diff options
Diffstat (limited to 'sysdeps/ieee754/ldbl-96/s_erfl.c')
| -rw-r--r-- | sysdeps/ieee754/ldbl-96/s_erfl.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/sysdeps/ieee754/ldbl-96/s_erfl.c b/sysdeps/ieee754/ldbl-96/s_erfl.c index 47e4b9e909..c27de812ca 100644 --- a/sysdeps/ieee754/ldbl-96/s_erfl.c +++ b/sysdeps/ieee754/ldbl-96/s_erfl.c @@ -105,6 +105,7 @@ #include <errno.h> +#include <float.h> #include <math.h> #include <math_private.h> @@ -120,8 +121,6 @@ tiny = 1e-4931L, */ /* 2/sqrt(pi) - 1 */ efx = 1.2837916709551257389615890312154517168810E-1L, - /* 8 * (2/sqrt(pi) - 1) */ - efx8 = 1.0270333367641005911692712249723613735048E0L, pp[6] = { 1.122751350964552113068262337278335028553E6L, @@ -272,7 +271,16 @@ __erfl (long double x) if (ix < 0x3fde8000) /* |x|<2**-33 */ { if (ix < 0x00080000) - return 0.125 * (8.0 * x + efx8 * x); /*avoid underflow */ + { + /* Avoid spurious underflow. */ + long double ret = 0.0625 * (16.0 * x + (16.0 * efx) * x); + if (fabsl (ret) < LDBL_MIN) + { + long double force_underflow = ret * ret; + math_force_eval (force_underflow); + } + return ret; + } return x + efx * x; } z = x * x; |