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-rw-r--r--sysdeps/libm-ieee754/s_nan.c30
1 files changed, 12 insertions, 18 deletions
diff --git a/sysdeps/libm-ieee754/s_nan.c b/sysdeps/libm-ieee754/s_nan.c
index 0d065d5c72..35d92646c0 100644
--- a/sysdeps/libm-ieee754/s_nan.c
+++ b/sysdeps/libm-ieee754/s_nan.c
@@ -18,31 +18,25 @@
    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
    Boston, MA 02111-1307, USA.  */
 
-/* XXX The ISO C 9X standard mentions a `n-char-sequence' which is provided
-   as the argument to this function but I have no clue what this means.
-   Perhaps it is a description of the bits set in the mantissa.  */
 #include <math.h>
-#ifdef HANDLE_TAGP
-# include <stdlib.h>
-# include <string.h>
-#else
-# include <ieee754.h>
-#endif
+#include <stdlib.h>
+#include <string.h>
+#include <ieee754.h>
 
 
 double
 __nan (const char *tagp)
 {
-#ifdef HANDLE_TAGP
-  /* If we ever should have use of the TAGP parameter we will use the
-     strtod function to analyze it.  */
-  char buf[6 + strlen (tagp)];
-  sprintf (buf, "NAN(%s)", tagp);
-  return strtod (buf, NULL);
-#else
   static const union ieee754_double nan_value =
-  { ieee: { mantissa1: 0x1, mantissa0: 0x0, exponent: 0x7ff, negative: 0 } };
+  { ieee: { mantissa1: 0, mantissa0: 0x80000, exponent: 0x7ff, negative: 0 } };
+
+  if (tagp[0] != '\0')
+    {
+      char buf[6 + strlen (tagp)];
+      sprintf (buf, "NAN(%s)", tagp);
+      return strtod (buf, NULL);
+    }
+
   return nan_value.d;
-#endif
 }
 weak_alias (__nan, nan)