Improve clog, clog10 handling of values with real or imaginary part slightly above 1 (bug 13629).

1 files changed, 7 insertions, 0 deletions

diff --git a/math/s_clog10f.c b/math/s_clog10f.c
index eb1b895aec..c61e8af8ce 100644
--- a/math/s_clog10f.c
+++ b/math/s_clog10f.c
@@ -83,6 +83,13 @@ __clog10f (__complex__ float x)
 	  else
 	    __real__ result = __log1pf (absy2) * ((float) M_LOG10E / 2.0f);
 	}
+      else if (absx > 1.0f && absx < 2.0f && absy < 1.0f && scale == 0)
+	{
+	  float d2m1 = (absx - 1.0f) * (absx + 1.0f);
+	  if (absy >= FLT_EPSILON)
+	    d2m1 += absy * absy;
+	  __real__ result = __log1pf (d2m1) * ((float) M_LOG10E / 2.0f);
+	}
       else
 	{
 	  float d = __ieee754_hypotf (absx, absy);