finalise NEWS.stable

[gnulib.git] / lib / vasnprintf.c

diff --git a/lib/vasnprintf.c b/lib/vasnprintf.c
index 13b60c4..40789f9 100644 (file)
--- a/lib/vasnprintf.c
+++ b/lib/vasnprintf.c
@@ -553,32 +553,61 @@ divide (mpn_t a, mpn_t b, mpn_t *q)
       size_t s;
       {
         mp_limb_t msd = b_ptr[b_len - 1]; /* = b[n-1], > 0 */
-        s = 31;
-        if (msd >= 0x10000)
-          {
-            msd = msd >> 16;
-            s -= 16;
-          }
-        if (msd >= 0x100)
-          {
-            msd = msd >> 8;
-            s -= 8;
-          }
-        if (msd >= 0x10)
-          {
-            msd = msd >> 4;
-            s -= 4;
-          }
-        if (msd >= 0x4)
+        /* Determine s = GMP_LIMB_BITS - integer_length (msd).
+           Code copied from gnulib's integer_length.c.  */
+# if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+        s = __builtin_clz (msd);
+# else
+#  if defined DBL_EXPBIT0_WORD && defined DBL_EXPBIT0_BIT
+        if (GMP_LIMB_BITS <= DBL_MANT_BIT)
           {
-            msd = msd >> 2;
-            s -= 2;
+            /* Use 'double' operations.
+               Assumes an IEEE 754 'double' implementation.  */
+#   define DBL_EXP_MASK ((DBL_MAX_EXP - DBL_MIN_EXP) | 7)
+#   define DBL_EXP_BIAS (DBL_EXP_MASK / 2 - 1)
+#   define NWORDS \
+     ((sizeof (double) + sizeof (unsigned int) - 1) / sizeof (unsigned int))
+            union { double value; unsigned int word[NWORDS]; } m;
+
+            /* Use a single integer to floating-point conversion.  */
+            m.value = msd;
+
+            s = GMP_LIMB_BITS
+                - (((m.word[DBL_EXPBIT0_WORD] >> DBL_EXPBIT0_BIT) & DBL_EXP_MASK)
+                   - DBL_EXP_BIAS);
           }
-        if (msd >= 0x2)
+        else
+#   undef NWORDS
+#  endif
           {
-            msd = msd >> 1;
-            s -= 1;
+            s = 31;
+            if (msd >= 0x10000)
+              {
+                msd = msd >> 16;
+                s -= 16;
+              }
+            if (msd >= 0x100)
+              {
+                msd = msd >> 8;
+                s -= 8;
+              }
+            if (msd >= 0x10)
+              {
+                msd = msd >> 4;
+                s -= 4;
+              }
+            if (msd >= 0x4)
+              {
+                msd = msd >> 2;
+                s -= 2;
+              }
+            if (msd >= 0x2)
+              {
+                msd = msd >> 1;
+                s -= 1;
+              }
           }
+# endif
       }
       /* 0 <= s < GMP_LIMB_BITS.
          Copy b, shifting it left by s bits.  */
@@ -885,9 +914,9 @@ decode_long_double (long double x, int *ep, mpn_t *mp)
   y = frexpl (x, &exp);
   if (!(y >= 0.0L && y < 1.0L))
     abort ();
-  /* x = 2^exp * y = 2^(exp - LDBL_MANT_BIT) * (y * LDBL_MANT_BIT), and the
+  /* x = 2^exp * y = 2^(exp - LDBL_MANT_BIT) * (y * 2^LDBL_MANT_BIT), and the
      latter is an integer.  */
-  /* Convert the mantissa (y * LDBL_MANT_BIT) to a sequence of limbs.
+  /* Convert the mantissa (y * 2^LDBL_MANT_BIT) to a sequence of limbs.
      I'm not sure whether it's safe to cast a 'long double' value between
      2^31 and 2^32 to 'unsigned int', therefore play safe and cast only
      'long double' values between 0 and 2^16 (to 'unsigned int' or 'int',
@@ -935,11 +964,11 @@ decode_long_double (long double x, int *ep, mpn_t *mp)
         abort ();
       m.limbs[--i] = (hi << (GMP_LIMB_BITS / 2)) | lo;
     }
-#if 0 /* On FreeBSD 6.1/x86, 'long double' numbers sometimes have excess
-         precision.  */
+#  if 0 /* On FreeBSD 6.1/x86, 'long double' numbers sometimes have excess
+           precision.  */
   if (!(y == 0.0L))
     abort ();
-#endif
+#  endif
   /* Normalise.  */
   while (m.nlimbs > 0 && m.limbs[m.nlimbs - 1] == 0)
     m.nlimbs--;
@@ -973,9 +1002,9 @@ decode_double (double x, int *ep, mpn_t *mp)
   y = frexp (x, &exp);
   if (!(y >= 0.0 && y < 1.0))
     abort ();
-  /* x = 2^exp * y = 2^(exp - DBL_MANT_BIT) * (y * DBL_MANT_BIT), and the
+  /* x = 2^exp * y = 2^(exp - DBL_MANT_BIT) * (y * 2^DBL_MANT_BIT), and the
      latter is an integer.  */
-  /* Convert the mantissa (y * DBL_MANT_BIT) to a sequence of limbs.
+  /* Convert the mantissa (y * 2^DBL_MANT_BIT) to a sequence of limbs.
      I'm not sure whether it's safe to cast a 'double' value between
      2^31 and 2^32 to 'unsigned int', therefore play safe and cast only
      'double' values between 0 and 2^16 (to 'unsigned int' or 'int',
@@ -1753,8 +1782,9 @@ VASNPRINTF (DCHAR_T *resultbuf, size_t *lengthp,
     return NULL;
 
 #define CLEANUP() \
-  free (d.dir);                                                         \
-  if (a.arg)                                                            \
+  if (d.dir != d.direct_alloc_dir)                                      \
+    free (d.dir);                                                       \
+  if (a.arg != a.direct_alloc_arg)                                      \
     free (a.arg);
 
   if (PRINTF_FETCHARGS (args, &a) < 0)