Rename module 'memxfrm' to 'amemxfrm'.

[gnulib.git] / lib / isnan.c

diff --git a/lib/isnan.c b/lib/isnan.c
index 5efb62b..ee9fa8b 100644 (file)
--- a/lib/isnan.c
+++ b/lib/isnan.c
@@ -1,24 +1,35 @@
 /* Test for NaN that does not need libm.
-   Copyright (C) 2007 Free Software Foundation, Inc.
+   Copyright (C) 2007-2010 Free Software Foundation, Inc.
 
-   This program is free software; you can redistribute it and/or modify
+   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
-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
 
-   You should have received a copy of the GNU General Public License along
-   with this program; if not, write to the Free Software Foundation,
-   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 /* Written by Bruno Haible <bruno@clisp.org>, 2007.  */
 
 #include <config.h>
 
+/* Specification.  */
+#ifdef USE_LONG_DOUBLE
+/* Specification found in math.h or isnanl-nolibm.h.  */
+extern int rpl_isnanl (long double x);
+#elif ! defined USE_FLOAT
+/* Specification found in math.h or isnand-nolibm.h.  */
+extern int rpl_isnand (double x);
+#else /* defined USE_FLOAT */
+/* Specification found in math.h or isnanf-nolibm.h.  */
+extern int rpl_isnanf (float x);
+#endif
+
 #include <float.h>
 #include <string.h>
 
@@ -37,7 +48,7 @@
 # define SIZE SIZEOF_LDBL
 # define L_(literal) literal##L
 #elif ! defined USE_FLOAT
-# define FUNC rpl_isnan
+# define FUNC rpl_isnand
 # define DOUBLE double
 # define MAX_EXP DBL_MAX_EXP
 # define MIN_EXP DBL_MIN_EXP
@@ -129,10 +140,10 @@ FUNC (DOUBLE x)
        -Infinity, which have the same exponent.  */
     m.value = x;
     if (((m.word[EXPBIT0_WORD] ^ nan.word[EXPBIT0_WORD])
-        & (EXP_MASK << EXPBIT0_BIT))
-       == 0)
+         & (EXP_MASK << EXPBIT0_BIT))
+        == 0)
       return (memcmp (&m.value, &plus_inf, SIZE) != 0
-             && memcmp (&m.value, &minus_inf, SIZE) != 0);
+              && memcmp (&m.value, &minus_inf, SIZE) != 0);
     else
       return 0;
   }
@@ -141,7 +152,21 @@ FUNC (DOUBLE x)
   /* The configuration did not find sufficient information.  Give up about
      the signaling NaNs, handle only the quiet NaNs.  */
   if (x == x)
-    return 0;
+    {
+# if defined USE_LONG_DOUBLE && ((defined __ia64 && LDBL_MANT_DIG == 64) || (defined __x86_64__ || defined __amd64__) || (defined __i386 || defined __i386__ || defined _I386 || defined _M_IX86 || defined _X86_))
+      /* Detect any special bit patterns that pass ==; see comment above.  */
+      memory_double m1;
+      memory_double m2;
+
+      memset (&m1.value, 0, SIZE);
+      memset (&m2.value, 0, SIZE);
+      m1.value = x;
+      m2.value = x + (x ? 0.0L : -0.0L);
+      if (memcmp (&m1.value, &m2.value, SIZE) != 0)
+        return 1;
+# endif
+      return 0;
+    }
   else
     return 1;
 #endif