strtoumax: fix typo in previous commit.

[gnulib.git] / lib / copysignl.c

diff --git a/lib/copysignl.c b/lib/copysignl.c
index 95947f4..cc65a5e 100644 (file)
--- a/lib/copysignl.c
+++ b/lib/copysignl.c
@@ -1,5 +1,5 @@
 /* Copy sign into another 'long double' number.
-   Copyright (C) 2011 Free Software Foundation, Inc.
+   Copyright (C) 2011-2013 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -19,8 +19,54 @@
 /* Specification.  */
 #include <math.h>
 
+#if HAVE_SAME_LONG_DOUBLE_AS_DOUBLE
+
 long double
 copysignl (long double x, long double y)
 {
+  return copysign (x, y);
+}
+
+#else
+
+# if defined __hpux && !defined __GNUC__
+
+#  include <float.h>
+
+/* HP cc on HP-UX 10.20 has a bug with the constant expression -0.0L.  */
+static long double
+compute_minus_zerol (void)
+{
+  return -LDBL_MIN * LDBL_MIN;
+}
+#  define minus_zerol compute_minus_zerol ()
+
+/* HP cc on HP-UX 11 has a bug: When x is a positive zero, - x comes out
+   as a positive zero, rather than as a minus zero.  Work around it.  */
+static long double
+unary_minus (long double x)
+{
+  if (x == 0.0L)
+    {
+      if (signbit (x))
+        return 0.0L;
+      else
+        return minus_zerol;
+    }
+  else
+    return - x;
+}
+
+# endif
+
+long double
+copysignl (long double x, long double y)
+{
+# if defined __hpux && !defined __GNUC__
+  return (signbit (x) != signbit (y) ? unary_minus (x) : x);
+# else
   return (signbit (x) != signbit (y) ? - x : x);
+# endif
 }
+
+#endif