diff options
Diffstat (limited to 'sysdeps/ieee754/dbl-64/s_log1p.c')
| -rw-r--r-- | sysdeps/ieee754/dbl-64/s_log1p.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/sysdeps/ieee754/dbl-64/s_log1p.c b/sysdeps/ieee754/dbl-64/s_log1p.c index 86bbfbacaf..cff555b0aa 100644 --- a/sysdeps/ieee754/dbl-64/s_log1p.c +++ b/sysdeps/ieee754/dbl-64/s_log1p.c @@ -78,6 +78,7 @@ * See HP-15C Advanced Functions Handbook, p.193. */ +#include <float.h> #include <math.h> #include <math_private.h> @@ -118,7 +119,14 @@ __log1p (double x) { math_force_eval (two54 + x); /* raise inexact */ if (ax < 0x3c900000) /* |x| < 2**-54 */ - return x; + { + if (fabs (x) < DBL_MIN) + { + double force_underflow = x * x; + math_force_eval (force_underflow); + } + return x; + } else return x - x * x * 0.5; } |