a & SCFX_MASK_(SCFX_IEEE_FLOAT_M_SIZE); +} + + +inline bool +scfx_ieee_float::is_zero() const +{ + return (exponent() == SCFX_IEEE_FLOAT_E_MIN - 1 && mantissa() == 0U); +} + +inline bool +scfx_ieee_float::is_subnormal() const +{ + return (exponent() == SCFX_IEEE_FLOAT_E_MIN - 1 && mantissa() != 0U); +} + +inline bool +scfx_ieee_float::is_normal() const +{ + return (exponent() >= SCFX_IEEE_FLOAT_E_MIN && + exponent() <= SCFX_IEEE_FLOAT_E_MAX); +} + +inline bool +scfx_ieee_float::is_inf() const +{ + return (exponent() == SCFX_IEEE_FLOAT_E_MAX + 1 && mantissa() == 0U); +} + +inline bool +scfx_ieee_float::is_nan() const +{ + return (exponent() == SCFX_IEEE_FLOAT_E_MAX + 1 && mantissa() != 0U); +} + +inline void +scfx_ieee_float::set_inf() +{ + exponent(SCFX_IEEE_FLOAT_E_MAX + 1); + mantissa(0U); +} + +inline void +scfx_ieee_float::set_nan() +{ + exponent(SCFX_IEEE_FLOAT_E_MAX + 1); + mantissa((unsigned int)-1); +} + + +// ---------------------------------------------------------------------------- +// FUNCTION : scfx_pow2 +// +// Computes 2.0**exp in double-precision. +// ---------------------------------------------------------------------------- + +inline double +scfx_pow2(int exp) +{ + scfx_ieee_double r; + if (exp < SCFX_IEEE_DOUBLE_E_MIN) { + r = 0.0; + // handle subnormal case + exp -= SCFX_IEEE_DOUBLE_E_MIN; + if ((exp += 20) >= 0) { + r.mantissa0(1U << exp); + } else if ((exp += 32) >= 0) { + r.mantissa1(1U << exp); + } + } else if (exp > SCFX_IEEE_DOUBLE_E_MAX) { + r.set_inf(); + } else { + r = 1.0; + r.exponent(exp); + } + return r; +} + + +// ---------------------------------------------------------------------------- +// FUNCTION : uint64_to_double +// +// Platform independent conversion from double uint64 to double. +// Needed because VC++6 doesn't support this conversion. +// ---------------------------------------------------------------------------- + +inline double +uint64_to_double(uint64 a) +{ +#if defined(__clang__) + // conversion from uint64 to double not implemented; use int64 + double tmp = static_cast<double>(static_cast<int64>(a)); + return (tmp >= 0) ? tmp : tmp + sc_dt::scfx_pow2(64); +#else + return static_cast<double>(a); +#endif +} + +} // namespace sc_dt + +#undef SCFX_MASK_ + +#endif // __SYSTEMC_EXT_DT_FX_SCFX_IEEE_HH__ |