diff options
Diffstat (limited to 'math/s_clogf.c')
| -rw-r--r-- | math/s_clogf.c | 36 |
1 files changed, 27 insertions, 9 deletions
diff --git a/math/s_clogf.c b/math/s_clogf.c index e20e594964..088730cfd2 100644 --- a/math/s_clogf.c +++ b/math/s_clogf.c @@ -41,21 +41,21 @@ __clogf (__complex__ float x) { /* Neither real nor imaginary part is NaN. */ float absx = fabsf (__real__ x), absy = fabsf (__imag__ x); - float d; int scale = 0; + if (absx < absy) + { + float t = absx; + absx = absy; + absy = t; + } + if (absx > FLT_MAX / 2.0f) { scale = -1; absx = __scalbnf (absx, scale); absy = (absy >= FLT_MIN * 2.0f ? __scalbnf (absy, scale) : 0.0f); } - else if (absy > FLT_MAX / 2.0f) - { - scale = -1; - absx = (absx >= FLT_MIN * 2.0f ? __scalbnf (absx, scale) : 0.0f); - absy = __scalbnf (absy, scale); - } else if (absx < FLT_MIN && absy < FLT_MIN) { scale = FLT_MANT_DIG; @@ -63,9 +63,27 @@ __clogf (__complex__ float x) absy = __scalbnf (absy, scale); } - d = __ieee754_hypotf (absx, absy); + if (absx == 1.0f && scale == 0) + { + float absy2 = absy * absy; + if (absy2 <= FLT_MIN * 2.0f) + { +#if __FLT_EVAL_METHOD__ == 0 + __real__ result = absy2 / 2.0f - absy2 * absy2 / 4.0f; +#else + volatile float force_underflow = absy2 * absy2 / 4.0f; + __real__ result = absy2 / 2.0f - force_underflow; +#endif + } + else + __real__ result = __log1pf (absy2) / 2.0f; + } + else + { + float d = __ieee754_hypotf (absx, absy); + __real__ result = __ieee754_logf (d) - scale * (float) M_LN2; + } - __real__ result = __ieee754_logf (d) - scale * (float) M_LN2; __imag__ result = __ieee754_atan2f (__imag__ x, __real__ x); } else |