d034f5145c
setjmp/longjmp now save/restore the signal mask on BSD 4.2 systems, some minor mods in atof
81 lines
1.1 KiB
C
81 lines
1.1 KiB
C
/* $Header$ */
|
|
#ifndef NOFLOAT
|
|
#include <ctype.h>
|
|
|
|
extern double ldexp();
|
|
|
|
double
|
|
atof(p)
|
|
register char *p;
|
|
{
|
|
register int c;
|
|
int exp = 0, sign = 1, expsign = 0;
|
|
double fl;
|
|
double big = (double)(1L << 30) * (1L << 22);
|
|
|
|
while (isspace(*p)) p++;
|
|
c = *p;
|
|
|
|
switch (c) {
|
|
case '-':
|
|
sign = -1;
|
|
case '+':
|
|
p++;
|
|
}
|
|
|
|
fl = 0.0;
|
|
while (isdigit(c = *p++)) {
|
|
if (fl < big)
|
|
fl = 10.0 * fl + (double)(c - '0');
|
|
else
|
|
exp++;
|
|
}
|
|
if (c == '.') {
|
|
while (isdigit(c = *p++)) {
|
|
if (fl < big) {
|
|
fl = 10.0 * fl + (double) (c - '0');
|
|
exp--;
|
|
}
|
|
}
|
|
}
|
|
if (fl == 0) return 0;
|
|
if (c == 'E' || c == 'e') {
|
|
int exp1 = 0;
|
|
int sign = 1;
|
|
|
|
switch (*p) {
|
|
case '-':
|
|
sign = -1;
|
|
case '+':
|
|
p++;
|
|
}
|
|
while (isdigit(c = *p++)) {
|
|
exp1 = 10 * exp1 + c - '0';
|
|
}
|
|
exp += sign * exp1;
|
|
}
|
|
|
|
if (exp < 0) {
|
|
expsign = 1;
|
|
exp = -exp;
|
|
}
|
|
|
|
if (exp != 0) {
|
|
int oldexp = exp;
|
|
double exp5 = 5.0;
|
|
double correction = 1.0;
|
|
|
|
while (exp) {
|
|
if (exp % 2) correction *= exp5;
|
|
exp /= 2;
|
|
exp5 *= exp5;
|
|
}
|
|
if (expsign) fl = fl / correction;
|
|
else fl = fl * correction;
|
|
|
|
fl = ldexp(fl, expsign ? -oldexp : oldexp);
|
|
}
|
|
|
|
return sign * fl;
|
|
}
|
|
#endif
|