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| author | Joseph Myers <joseph@codesourcery.com> | 2013-05-01 10:07:00 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2013-05-01 10:07:00 +0000 |
| commit | 10de07f5fdd9eaf3a808d4461401f5b661095614 (patch) | |
| tree | 844a1ed48df767e65d46a429f0e1b062e0e2fad5 /math/s_catanf.c | |
| parent | cb4d54147e620f4267d1c675bf2daec0a8e7c809 (diff) | |
| download | glibc-10de07f5fdd9eaf3a808d4461401f5b661095614.tar.gz glibc-10de07f5fdd9eaf3a808d4461401f5b661095614.tar.xz glibc-10de07f5fdd9eaf3a808d4461401f5b661095614.zip | |
Fix catan, catanh spurious underflows (bug 15423).
Diffstat (limited to 'math/s_catanf.c')
| -rw-r--r-- | math/s_catanf.c | 43 |
1 files changed, 27 insertions, 16 deletions
diff --git a/math/s_catanf.c b/math/s_catanf.c index 698e2af461..0713565c86 100644 --- a/math/s_catanf.c +++ b/math/s_catanf.c @@ -78,7 +78,7 @@ __catanf (__complex__ float x) } else { - float r2, num, den, f, absx, absy; + float den, absx, absy; absx = fabsf (__real__ x); absy = fabsf (__imag__ x); @@ -89,10 +89,10 @@ __catanf (__complex__ float x) absy = t; } - if (absx >= 1.0f) - den = (1.0f - absx) * (1.0f + absx) - absy * absy; - else if (absx >= 0.75f && absy < FLT_EPSILON / 2.0f) + if (absy < FLT_EPSILON / 2.0f) den = (1.0f - absx) * (1.0f + absx); + else if (absx >= 1.0f) + den = (1.0f - absx) * (1.0f + absx) - absy * absy; else if (absx >= 0.75f || absy >= 0.5f) den = -__x2y2m1f (absx, absy); else @@ -100,21 +100,32 @@ __catanf (__complex__ float x) __real__ res = 0.5f * __ieee754_atan2f (2.0f * __real__ x, den); - r2 = __real__ x * __real__ x; + if (fabsf (__imag__ x) == 1.0f + && fabsf (__real__ x) < FLT_EPSILON * FLT_EPSILON) + __imag__ res = (__copysignf (0.5f, __imag__ x) + * ((float) M_LN2 + - __ieee754_logf (fabsf (__real__ x)))); + else + { + float r2 = 0.0f, num, f; - num = __imag__ x + 1.0f; - num = r2 + num * num; + if (fabsf (__real__ x) >= FLT_EPSILON * FLT_EPSILON) + r2 = __real__ x * __real__ x; - den = __imag__ x - 1.0f; - den = r2 + den * den; + num = __imag__ x + 1.0f; + num = r2 + num * num; - f = num / den; - if (f < 0.5f) - __imag__ res = 0.25f * __ieee754_logf (f); - else - { - num = 4.0f * __imag__ x; - __imag__ res = 0.25f * __log1pf (num / den); + den = __imag__ x - 1.0f; + den = r2 + den * den; + + f = num / den; + if (f < 0.5f) + __imag__ res = 0.25f * __ieee754_logf (f); + else + { + num = 4.0f * __imag__ x; + __imag__ res = 0.25f * __log1pf (num / den); + } } } |