X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fisnan.c;h=ee9fa8b6440d9758a7906eeeae2518bdb962cf5c;hb=91fd3b18b755b77c4bb3f7556ddedb055c16c834;hp=32457140623aa88a0c694e0ab82376c9a9144cf0;hpb=15b93a23d220ccdf3d29bf6f9b8fbf7e50269f9f;p=gnulib.git

diff --git a/lib/isnan.c b/lib/isnan.c
index 324571406..ee9fa8b64 100644
--- 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
@@ -72,23 +83,56 @@ int
 FUNC (DOUBLE x)
 {
 #ifdef KNOWN_EXPBIT0_LOCATION
+# 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_))
+  /* Special CPU dependent code is needed to treat bit patterns outside the
+     IEEE 754 specification (such as Pseudo-NaNs, Pseudo-Infinities,
+     Pseudo-Zeroes, Unnormalized Numbers, and Pseudo-Denormals) as NaNs.
+     These bit patterns are:
+       - exponent = 0x0001..0x7FFF, mantissa bit 63 = 0,
+       - exponent = 0x0000, mantissa bit 63 = 1.
+     The NaN bit pattern is:
+       - exponent = 0x7FFF, mantissa >= 0x8000000000000001.  */
+  memory_double m;
+  unsigned int exponent;
+
+  m.value = x;
+  exponent = (m.word[EXPBIT0_WORD] >> EXPBIT0_BIT) & EXP_MASK;
+#  ifdef WORDS_BIGENDIAN
+  /* Big endian: EXPBIT0_WORD = 0, EXPBIT0_BIT = 16.  */
+  if (exponent == 0)
+    return 1 & (m.word[0] >> 15);
+  else if (exponent == EXP_MASK)
+    return (((m.word[0] ^ 0x8000U) << 16) | m.word[1] | (m.word[2] >> 16)) != 0;
+  else
+    return 1 & ~(m.word[0] >> 15);
+#  else
+  /* Little endian: EXPBIT0_WORD = 2, EXPBIT0_BIT = 0.  */
+  if (exponent == 0)
+    return (m.word[1] >> 31);
+  else if (exponent == EXP_MASK)
+    return ((m.word[1] ^ 0x80000000U) | m.word[0]) != 0;
+  else
+    return (m.word[1] >> 31) ^ 1;
+#  endif
+# else
   /* Be careful to not do any floating-point operation on x, such as x == x,
      because x may be a signaling NaN.  */
-# if defined __SUNPRO_C || defined __DECC
+#  if defined __SUNPRO_C || defined __DECC || (defined __sgi && !defined __GNUC__)
   /* The Sun C 5.0 compilers and the Compaq (ex-DEC) 6.4 compilers don't
      recognize the initializers as constant expressions.  The latter compiler
      also fails when constant-folding 0.0 / 0.0 even when constant-folding is
-     not required.  */
+     not required.  The SGI MIPSpro C compiler complains about "floating-point
+     operation result is out of range".  */
   static DOUBLE zero = L_(0.0);
   memory_double nan;
   DOUBLE plus_inf = L_(1.0) / L_(0.0);
   DOUBLE minus_inf = -L_(1.0) / L_(0.0);
   nan.value = zero / zero;
-# else
+#  else
   static memory_double nan = { L_(0.0) / L_(0.0) };
   static DOUBLE plus_inf = L_(1.0) / L_(0.0);
   static DOUBLE minus_inf = -L_(1.0) / L_(0.0);
-# endif
+#  endif
   {
     memory_double m;
 
@@ -96,18 +140,33 @@ 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;
   }
+# endif
 #else
   /* 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