diff options
Diffstat (limited to 'math/s_ctanh.c')
| -rw-r--r-- | math/s_ctanh.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/math/s_ctanh.c b/math/s_ctanh.c index d288b7d168..fee1910551 100644 --- a/math/s_ctanh.c +++ b/math/s_ctanh.c @@ -53,11 +53,20 @@ __ctanh (__complex__ double x) double sinix, cosix; double den; const int t = (int) ((DBL_MAX_EXP - 1) * M_LN2 / 2); + int icls = fpclassify (__imag__ x); /* tanh(x+iy) = (sinh(2x) + i*sin(2y))/(cosh(2x) + cos(2y)) = (sinh(x)*cosh(x) + i*sin(y)*cos(y))/(sinh(x)^2 + cos(y)^2). */ - __sincos (__imag__ x, &sinix, &cosix); + if (__builtin_expect (icls != FP_SUBNORMAL, 1)) + { + __sincos (__imag__ x, &sinix, &cosix); + } + else + { + sinix = __imag__ x; + cosix = 1.0; + } if (fabs (__real__ x) > t) { |