X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fceil.c;h=b30902cbfd6dc059e2afbc7d1cf974da67fc29a9;hb=1a6fbdd7d28dff1868c5eb0baf0029b27e42526a;hp=b5a0316cf1798e2a773da99103f04b696d3681ed;hpb=c7f33ef75bc531bc875e34019324811962b001d1;p=gnulib.git

diff --git a/lib/ceil.c b/lib/ceil.c
index b5a0316cf..b30902cbf 100644
--- a/lib/ceil.c
+++ b/lib/ceil.c
@@ -1,5 +1,5 @@
 /* Round towards positive infinity.
-   Copyright (C) 2007 Free Software Foundation, Inc.
+   Copyright (C) 2007, 2010-2011 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
@@ -23,23 +23,35 @@
 
 #include <float.h>
 
+#undef MIN
+
 #ifdef USE_LONG_DOUBLE
 # define FUNC ceill
 # define DOUBLE long double
 # define MANT_DIG LDBL_MANT_DIG
+# define MIN LDBL_MIN
 # define L_(literal) literal##L
 #elif ! defined USE_FLOAT
 # define FUNC ceil
 # define DOUBLE double
 # define MANT_DIG DBL_MANT_DIG
+# define MIN DBL_MIN
 # define L_(literal) literal
 #else /* defined USE_FLOAT */
 # define FUNC ceilf
 # define DOUBLE float
 # define MANT_DIG FLT_MANT_DIG
+# define MIN FLT_MIN
 # define L_(literal) literal##f
 #endif
 
+/* -0.0.  See minus-zero.h.  */
+#if defined __hpux || defined __sgi || defined __ICC
+# define MINUS_ZERO (-MIN * MIN)
+#else
+# define MINUS_ZERO L_(-0.0)
+#endif
+
 /* 2^(MANT_DIG-1).  */
 static const DOUBLE TWO_MANT_DIG =
   /* Assume MANT_DIG <= 5 * 31.
@@ -67,27 +79,31 @@ FUNC (DOUBLE x)
     {
       /* Avoid rounding errors for values near 2^k, where k >= MANT_DIG-1.  */
       if (z < TWO_MANT_DIG)
-	{
-	  /* Round to the next integer (nearest or up or down, doesn't matter).  */
-	  z += TWO_MANT_DIG;
-	  z -= TWO_MANT_DIG;
-	  /* Enforce rounding up.  */
-	  if (z < y)
-	    z += L_(1.0);
-	}
+        {
+          /* Round to the next integer (nearest or up or down, doesn't matter).  */
+          z += TWO_MANT_DIG;
+          z -= TWO_MANT_DIG;
+          /* Enforce rounding up.  */
+          if (z < y)
+            z += L_(1.0);
+        }
     }
   else if (z < L_(0.0))
     {
+      /* For -1 < x < 0, return -0.0 regardless of the current rounding
+         mode.  */
+      if (z > L_(-1.0))
+        z = MINUS_ZERO;
       /* Avoid rounding errors for values near -2^k, where k >= MANT_DIG-1.  */
-      if (z > - TWO_MANT_DIG)
-	{
-	  /* Round to the next integer (nearest or up or down, doesn't matter).  */
-	  z -= TWO_MANT_DIG;
-	  z += TWO_MANT_DIG;
-	  /* Enforce rounding up.  */
-	  if (z < y)
-	    z += L_(1.0);
-	}
+      else if (z > - TWO_MANT_DIG)
+        {
+          /* Round to the next integer (nearest or up or down, doesn't matter).  */
+          z -= TWO_MANT_DIG;
+          z += TWO_MANT_DIG;
+          /* Enforce rounding up.  */
+          if (z < y)
+            z += L_(1.0);
+        }
     }
   return z;
 }