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software/libbase: strtod

This commit is contained in:
Sebastien Bourdeauducq 2012-05-25 23:26:17 +02:00
parent 99070f0afd
commit a481db612a
3 changed files with 235 additions and 85 deletions
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2
software/libbase/Makefile
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@ -1,7 +1,7 @@
M2DIR=../..
include $(M2DIR)/software/common.mak
OBJECTS=divsi3.o setjmp.o libc.o crc16.o crc32.o console.o timer.o system.o board.o uart.o softfloat.o softfloat-glue.o vsnprintf.o atof.o
OBJECTS=divsi3.o setjmp.o libc.o crc16.o crc32.o console.o timer.o system.o board.o uart.o softfloat.o softfloat-glue.o vsnprintf.o strtod.o
all: libbase.a

84
software/libbase/atof.c
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@ -1,84 +0,0 @@
/* atof.c: converts an ASCII string to float
Copyright (C) 2003 Jesus Calvino-Fraga, jesusc@ieee.org
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
#include <stdlib.h>
#include <ctype.h>
float atof(const char * s)
{
float value, fraction;
char iexp;
char sign;
//Skip leading blanks
while (isspace(*s)) s++;
//Get the sign
if (*s == '-')
{
sign=1;
s++;
}
else
{
sign=0;
if (*s == '+') s++;
}
//Get the integer part
for (value=0.0f; isdigit(*s); s++)
{
value=10.0f*value+(*s-'0');
}
//Get the fraction
if (*s == '.')
{
s++;
for (fraction=0.1f; isdigit(*s); s++)
{
value+=(*s-'0')*fraction;
fraction*=0.1f;
}
}
//Finally, the exponent (not very efficient, but enough for now)
if (toupper(*s)=='E')
{
s++;
iexp=(char)atoi(s);
{
while(iexp!=0)
{
if(iexp<0)
{
value*=0.1f;
iexp++;
}
else
{
value*=10.0f;
iexp--;
}
}
}
}
if(sign) value*=-1.0f;
return (value);
}

234
software/libbase/strtod.c Normal file
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@ -0,0 +1,234 @@
/****************************************************************************
* lib/string/lib_strtod.c
* Convert string to double
*
* Copyright (C) 2002 Michael Ringgaard. All rights reserved.
* Copyright (C) 2006-2007 H. Peter Anvin.
*
* 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.
* 3. Neither the name of the project nor the names of its contributors
* 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <stdlib.h>
#include <ctype.h>
#include <errno.h>
/****************************************************************************
* Pre-processor definitions
****************************************************************************/
/* These are predefined with GCC, but could be issues for other compilers. If
* not defined, an arbitrary big number is put in for now. These should be
* added to nuttx/compiler for your compiler.
*/
#if !defined(__DBL_MIN_EXP__) || !defined(__DBL_MAX_EXP__)
# ifdef CONFIG_CPP_HAVE_WARNING
# warning "Size of exponent is unknown"
# endif
# undef __DBL_MIN_EXP__
# define __DBL_MIN_EXP__ (-1021)
# undef __DBL_MAX_EXP__
# define __DBL_MAX_EXP__ (1024)
#endif
/****************************************************************************
* Private Functions
****************************************************************************/
static inline int is_real(double x)
{
const double infinite = 1.0/0.0;
return (x < infinite) && (x >= -infinite);
}
/****************************************************************************
* Public Functions
****************************************************************************/
/***************************************************(************************
* Name: strtod
*
* Description:
* Convert a string to a double value
*
****************************************************************************/
double strtod(const char *str, char **endptr)
{
double number;
int exponent;
int negative;
char *p = (char *) str;
double p10;
int n;
int num_digits;
int num_decimals;
const double infinite = 1.0/0.0;
/* Skip leading whitespace */
while (isspace(*p))
{
p++;
}
/* Handle optional sign */
negative = 0;
switch (*p)
{
case '-':
negative = 1; /* Fall through to increment position */
case '+':
p++;
}
number = 0.;
exponent = 0;
num_digits = 0;
num_decimals = 0;
/* Process string of digits */
while (isdigit(*p))
{
number = number * 10. + (*p - '0');
p++;
num_digits++;
}
/* Process decimal part */
if (*p == '.')
{
p++;
while (isdigit(*p))
{
number = number * 10. + (*p - '0');
p++;
num_digits++;
num_decimals++;
}
exponent -= num_decimals;
}
if (num_digits == 0)
{
errno = ERANGE;
return 0.0;
}
/* Correct for sign */
if (negative)
{
number = -number;
}
/* Process an exponent string */
if (*p == 'e' || *p == 'E')
{
/* Handle optional sign */
negative = 0;
switch(*++p)
{
case '-':
negative = 1; /* Fall through to increment pos */
case '+':
p++;
}
/* Process string of digits */
n = 0;
while (isdigit(*p))
{
n = n * 10 + (*p - '0');
p++;
}
if (negative)
{
exponent -= n;
}
else
{
exponent += n;
}
}
if (exponent < __DBL_MIN_EXP__ ||
exponent > __DBL_MAX_EXP__)
{
errno = ERANGE;
return infinite;
}
/* Scale the result */
p10 = 10.;
n = exponent;
if (n < 0) n = -n;
while (n)
{
if (n & 1)
{
if (exponent < 0)
{
number /= p10;
}
else
{
number *= p10;
}
}
n >>= 1;
p10 *= p10;
}
if (!is_real(number))
{
errno = ERANGE;
}
if (endptr)
{
*endptr = p;
}
return number;
}