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/*
* This file is a part of TTMath Mathematical Library
* and is distributed under the (new) BSD licence.
* Author: Tomasz Sowa <t.sowa@slimaczek.pl>
*/
/*
* Copyright (c) 2006-2007, Tomasz Sowa
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* * Neither the name Tomasz Sowa nor the names of contributors to this
* project may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef headerfilettmathbig
#define headerfilettmathbig
/*!
\file ttmathbig.h
\brief A Class for representing floating point numbers
*/
#include "ttmathint.h"
#include <iostream>
namespace ttmath
{
/*!
\brief Big implements the floating point numbers
*/
template <uint exp,uint man>
class Big
{
/*
value = mantissa * 2^exponent
exponent - an integer value with a sign
mantissa - an integer value without a sing
mantissa must be pushed into the left side that is the highest bit from
mantissa must be one (of course if there's another value than zero) -- this job
(pushing bits into the left side) making Standardizing() method
for example:
if we want to store value one (1) into our Big object we must:
set mantissa to 1
set exponent to 0
set info to 0
and call method Standardizing()
*/
public:
Int<exp> exponent;
UInt<man> mantissa;
unsigned char info;
/*!
the number of a bit from 'info' which means that a value is with the sign
(when the bit is set)
*/
#define TTMATH_BIG_SIGN 128
public:
/*!
this method moves all bits from mantissa into its left side
(suitably changes the exponent) or if the mantissa is zero
it sets the exponent as zero as well
it can return a carry
the carry will be when we don't have enough space in the exponent
you don't have to use this method if you don't change the mantissa
and exponent directly
*/
uint Standardizing()
{
if( mantissa.IsTheHighestBitSet() )
return 0;
if( CorrectZero() )
return 0;
uint comp = mantissa.CompensationToLeft();
return exponent.Sub( comp );
}
private:
/*!
if mantissa is equal zero this method sets exponent to zero and
info without the sign
it returns true if there was the correction
*/
bool CorrectZero()
{
if( mantissa.IsZero() )
{
Abs();
exponent.SetZero();
return true;
}
return false;
}
public:
/*!
it sets value zero
*/
void SetZero()
{
info = 0;
exponent.SetZero();
mantissa.SetZero();
/*
we don't have to compensate zero
*/
}
/*!
it sets value one
*/
void SetOne()
{
FromUInt(1);
}
/*!
it sets value 0.5
*/
void Set05()
{
FromUInt(1);
exponent.SubOne();
}
/*!
it sets value pi
*/
void SetPi()
{
// this is a static table which represents the value Pi (mantissa of it)
// (first is the highest word)
// we must define this table as 'unsigned int' because
// both on 32bit and 64bit platforms this table is 32bit
static const unsigned int temp_table[] = {
0xc90fdaa2, 0x2168c234, 0xc4c6628b, 0x80dc1cd1, 0x29024e08, 0x8a67cc74, 0x020bbea6, 0x3b139b22,
0x514a0879, 0x8e3404dd, 0xef9519b3, 0xcd3a431b, 0x302b0a6d, 0xf25f1437, 0x4fe1356d, 0x6d51c245,
0xe485b576, 0x625e7ec6, 0xf44c42e9, 0xa637ed6b, 0x0bff5cb6, 0xf406b7ed, 0xee386bfb, 0x5a899fa5,
0xae9f2411, 0x7c4b1fe6, 0x49286651, 0xece45b3d, 0xc2007cb8, 0xa163bf05, 0x98da4836, 0x1c55d39a,
0x69163fa8, 0xfd24cf5f, 0x83655d23, 0xdca3ad96, 0x1c62f356, 0x208552bb, 0x9ed52907, 0x7096966d,
0x670c354e, 0x4abc9804, 0xf1746c08, 0xca18217c, 0x32905e46, 0x2e36ce3b, 0xe39e772c, 0x180e8603,
0x9b2783a2, 0xec07a28f, 0xb5c55df0, 0x6f4c52c9, 0xde2bcbf6, 0x95581718, 0x3995497c, 0xea956ae5,
0x15d22618, 0x98fa0510, 0x15728e5a, 0x8aaac42d, 0xad33170d, 0x04507a33, 0xa85521ab, 0xdf1cba64,
0xecfb8504, 0x58dbef0a, 0x8aea7157, 0x5d060c7d, 0xb3970f85, 0xa6e1e4c7, 0xabf5ae8c, 0xdb0933d7,
0x1e8c94e0, 0x4a25619d, 0xcee3d226, 0x1ad2ee6b, 0xf12ffa06, 0xd98a0864, 0xd8760273, 0x3ec86a64,
0x521f2b18, 0x177b200c, 0xbbe11757, 0x7a615d6c, 0x770988c0, 0xbad946e2, 0x08e24fa0, 0x74e5ab31,
0x43db5bfc, 0xe0fd108e, 0x4b82d120, 0xa9210801, 0x1a723c12, 0xa787e6d7, 0x88719a10, 0xbdba5b26,
0x99c32718, 0x6af4e23c, 0x1a946834, 0xb6150bda, 0x2583e9ca, 0x2ad44ce8, 0xdbbbc2db, 0x04de8ef9,
0x2e8efc14, 0x1fbecaa6, 0x287c5947, 0x4e6bc05d, 0x99b2964f, 0xa090c3a2, 0x233ba186, 0x515be7ed,
0x1f612970, 0xcee2d7af, 0xb81bdd76, 0x2170481c, 0xd0069127, 0xd5b05aa9, 0x93b4ea98, 0x8d8fddc1,
0x86ffb7dc, 0x90a6c08f, 0x4df435c9, 0x34028492, 0x36c3fab4, 0xd27c7026, 0xc1d4dcb2, 0x602646df // (last one was: 0x602646de)
// 0xc9751e76, ...
// (the last word was rounded up because the next one is 0xc9751e76 -- first bit is one 0xc..)
// 128 32bit words for the mantissa -- about 1232 valid digits (decimal)
};
// the value of PI is comming from the website "Paul's 8192 Digits of Pi"
// http://www.escape.com/~paulg53/math/pi/8192.html
// 2999 digits were taken from this website
// (later they were compared with http://zenwerx.com/pi.php)
// and they were set into Big<1,300> type (using operator=(const char*) on 32bit platform)
// and then the first 128 words were taken into this table
// (TTMATH_BUILTIN_VARIABLES_SIZE on 32bit platform should have the value 128,
// and on 64bit platform value 64 (128/2=64))
mantissa.SetFromTable(temp_table, sizeof(temp_table) / sizeof(int));
exponent = -sint(man)*sint(TTMATH_BITS_PER_UINT) + 2;
info = 0;
}
/*!
it sets value 0.5 * pi
*/
void Set05Pi()
{
SetPi();
exponent = -sint(man)*sint(TTMATH_BITS_PER_UINT) + 1;
}
/*!
it sets value 2 * pi
*/
void Set2Pi()
{
SetPi();
exponent = -sint(man)*sint(TTMATH_BITS_PER_UINT) + 3;
}
/*!
it sets value e
(the base of the natural logarithm)
*/
void SetE()
{
static const unsigned int temp_table[] = {
0xadf85458, 0xa2bb4a9a, 0xafdc5620, 0x273d3cf1, 0xd8b9c583, 0xce2d3695, 0xa9e13641, 0x146433fb,
0xcc939dce, 0x249b3ef9, 0x7d2fe363, 0x630c75d8, 0xf681b202, 0xaec4617a, 0xd3df1ed5, 0xd5fd6561,
0x2433f51f, 0x5f066ed0, 0x85636555, 0x3ded1af3, 0xb557135e, 0x7f57c935, 0x984f0c70, 0xe0e68b77,
0xe2a689da, 0xf3efe872, 0x1df158a1, 0x36ade735, 0x30acca4f, 0x483a797a, 0xbc0ab182, 0xb324fb61,
0xd108a94b, 0xb2c8e3fb, 0xb96adab7, 0x60d7f468, 0x1d4f42a3, 0xde394df4, 0xae56ede7, 0x6372bb19,
0x0b07a7c8, 0xee0a6d70, 0x9e02fce1, 0xcdf7e2ec, 0xc03404cd, 0x28342f61, 0x9172fe9c, 0xe98583ff,
0x8e4f1232, 0xeef28183, 0xc3fe3b1b, 0x4c6fad73, 0x3bb5fcbc, 0x2ec22005, 0xc58ef183, 0x7d1683b2,
0xc6f34a26, 0xc1b2effa, 0x886b4238, 0x611fcfdc, 0xde355b3b, 0x6519035b, 0xbc34f4de, 0xf99c0238,
0x61b46fc9, 0xd6e6c907, 0x7ad91d26, 0x91f7f7ee, 0x598cb0fa, 0xc186d91c, 0xaefe1309, 0x85139270,
0xb4130c93, 0xbc437944, 0xf4fd4452, 0xe2d74dd3, 0x64f2e21e, 0x71f54bff, 0x5cae82ab, 0x9c9df69e,
0xe86d2bc5, 0x22363a0d, 0xabc52197, 0x9b0deada, 0x1dbf9a42, 0xd5c4484e, 0x0abcd06b, 0xfa53ddef,
0x3c1b20ee, 0x3fd59d7c, 0x25e41d2b, 0x669e1ef1, 0x6e6f52c3, 0x164df4fb, 0x7930e9e4, 0xe58857b6,
0xac7d5f42, 0xd69f6d18, 0x7763cf1d, 0x55034004, 0x87f55ba5, 0x7e31cc7a, 0x7135c886, 0xefb4318a,
0xed6a1e01, 0x2d9e6832, 0xa907600a, 0x918130c4, 0x6dc778f9, 0x71ad0038, 0x092999a3, 0x33cb8b7a,
0x1a1db93d, 0x7140003c, 0x2a4ecea9, 0xf98d0acc, 0x0a8291cd, 0xcec97dcf, 0x8ec9b55a, 0x7f88a46b,
0x4db5a851, 0xf44182e1, 0xc68a007e, 0x5e0dd902, 0x0bfd64b6, 0x45036c7a, 0x4e677d2c, 0x38532a3a
//0x23ba4442,...
// 128 32bit words for the mantissa -- about 1232 valid digits (decimal)
};
// above value was calculated using Big<1,300> on 32bit platform
// and then the first 128 words were taken,
// the calculating was made by using ExpSurrounding0(1) method
// which took 1110 iterations
// (TTMATH_BUILTIN_VARIABLES_SIZE on 32bit platform should have the value 128,
// and on 64bit platform value 64 (128/2=64))
mantissa.SetFromTable(temp_table, sizeof(temp_table) / sizeof(int));
exponent = -sint(man)*sint(TTMATH_BITS_PER_UINT) + 2;
info = 0;
}
/*!
it sets value ln(2)
the natural logarithm from value 2
*/
void SetLn2()
{
static const unsigned int temp_table[] = {
0xb17217f7, 0xd1cf79ab, 0xc9e3b398, 0x03f2f6af, 0x40f34326, 0x7298b62d, 0x8a0d175b, 0x8baafa2b,
0xe7b87620, 0x6debac98, 0x559552fb, 0x4afa1b10, 0xed2eae35, 0xc1382144, 0x27573b29, 0x1169b825,
0x3e96ca16, 0x224ae8c5, 0x1acbda11, 0x317c387e, 0xb9ea9bc3, 0xb136603b, 0x256fa0ec, 0x7657f74b,
0x72ce87b1, 0x9d6548ca, 0xf5dfa6bd, 0x38303248, 0x655fa187, 0x2f20e3a2, 0xda2d97c5, 0x0f3fd5c6,
0x07f4ca11, 0xfb5bfb90, 0x610d30f8, 0x8fe551a2, 0xee569d6d, 0xfc1efa15, 0x7d2e23de, 0x1400b396,
0x17460775, 0xdb8990e5, 0xc943e732, 0xb479cd33, 0xcccc4e65, 0x9393514c, 0x4c1a1e0b, 0xd1d6095d,
0x25669b33, 0x3564a337, 0x6a9c7f8a, 0x5e148e82, 0x074db601, 0x5cfe7aa3, 0x0c480a54, 0x17350d2c,
0x955d5179, 0xb1e17b9d, 0xae313cdb, 0x6c606cb1, 0x078f735d, 0x1b2db31b, 0x5f50b518, 0x5064c18b,
0x4d162db3, 0xb365853d, 0x7598a195, 0x1ae273ee, 0x5570b6c6, 0x8f969834, 0x96d4e6d3, 0x30af889b,
0x44a02554, 0x731cdc8e, 0xa17293d1, 0x228a4ef9, 0x8d6f5177, 0xfbcf0755, 0x268a5c1f, 0x9538b982,
0x61affd44, 0x6b1ca3cf, 0x5e9222b8, 0x8c66d3c5, 0x422183ed, 0xc9942109, 0x0bbb16fa, 0xf3d949f2,
0x36e02b20, 0xcee886b9, 0x05c128d5, 0x3d0bd2f9, 0x62136319, 0x6af50302, 0x0060e499, 0x08391a0c,
0x57339ba2, 0xbeba7d05, 0x2ac5b61c, 0xc4e9207c, 0xef2f0ce2, 0xd7373958, 0xd7622658, 0x901e646a,
0x95184460, 0xdc4e7487, 0x156e0c29, 0x2413d5e3, 0x61c1696d, 0xd24aaebd, 0x473826fd, 0xa0c238b9,
0x0ab111bb, 0xbd67c724, 0x972cd18b, 0xfbbd9d42, 0x6c472096, 0xe76115c0, 0x5f6f7ceb, 0xac9f45ae,
0xcecb72f1, 0x9c38339d, 0x8f682625, 0x0dea891e, 0xf07afff3, 0xa892374e, 0x175eb4af, 0xc8daadd9 // (last one was: 0xc8daadd8)
// 0x85db6ab0, ...
// (the last word was rounded up because the next one is 0x85db6ab0 -- first bit is one 0x8..)
// 128 32bit words for the mantissa -- about 1232 valid digits (decimal)
};
// above value was calculated using Big<1,300> on 32bit platform
// and then the first 128 words were taken,
// the calculating was made by using LnSurrounding1(2) method
// which took 3030 iterations
// (TTMATH_BUILTIN_VARIABLES_SIZE on 32bit platform should have the value 128,
// and on 64bit platform value 64 (128/2=64))
mantissa.SetFromTable(temp_table, sizeof(temp_table) / sizeof(int));
exponent = -sint(man)*sint(TTMATH_BITS_PER_UINT);
info = 0;
}
/*!
it sets value ln(10)
the natural logarithm from value 10
I introduced this constant especially to make the conversion ToString()
being faster. In fact the method ToString() is keeping values of logarithms
it has calculated but it must calculate the logarithm at least once.
If a program, which uses this library, is running for a long time this
would be ok, but for programs which are running shorter, for example for
CGI applications which only once are printing values, this would be much
inconvenience. Then if we're printing with base (radix) 10 and the mantissa
of our value is smaller than or equal to TTMATH_BUILTIN_VARIABLES_SIZE
we don't calculate the logarithm but take it from this constant.
*/
void SetLn10()
{
static const unsigned int temp_table[] = {
0x935d8ddd, 0xaaa8ac16, 0xea56d62b, 0x82d30a28, 0xe28fecf9, 0xda5df90e, 0x83c61e82, 0x01f02d72,
0x962f02d7, 0xb1a8105c, 0xcc70cbc0, 0x2c5f0d68, 0x2c622418, 0x410be2da, 0xfb8f7884, 0x02e516d6,
0x782cf8a2, 0x8a8c911e, 0x765aa6c3, 0xb0d831fb, 0xef66ceb0, 0x4ab3c6fa, 0x5161bb49, 0xd219c7bb,
0xca67b35b, 0x23605085, 0x8e93368d, 0x44789c4f, 0x5b08b057, 0xd5ede20f, 0x469ea58e, 0x9305e981,
0xe2478fca, 0xad3aee98, 0x9cd5b42e, 0x6a271619, 0xa47ecb26, 0x978c5d4f, 0xdb1d28ea, 0x57d4fdc0,
0xe40bf3cc, 0x1e14126a, 0x45765cde, 0x268339db, 0xf47fa96d, 0xeb271060, 0xaf88486e, 0xa9b7401e,
0x3dfd3c51, 0x748e6d6e, 0x3848c8d2, 0x5faf1bca, 0xe88047f1, 0x7b0d9b50, 0xa949eaaa, 0xdf69e8a5,
0xf77e3760, 0x4e943960, 0xe38a5700, 0xffde2db1, 0xad6bfbff, 0xd821ba0a, 0x4cb0466d, 0x61ba648e,
0xef99c8e5, 0xf6974f36, 0x3982a78c, 0xa45ddfc8, 0x09426178, 0x19127a6e, 0x3b70fcda, 0x2d732d47,
0xb5e4b1c8, 0xc0e5a10a, 0xaa6604a5, 0x324ec3dc, 0xbc64ea80, 0x6e198566, 0x1f1d366c, 0x20663834,
0x4d5e843f, 0x20642b97, 0x0a62d18e, 0x478f7bd5, 0x8fcd0832, 0x4a7b32a6, 0xdef85a05, 0xeb56323a,
0x421ef5e0, 0xb00410a0, 0xa0d9c260, 0x794a976f, 0xf6ff363d, 0xb00b6b33, 0xf42c58de, 0xf8a3c52d,
0xed69b13d, 0xc1a03730, 0xb6524dc1, 0x8c167e86, 0x99d6d20e, 0xa2defd2b, 0xd006f8b4, 0xbe145a2a,
0xdf3ccbb3, 0x189da49d, 0xbc1261c8, 0xb3e4daad, 0x6a36cecc, 0xb2d5ae5b, 0x89bf752f, 0xb5dfb353,
0xff3065c4, 0x0cfceec8, 0x1be5a9a9, 0x67fddc57, 0xc4b83301, 0x006bf062, 0x4b40ed7a, 0x56c6cdcd,
0xa2d6fe91, 0x388e9e3e, 0x48a93f5f, 0x5e3b6eb4, 0xb81c4a5b, 0x53d49ea6, 0x8e668aea, 0xba83c7f9 // (last one was: 0xba83c7f8)
///0xfb5f06c3, ...
//(the last word was rounded up because the next one is 0xfb5f06c3 -- first bit is one 0xf..)
// 128 32bit words for the mantissa -- about 1232 valid digits (decimal)
};
// above value was calculated using Big<1,300> on 32bit platform
// and then the first 128 32bit words were taken,
// the calculating was made by using LnSurrounding1(10) method
// which took 16555 iterations
// (the formula used in LnSurrounding1(x) converges badly when
// the x is greater than one but in fact we can use it, only the
// number of iterations will be greater)
// (TTMATH_BUILTIN_VARIABLES_SIZE on 32bit platform should have the value 128,
// and on 64bit platform value 64 (128/2=64))
mantissa.SetFromTable(temp_table, sizeof(temp_table) / sizeof(int));
exponent = -sint(man)*sint(TTMATH_BITS_PER_UINT) + 2;
info = 0;
}
/*!
it sets the maximum value which can be held in this type
*/
void SetMax()
{
info = 0;
mantissa.SetMax();
exponent.SetMax();
// we don't have to use 'Standardizing()' because the last bit from
// the mantissa is set
}
/*!
it sets the minimum value which can be held in this type
*/
void SetMin()
{
info = 0;
mantissa.SetMax();
exponent.SetMax();
SetSign();
// we don't have to use 'Standardizing()' because the last bit from
// the mantissa is set
}
/*!
it's testing whether there is a value zero or not
*/
bool IsZero() const
{
/*
we only have to test the mantissa
*/
return mantissa.IsZero();
}
/*!
it returns true when there's the sign set
*/
bool IsSign() const
{
return (info & TTMATH_BIG_SIGN) == TTMATH_BIG_SIGN;
}
/*!
it clears the sign
(there'll be an absolute value)
e.g.
-1 -> 1
2 -> 2
*/
void Abs()
{
info &= ~TTMATH_BIG_SIGN;
}
/*!
it remains the 'sign' of the value
e.g. -2 = 1
0 = 0
10 = 1
*/
void Sgn()
{
if( IsSign() )
{
SetOne();
SetSign();
}
else
if( IsZero() )
SetZero();
else
SetOne();
}
/*!
it sets the sign
e.g.
-1 -> -1
2 -> -2
*/
void SetSign()
{
if( IsZero() )
return;
info |= TTMATH_BIG_SIGN;
}
/*!
it changes the sign
e.g.
-1 -> 1
2 -> -2
*/
void ChangeSign()
{
if( IsZero() )
return;
info = (info & (~TTMATH_BIG_SIGN)) | ((~info) & TTMATH_BIG_SIGN);
}
/*!
*
* basic mathematic functions
*
*/
/*!
Addition this = this + ss2
it returns carry if the sum is too big
*/
uint Add(Big<exp, man> ss2)
{
Int<exp> exp_offset( exponent );
Int<exp> mantissa_size_in_bits( man * TTMATH_BITS_PER_UINT );
uint c = 0;
exp_offset.Sub( ss2.exponent );
exp_offset.Abs();
// abs(this) will be >= abs(ss2)
if( SmallerWithoutSignThan(ss2) )
{
Big<exp, man> temp(ss2);
ss2 = *this;
*this = temp;
}
if( exp_offset > mantissa_size_in_bits )
{
// the second value is too short for taking into consideration in the sum
return 0;
}
else
if( exp_offset < mantissa_size_in_bits )
{
// moving 'exp_offset' times
ss2.mantissa.Rcr( exp_offset.ToInt(), 0 );
}
else
{
// exp_offset == mantissa_size_in_bits
// we're rounding 'this' about one (up or down depending on a ss2 sign)
ss2.mantissa.SetOne();
}
if( IsSign() == ss2.IsSign() )
{
// values have the same signs
if( mantissa.Add(ss2.mantissa) )
{
mantissa.Rcr(1);
c = exponent.AddOne();
}
}
else
{
// values have different signs
if( mantissa.Sub(ss2.mantissa) )
{
mantissa.Rcl(1);
c = exponent.SubOne();
}
}
c += Standardizing();
return (c==0)? 0 : 1;
}
/*!
Subtraction this = this - ss2
it returns carry if the result is too big
*/
uint Sub(Big<exp, man> ss2)
{
ss2.ChangeSign();
return Add(ss2);
}
/*!
multiplication this = this * ss2
this method returns carry
*/
uint Mul(const Big<exp, man> & ss2)
{
TTMATH_REFERENCE_ASSERT( ss2 )
UInt<man*2> man_result;
uint i,c;
// man_result = mantissa * ss2.mantissa
mantissa.MulBig(ss2.mantissa, man_result);
// 'i' will be from 0 to man*TTMATH_BITS_PER_UINT
// because mantissa and ss2.mantissa are standardized
// (the highest bit in man_result is set to 1 or
// if there is a zero value in man_result the method CompensationToLeft()
// returns 0 but we'll correct this at the end in Standardizing() method)
i = man_result.CompensationToLeft();
c = exponent.Add( man * TTMATH_BITS_PER_UINT - i );
c += exponent.Add( ss2.exponent );
for(i=0 ; i<man ; ++i)
mantissa.table[i] = man_result.table[i+man];
if( IsSign() == ss2.IsSign() )
{
// the signs are the same, the result is positive
Abs();
}
else
{
// the signs are different, the result is negative
SetSign();
}
c += Standardizing();
return (c==0)? 0 : 1;
}
/*!
division this = this / ss2
this method returns carry (in a division carry can be as well)
(it also returns 0 if ss2 is zero)
*/
uint Div(const Big<exp, man> & ss2)
{
TTMATH_REFERENCE_ASSERT( ss2 )
UInt<man*2> man1;
UInt<man*2> man2;
uint i,c;
if( ss2.IsZero() )
{
// we don't divide by zero
return 1;
}
for(i=0 ; i<man ; ++i)
{
man1.table[i+man] = mantissa.table[i];
man2.table[i] = ss2.mantissa.table[i];
}
for(i=0 ; i<man ; ++i)
{
man1.table[i] = 0;
man2.table[i+man] = 0;
}
man1.Div(man2);
i = man1.CompensationToLeft();
c = exponent.Sub(i);
c += exponent.Sub(ss2.exponent);
for(i=0 ; i<man ; ++i)
mantissa.table[i] = man1.table[i+man];
if( IsSign() == ss2.IsSign() )
Abs();
else
SetSign();
c += Standardizing();
return (c==0)? 0 : 1;
}
/*!
the remainder from the division
e.g.
12.6 mod 3 = 0.6 because 12.6 = 3*4 + 0.6
-12.6 mod 3 = -0.6
12.6 mod -3 = 0.6
-12.6 mod -3 = -0.6
it means:
in other words: this(old) = ss2 * q + this(new)(result)
*/
uint Mod(const Big<exp, man> & ss2)
{
TTMATH_REFERENCE_ASSERT( ss2 )
uint c = 0;
Big<exp, man> temp(*this);
c += temp.Div(ss2);
temp.SkipFraction();
c += temp.Mul(ss2);
c += Sub(temp);
return (c==0)? 0 : 1;
}
/*!
power this = this ^ pow
pow without a sign
binary algorithm (r-to-l)
*/
template<uint pow_size>
uint PowUInt(UInt<pow_size> pow)
{
if(pow.IsZero() && IsZero())
// we don't define zero^zero
return 1;
Big<exp, man> start(*this);
Big<exp, man> result;
result.SetOne();
while( !pow.IsZero() )
{
if( pow.table[0] & 1 )
if( result.Mul(start) )
return 1;
if( start.Mul(start) )
return 1;
pow.Rcr();
}
*this = result;
return 0;
}
/*!
power this = this ^ pow
p can be with a sign
p can be negative
*/
template<uint pow_size>
uint PowInt(Int<pow_size> pow)
{
if( !pow.IsSign() )
return PowUInt(pow);
if( IsZero() )
// if 'p' is negative then
// 'this' must be different from zero
return 1;
if( pow.ChangeSign() )
return 1;
Big<exp, man> t(*this);
if( t.PowUInt(pow) )
return 1;
SetOne();
if( Div(t) )
return 1;
return 0;
}
/*!
this method returns true if 'this' mod 2 is equal one
*/
bool Mod2() const
{
if( exponent>sint(0) || exponent<=-sint(man*TTMATH_BITS_PER_UINT) )
return false;
sint exp_int = exponent.ToInt();
// 'exp_int' is negative (or zero), we set its as positive
exp_int = -exp_int;
// !!! here we'll use a new method (method for testing a bit)
uint value = mantissa.table[ exp_int / TTMATH_BITS_PER_UINT ];
value >>= (uint(exp_int) % TTMATH_BITS_PER_UINT);
return bool(value & 1);
}
/*!
power this = this ^ abs([pow])
pow without a sign and without a fraction
*/
uint PowBUInt(Big<exp, man> pow)
{
if( pow.IsZero() && IsZero() )
return 1;
if( pow.IsSign() )
pow.Abs();
Big<exp, man> start(*this), start_temp;
Big<exp, man> result;
Big<exp, man> one;
Int<exp> e_one;
e_one.SetOne();
one.SetOne();
result.SetOne();
while( pow >= one )
{
if( pow.Mod2() )
if( result.Mul(start) )
return 1;
start_temp = start;
if( start.Mul(start_temp) )
return 1;
pow.exponent.Sub( e_one );
}
*this = result;
return 0;
}
/*!
power this = this ^ [pow]
pow without a fraction
pow can be negative
*/
uint PowBInt(const Big<exp, man> & pow)
{
TTMATH_REFERENCE_ASSERT( pow )
if( !pow.IsSign() )
return PowBUInt(pow);
if( IsZero() )
// if 'pow' is negative then
// 'this' must be different from zero
return 1;
Big<exp, man> temp(*this);
if( temp.PowBUInt(pow) )
return 1;
SetOne();
if( Div(temp) )
return 1;
return 0;
}
/*!
power this = this ^ pow
this *must* be greater than zero (this > 0)
pow can be negative and with fraction
return values:
1 - carry
2 - incorrect argument ('this')
*/
uint PowFrac(const Big<exp, man> & pow)
{
TTMATH_REFERENCE_ASSERT( pow )
Big<exp, man> temp;
uint c = temp.Ln(*this);
c += temp.Mul(pow);
c += Exp(temp);
return (c==0)? 0 : 1;
}
/*!
power this = this ^ pow
pow can be negative and with fraction
return values:
1 - carry
2 - incorrect argument ('this' or 'pow')
*/
uint Pow(const Big<exp, man> & pow)
{
TTMATH_REFERENCE_ASSERT( pow )
if( IsZero() )
{
// 0^pow will be 0 only for pow>0
if( pow.IsSign() || pow.IsZero() )
return 2;
SetZero();
return 0;
}
Big<exp, man> pow_frac( pow );
pow_frac.RemainFraction();
if( pow_frac.IsZero() )
return PowBInt( pow );
// pow is with fraction (not integer)
// result = e^(pow * ln(this) ) where 'this' must be greater than 0
return PowFrac(pow);
}
private:
/*!
Exponent this = exp(x) = e^x where x is in (-1,1)
we're using the formula exp(x) = 1 + (x)/(1!) + (x^2)/(2!) + (x^3)/(3!) + ...
*/
void ExpSurrounding0(const Big<exp,man> & x)
{
TTMATH_REFERENCE_ASSERT( x )
Big<exp,man> denominator, denominator_i;
Big<exp,man> one, old_value, next_part;
Big<exp,man> numerator = x;
SetOne();
one.SetOne();
denominator.SetOne();
denominator_i.SetOne();
// this is only to avoid getting a warning about an uninitialized object
// gcc 4.1.2 reports: 'old_value.info' may be used uninitialized in this function
// (in fact we will initialize it later when the condition 'testing' is fulfilled)
old_value.info = 0;
// every 'step_test' times we make a test
const uint step_test = 5;
// we begin from 1 in order to not testing at the start
for(uint i=1 ; i<=TTMATH_ARITHMETIC_MAX_LOOP ; ++i)
{
bool testing = ((i % step_test) == 0);
if( testing )
old_value = *this;
next_part = numerator;
if( next_part.Div( denominator ) )
// if there is a carry here we only break the loop
// however the result we return as good
// it means there are too many parts of the formula
break;
// there shouldn't be a carry here
Add( next_part );
if( testing && old_value==*this )
// we've added a next part of the formula but the result
// is still the same then we break the loop
break;
// we set the denominator and the numerator for a next part of the formula
if( denominator_i.Add(one) )
// if there is a carry here the result we return as good
break;
if( denominator.Mul(denominator_i) )
break;
if( numerator.Mul(x) )
break;
}
}
public:
/*!
Exponent this = exp(x) = e^x
we're using the fact that our value is stored in form of:
x = mantissa * 2^exponent
then
e^x = e^(mantissa* 2^exponent) or
e^x = (e^mantissa)^(2^exponent)
'Exp' returns a carry if we can't count the result ('x' is too big)
*/
uint Exp(const Big<exp,man> & x)
{
uint c = 0;
if( x.IsZero() )
{
SetOne();
return 0;
}
// m will be the value of the mantissa in range (-1,1)
Big<exp,man> m(x);
m.exponent = -sint(man*TTMATH_BITS_PER_UINT);
// 'e_' will be the value of '2^exponent'
// e_.mantissa.table[man-1] = TTMATH_UINT_HIGHEST_BIT; and
// e_.exponent.Add(1) mean:
// e_.mantissa.table[0] = 1;
// e_.Standardizing();
// e_.exponent.Add(man*TTMATH_BITS_PER_UINT)
// (we must add 'man*TTMATH_BITS_PER_UINT' because we've taken it from the mantissa)
Big<exp,man> e_(x);
e_.mantissa.SetZero();
e_.mantissa.table[man-1] = TTMATH_UINT_HIGHEST_BIT;
c += e_.exponent.Add(1);
e_.Abs();
/*
now we've got:
m - the value of the mantissa in range (-1,1)
e_ - 2^exponent
e_ can be as:
...2^-2, 2^-1, 2^0, 2^1, 2^2 ...
...1/4 , 1/2 , 1 , 2 , 4 ...
above one e_ is integer
if e_ is greater than 1 we calculate the exponent as:
e^(m * e_) = ExpSurrounding0(m) ^ e_
and if e_ is smaller or equal one we calculate the exponent in this way:
e^(m * e_) = ExpSurrounding0(m* e_)
because if e_ is smaller or equal 1 then the product of m*e_ is smaller or equal m
*/
if( e_ <= 1 )
{
m.Mul(e_);
ExpSurrounding0(m);
}
else
{
ExpSurrounding0(m);
c += PowBUInt(e_);
}
return (c==0)? 0 : 1;
}
private:
/*!
Natural logarithm this = ln(x) where x in range <1,2)
we're using the formula:
ln x = 2 * [ (x-1)/(x+1) + (1/3)((x-1)/(x+1))^3 + (1/5)((x-1)/(x+1))^5 + ... ]
*/
void LnSurrounding1(const Big<exp,man> & x)
{
Big<exp,man> old_value, next_part, denominator, one, two, x1(x), x2(x);
one.SetOne();
if( x == one )
{
// LnSurrounding1(1) is 0
SetZero();
return;
}
two = 2;
x1.Sub(one);
x2.Add(one);
x1.Div(x2);
x2 = x1;
x2.Mul(x1);
denominator.SetOne();
SetZero();
// this is only to avoid getting a warning about an uninitialized object
// gcc 4.1.2 reports: 'old_value.info' may be used uninitialized in this function
// (in fact we will initialize it later when the condition 'testing' is fulfilled)
old_value.info = 0;
// every 'step_test' times we make a test
const uint step_test = 5;
// we begin from 1 in order to not testing at the beginning
for(uint i=1 ; i<=TTMATH_ARITHMETIC_MAX_LOOP ; ++i)
{
bool testing = ((i % step_test) == 0);
next_part = x1;
if( next_part.Div(denominator) )
// if there is a carry here we only break the loop
// however the result we return as good
// it means there are too many parts of the formula
break;
if( testing )
old_value = *this;
// there shouldn't be a carry here
Add(next_part);
if( testing && old_value == *this )
// we've added next (step_test) parts of the formula but the result
// is still the same then we break the loop
break;
if( x1.Mul(x2) )
// if there is a carry here the result we return as good
break;
if( denominator.Add(two) )
break;
}
// this = this * 2
// ( there can't be a carry here because we calculate the logarithm between <1,2) )
exponent.AddOne();
}
public:
/*!
Natural logarithm this = ln(x)
(a logarithm with the base equal 'e')
we're using the fact that our value is stored in form of:
x = mantissa * 2^exponent
then
ln(x) = ln (mantissa * 2^exponent) = ln (mantissa) + (exponent * ln (2))
the mantissa we'll show as a value from range <1,2) because the logarithm
is decreasing too fast when 'x' is going to 0
return values:
0 - ok
1 - overflow
2 - incorrect argument (x<=0)
parts: look at the LnSurrounding1() method
*/
uint Ln(const Big<exp,man> & x)
{
TTMATH_REFERENCE_ASSERT( x )
if( x.IsSign() || x.IsZero() )
return 2;
// m will be the value of the mantissa in range <1,2)
Big<exp,man> m(x);
m.exponent = -sint(man*TTMATH_BITS_PER_UINT - 1);
LnSurrounding1(m);
Big<exp,man> exponent_temp;
exponent_temp.FromInt( x.exponent );
// we must add 'man*TTMATH_BITS_PER_UINT-1' because we've taken it from the mantissa
uint c = exponent_temp.Add(man*TTMATH_BITS_PER_UINT-1);
Big<exp,man> ln2;
ln2.SetLn2();
c += exponent_temp.Mul(ln2);
c += Add(exponent_temp);
return (c==0)? 0 : 1;
}
/*!
Logarithm with a base 'base' -- this = Log(x) with a base 'base'
we're using the formula:
Log(x) with 'base' = ln(x) / ln(base)
return values:
0 - ok
1 - overflow
2 - incorrect argument (x<=0)
3 - incorrect base (a<=0 lub a=1)
parts: look at the LnSurrounding1() method
we pass this value only into 'ln(x)' method
because if we passed 'parts' into 'ln(base)' as well then
the error (after dividing) would be too great
*/
uint Log(const Big<exp,man> & x, const Big<exp,man> & base)
{
TTMATH_REFERENCE_ASSERT( base )
TTMATH_REFERENCE_ASSERT( x )
if( x.IsSign() || x.IsZero() )
return 2;
Big<exp,man> denominator;;
denominator.SetOne();
if( base.IsSign() || base.IsZero() || base==denominator )
return 3;
if( x == denominator ) // (this is: if x == 1)
{
// log(1) is 0
SetZero();
return 0;
}
// another error values we've tested at the start
// there can be only a carry
uint c = Ln(x);
// we don't pass the 'parts' here (the error after dividing would be to great)
c += denominator.Ln(base);
c += Div(denominator);
return (c==0)? 0 : 1;
}
/*!
*
* convertion method
*
*/
/*!
this method sets 'result' as the one word of type sint
if the value is too big this method returns a carry (1)
*/
uint ToInt(sint & result) const
{
result = 0;
if( IsZero() )
return 0;
sint maxbit = -sint(man*TTMATH_BITS_PER_UINT);
if( exponent > maxbit + sint(TTMATH_BITS_PER_UINT) )
// if exponent > (maxbit + sint(TTMATH_BITS_PER_UINT)) the value can't be passed
// into the 'sint' type (it's too big)
return 1;
if( exponent <= maxbit )
// our value is from range (-1,1) and we return zero
return 0;
UInt<man> mantissa_temp(mantissa);
// exponent is from a range of (-maxbit,0>
sint how_many_bits = exponent.ToInt();
// how_many_bits is negative, we'll make it positive
how_many_bits = -how_many_bits;
// we're taking into an account only the last word in a mantissa table
mantissa_temp.Rcr( how_many_bits % TTMATH_BITS_PER_UINT, 0 );
result = mantissa_temp.table[ man-1 ];
// the exception for the minimal value
if( IsSign() && result == TTMATH_UINT_HIGHEST_BIT )
return 0;
if( (result & TTMATH_UINT_HIGHEST_BIT) != 0 )
// the value is too big
return 1;
if( IsSign() )
result = -sint(result);
return 0;
}
/*!
this method sets the value in 'result'
if the value is too big this method returns a carry (1)
*/
template<uint int_size>
uint ToInt(Int<int_size> & result) const
{
result.SetZero();
if( IsZero() )
return 0;
sint maxbit = -sint(man*TTMATH_BITS_PER_UINT);
if( exponent > maxbit + sint(int_size*TTMATH_BITS_PER_UINT) )
// if exponent > (maxbit + sint(int_size*TTMATH_BITS_PER_UINT)) the value can't be passed
// into the 'Int<int_size>' type (it's too big)
return 1;
if( exponent <= maxbit )
// our value is from range (-1,1) and we return zero
return 0;
UInt<man> mantissa_temp(mantissa);
sint how_many_bits = exponent.ToInt();
if( how_many_bits < 0 )
{
how_many_bits = -how_many_bits;
uint index = how_many_bits / TTMATH_BITS_PER_UINT;
mantissa_temp.Rcr( how_many_bits % TTMATH_BITS_PER_UINT, 0 );
for(uint i=index, a=0 ; i<man ; ++i,++a)
result.table[a] = mantissa_temp.table[i];
}
else
{
uint index = how_many_bits / TTMATH_BITS_PER_UINT;
for(uint i=0 ; i<man ; ++i)
result.table[index+i] = mantissa_temp.table[i];
result.Rcl( how_many_bits % TTMATH_BITS_PER_UINT, 0 );
}
// the exception for the minimal value
if( IsSign() )
{
Int<int_size> min;
min.SetMin();
if( result == min )
return 0;
}
if( (result.table[int_size-1] & TTMATH_UINT_HIGHEST_BIT) != 0 )
// the value is too big
return 1;
if( IsSign() )
result.ChangeSign();
return 0;
}
/*!
a method for converting 'uint' to this class
*/
void FromUInt(uint value)
{
info = 0;
for(uint i=0 ; i<man-1 ; ++i)
mantissa.table[i] = 0;
mantissa.table[man-1] = value;
exponent = -sint(man-1) * sint(TTMATH_BITS_PER_UINT);
// there shouldn't be a carry because 'value' has the 'uint' type
Standardizing();
}
/*!
a method for converting 'sint' to this class
*/
void FromInt(sint value)
{
bool is_sign = false;
if( value < 0 )
{
value = -value;
is_sign = true;
}
FromUInt(uint(value));
if( is_sign )
SetSign();
}
/*!
an operator= for converting 'sint' to this class
*/
Big<exp, man> & operator=(sint value)
{
FromInt(value);
return *this;
}
/*!
an operator= for converting 'uint' to this class
*/
Big<exp, man> & operator=(uint value)
{
FromUInt(value);
return *this;
}
/*!
a constructor for converting 'sint' to this class
*/
Big(sint value)
{
FromInt(value);
}
/*!
a constructor for converting 'uint' to this class
*/
Big(uint value)
{
FromUInt(value);
}
#ifdef TTMATH_PLATFORM64
/*!
in 64bit platforms we must define additional operators and contructors
in order to allow a user initializing the objects in this way:
Big<...> type = 20;
or
Big<...> type;
type = 30;
decimal constants such as 20, 30 etc. are integer literal of type int,
if the value is greater it can even be long int,
0 is an octal integer of type int
(ISO 14882 p2.13.1 Integer literals)
*/
/*!
an operator= for converting 'signed int' to this class
***this operator is created only on a 64bit platform***
it takes one argument of 32bit
*/
Big<exp, man> & operator=(signed int value)
{
FromInt(sint(value));
return *this;
}
/*!
an operator= for converting 'unsigned int' to this class
***this operator is created only on a 64bit platform***
it takes one argument of 32bit
*/
Big<exp, man> & operator=(unsigned int value)
{
FromUInt(uint(value));
return *this;
}
/*!
a constructor for converting 'signed int' to this class
***this constructor is created only on a 64bit platform***
it takes one argument of 32bit
*/
Big(signed int value)
{
FromInt(sint(value));
}
/*!
a constructor for converting 'unsigned int' to this class
***this constructor is created only on a 64bit platform***
it takes one argument of 32bit
*/
Big(unsigned int value)
{
FromUInt(uint(value));
}
#endif
/*!
a method for converting from 'Int<int_size>' to this class
*/
template<uint int_size>
void FromInt(Int<int_size> value)
{
info = 0;
bool is_sign = false;
if( value.IsSign() )
{
value.ChangeSign();
is_sign = true;
}
uint minimum_size = (int_size < man)? int_size : man;
sint compensation = (sint)value.CompensationToLeft();
exponent = (sint(int_size)-sint(man)) * sint(TTMATH_BITS_PER_UINT) - compensation;
// copying the highest words
uint i;
for(i=1 ; i<=minimum_size ; ++i)
mantissa.table[man-i] = value.table[int_size-i];
// setting the rest of mantissa.table into zero (if some has left)
for( ; i<=man ; ++i)
mantissa.table[man-i] = 0;
if( is_sign )
SetSign();
}
/*!
an operator= for converting from 'Int<int_size>' to this class
*/
template<uint int_size>
Big<exp,man> & operator=(const Int<int_size> & value)
{
FromInt(value);
return *this;
}
/*!
a constructor for converting from 'Int<int_size>' to this class
*/
template<uint int_size>
Big(const Int<int_size> & value)
{
FromInt(value);
}
/*!
a default constructor
warning: we don't set any of the members to zero etc.
*/
Big()
{
}
/*!
a destructor
*/
~Big()
{
}
/*!
the default assignment operator
*/
Big<exp,man> & operator=(const Big<exp,man> & value)
{
info = value.info;
exponent = value.exponent;
mantissa = value.mantissa;
return *this;
}
/*!
a constructor for copying from another object of this class
*/
Big(const Big<exp,man> & value)
{
operator=(value);
}
/*!
a method for converting the value into the string with a base equal 'base'
input:
base - the base on which the value will be shown
if 'always_scientific' is true the result will be shown in 'scientific' mode
if 'always_scientific' is false the result will be shown
either as 'scientific' or 'normal' mode, it depends whether the abs(exponent)
is greater than 'when_scientific' or not, if it's greater the value
will be printed as 'scientific'
if 'max_digit_after_comma' is equal -1 that all digits in the mantissa
will be printed
if 'max_digit_after_comma' is equal -2 that not mattered digits
in the mantissa will be cut off
(zero characters at the end -- after the comma operator)
if 'max_digit_after_comma' is equal or greater than zero
that only 'max_digit_after_comma' after the comma operator will be shown
(if 'max_digit_after_comma' is equal zero there'll be shown only
integer value without the comma)
for example when the value is:
12.345678 and max_digit_after_comma is 4
then the result will be
12.3457 (the last digit was rounded)
if there isn't the comma operator (when the value is too big and we're printing
it not as scientific) 'max_digit_after_comma' will be ignored
output:
return value:
0 - ok and 'result' will be an object of type std::string which holds the value
1 - if there was a carry
*/
uint ToString( std::string & result,
uint base = 10,
bool always_scientific = false,
sint when_scientific = 15,
sint max_digit_after_comma = -2 ) const
{
static char error_overflow_msg[] = "overflow";
result.erase();
if(base<2 || base>16)
{
result = error_overflow_msg;
return 1;
}
if( IsZero() )
{
result = "0";
return 0;
}
/*
since 'base' is greater or equal 2 that 'new_exp' of type 'Int<exp>' should
hold the new value of exponent but we're using 'Int<exp+1>' because
if the value for example would be 'max()' then we couldn't show it
max() -> 11111111 * 2 ^ 11111111111 (bin)(the mantissa and exponent have all bits set)
if we were using 'Int<exp>' we couldn't show it in this format:
1,1111111 * 2 ^ 11111111111 (bin)
because we have to add something to the mantissa and because
mantissa is full we can't do it and it'll be a carry
(look at ToString_SetCommaAndExponent(...))
when the base would be greater than two (for example 10)
we could use 'Int<exp>' here
*/
Int<exp+1> new_exp;
if( ToString_CreateNewMantissaAndExponent(result, base, new_exp) )
{
result = error_overflow_msg;
return 1;
}
/*
we're rounding the mantissa only if the base is different from 2,4,8 or 16
(this formula means that the number of bits in the base is greater than one)
*/
if( base!=2 && base!=4 && base!=8 && base!=16 )
if( ToString_RoundMantissa(result, base, new_exp) )
{
result = error_overflow_msg;
return 1;
}
if( ToString_SetCommaAndExponent( result, base, new_exp, always_scientific,
when_scientific, max_digit_after_comma ) )
{
result = error_overflow_msg;
return 1;
}
if( IsSign() )
result.insert(result.begin(), '-');
// converted successfully
return 0;
}
private:
/*!
in the method 'ToString_CreateNewMantissaAndExponent()' we're using
type 'Big<exp+1,man>' and we should have the ability to use some
necessary methods from that class (methods which are private here)
*/
friend class Big<exp-1,man>;
/*!
an auxiliary method for converting into the string (private)
input:
base - the base in range <2,16>
output:
return values:
0 - ok
1 - if there was a carry
new_man - the new mantissa for 'base'
new_exp - the new exponent for 'base'
mathematic part:
the value is stored as:
value = mantissa * 2^exponent
we want to show 'value' as:
value = new_man * base^new_exp
then 'new_man' we'll print using the standard method from UInt<> type for printing
and 'new_exp' is the offset of the comma operator in a system of a base 'base'
value = mantissa * 2^exponent
value = mantissa * 2^exponent * (base^new_exp / base^new_exp)
value = mantissa * (2^exponent / base^new_exp) * base^new_exp
look at the part (2^exponent / base^new_exp), there'll be good if we take
a 'new_exp' equal that value when the (2^exponent / base^new_exp) will be equal one
on account of the 'base' is not as power of 2 (can be from 2 to 16),
this formula will not be true for integer 'new_exp' then in our case we take
'base^new_exp' _greater_ than '2^exponent'
if 'base^new_exp' were smaller than '2^exponent' the new mantissa could be
greater than the max value of the container UInt<man>
value = mantissa * (2^exponent / base^new_exp) * base^new_exp
let M = mantissa * (2^exponent / base^new_exp) then
value = M * base^new_exp
in our calculation we treat M as floating value showing it as:
M = mm * 2^ee where ee will be <= 0
next we'll move all bits of mm into the right when ee is equal zero
abs(ee) must not to be too big that only few bits from mm we can leave
then we'll have:
M = mmm * 2^0
'mmm' is the new_man which we're looking for
new_exp we calculate in this way:
2^exponent <= base^new_exp
new_exp >= log base (2^exponent) <- logarithm with the base 'base' from (2^exponent)
but we need 'new'exp' as integer then we take:
new_exp = [log base (2^exponent)] + 1 <- where [x] means integer value from x
*/
uint ToString_CreateNewMantissaAndExponent( std::string & new_man, uint base,
Int<exp+1> & new_exp) const
{
uint c = 0;
if(base<2 || base>16)
return 1;
// the speciality for base equal 2
if( base == 2 )
return ToString_CreateNewMantissaAndExponent_Base2(new_man, new_exp);
// this = mantissa * 2^exponent
// temp = +1 * 2^exponent
// we're using a bigger type than 'big<exp,man>' (look below)
Big<exp+1,man> temp;
temp.info = 0;
temp.exponent = exponent;
temp.mantissa.SetOne();
c += temp.Standardizing();
// new_exp_ = [log base (2^exponent)] + 1
Big<exp+1,man> new_exp_;
c += new_exp_.ToString_Log(temp, base); // this logarithm isn't very complicated
new_exp_.SkipFraction();
temp.SetOne();
c += new_exp_.Add( temp );
// because 'base^new_exp' is >= '2^exponent' then
// because base is >= 2 then we've got:
// 'new_exp_' must be smaller or equal 'new_exp'
// and we can pass it into the Int<exp> type
// (in fact we're using a greater type then it'll be ok)
c += new_exp_.ToInt(new_exp);
// base_ = base
Big<exp+1,man> base_(base);
// base_ = base_ ^ new_exp_
c += base_.Pow( new_exp_ );
// if we hadn't used a bigger type than 'Big<exp,man>' then the result
// of this formula 'Pow(...)' would have been with an overflow
// temp = mantissa * 2^exponent / base_^new_exp_
// the sign don't interest us here
temp.mantissa = mantissa;
temp.exponent = exponent;
c += temp.Div( base_ );
// moving all bits of the mantissa into the right
// (how many times to move depend on the exponent)
c += temp.ToString_MoveMantissaIntoRight();
// because we took 'new_exp' as small as it was
// possible ([log base (2^exponent)] + 1) that after the division
// (temp.Div( base_ )) the value of exponent should be equal zero or
// minimum smaller than zero then we've got the mantissa which has
// maximum valid bits
temp.mantissa.ToString(new_man, base);
// because we had used a bigger type for calculating I think we
// shouldn't have had a carry
// (in the future this can be changed)
return (c==0)? 0 : 1;
}
/*!
this method calculates the logarithm
it is used by ToString_CreateNewMantissaAndExponent() method
it's not too complicated
because x=+1*2^exponent (mantissa is one) then during the calculation
the Ln(x) will not be making the long formula from LnSurrounding1()
and only we have to calculate 'Ln(base)' but it'll be calculated
only once, the next time we will get it from the 'history'
x is greater than 0
base is in <2,16> range
*/
uint ToString_Log(const Big<exp,man> & x, uint base)
{
TTMATH_REFERENCE_ASSERT( x )
TTMATH_ASSERT( base>=2 && base<=16 )
Big<exp,man> temp;
temp.SetOne();
if( x == temp )
{
// log(1) is 0
SetZero();
return 0;
}
// there can be only a carry
// because the 'x' is in '1+2*exponent' form then
// the long formula from LnSurrounding1() will not be calculated
// (LnSurrounding1() will return one immediately)
uint c = Ln(x);
static Big<exp,man> log_history[15] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
/*
static Big<exp,man> log_history[15] = { sint(0),sint(0),sint(0),sint(0),sint(0),
sint(0),sint(0),sint(0),sint(0),sint(0),
sint(0),sint(0),sint(0),sint(0),sint(0) };
*/
uint index = base - 2;
if( log_history[index].IsZero() )
{
// we don't have 'base' in 'log_history' then we calculate it now
if( base==10 && man<=TTMATH_BUILTIN_VARIABLES_SIZE )
{
// for the base equal 10 we're using SelLn10() instead of calculating it
// (only if we have sufficient big the constant)
temp.SetLn10();
}
else
{
Big<exp,man> base_(base);
c += temp.Ln(base_);
}
// the next time we'll get the 'Ln(base)' from the history,
// this 'log_history' can have (16-2+1) items max
log_history[index] = temp;
c += Div(temp);
}
else
{
// we've calculated the 'Ln(base)' beforehand and we're getting it now
c += Div( log_history[index] );
}
return (c==0)? 0 : 1;
}
/*!
an auxiliary method for converting into the string (private)
this method moving all bits from mantissa into the right side
the exponent tell us how many times moving (the exponent is <=0)
*/
uint ToString_MoveMantissaIntoRight()
{
if( exponent.IsZero() )
return 0;
// exponent can't be greater than zero
// because we would cat the highest bits of the mantissa
if( !exponent.IsSign() )
return 1;
if( exponent <= -sint(man*TTMATH_BITS_PER_UINT) )
// if 'exponent' is <= than '-sint(man*TTMATH_BITS_PER_UINT)'
// it means that we must cut the whole mantissa
// (there'll not be any of the valid bits)
return 1;
// e will be from (-man*TTMATH_BITS_PER_UINT, 0>
sint e = -( exponent.ToInt() );
mantissa.Rcr(e,0);
return 0;
}
/*!
a special method similar to the 'ToString_CreateNewMantissaAndExponent'
when the 'base' is equal 2
we use it because if base is equal 2 we don't have to make those
complicated calculations and the output is directly from the source
(there will not be any small distortions)
(we can make that speciality when the base is 4,8 or 16 as well
but maybe in further time)
*/
uint ToString_CreateNewMantissaAndExponent_Base2( std::string & new_man,
Int<exp+1> & new_exp ) const
{
for( sint i=man-1 ; i>=0 ; --i )
{
uint value = mantissa.table[i];
for( uint bit=0 ; bit<TTMATH_BITS_PER_UINT ; ++bit )
{
if( (value & TTMATH_UINT_HIGHEST_BIT) != 0 )
new_man += '1';
else
new_man += '0';
value <<= 1;
}
}
new_exp = exponent;
return 0;
}
/*!
an auxiliary method for converting into the string
this method roundes the last character from the new mantissa
(it's used in systems where the base is different from 2)
*/
uint ToString_RoundMantissa(std::string & new_man, uint base, Int<exp+1> & new_exp) const
{
// we must have minimum two characters
if( new_man.length() < 2 )
return 0;
std::string::size_type i = new_man.length() - 1;
// we're erasing the last character
uint digit = UInt<man>::CharToDigit( new_man[i] );
new_man.erase( i, 1 );
uint carry = new_exp.AddOne();
// if the last character is greater or equal 'base/2'
// we'll add one into the new mantissa
if( digit >= base / 2 )
ToString_RoundMantissa_AddOneIntoMantissa(new_man, base);
return carry;
}
/*!
an auxiliary method for converting into the string
this method addes one into the new mantissa
*/
void ToString_RoundMantissa_AddOneIntoMantissa(std::string & new_man, uint base) const
{
if( new_man.empty() )
return;
sint i = sint( new_man.length() ) - 1;
bool was_carry = true;
for( ; i>=0 && was_carry ; --i )
{
// we can have the comma as well because
// we're using this method later in ToString_CorrectDigitsAfterComma_Round()
// (we're only ignoring it)
if( new_man[i] == TTMATH_COMMA_CHARACTER_1 )
continue;
// we're adding one
uint digit = UInt<man>::CharToDigit( new_man[i] ) + 1;
if( digit == base )
digit = 0;
else
was_carry = false;
new_man[i] = UInt<man>::DigitToChar( digit );
}
if( i<0 && was_carry )
new_man.insert( new_man.begin() , '1' );
}
/*!
an auxiliary method for converting into the string
this method sets the comma operator and/or puts the exponent
into the string
*/
uint ToString_SetCommaAndExponent( std::string & new_man, uint base, Int<exp+1> & new_exp,
bool always_scientific,
sint when_scientific,
sint max_digit_after_comma ) const
{
uint carry = 0;
if( new_man.empty() )
return carry;
Int<exp+1> scientific_exp( new_exp );
// 'new_exp' depends on the 'new_man' which is stored like this e.g:
// 32342343234 (the comma is at the end)
// we'd like to show it in this way:
// 3.2342343234 (the 'scientific_exp' is connected with this example)
sint offset = sint( new_man.length() ) - 1;
carry += scientific_exp.Add( offset );
// there shouldn't have been a carry because we're using
// a greater type -- 'Int<exp+1>' instead of 'Int<exp>'
if( !always_scientific )
{
if( scientific_exp > when_scientific || scientific_exp < -sint(when_scientific) )
always_scientific = true;
}
// 'always_scientific' could be changed
if( !always_scientific )
ToString_SetCommaAndExponent_Normal(new_man, base, new_exp, max_digit_after_comma);
else
// we're passing the 'scientific_exp' instead of 'new_exp' here
ToString_SetCommaAndExponent_Scientific(new_man, base, scientific_exp, max_digit_after_comma);
return (carry==0)? 0 : 1;
}
/*!
an auxiliary method for converting into the string
*/
void ToString_SetCommaAndExponent_Normal(std::string & new_man, uint base,
Int<exp+1> & new_exp, sint max_digit_after_comma) const
{
//if( new_exp >= 0 )
if( !new_exp.IsSign() )
return ToString_SetCommaAndExponent_Normal_AddingZero(new_man, new_exp);
else
return ToString_SetCommaAndExponent_Normal_SetCommaInside(new_man, base, new_exp, max_digit_after_comma);
}
/*!
an auxiliary method for converting into the string
*/
void ToString_SetCommaAndExponent_Normal_AddingZero(std::string & new_man,
Int<exp+1> & new_exp) const
{
// we're adding zero characters at the end
// 'i' will be smaller than 'when_scientific' (or equal)
uint i = new_exp.ToInt();
if( new_man.length() + i > new_man.capacity() )
// about 6 characters more (we'll need it for the comma or something)
new_man.reserve( new_man.length() + i + 6 );
for( ; i>0 ; --i)
new_man += '0';
}
/*!
an auxiliary method for converting into the string
*/
void ToString_SetCommaAndExponent_Normal_SetCommaInside(std::string & new_man,
uint base, Int<exp+1> & new_exp, sint max_digit_after_comma) const
{
// new_exp is < 0
sint new_man_len = sint(new_man.length()); // 'new_man_len' with a sign
sint e = -( new_exp.ToInt() ); // 'e' will be positive
if( new_exp > -new_man_len )
{
// we're setting the comma within the mantissa
sint index = new_man_len - e;
new_man.insert( new_man.begin() + index, TTMATH_COMMA_CHARACTER_1);
}
else
{
// we're adding zero characters before the mantissa
uint how_many = e - new_man_len;
std::string man_temp(how_many+1, '0');
man_temp.insert( man_temp.begin()+1, TTMATH_COMMA_CHARACTER_1);
new_man.insert(0, man_temp);
}
ToString_CorrectDigitsAfterComma(new_man, base, max_digit_after_comma);
}
/*!
an auxiliary method for converting into the string
*/
void ToString_SetCommaAndExponent_Scientific( std::string & new_man,
uint base,
Int<exp+1> & scientific_exp,
sint max_digit_after_comma ) const
{
if( new_man.empty() )
return;
new_man.insert( new_man.begin()+1, TTMATH_COMMA_CHARACTER_1 );
ToString_CorrectDigitsAfterComma(new_man, base, max_digit_after_comma);
if( base == 10 )
{
new_man += 'e';
if( !scientific_exp.IsSign() )
new_man += "+";
}
else
{
// the 10 here is meant as the base 'base'
// (no matter which 'base' we're using there'll always be 10 here)
new_man += "*10^";
}
std::string temp_exp;
scientific_exp.ToString( temp_exp, base );
new_man += temp_exp;
}
/*!
an auxiliary method for converting into the string
we can call this method only if we've put the comma operator into the mantissa's string
*/
void ToString_CorrectDigitsAfterComma(std::string & new_man, uint base,
sint max_digit_after_comma) const
{
switch( max_digit_after_comma )
{
case -1:
// the mantissa will be unchanged
break;
case -2:
ToString_CorrectDigitsAfterComma_CutOffZeroCharacters(new_man);
break;
default:
ToString_CorrectDigitsAfterComma_Round(new_man, base, max_digit_after_comma);
break;
}
}
/*!
an auxiliary method for converting into the string
*/
void ToString_CorrectDigitsAfterComma_CutOffZeroCharacters(std::string & new_man) const
{
// minimum two characters
if( new_man.length() < 2 )
return;
// we're looking for the index of the last character which is not zero
uint i = uint( new_man.length() ) - 1;
for( ; i>0 && new_man[i]=='0' ; --i );
// if there is another character than zero at the end
// we're finishing
if( i == new_man.length() - 1 )
return;
// if directly before the first zero is the comma operator
// we're cutting it as well
if( i>0 && new_man[i]==TTMATH_COMMA_CHARACTER_1 )
--i;
new_man.erase(i+1, new_man.length()-i-1);
}
/*!
an auxiliary method for converting into the string
*/
void ToString_CorrectDigitsAfterComma_Round(std::string & new_man, uint base,
sint max_digit_after_comma) const
{
// first we're looking for the comma operator
std::string::size_type index = new_man.find(TTMATH_COMMA_CHARACTER_1, 0);
if( index == std::string::npos )
// nothing was found (actually there can't be this situation)
return;
// we're calculating how many digits there are at the end (after the comma)
// 'after_comma' will be greater than zero because at the end
// we have at least one digit
std::string::size_type after_comma = new_man.length() - index - 1;
// if 'max_digit_after_comma' is greater than 'after_comma' (or equal)
// we don't have anything for cutting
if( std::string::size_type(max_digit_after_comma) >= after_comma )
return;
uint last_digit = UInt<man>::CharToDigit( new_man[ index + max_digit_after_comma + 1 ], base );
// we're cutting the rest of the string
new_man.erase(index + max_digit_after_comma + 1, after_comma - max_digit_after_comma);
if( max_digit_after_comma == 0 )
{
// we're cutting the comma operator as well
// (it's not needed now because we've cut the whole rest after the comma)
new_man.erase(index, 1);
}
if( last_digit >= base / 2 )
// we must round here
ToString_RoundMantissa_AddOneIntoMantissa(new_man, base);
}
public:
/*!
a method for converting a string into its value
it returns 1 if the value will be too big -- we cannot pass it into the range
of our class Big<exp,man>
that means only digits before the comma operator can make this value too big,
all digits after the comma we can ignore
'source' - pointer to the string for parsing
if 'after_source' is set that when this method will have finished its job
it set the pointer to the new first character after this parsed value
*/
uint FromString(const char * source, uint base = 10, const char ** after_source = 0)
{
bool is_sign;
if( base<2 || base>16 )
{
if( after_source )
*after_source = source;
return 1;
}
SetZero();
FromString_TestNewBase( source, base );
FromString_TestSign( source, is_sign );
uint c = FromString_ReadPartBeforeComma( source, base );
if( FromString_TestCommaOperator(source) )
c += FromString_ReadPartAfterComma( source, base );
if( base==10 && FromString_TestScientific(source) )
c += FromString_ReadPartScientific( source );
if( is_sign && !IsZero() )
ChangeSign();
if( after_source )
*after_source = source;
return (c==0)? 0 : 1;
}
private:
/*!
we're testing whether a user wants to change the base
if there's a '#' character it means that the user wants the base to be 16,
if '&' the base will be 2
*/
void FromString_TestNewBase( const char * & source, uint & base )
{
UInt<man>::SkipWhiteCharacters(source);
if( *source == '#' )
{
base = 16;
++source;
}
else
if( *source == '&' )
{
base = 2;
++source;
}
}
/*!
we're testing whether the value is with the sign
(this method is used from 'FromString_ReadPartScientific' too)
*/
void FromString_TestSign( const char * & source, bool & is_sign )
{
UInt<man>::SkipWhiteCharacters(source);
is_sign = false;
if( *source == '-' )
{
is_sign = true;
++source;
}
else
if( *source == '+' )
{
++source;
}
}
/*!
we're testing whether is there a comma operator
*/
bool FromString_TestCommaOperator(const char * & source)
{
if( (*source == TTMATH_COMMA_CHARACTER_1) ||
(*source == TTMATH_COMMA_CHARACTER_2 && TTMATH_COMMA_CHARACTER_2 != 0 ) )
{
++source;
return true;
}
return false;
}
/*!
this method reads the first part of a string
(before the comma operator)
*/
uint FromString_ReadPartBeforeComma( const char * & source, uint base )
{
sint character;
Big<exp, man> temp;
Big<exp, man> base_( base );
UInt<man>::SkipWhiteCharacters( source );
for( ; (character=UInt<man>::CharToDigit(*source, base)) != -1 ; ++source )
{
temp = character;
if( Mul(base_) )
return 1;
if( Add(temp) )
return 1;
}
return 0;
}
/*!
this method reads the second part of a string
(after the comma operator)
*/
uint FromString_ReadPartAfterComma( const char * & source, uint base )
{
sint character;
uint c = 0, index = 1;
Big<exp, man> part, power, old_value, base_( base );
// we don't remove any white characters here
// this is only to avoid getting a warning about an uninitialized object
// gcc 4.1.2 reports: 'old_value.info' may be used uninitialized in this function
// (in fact we will initialize it later when the condition 'testing' is fulfilled)
old_value.info = 0;
power.SetOne();
for( ; (character=UInt<man>::CharToDigit(*source, base)) != -1 ; ++source, ++index )
{
part = character;
if( power.Mul( base_ ) )
// there's no sens to add the next parts, but we can't report this
// as an error (this is only inaccuracy)
break;
if( part.Div( power ) )
break;
// every 5 iteration we make a test whether the value will be changed or not
// (character must be different from zero to this test)
bool testing = (character != 0 && (index % 5) == 0);
if( testing )
old_value = *this;
// there actually shouldn't be a carry here
c += Add( part );
if( testing && old_value == *this )
// after adding 'part' the value has not been changed
// there's no sense to add any next parts
break;
}
// we could break the parsing somewhere in the middle of the string,
// but the result (value) still can be good
// we should set a correct value of 'source' now
for( ; UInt<man>::CharToDigit(*source, base) != -1 ; ++source );
return (c==0)? 0 : 1;
}
/*!
we're testing whether is there the character 'e'
this character is only allowed when we're using the base equals 10
*/
bool FromString_TestScientific(const char * & source)
{
UInt<man>::SkipWhiteCharacters(source);
if( *source=='e' || *source=='E' )
{
++source;
return true;
}
return false;
}
/*!
this method reads the exponent (after 'e' character) when there's a scientific
format of value and only when we're using the base equals 10
*/
uint FromString_ReadPartScientific( const char * & source )
{
uint c = 0;
Big<exp, man> new_exponent, temp;
bool was_sign = false;
FromString_TestSign( source, was_sign );
FromString_ReadPartScientific_ReadExponent( source, new_exponent );
if( was_sign )
new_exponent.ChangeSign();
temp = 10;
c += temp.PowBInt( new_exponent );
c += Mul(temp);
return (c==0)? 0 : 1;
}
/*!
this method reads the value of the extra exponent when scientific format is used
(only when base == 10)
*/
uint FromString_ReadPartScientific_ReadExponent( const char * & source, Big<exp, man> & new_exponent )
{
sint character;
Big<exp, man> base, temp;
UInt<man>::SkipWhiteCharacters(source);
new_exponent.SetZero();
base = 10;
for( ; (character=UInt<man>::CharToDigit(*source, 10)) != -1 ; ++source )
{
temp = character;
if( new_exponent.Mul(base) )
return 1;
if( new_exponent.Add(temp) )
return 1;
}
return 0;
}
public:
/*!
a method for converting a string into its value
*/
uint FromString(const std::string & string, uint base = 10)
{
return FromString( string.c_str(), base );
}
/*!
a constructor for converting a string into this class
*/
Big(const char * string)
{
FromString( string );
}
/*!
a constructor for converting a string into this class
*/
Big(const std::string & string)
{
FromString( string.c_str() );
}
/*!
an operator= for converting a string into its value
*/
Big<exp, man> & operator=(const char * string)
{
FromString( string );
return *this;
}
/*!
an operator= for converting a string into its value
*/
Big<exp, man> & operator=(const std::string & string)
{
FromString( string.c_str() );
return *this;
}
/*!
*
* methods for comparing
*
*/
/*!
this method performs the formula 'abs(this) < abs(ss2)'
and returns the result
(in other words it treats 'this' and 'ss2' as values without a sign)
*/
bool SmallerWithoutSignThan(const Big<exp,man> & ss2) const
{
// we should check the mantissas beforehand because sometimes we can have
// a mantissa set to zero but in the exponent something another value
// (maybe we've forgotten about calling CorrectZero() ?)
if( mantissa.IsZero() )
{
if( ss2.mantissa.IsZero() )
// we've got two zeroes
return false;
else
// this==0 and ss2!=0
return true;
}
if( ss2.mantissa.IsZero() )
// this!=0 and ss2==0
return false;
// we're using the fact that all bits in mantissa are pushed
// into the left side -- Standardizing()
if( exponent == ss2.exponent )
return mantissa < ss2.mantissa;
return exponent < ss2.exponent;
}
/*!
this method performs the formula 'abs(this) > abs(ss2)'
and returns the result
(in other words it treats 'this' and 'ss2' as values without a sign)
*/
bool GreaterWithoutSignThan(const Big<exp,man> & ss2) const
{
// we should check the mantissas beforehand because sometimes we can have
// a mantissa set to zero but in the exponent something another value
// (maybe we've forgotten about calling CorrectZero() ?)
if( mantissa.IsZero() )
{
if( ss2.mantissa.IsZero() )
// we've got two zeroes
return false;
else
// this==0 and ss2!=0
return false;
}
if( ss2.mantissa.IsZero() )
// this!=0 and ss2==0
return true;
// we're using the fact that all bits in mantissa are pushed
// into the left side -- Standardizing()
if( exponent == ss2.exponent )
return mantissa > ss2.mantissa;
return exponent > ss2.exponent;
}
/*!
this method performs the formula 'abs(this) == abs(ss2)'
and returns the result
(in other words it treats 'this' and 'ss2' as values without a sign)
*/
bool EqualWithoutSign(const Big<exp,man> & ss2) const
{
// we should check the mantissas beforehand because sometimes we can have
// a mantissa set to zero but in the exponent something another value
// (maybe we've forgotten about calling CorrectZero() ?)
if( mantissa.IsZero() )
{
if( ss2.mantissa.IsZero() )
// we've got two zeroes
return true;
else
// this==0 and ss2!=0
return false;
}
if( ss2.mantissa.IsZero() )
// this!=0 and ss2==0
return false;
if( exponent==ss2.exponent && mantissa==ss2.mantissa )
return true;
return false;
}
bool operator<(const Big<exp,man> & ss2) const
{
if( IsSign() && !ss2.IsSign() )
// this<0 and ss2>=0
return true;
if( !IsSign() && ss2.IsSign() )
// this>=0 and ss2<0
return false;
// both signs are the same
if( IsSign() )
return ss2.SmallerWithoutSignThan( *this );
return SmallerWithoutSignThan( ss2 );
}
bool operator==(const Big<exp,man> & ss2) const
{
if( IsSign() != ss2.IsSign() )
return false;
return EqualWithoutSign( ss2 );
}
bool operator>(const Big<exp,man> & ss2) const
{
if( IsSign() && !ss2.IsSign() )
// this<0 and ss2>=0
return false;
if( !IsSign() && ss2.IsSign() )
// this>=0 and ss2<0
return true;
// both signs are the same
if( IsSign() )
return ss2.GreaterWithoutSignThan( *this );
return GreaterWithoutSignThan( ss2 );
}
bool operator>=(const Big<exp,man> & ss2) const
{
return !operator<( ss2 );
}
bool operator<=(const Big<exp,man> & ss2) const
{
return !operator>( ss2 );
}
bool operator!=(const Big<exp,man> & ss2) const
{
return !operator==(ss2);
}
/*!
*
* standard mathematical operators
*
*/
/*!
an operator for changing the sign
it's not changing 'this' but the changed value will be returned
*/
Big<exp,man> operator-() const
{
Big<exp,man> temp(*this);
temp.ChangeSign();
return temp;
}
Big<exp,man> operator-(const Big<exp,man> & ss2) const
{
Big<exp,man> temp(*this);
temp.Sub(ss2);
return temp;
}
Big<exp,man> & operator-=(const Big<exp,man> & ss2)
{
Sub(ss2);
return *this;
}
Big<exp,man> operator+(const Big<exp,man> & ss2) const
{
Big<exp,man> temp(*this);
temp.Add(ss2);
return temp;
}
Big<exp,man> & operator+=(const Big<exp,man> & ss2)
{
Add(ss2);
return *this;
}
Big<exp,man> operator*(const Big<exp,man> & ss2) const
{
Big<exp,man> temp(*this);
temp.Mul(ss2);
return temp;
}
Big<exp,man> & operator*=(const Big<exp,man> & ss2)
{
Mul(ss2);
return *this;
}
Big<exp,man> operator/(const Big<exp,man> & ss2) const
{
Big<exp,man> temp(*this);
temp.Div(ss2);
return temp;
}
Big<exp,man> & operator/=(const Big<exp,man> & ss2)
{
Div(ss2);
return *this;
}
/*!
this method makes an integer value by skipping any fractions
for example:
10.7 will be 10
12.1 -- 12
-20.2 -- 20
-20.9 -- 20
-0.7 -- 0
0.8 -- 0
*/
void SkipFraction()
{
if( IsZero() )
return;
if( !exponent.IsSign() )
// exponent >=0 -- the value don't have any fractions
return;
if( exponent <= -sint(man*TTMATH_BITS_PER_UINT) )
{
// the value is from (-1,1), we return zero
SetZero();
return;
}
// exponent is in range (-man*TTMATH_BITS_PER_UINT, 0)
sint e = exponent.ToInt();
mantissa.ClearFirstBits( -e );
// we don't have to standardize 'Standardizing()' the value because
// there's at least one bit in the mantissa
// (the highest bit which we didn't touch)
}
/*!
this method remains only a fraction from the value
for example:
30.56 will be 0.56
-12.67 -- -0.67
*/
void RemainFraction()
{
if( IsZero() )
return;
if( !exponent.IsSign() )
{
// exponent >= 0 -- the value doesn't have any fractions
// we return zero
SetZero();
return;
}
if( exponent <= -sint(man*TTMATH_BITS_PER_UINT) )
{
// the value is from (-1,1)
// we don't make anything with the value
return;
}
// e will be from (-man*TTMATH_BITS_PER_UINT, 0)
sint e = exponent.ToInt();
sint how_many_bits_leave = sint(man*TTMATH_BITS_PER_UINT) + e; // there'll be a subtraction -- e is negative
mantissa.Rcl( how_many_bits_leave, 0);
// there'll not be a carry because the exponent is too small
exponent.Sub( how_many_bits_leave );
// we must call Standardizing() here
Standardizing();
}
/*!
this method rounds to the nearest integer value
(it returns a carry if it was)
for example:
2.3 = 2
2.8 = 3
-2.3 = -2
-2.8 = 3
*/
uint Round()
{
Big<exp,man> half;
uint c;
half.Set05();
if( IsSign() )
{
// 'this' is < 0
c = Sub( half );
}
else
{
// 'this' is >= 0
c = Add( half );
}
SkipFraction();
return c;
}
/*!
*
* input/output operators for standard streams
*
*/
friend std::ostream & operator<<(std::ostream & s, const Big<exp,man> & l)
{
std::string ss;
l.ToString(ss);
s << ss;
return s;
}
friend std::istream & operator>>(std::istream & s, Big<exp,man> & l)
{
std::string ss;
// 'char' for operator>>
unsigned char z;
bool was_comma = false;
// operator>> omits white characters if they're set for ommiting
s >> z;
if( z=='-' || z=='+' )
{
ss += z;
s >> z; // we're reading a next character (white characters can be ommited)
}
// we're reading only digits (base=10) and only one comma operator
while( s.good() &&
( UInt<man>::CharToDigit(z, 10)>=0 || (!was_comma && z==TTMATH_COMMA_CHARACTER_1) )
)
{
if( z == TTMATH_COMMA_CHARACTER_1 )
was_comma = true;
ss += z;
z = s.get();
}
// we're leaving the last readed character
// (it's not belonging to the value)
s.unget();
l.FromString( ss );
return s;
}
};
} // namespace
#endif
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