diff options
Diffstat (limited to 'stdlib/strtod_l.c')
| -rw-r--r-- | stdlib/strtod_l.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/stdlib/strtod_l.c b/stdlib/strtod_l.c index c39bb35b09..e13ab1e7e1 100644 --- a/stdlib/strtod_l.c +++ b/stdlib/strtod_l.c @@ -1189,7 +1189,16 @@ ____STRTOF_INTERNAL (nptr, endptr, group, loc) if (__glibc_unlikely (exponent > MAX_10_EXP + 1 - (intmax_t) int_no)) return overflow_value (negative); - if (__glibc_unlikely (exponent < MIN_10_EXP - (DIG + 1))) + /* 10^(MIN_10_EXP-1) is not normal. Thus, 10^(MIN_10_EXP-1) / + 2^MANT_DIG is below half the least subnormal, so anything with a + base-10 exponent less than the base-10 exponent (which is + MIN_10_EXP - 1 - ceil(MANT_DIG*log10(2))) of that value + underflows. DIG is floor((MANT_DIG-1)log10(2)), so an exponent + below MIN_10_EXP - (DIG + 3) underflows. But EXPONENT is + actually an exponent multiplied only by a fractional part, not an + integer part, so an exponent below MIN_10_EXP - (DIG + 2) + underflows. */ + if (__glibc_unlikely (exponent < MIN_10_EXP - (DIG + 2))) return underflow_value (negative); if (int_no > 0) @@ -1356,7 +1365,7 @@ ____STRTOF_INTERNAL (nptr, endptr, group, loc) assert (dig_no > int_no && exponent <= 0 - && exponent >= MIN_10_EXP - (DIG + 1)); + && exponent >= MIN_10_EXP - (DIG + 2)); /* We need to compute MANT_DIG - BITS fractional bits that lie within the mantissa of the result, the following bit for |