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| author | Joseph Myers <joseph@codesourcery.com> | 2012-07-26 11:31:35 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2012-07-26 11:31:35 +0000 |
| commit | da865e95bcf9a5365de78fa6b5c681aca0a1bb46 (patch) | |
| tree | 783e2a5f2befa846dc208ec14b7dcde164c7b205 /math/s_clog10l.c | |
| parent | 3129cfc6ec7be65a0bdc1f82432ee421c1c65a77 (diff) | |
| download | glibc-da865e95bcf9a5365de78fa6b5c681aca0a1bb46.tar.gz glibc-da865e95bcf9a5365de78fa6b5c681aca0a1bb46.tar.xz glibc-da865e95bcf9a5365de78fa6b5c681aca0a1bb46.zip | |
Improve clog, clog10 handling of values with real or imaginary part 1 (bug 13629).
Diffstat (limited to 'math/s_clog10l.c')
| -rw-r--r-- | math/s_clog10l.c | 30 |
1 files changed, 21 insertions, 9 deletions
diff --git a/math/s_clog10l.c b/math/s_clog10l.c index 3e0ceaa2a8..2a380f6f3b 100644 --- a/math/s_clog10l.c +++ b/math/s_clog10l.c @@ -44,21 +44,21 @@ __clog10l (__complex__ long double x) { /* Neither real nor imaginary part is NaN. */ long double absx = fabsl (__real__ x), absy = fabsl (__imag__ x); - long double d; int scale = 0; + if (absx < absy) + { + long double t = absx; + absx = absy; + absy = t; + } + if (absx > LDBL_MAX / 2.0L) { scale = -1; absx = __scalbnl (absx, scale); absy = (absy >= LDBL_MIN * 2.0L ? __scalbnl (absy, scale) : 0.0L); } - else if (absy > LDBL_MAX / 2.0L) - { - scale = -1; - absx = (absx >= LDBL_MIN * 2.0L ? __scalbnl (absx, scale) : 0.0L); - absy = __scalbnl (absy, scale); - } else if (absx < LDBL_MIN && absy < LDBL_MIN) { scale = LDBL_MANT_DIG; @@ -66,9 +66,21 @@ __clog10l (__complex__ long double x) absy = __scalbnl (absy, scale); } - d = __ieee754_hypotl (absx, absy); + if (absx == 1.0L && scale == 0) + { + long double absy2 = absy * absy; + if (absy2 <= LDBL_MIN * 2.0L * M_LN10l) + __real__ result + = (absy2 / 2.0L - absy2 * absy2 / 4.0L) * M_LOG10El; + else + __real__ result = __log1pl (absy2) * (M_LOG10El / 2.0L); + } + else + { + long double d = __ieee754_hypotl (absx, absy); + __real__ result = __ieee754_log10l (d) - scale * M_LOG10_2l; + } - __real__ result = __ieee754_log10l (d) - scale * M_LOG10_2l; __imag__ result = M_LOG10El * __ieee754_atan2l (__imag__ x, __real__ x); } else |