care is taken that the setting of errno correctly reflects underflow
condition. scanning exact denormal values does not result in ERANGE,
nor does scanning values (such as the usual string definition of
FLT_MIN) which are actually less than the smallest normal number but
which round to a normal result.
only the decimal case is handled so far; hex float require a separate
fix to come later.
+#define CONCAT2(x,y) x ## y
+#define CONCAT(x,y) CONCAT2(x,y)
static long long scanexp(FILE *f, int pok)
{
static long long scanexp(FILE *f, int pok)
{
int gotdig = 0, gotrad = 0;
int rp;
int e2;
int gotdig = 0, gotrad = 0;
int rp;
int e2;
+ int emax = -emin-bits+3;
+ int denormal = 0;
long double y;
long double frac=0;
long double bias=0;
long double y;
long double frac=0;
long double bias=0;
if (bits > LDBL_MANT_DIG+e2-emin) {
bits = LDBL_MANT_DIG+e2-emin;
if (bits<0) bits=0;
if (bits > LDBL_MANT_DIG+e2-emin) {
bits = LDBL_MANT_DIG+e2-emin;
if (bits<0) bits=0;
}
/* Calculate bias term to force rounding, move out lower bits */
}
/* Calculate bias term to force rounding, move out lower bits */
- y = scalbnl(y, e2);
-
- if (!y) errno = ERANGE;
+ if ((e2+LDBL_MANT_DIG & INT_MAX) > emax-5) {
+ if (fabs(y) >= CONCAT(0x1p, LDBL_MANT_DIG)) {
+ if (denormal && bits==LDBL_MANT_DIG+e2-emin)
+ denormal = 0;
+ y *= 0.5;
+ e2++;
+ }
+ if (e2+LDBL_MANT_DIG>emax || (denormal && frac))
+ errno = ERANGE;
+ }
}
static long double hexfloat(FILE *f, int bits, int emin, int sign, int pok)
}
static long double hexfloat(FILE *f, int bits, int emin, int sign, int pok)