From: Richard B. Kreckel <kreckel@ginac.de>
Date: Thu, 22 Dec 2011 02:01:29 +0000 (-0500)
Subject: Fix sign errr in some cacosh results
X-Git-Tag: glibc-2.15~36
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b27e24b8746b20d9ded426f202b79c3b7aeb953e;p=thirdparty%2Fglibc.git

Fix sign errr in some cacosh results
---

diff --git a/ChangeLog b/ChangeLog
index 51f148d41e3..1ccc3ddab06 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2011-11-18  Richard B. Kreckel  <kreckel@ginac.de>
+
+	[BZ #13305]
+	* math/s_cacosh.c: Fix rare miscomputation in cacosh().
+	* math/s_cacoshf.c: Likewise.
+	* math/s_cacoshl.c: Likewise.
+
 2011-12-21  Ulrich Drepper  <drepper@gmail.com>
 
 	[BZ #13439]
diff --git a/NEWS b/NEWS
index aba4a8db752..7e4e1692e95 100644
--- a/NEWS
+++ b/NEWS
@@ -12,8 +12,8 @@ Version 2.15
   6779, 6783, 9696, 10103, 10709, 11589, 12403, 12847, 12868, 12852, 12874,
   12885, 12892, 12907, 12922, 12935, 13007, 13021, 13067, 13068, 13090,
   13092, 13114, 13118, 13123, 13134, 13138, 13147, 13150, 13179, 13192,
-  13268, 13276, 13291, 13335, 13337, 13344, 13358, 13367, 13439, 13446,
-  13472, 13484, 13506, 13515, 13524
+  13268, 13276, 13291, 13305, 13335, 13337, 13344, 13358, 13367, 13439,
+  13446, 13472, 13484, 13506, 13515, 13524
 
 * New program pldd to list loaded object of a process
   Implemented by Ulrich Drepper.
diff --git a/math/s_cacosh.c b/math/s_cacosh.c
index bec6d3827e2..df5ce6945d4 100644
--- a/math/s_cacosh.c
+++ b/math/s_cacosh.c
@@ -74,17 +74,13 @@ __cacosh (__complex__ double x)
 
       y = __csqrt (y);
 
-      if (__real__ x < 0.0)
+      if (signbit (__real__ x))
 	y = -y;
 
       __real__ y += __real__ x;
       __imag__ y += __imag__ x;
 
       res = __clog (y);
-
-      /* We have to use the positive branch.  */
-      if (__real__ res < 0.0)
-	res = -res;
     }
 
   return res;
diff --git a/math/s_cacoshf.c b/math/s_cacoshf.c
index 0d6bd75dd7a..aa4696f10b2 100644
--- a/math/s_cacoshf.c
+++ b/math/s_cacoshf.c
@@ -1,5 +1,5 @@
 /* Return arc hyperbole cosine for float value.
-   Copyright (C) 1997, 2006 Free Software Foundation, Inc.
+   Copyright (C) 1997, 2006, 2011 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
 
@@ -67,7 +67,6 @@ __cacoshf (__complex__ float x)
     }
   else
     {
-#if 1
       __complex__ float y;
 
       __real__ y = (__real__ x - __imag__ x) * (__real__ x + __imag__ x) - 1.0;
@@ -75,30 +74,13 @@ __cacoshf (__complex__ float x)
 
       y = __csqrtf (y);
 
-      if (__real__ x < 0.0)
+      if (signbit (__real__ x))
 	y = -y;
 
       __real__ y += __real__ x;
       __imag__ y += __imag__ x;
 
       res = __clogf (y);
-#else
-      float re2 = __real__ x * __real__ x;
-      float im2 = __imag__ x * __imag__ x;
-      float sq = re2 - im2 - 1.0;
-      float ro = __ieee754_sqrtf (sq * sq + 4 * re2 * im2);
-      float a = __ieee754_sqrtf ((sq + ro) / 2.0);
-      float b = __ieee754_sqrtf ((-sq + ro) / 2.0);
-
-      __real__ res = 0.5 * __ieee754_logf (re2 + __real__ x * 2 * a
-					   + im2 + __imag__ x * 2 * b
-					   + ro);
-      __imag__ res = __ieee754_atan2f (__imag__ x + b, __real__ x + a);
-#endif
-
-      /* We have to use the positive branch.  */
-      if (__real__ res < 0.0)
-	res = -res;
     }
 
   return res;
diff --git a/math/s_cacoshl.c b/math/s_cacoshl.c
index 36f7a5f70e1..b90b196959f 100644
--- a/math/s_cacoshl.c
+++ b/math/s_cacoshl.c
@@ -74,17 +74,13 @@ __cacoshl (__complex__ long double x)
 
       y = __csqrtl (y);
 
-      if (__real__ x < 0.0)
+      if (signbit (__real__ x))
 	y = -y;
 
       __real__ y += __real__ x;
       __imag__ y += __imag__ x;
 
       res = __clogl (y);
-
-      /* We have to use the positive branch.  */
-      if (__real__ res < 0.0)
-	res = -res;
     }
 
   return res;