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| author | Joseph Myers <joseph@codesourcery.com> | 2012-09-25 19:43:49 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2012-09-25 19:43:49 +0000 |
| commit | d032e0d29b6ed9d3844916ada0ead19c3190ff9a (patch) | |
| tree | a0ebd8e356dd8608c8e207d6a509a48b716ca537 /math/s_clog.c | |
| parent | c8cb2a522493dc4a2d7f41694b00274eea2f5782 (diff) | |
| download | glibc-d032e0d29b6ed9d3844916ada0ead19c3190ff9a.tar.gz glibc-d032e0d29b6ed9d3844916ada0ead19c3190ff9a.tar.xz glibc-d032e0d29b6ed9d3844916ada0ead19c3190ff9a.zip | |
Fix inaccuracy of clog, clog10 near |z| = 1 (bug 13629).
Diffstat (limited to 'math/s_clog.c')
| -rw-r--r-- | math/s_clog.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/math/s_clog.c b/math/s_clog.c index 2593066001..79b1f375d7 100644 --- a/math/s_clog.c +++ b/math/s_clog.c @@ -85,6 +85,19 @@ __clog (__complex__ double x) d2m1 += absy * absy; __real__ result = __log1p (d2m1) / 2.0; } + else if (absx < 1.0 + && absx >= 0.75 + && absy < DBL_EPSILON / 2.0 + && scale == 0) + { + double d2m1 = (absx - 1.0) * (absx + 1.0); + __real__ result = __log1p (d2m1) / 2.0; + } + else if (absx < 1.0 && (absx >= 0.75 || absy >= 0.5) && scale == 0) + { + double d2m1 = __x2y2m1 (absx, absy); + __real__ result = __log1p (d2m1) / 2.0; + } else { double d = __ieee754_hypot (absx, absy); |