/*
* %CopyrightBegin%
*
* Copyright Ericsson AB 1997-2013. All Rights Reserved.
*
* The contents of this file are subject to the Erlang Public License,
* Version 1.1, (the "License"); you may not use this file except in
* compliance with the License. You should have received a copy of the
* Erlang Public License along with this software. If not, it can be
* retrieved online at http://www.erlang.org/.
*
* Software distributed under the License is distributed on an "AS IS"
* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
* the License for the specific language governing rights and limitations
* under the License.
*
* %CopyrightEnd%
*/
/* Float conversions */
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include "sys.h"
#include "signal.h"
/* global variable for floating point checks, (see sys.h) */
/* Note! This is part of the interface Machine <---> sys.c */
volatile int erl_fp_exception = 0;
static void fpe_exception(int sig);
void
erts_sys_init_float(void)
{
}
void erts_thread_init_float(void)
{
}
void erts_thread_disable_fpe(void)
{
}
/*
** These two functions should maybe use localeconv() to pick up
** the current radix character, but since it is uncertain how
** expensive such a system call is, and since no-one has heard
** of other radix characters than '.' and ',' an ad-hoc
** low execution time solution is used instead.
*/
int
sys_chars_to_double(char *buf, double *fp)
{
char *s = buf, *t, *dp;
/* Robert says that something like this is what he really wanted:
* (The [.,] radix test is NOT what Robert wanted - it was added later)
*
* 7 == sscanf(Tbuf, "%[+-]%[0-9][.,]%[0-9]%[eE]%[+-]%[0-9]%s", ....);
* if (*s2 == 0 || *s3 == 0 || *s4 == 0 || *s6 == 0 || *s7)
* break;
*/
/* Scan string to check syntax. */
if (*s == '+' || *s == '-') s++;
if (!isdigit(*s)) /* Leading digits. */
return -1;
while (isdigit(*s)) s++;
if (*s != '.' && *s != ',')/* Decimal part. */
return -1;
dp = s++; /* Remember decimal point pos just in case */
if (!isdigit(*s))
return -1;
while (isdigit(*s)) s++;
if (*s == 'e' || *s == 'E') {
/* There is an exponent. */
s++;
if (*s == '+' || *s == '-') s++;
if (!isdigit(*s))
return -1;
while (isdigit(*s)) s++;
}
if (*s) /* That should be it */
return -1;
errno = 0;
*fp = strtod(buf, &t);
if (t != s) { /* Whole string not scanned */
/* Try again with other radix char */
*dp = (*dp == '.') ? ',' : '.';
errno = 0;
*fp = strtod(buf, &t);
if (t != s) { /* Whole string not scanned */
return -1;
}
}
if (*fp < -1.0e-307 || 1.0e-307 < *fp) {
if (errno == ERANGE) {
return -1;
}
} else {
if (errno == ERANGE) {
/* Special case: Windows (at least some) regard very small
* i.e non-normalized numbers as a range error for strtod().
* But not for atof.
*/
*fp = atof(buf);
}
}
return 0;
}
/*
** Convert a double to ascii format 0.dddde[+|-]ddd
** return number of characters converted or -1 if error.
*/
int
sys_double_to_chars_ext(double fp, char *buffer, size_t buffer_size, size_t decimals)
{
char *s = buffer;
if (erts_snprintf(buffer, buffer_size, "%.*e", decimals, fp) >= buffer_size)
return -1;
/* Search upto decimal point */
if (*s == '+' || *s == '-') s++;
while (isdigit(*s)) s++;
if (*s == ',') *s++ = '.'; /* Replace ',' with '.' */
/* Scan to end of string */
while (*s) s++;
return s-buffer; /* i.e strlen(buffer) */
}
#ifdef USE_MATHERR
int
matherr(struct _exception *exc)
{
erl_fp_exception = 1;
DEBUGF(("FP exception (matherr) (0x%x) (%d)\n", exc->type, erl_fp_exception));
return 1;
}
#endif
static void
fpe_exception(int sig)
{
erl_fp_exception = 1;
DEBUGF(("FP exception\n"));
}
