diff options
Diffstat (limited to 'math/s_csqrtf.c')
| -rw-r--r-- | math/s_csqrtf.c | 26 |
1 files changed, 19 insertions, 7 deletions
diff --git a/math/s_csqrtf.c b/math/s_csqrtf.c index 6539ba2249..5a274fd87b 100644 --- a/math/s_csqrtf.c +++ b/math/s_csqrtf.c @@ -75,7 +75,11 @@ __csqrtf (__complex__ float x) } else if (__builtin_expect (rcls == FP_ZERO, 0)) { - float r = __ieee754_sqrtf (0.5 * fabsf (__imag__ x)); + float r; + if (fabsf (__imag__ x) >= 2.0f * FLT_MIN) + r = __ieee754_sqrtf (0.5f * fabsf (__imag__ x)); + else + r = 0.5f * __ieee754_sqrtf (2.0f * fabsf (__imag__ x)); __real__ res = r; __imag__ res = __copysignf (r, __imag__ x); @@ -85,13 +89,21 @@ __csqrtf (__complex__ float x) float d, r, s; int scale = 0; - if (fabsf (__real__ x) > FLT_MAX / 2.0f - || fabsf (__imag__ x) > FLT_MAX / 2.0f) + if (fabsf (__real__ x) > FLT_MAX / 4.0f) { scale = 1; __real__ x = __scalbnf (__real__ x, -2 * scale); __imag__ x = __scalbnf (__imag__ x, -2 * scale); } + else if (fabsf (__imag__ x) > FLT_MAX / 4.0f) + { + scale = 1; + if (fabsf (__real__ x) >= 4.0f * FLT_MIN) + __real__ x = __scalbnf (__real__ x, -2 * scale); + else + __real__ x = 0.0f; + __imag__ x = __scalbnf (__imag__ x, -2 * scale); + } else if (fabsf (__real__ x) < FLT_MIN && fabsf (__imag__ x) < FLT_MIN) { @@ -105,13 +117,13 @@ __csqrtf (__complex__ float x) to avoid cancellation error in d +/- Re x. */ if (__real__ x > 0) { - r = __ieee754_sqrtf (0.5f * d + 0.5f * __real__ x); - s = (0.5f * __imag__ x) / r; + r = __ieee754_sqrtf (0.5f * (d + __real__ x)); + s = 0.5f * (__imag__ x / r); } else { - s = __ieee754_sqrtf (0.5f * d - 0.5f * __real__ x); - r = fabsf ((0.5f * __imag__ x) / s); + s = __ieee754_sqrtf (0.5f * (d - __real__ x)); + r = fabsf (0.5f * (__imag__ x / s)); } if (scale) |