diff options
Diffstat (limited to 'math/s_csqrt.c')
| -rw-r--r-- | math/s_csqrt.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/math/s_csqrt.c b/math/s_csqrt.c index 66505afffb..75da2e7449 100644 --- a/math/s_csqrt.c +++ b/math/s_csqrt.c @@ -118,12 +118,28 @@ __csqrt (__complex__ double x) if (__real__ x > 0) { r = __ieee754_sqrt (0.5 * (d + __real__ x)); - s = 0.5 * (__imag__ x / r); + if (scale == 1 && fabs (__imag__ x) < 1.0) + { + /* Avoid possible intermediate underflow. */ + s = __imag__ x / r; + r = __scalbn (r, scale); + scale = 0; + } + else + s = 0.5 * (__imag__ x / r); } else { s = __ieee754_sqrt (0.5 * (d - __real__ x)); - r = fabs (0.5 * (__imag__ x / s)); + if (scale == 1 && fabs (__imag__ x) < 1.0) + { + /* Avoid possible intermediate underflow. */ + r = fabs (__imag__ x / s); + s = __scalbn (s, scale); + scale = 0; + } + else + r = fabs (0.5 * (__imag__ x / s)); } if (scale) |