You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
221 lines
6.2 KiB
221 lines
6.2 KiB
7 years ago
|
/* Copyright (c) 2002-2005 Michael Stumpf <mistumpf@de.pepperl-fuchs.com>
|
||
|
|
Copyright (c) 2006,2008 Dmitry Xmelkov
|
||
|
|
|
||
|
|
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 of the copyright holders nor the names of
|
||
|
|
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. */
|
||
|
|
|
||
|
|
/* $Id: strtod.c 2191 2010-11-05 13:45:57Z arcanum $ */
|
||
|
|
|
||
|
|
#include <errno.h>
|
||
|
|
#include <limits.h>
|
||
|
|
#include <math.h> /* INFINITY, NAN */
|
||
|
|
#include <strings.h>
|
||
|
|
#include <stdint.h>
|
||
|
|
#include "avrlibc.h"
|
||
|
|
|
||
|
|
/* Only GCC 4.2 calls the library function to convert an unsigned long
|
||
|
|
to float. Other GCC-es (including 4.3) use a signed long to float
|
||
|
|
conversion along with a large inline code to correct the result. */
|
||
|
|
extern double __floatunsisf (unsigned long);
|
||
|
|
|
||
|
|
static const float pwr_p10 [6] = {
|
||
|
|
1e+1, 1e+2, 1e+4, 1e+8, 1e+16, 1e+32
|
||
|
|
};
|
||
|
|
static const float pwr_m10 [6] = {
|
||
|
|
1e-1, 1e-2, 1e-4, 1e-8, 1e-16, 1e-32
|
||
|
|
};
|
||
|
|
|
||
|
|
/* PSTR() is not used to save 1 byte per string: '\0' at the tail. */
|
||
|
|
static const char pstr_inf[] = {'I','N','F'};
|
||
|
|
static const char pstr_inity[] = {'I','N','I','T','Y'};
|
||
|
|
static const char pstr_nan[] = {'N','A','N'};
|
||
|
|
|
||
|
|
/** The strtod() function converts the initial portion of the string pointed
|
||
|
|
to by \a nptr to double representation.
|
||
|
|
|
||
|
|
The expected form of the string is an optional plus ( \c '+' ) or minus
|
||
|
|
sign ( \c '-' ) followed by a sequence of digits optionally containing
|
||
|
|
a decimal-point character, optionally followed by an exponent. An
|
||
|
|
exponent consists of an \c 'E' or \c 'e', followed by an optional plus
|
||
|
|
or minus sign, followed by a sequence of digits.
|
||
|
|
|
||
|
|
Leading white-space characters in the string are skipped.
|
||
|
|
|
||
|
|
The strtod() function returns the converted value, if any.
|
||
|
|
|
||
|
|
If \a endptr is not \c NULL, a pointer to the character after the last
|
||
|
|
character used in the conversion is stored in the location referenced by
|
||
|
|
\a endptr.
|
||
|
|
|
||
|
|
If no conversion is performed, zero is returned and the value of
|
||
|
|
\a nptr is stored in the location referenced by \a endptr.
|
||
|
|
|
||
|
|
If the correct value would cause overflow, plus or minus \c INFINITY is
|
||
|
|
returned (according to the sign of the value), and \c ERANGE is stored
|
||
|
|
in \c errno. If the correct value would cause underflow, zero is
|
||
|
|
returned and \c ERANGE is stored in \c errno.
|
||
|
|
*/
|
||
|
|
|
||
|
|
double
|
||
|
|
avr_strtod (const char * nptr, char ** endptr)
|
||
|
|
{
|
||
|
|
union {
|
||
|
|
unsigned long u32;
|
||
|
|
float flt;
|
||
|
|
} x;
|
||
|
|
unsigned char c;
|
||
|
|
int exp;
|
||
|
|
|
||
|
|
unsigned char flag;
|
||
|
|
#define FL_MINUS 0x01 /* number is negative */
|
||
|
|
#define FL_ANY 0x02 /* any digit was readed */
|
||
|
|
#define FL_OVFL 0x04 /* overflow was */
|
||
|
|
#define FL_DOT 0x08 /* decimal '.' was */
|
||
|
|
#define FL_MEXP 0x10 /* exponent 'e' is neg. */
|
||
|
|
|
||
|
|
if (endptr)
|
||
|
|
*endptr = (char *)nptr;
|
||
|
|
|
||
|
|
do {
|
||
|
|
c = *nptr++;
|
||
|
|
} while (c!=0&&c<=' ');
|
||
|
|
|
||
|
|
flag = 0;
|
||
|
|
if (c == '-') {
|
||
|
|
flag = FL_MINUS;
|
||
|
|
c = *nptr++;
|
||
|
|
} else if (c == '+') {
|
||
|
|
c = *nptr++;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (!strncasecmp(nptr - 1, pstr_inf, 3)) {
|
||
|
|
nptr += 2;
|
||
|
|
if (!strncasecmp(nptr, pstr_inity, 5))
|
||
|
|
nptr += 5;
|
||
|
|
if (endptr)
|
||
|
|
*endptr = (char *)nptr;
|
||
|
|
return flag & FL_MINUS ? -INFINITY : +INFINITY;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* NAN() construction is not realised.
|
||
|
|
Length would be 3 characters only. */
|
||
|
|
if (!strncasecmp(nptr - 1, pstr_nan, 3)) {
|
||
|
|
if (endptr)
|
||
|
|
*endptr = (char *)nptr + 2;
|
||
|
|
return NAN;
|
||
|
|
}
|
||
|
|
|
||
|
|
x.u32 = 0;
|
||
|
|
exp = 0;
|
||
|
|
while (1) {
|
||
|
|
|
||
|
|
c -= '0';
|
||
|
|
|
||
|
|
if (c <= 9) {
|
||
|
|
flag |= FL_ANY;
|
||
|
|
if (flag & FL_OVFL) {
|
||
|
|
if (!(flag & FL_DOT))
|
||
|
|
exp += 1;
|
||
|
|
} else {
|
||
|
|
if (flag & FL_DOT)
|
||
|
|
exp -= 1;
|
||
|
|
/* x.u32 = x.u32 * 10 + c */
|
||
|
|
x.u32 = (((x.u32 << 2) + x.u32) << 1) + c;
|
||
|
|
if (x.u32 >= (ULONG_MAX - 9) / 10)
|
||
|
|
flag |= FL_OVFL;
|
||
|
|
}
|
||
|
|
|
||
|
|
} else if (c == (('.'-'0') & 0xff) && !(flag & FL_DOT)) {
|
||
|
|
flag |= FL_DOT;
|
||
|
|
} else {
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
c = *nptr++;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (c == (('e'-'0') & 0xff) || c == (('E'-'0') & 0xff))
|
||
|
|
{
|
||
|
|
int i;
|
||
|
|
c = *nptr++;
|
||
|
|
i = 2;
|
||
|
|
if (c == '-') {
|
||
|
|
flag |= FL_MEXP;
|
||
|
|
c = *nptr++;
|
||
|
|
} else if (c == '+') {
|
||
|
|
c = *nptr++;
|
||
|
|
} else {
|
||
|
|
i = 1;
|
||
|
|
}
|
||
|
|
c -= '0';
|
||
|
|
if (c > 9) {
|
||
|
|
nptr -= i;
|
||
|
|
} else {
|
||
|
|
i = 0;
|
||
|
|
do {
|
||
|
|
if (i < 3200)
|
||
|
|
i = (((i << 2) + i) << 1) + c; /* i = 10*i + c */
|
||
|
|
c = *nptr++ - '0';
|
||
|
|
} while (c <= 9);
|
||
|
|
if (flag & FL_MEXP)
|
||
|
|
i = -i;
|
||
|
|
exp += i;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if ((flag & FL_ANY) && endptr)
|
||
|
|
*endptr = (char *)nptr - 1;
|
||
|
|
|
||
|
|
x.flt = __floatunsisf (x.u32); /* manually */
|
||
|
|
if ((flag & FL_MINUS) && (flag & FL_ANY))
|
||
|
|
x.flt = -x.flt;
|
||
|
|
|
||
|
|
if (x.flt != 0) {
|
||
|
|
int pwr;
|
||
|
|
if (exp < 0) {
|
||
|
|
nptr = (void *)(pwr_m10 + 5);
|
||
|
|
exp = -exp;
|
||
|
|
} else {
|
||
|
|
nptr = (void *)(pwr_p10 + 5);
|
||
|
|
}
|
||
|
|
for (pwr = 32; pwr; pwr >>= 1) {
|
||
|
|
for (; exp >= pwr; exp -= pwr) {
|
||
|
|
union {
|
||
|
|
unsigned long u32;
|
||
|
|
float flt;
|
||
|
|
} y;
|
||
|
|
y.u32 = (uint32_t) *((float *)nptr);
|
||
|
|
x.flt *= y.flt;
|
||
|
|
}
|
||
|
|
nptr -= sizeof(float);
|
||
|
|
}
|
||
|
|
if (!isfinite(x.flt) || x.flt == 0)
|
||
|
|
errno = ERANGE;
|
||
|
|
}
|
||
|
|
|
||
|
|
return x.flt;
|
||
|
|
}
|