amath/lib/dconv/dprint.cpp

693 lines
24 KiB
C++

/******************************************************************************
Copyright (c) 2014 Ryan Juckett
http://www.ryanjuckett.com/
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
3. This notice may not be removed or altered from any source
distribution.
*******************************************************************************
Copyright (c) 2015-2017 Carsten Sonne Larsen <cs@innolan.dk>
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. 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.
THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
The origin source code can be obtained from:
http://www.ryanjuckett.com/
******************************************************************************/
#include "clib.h"
#include "dmath.h"
#include "dprint.h"
#include "dragon4.h"
#include <dstandard.h>
#define memcpy MemCopy
#define memmove MemCopy
//******************************************************************************
// Helper union to decompose a 32-bit IEEE float.
// sign: 1 bit
// exponent: 8 bits
// mantissa: 23 bits
//******************************************************************************
union tFloatUnion32
{
tB IsNegative() const {
return (m_integer >> 31) != 0;
}
tU32 GetExponent() const {
return (m_integer >> 23) & 0xFF;
}
tU32 GetMantissa() const {
return m_integer & 0x7FFFFF;
}
tF32 m_floatingPoint;
tU32 m_integer;
};
//******************************************************************************
// Helper union to decompose a 64-bit IEEE float.
// sign: 1 bit
// exponent: 11 bits
// mantissa: 52 bits
//******************************************************************************
union tFloatUnion64
{
tB IsNegative() const {
return (m_integer >> 63) != 0;
}
tU32 GetExponent() const {
return (m_integer >> 52) & 0x7FF;
}
tU64 GetMantissa() const {
return m_integer & 0xFFFFFFFFFFFFFull;
}
tF64 m_floatingPoint;
tU64 m_integer;
};
//******************************************************************************
// Outputs the positive number with positional notation: ddddd.dddd
// The output is always NUL terminated and the output length (not including the
// NUL) is returned.
//******************************************************************************
tU32 FormatPositional
(
tC8 * pOutBuffer, // buffer to output into
tU32 bufferSize, // maximum characters that can be printed to pOutBuffer
tU64 mantissa, // value significand
tS32 exponent, // value exponent in base 2
tU32 mantissaHighBitIdx, // index of the highest set mantissa bit
tB hasUnequalMargins, // is the high margin twice as large as the low margin
tS32 precision, // Negative prints as many digits as are needed for a unique
tC8 decimalPoint // Character before the decimals
// number. Positive specifies the maximum number of
// significant digits to print past the decimal point.
)
{
RJ_ASSERT(bufferSize > 0);
tS32 printExponent;
tU32 numPrintDigits;
tU32 maxPrintLen = bufferSize - 1;
if (precision < 0)
{
numPrintDigits = Dragon4( mantissa,
exponent,
mantissaHighBitIdx,
hasUnequalMargins,
CutoffMode_Unique,
0,
pOutBuffer,
maxPrintLen,
&printExponent );
}
else
{
numPrintDigits = Dragon4( mantissa,
exponent,
mantissaHighBitIdx,
hasUnequalMargins,
CutoffMode_FractionLength,
precision,
pOutBuffer,
maxPrintLen,
&printExponent );
}
RJ_ASSERT( numPrintDigits > 0 );
RJ_ASSERT( numPrintDigits <= bufferSize );
// track the number of digits past the decimal point that have been printed
tU32 numFractionDigits = 0;
// if output has a whole number
if (printExponent >= 0)
{
// leave the whole number at the start of the buffer
tU32 numWholeDigits = printExponent+1;
if (numPrintDigits < numWholeDigits)
{
// don't overflow the buffer
if (numWholeDigits > maxPrintLen)
numWholeDigits = maxPrintLen;
// add trailing zeros up to the decimal point
for ( ; numPrintDigits < numWholeDigits; ++numPrintDigits )
pOutBuffer[numPrintDigits] = '0';
}
// insert the decimal point prior to the fraction
else if (numPrintDigits > (tU32)numWholeDigits)
{
numFractionDigits = numPrintDigits - numWholeDigits;
tU32 maxFractionDigits = maxPrintLen - numWholeDigits - 1;
if (numFractionDigits > maxFractionDigits)
numFractionDigits = maxFractionDigits;
memmove(pOutBuffer + numWholeDigits + 1, pOutBuffer + numWholeDigits, numFractionDigits);
pOutBuffer[numWholeDigits] = decimalPoint;
numPrintDigits = numWholeDigits + 1 + numFractionDigits;
}
}
else
{
// shift out the fraction to make room for the leading zeros
if (maxPrintLen > 2)
{
tU32 numFractionZeros = (tU32)-printExponent - 1;
tU32 maxFractionZeros = maxPrintLen - 2;
if (numFractionZeros > maxFractionZeros)
numFractionZeros = maxFractionZeros;
tU32 digitsStartIdx = 2 + numFractionZeros;
// shift the significant digits right such that there is room for leading zeros
numFractionDigits = numPrintDigits;
tU32 maxFractionDigits = maxPrintLen - digitsStartIdx;
if (numFractionDigits > maxFractionDigits)
numFractionDigits = maxFractionDigits;
memmove(pOutBuffer + digitsStartIdx, pOutBuffer, numFractionDigits);
// insert the leading zeros
for (tU32 i = 2; i < digitsStartIdx; ++i)
pOutBuffer[i] = '0';
// update the counts
numFractionDigits += numFractionZeros;
numPrintDigits = numFractionDigits;
}
// add the decimal point
if (maxPrintLen > 1)
{
pOutBuffer[1] = decimalPoint;
numPrintDigits += 1;
}
// add the initial zero
if (maxPrintLen > 0)
{
pOutBuffer[0] = '0';
numPrintDigits += 1;
}
}
// add trailing zeros up to precision length
if (precision > (tS32)numFractionDigits && numPrintDigits < maxPrintLen)
{
// add a decimal point if this is the first fractional digit we are printing
if (numFractionDigits == 0)
{
pOutBuffer[numPrintDigits++] = decimalPoint;
}
// compute the number of trailing zeros needed
tU32 totalDigits = numPrintDigits + (precision - numFractionDigits);
if (totalDigits > maxPrintLen)
totalDigits = maxPrintLen;
for ( ; numPrintDigits < totalDigits; ++numPrintDigits )
pOutBuffer[numPrintDigits] = '0';
}
// terminate the buffer
RJ_ASSERT( numPrintDigits <= maxPrintLen );
pOutBuffer[numPrintDigits] = '\0';
return numPrintDigits;
}
//******************************************************************************
// Outputs the positive number with scientific notation: d.dddde[sign]ddd
// The output is always NUL terminated and the output length (not including the
// NUL) is returned.
//******************************************************************************
tU32 FormatScientific
(
tC8 * pOutBuffer, // buffer to output into
tU32 bufferSize, // maximum characters that can be printed to pOutBuffer
tU64 mantissa, // value significand
tS32 exponent, // value exponent in base 2
tU32 mantissaHighBitIdx, // index of the highest set mantissa bit
tB hasUnequalMargins, // is the high margin twice as large as the low margin
tS32 precision, // Negative prints as many digits as are needed for a unique
tC8 decimalPoint // Character before the decimals
// number. Positive specifies the maximum number of
// significant digits to print past the decimal point.
)
{
RJ_ASSERT(bufferSize > 0);
tS32 printExponent;
tU32 numPrintDigits;
if (precision < 0)
{
numPrintDigits = Dragon4( mantissa,
exponent,
mantissaHighBitIdx,
hasUnequalMargins,
CutoffMode_Unique,
0,
pOutBuffer,
bufferSize,
&printExponent );
}
else
{
numPrintDigits = Dragon4( mantissa,
exponent,
mantissaHighBitIdx,
hasUnequalMargins,
CutoffMode_TotalLength,
precision + 1,
pOutBuffer,
bufferSize,
&printExponent );
}
RJ_ASSERT( numPrintDigits > 0 );
RJ_ASSERT( numPrintDigits <= bufferSize );
tC8 * pCurOut = pOutBuffer;
// keep the whole number as the first digit
if (bufferSize > 1)
{
pCurOut += 1;
bufferSize -= 1;
}
// insert the decimal point prior to the fractional number
tU32 numFractionDigits = numPrintDigits-1;
if (numFractionDigits > 0 && bufferSize > 1)
{
tU32 maxFractionDigits = bufferSize-2;
if (numFractionDigits > maxFractionDigits)
numFractionDigits = maxFractionDigits;
memmove(pCurOut + 1, pCurOut, numFractionDigits);
pCurOut[0] = decimalPoint;
pCurOut += (1 + numFractionDigits);
bufferSize -= (1 + numFractionDigits);
}
// add trailing zeros up to precision length
if (precision > (tS32)numFractionDigits && bufferSize > 1)
{
// add a decimal point if this is the first fractional digit we are printing
if (numFractionDigits == 0)
{
*pCurOut = decimalPoint;
++pCurOut;
--bufferSize;
}
// compute the number of trailing zeros needed
tU32 numZeros = (precision - numFractionDigits);
if (numZeros > bufferSize-1)
numZeros = bufferSize-1;
for (tC8 * pEnd = pCurOut + numZeros; pCurOut < pEnd; ++pCurOut )
*pCurOut = '0';
}
// print the exponent into a local buffer and copy into output buffer
if (bufferSize > 1)
{
tC8 exponentBuffer[5];
exponentBuffer[0] = 'e';
if (printExponent >= 0)
{
exponentBuffer[1] = '+';
}
else
{
exponentBuffer[1] = '-';
printExponent = -printExponent;
}
RJ_ASSERT(printExponent < 1000);
tU32 hundredsPlace = printExponent / 100;
tU32 tensPlace = (printExponent - hundredsPlace*100) / 10;
tU32 onesPlace = (printExponent - hundredsPlace*100 - tensPlace*10);
exponentBuffer[2] = (tC8)('0' + hundredsPlace);
exponentBuffer[3] = (tC8)('0' + tensPlace);
exponentBuffer[4] = (tC8)('0' + onesPlace);
// copy the exponent buffer into the output
tU32 maxExponentSize = bufferSize-1;
tU32 exponentSize = (5 < maxExponentSize) ? 5 : maxExponentSize;
memcpy( pCurOut, exponentBuffer, exponentSize );
pCurOut += exponentSize;
bufferSize -= exponentSize;
}
RJ_ASSERT( bufferSize > 0 );
pCurOut[0] = '\0';
return pCurOut - pOutBuffer;
}
//******************************************************************************
// Print a hexadecimal value with a given width.
// The output string is always NUL terminated and the string length (not
// including the NUL) is returned.
//******************************************************************************
static tU32 PrintHex(tC8 * pOutBuffer, tU32 bufferSize, tU64 value, tU32 width)
{
const tC8 digits[] = "0123456789abcdef";
RJ_ASSERT(bufferSize > 0);
tU32 maxPrintLen = bufferSize-1;
if (width > maxPrintLen)
width = maxPrintLen;
tC8 * pCurOut = pOutBuffer;
while (width > 0)
{
--width;
tU8 digit = (tU8)((value >> 4ull*(tU64)width) & 0xF);
*pCurOut = digits[digit];
++pCurOut;
}
*pCurOut = '\0';
return pCurOut - pOutBuffer;
}
//******************************************************************************
// Print special case values for infinities and NaNs.
// The output string is always NUL terminated and the string length (not
// including the NUL) is returned.
//******************************************************************************
static tU32 PrintInfNan(tC8 * pOutBuffer, tU32 bufferSize, tU64 mantissa, tU32 mantissaHexWidth)
{
RJ_ASSERT(bufferSize > 0);
tU32 maxPrintLen = bufferSize-1;
// Check for infinity
if (mantissa == 0)
{
// copy and make sure the buffer is terminated
tU32 printLen = (3 < maxPrintLen) ? 3 : maxPrintLen;
::memcpy( pOutBuffer, "Inf", printLen );
pOutBuffer[printLen] = '\0';
return printLen;
}
else
{
// copy and make sure the buffer is terminated
tU32 printLen = (3 < maxPrintLen) ? 3 : maxPrintLen;
::memcpy( pOutBuffer, "NaN", printLen );
pOutBuffer[printLen] = '\0';
// append HEX value
if (maxPrintLen > 3)
printLen += PrintHex(pOutBuffer+3, bufferSize-3, mantissa, mantissaHexWidth);
return printLen;
}
}
//******************************************************************************
// Print a 32-bit floating-point number as a decimal string.
// The output string is always NUL terminated and the string length (not
// including the NUL) is returned.
//******************************************************************************
tU32 PrintFloat32
(
tC8 * pOutBuffer, // buffer to output into
tU32 bufferSize, // size of pOutBuffer
tF32 value, // value to print
tPrintFloatFormat format, // format to print with
tS32 precision, // If negative, the minimum number of digits to represent a
tC8 decimalPoint // Character before the decimals
// unique 32-bit floating point value is output. Otherwise,
// this is the number of digits to print past the decimal point.
)
{
if (bufferSize == 0)
return 0;
if (bufferSize == 1)
{
pOutBuffer[0] = '\0';
return 1;
}
// deconstruct the floating point value
tFloatUnion32 floatUnion;
floatUnion.m_floatingPoint = value;
tU32 floatExponent = floatUnion.GetExponent();
tU32 floatMantissa = floatUnion.GetMantissa();
// output the sign
if (floatUnion.IsNegative())
{
pOutBuffer[0] = '-';
++pOutBuffer;
--bufferSize;
RJ_ASSERT(bufferSize > 0);
}
// if this is a special value
if (floatExponent == 0xFF)
{
return PrintInfNan(pOutBuffer, bufferSize, floatMantissa, 6);
}
// else this is a number
else
{
// factor the value into its parts
tU32 mantissa;
tS32 exponent;
tU32 mantissaHighBitIdx;
tB hasUnequalMargins;
if (floatExponent != 0)
{
// normalized
// The floating point equation is:
// value = (1 + mantissa/2^23) * 2 ^ (exponent-127)
// We convert the integer equation by factoring a 2^23 out of the exponent
// value = (1 + mantissa/2^23) * 2^23 * 2 ^ (exponent-127-23)
// value = (2^23 + mantissa) * 2 ^ (exponent-127-23)
// Because of the implied 1 in front of the mantissa we have 24 bits of precision.
// m = (2^23 + mantissa)
// e = (exponent-127-23)
mantissa = (1UL << 23) | floatMantissa;
exponent = floatExponent - 127 - 23;
mantissaHighBitIdx = 23;
hasUnequalMargins = (floatExponent != 1) && (floatMantissa == 0);
}
else
{
// denormalized
// The floating point equation is:
// value = (mantissa/2^23) * 2 ^ (1-127)
// We convert the integer equation by factoring a 2^23 out of the exponent
// value = (mantissa/2^23) * 2^23 * 2 ^ (1-127-23)
// value = mantissa * 2 ^ (1-127-23)
// We have up to 23 bits of precision.
// m = (mantissa)
// e = (1-127-23)
mantissa = floatMantissa;
exponent = 1 - 127 - 23;
mantissaHighBitIdx = LogBase2(mantissa);
hasUnequalMargins = false;
}
// format the value
switch (format)
{
case PrintFloatFormat_Positional:
return FormatPositional( pOutBuffer,
bufferSize,
mantissa,
exponent,
mantissaHighBitIdx,
hasUnequalMargins,
precision,
decimalPoint );
case PrintFloatFormat_Scientific:
return FormatScientific( pOutBuffer,
bufferSize,
mantissa,
exponent,
mantissaHighBitIdx,
hasUnequalMargins,
precision,
decimalPoint );
default:
pOutBuffer[0] = '\0';
return 0;
}
}
}
//******************************************************************************
// Print a 64-bit floating-point number as a decimal string.
// The output string is always NUL terminated and the string length (not
// including the NUL) is returned.
//******************************************************************************
tU32 PrintFloat64
(
tC8 * pOutBuffer, // buffer to output into
tU32 bufferSize, // size of pOutBuffer
tF64 value, // value to print
tPrintFloatFormat format, // format to print with
tS32 precision, // If negative, the minimum number of digits to represent a
tC8 decimalPoint // Character before the decimals
// unique 64-bit floating point value is output. Otherwise,
// this is the number of digits to print past the decimal point.
)
{
if (bufferSize == 0)
return 0;
if (bufferSize == 1)
{
pOutBuffer[0] = '\0';
return 1;
}
// deconstruct the floating point value
tFloatUnion64 floatUnion;
floatUnion.m_floatingPoint = value;
tU32 floatExponent = floatUnion.GetExponent();
tU64 floatMantissa = floatUnion.GetMantissa();
// output the sign
if (floatUnion.IsNegative())
{
pOutBuffer[0] = '-';
++pOutBuffer;
--bufferSize;
RJ_ASSERT(bufferSize > 0);
}
// if this is a special value
if (floatExponent == 0x7FF)
{
return PrintInfNan(pOutBuffer, bufferSize, floatMantissa, 13);
}
// else this is a number
else
{
// factor the value into its parts
tU64 mantissa;
tS32 exponent;
tU32 mantissaHighBitIdx;
tB hasUnequalMargins;
if (floatExponent != 0)
{
// normal
// The floating point equation is:
// value = (1 + mantissa/2^52) * 2 ^ (exponent-1023)
// We convert the integer equation by factoring a 2^52 out of the exponent
// value = (1 + mantissa/2^52) * 2^52 * 2 ^ (exponent-1023-52)
// value = (2^52 + mantissa) * 2 ^ (exponent-1023-52)
// Because of the implied 1 in front of the mantissa we have 53 bits of precision.
// m = (2^52 + mantissa)
// e = (exponent-1023+1-53)
mantissa = (1ull << 52) | floatMantissa;
exponent = floatExponent - 1023 - 52;
mantissaHighBitIdx = 52;
hasUnequalMargins = (floatExponent != 1) && (floatMantissa == 0);
}
else
{
// subnormal
// The floating point equation is:
// value = (mantissa/2^52) * 2 ^ (1-1023)
// We convert the integer equation by factoring a 2^52 out of the exponent
// value = (mantissa/2^52) * 2^52 * 2 ^ (1-1023-52)
// value = mantissa * 2 ^ (1-1023-52)
// We have up to 52 bits of precision.
// m = (mantissa)
// e = (1-1023-52)
mantissa = floatMantissa;
exponent = 1 - 1023 - 52;
mantissaHighBitIdx = LogBase2(mantissa);
hasUnequalMargins = false;
}
// format the value
switch (format)
{
case PrintFloatFormat_Positional:
return FormatPositional( pOutBuffer,
bufferSize,
mantissa,
exponent,
mantissaHighBitIdx,
hasUnequalMargins,
precision,
decimalPoint );
case PrintFloatFormat_Scientific:
return FormatScientific( pOutBuffer,
bufferSize,
mantissa,
exponent,
mantissaHighBitIdx,
hasUnequalMargins,
precision,
decimalPoint );
default:
pOutBuffer[0] = '\0';
return 0;
}
}
}