From d032e0d29b6ed9d3844916ada0ead19c3190ff9a Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Tue, 25 Sep 2012 19:43:49 +0000 Subject: Fix inaccuracy of clog, clog10 near |z| = 1 (bug 13629). --- math/s_clogl.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'math/s_clogl.c') diff --git a/math/s_clogl.c b/math/s_clogl.c index eaba572ce7..af3ed99714 100644 --- a/math/s_clogl.c +++ b/math/s_clogl.c @@ -85,6 +85,19 @@ __clogl (__complex__ long double x) d2m1 += absy * absy; __real__ result = __log1pl (d2m1) / 2.0L; } + else if (absx < 1.0L + && absx >= 0.75L + && absy < LDBL_EPSILON / 2.0L + && scale == 0) + { + long double d2m1 = (absx - 1.0L) * (absx + 1.0L); + __real__ result = __log1pl (d2m1) / 2.0L; + } + else if (absx < 1.0L && (absx >= 0.75L || absy >= 0.5L) && scale == 0) + { + long double d2m1 = __x2y2m1l (absx, absy); + __real__ result = __log1pl (d2m1) / 2.0L; + } else { long double d = __ieee754_hypotl (absx, absy); -- cgit 1.4.1