Makefile.am         |    7 +++++--
 doc/gmp.texi        |   13 ++++++++-----
 mpf/eq.c            |   32 +++++++++++++++++++++-----------
 mpf/set_str.c       |    9 +++++----
 mpz/perfpow.c       |   47 +++++++++++++++++++++++++++++++----------------
 tests/cxx/t-prec.cc |   29 ++++++++++++++++-------------
 6 files changed, 86 insertions(+), 51 deletions(-)

diff --git a/Makefile.am b/Makefile.am
index 94f7145..2203471 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -253,10 +253,13 @@ EXTRA_libgmp_la_SOURCES = tal-debug.c tal-notreent.c tal-reent.c
 libgmp_la_DEPENDENCIES = @TAL_OBJECT@		\
   $(MPF_OBJECTS) $(MPZ_OBJECTS) $(MPQ_OBJECTS)	\
   $(MPN_OBJECTS) @mpn_objs_in_libgmp@		\
-  $(PRINTF_OBJECTS)  $(SCANF_OBJECTS)
+  $(PRINTF_OBJECTS)  $(SCANF_OBJECTS)		\
+  $(srcdir)/libgmp.sym
 libgmp_la_LIBADD = $(libgmp_la_DEPENDENCIES)
 libgmp_la_LDFLAGS = $(GMP_LDFLAGS) $(LIBGMP_LDFLAGS) \
-  -version-info $(LIBGMP_LT_CURRENT):$(LIBGMP_LT_REVISION):$(LIBGMP_LT_AGE)
+  -version-info $(LIBGMP_LT_CURRENT):$(LIBGMP_LT_REVISION):$(LIBGMP_LT_AGE) \
+  -export-symbols $(srcdir)/libgmp.sym
+EXTRA_DIST += libgmp.sym
 
 
 # We need at least one .cc file in $(libgmpxx_la_SOURCES) so automake will
diff --git a/doc/gmp.texi b/doc/gmp.texi
index d2053b1..8f1a885 100644
--- a/doc/gmp.texi
+++ b/doc/gmp.texi
@@ -65,9 +65,9 @@ software''.  A copy of the license is included in
 @c  may want to search-and-replace to some online source.
 @c
 
-@dircategory GNU libraries
+@dircategory GNU Libraries
 @direntry
-* gmp: (gmp).                   GNU Multiple Precision Arithmetic Library.
+* gmp: (gmp).					GNU Multiple Precision Arithmetic Library.
 @end direntry
 
 @c  html <meta name="description" content="...">
@@ -4849,9 +4849,12 @@ Return non-zero if the first @var{op3} bits of @var{op1} and @var{op2} are
 equal, zero otherwise.  I.e., test if @var{op1} and @var{op2} are approximately
 equal.
 
-Caution: Currently only whole limbs are compared, and only in an exact
-fashion.  In the future values like 1000 and 0111 may be considered the same
-to 3 bits (on the basis that their difference is that small).
+Caution 1: All version of GMP up to version 4.2.4 compared just whole limbs,
+meaning sometimes more than @var{op3} bits, sometimes fewer.
+
+Caution 2: This function will consider XXX11...111 and XX100...000 different,
+even if ... is replaced by a semi-infinite number of bits.  Such numbers are
+really just one ulp off, and should be considered equal.
 @end deftypefun
 
 @deftypefun void mpf_reldiff (mpf_t @var{rop}, mpf_t @var{op1}, mpf_t @var{op2})
diff --git a/mpf/eq.c b/mpf/eq.c
index e10daf2..432ae94 100644
--- a/mpf/eq.c
+++ b/mpf/eq.c
@@ -1,6 +1,6 @@
 /* mpf_eq -- Compare two floats up to a specified bit #.
 
-Copyright 1993, 1995, 1996, 2001, 2002 Free Software Foundation, Inc.
+Copyright 1993, 1995, 1996, 2001, 2002, 2008 Free Software Foundation, Inc.
 
 This file is part of the GNU MP Library.
 
@@ -19,6 +19,7 @@ along with the GNU MP Library.  If not, see http://www.gnu.org/licenses/.  */
 
 #include "gmp.h"
 #include "gmp-impl.h"
+#include "longlong.h"
 
 int
 mpf_eq (mpf_srcptr u, mpf_srcptr v, unsigned long int n_bits)
@@ -26,6 +27,8 @@ mpf_eq (mpf_srcptr u, mpf_srcptr v, unsigned long int n_bits)
   mp_srcptr up, vp;
   mp_size_t usize, vsize, size, i;
   mp_exp_t uexp, vexp;
+  mp_limb_t diff;
+  int cnt;
 
   uexp = u->_mp_exp;
   vexp = v->_mp_exp;
@@ -53,10 +56,8 @@ mpf_eq (mpf_srcptr u, mpf_srcptr v, unsigned long int n_bits)
   /* U and V have the same sign and are both non-zero.  */
 
   /* 2. Are the exponents different?  */
-  if (uexp > vexp)
-    return 0;			/* ??? handle (uexp = vexp + 1)   */
-  if (vexp > uexp)
-    return 0;			/* ??? handle (vexp = uexp + 1)   */
+  if (uexp != vexp)
+    return 0;
 
   usize = ABS (usize);
   vsize = ABS (vsize);
@@ -93,17 +94,26 @@ mpf_eq (mpf_srcptr u, mpf_srcptr v, unsigned long int n_bits)
       size = usize;
     }
 
-  if (size > (n_bits + GMP_NUMB_BITS - 1) / GMP_NUMB_BITS)
-    size = (n_bits + GMP_NUMB_BITS - 1) / GMP_NUMB_BITS;
+  up += usize;			/* point just above most significant limb */
+  vp += vsize;			/* point just above most significant limb */
 
-  up += usize - size;
-  vp += vsize - size;
+  count_leading_zeros (cnt, up[-1]);
+  if ((vp[-1] >> (GMP_LIMB_BITS - 1 - cnt)) != 1)
+    return 0;			/* msb positions different */
 
-  for (i = size - 1; i >= 0; i--)
+  n_bits += cnt - GMP_NAIL_BITS;
+
+  size = MIN (size, (n_bits + GMP_NUMB_BITS - 1) / GMP_NUMB_BITS);
+
+  up -= size;			/* point at least significant relevant limb */
+  vp -= size;			/* point at least significant relevant limb */
+
+  for (i = size - 1; i > 0; i--)
     {
       if (up[i] != vp[i])
 	return 0;
     }
 
-  return 1;
+  diff = (up[0] ^ vp[0]) >> GMP_NUMB_BITS - 1 - (n_bits - 1) % GMP_NUMB_BITS;
+  return diff == 0;
 }
diff --git a/mpf/set_str.c b/mpf/set_str.c
index 6e43221..0417303 100644
--- a/mpf/set_str.c
+++ b/mpf/set_str.c
@@ -137,7 +137,12 @@ mpf_set_str (mpf_ptr x, const char *str, int base)
       c = (unsigned char) *++str;
     }
 
+  /* Default base to decimal.  */
+  if (base == 0)
+    base = 10;
+
   exp_base = base;
+
   if (base < 0)
     {
       exp_base = 10;
@@ -165,10 +170,6 @@ mpf_set_str (mpf_ptr x, const char *str, int base)
 	return -1;
     }
 
-  /* Default base to decimal.  */
-  if (base == 0)
-    base = 10;
-
   /* Locate exponent part of the input.  Look from the right of the string,
      since the exponent is usually a lot shorter than the mantissa.  */
   expptr = NULL;
diff --git a/mpz/perfpow.c b/mpz/perfpow.c
index 485a50a..be0b21c 100644
--- a/mpz/perfpow.c
+++ b/mpz/perfpow.c
@@ -1,7 +1,7 @@
 /* mpz_perfect_power_p(arg) -- Return non-zero if ARG is a perfect power,
    zero otherwise.
 
-Copyright 1998, 1999, 2000, 2001, 2005 Free Software Foundation, Inc.
+Copyright 1998, 1999, 2000, 2001, 2005, 2008 Free Software Foundation, Inc.
 
 This file is part of the GNU MP Library.
 
@@ -59,6 +59,8 @@ static const unsigned short primes[] =
 #define SMALLEST_OMITTED_PRIME 1009
 
 
+#define POW2P(a) (((a) & ((a) - 1)) == 0)
+
 int
 mpz_perfect_power_p (mpz_srcptr u)
 {
@@ -72,16 +74,13 @@ mpz_perfect_power_p (mpz_srcptr u)
   mp_size_t usize = SIZ (u);
   TMP_DECL;
 
-  if (usize == 0)
-    return 1;			/* consider 0 a perfect power */
+  if (mpz_cmpabs_ui (u, 1) <= 0)
+    return 1;			/* -1, 0, and +1 are perfect powers */
 
   n2 = mpz_scan1 (u, 0);
   if (n2 == 1)
     return 0;			/* 2 divides exactly once.  */
 
-  if (n2 != 0 && (n2 & 1) == 0 && usize < 0)
-    return 0;			/* 2 has even multiplicity with negative U */
-
   TMP_MARK;
 
   uns = ABS (usize) - n2 / BITS_PER_MP_LIMB;
@@ -89,6 +88,14 @@ mpz_perfect_power_p (mpz_srcptr u)
   MPZ_TMP_INIT (u2, uns);
 
   mpz_tdiv_q_2exp (u2, u, n2);
+  mpz_abs (u2, u2);
+
+  if (mpz_cmp_ui (u2, 1) == 0)
+    {
+      TMP_FREE;
+      /* factoring completed; consistent power */
+      return ! (usize < 0 && POW2P(n2));
+    }
 
   if (isprime (n2))
     goto n2prime;
@@ -97,6 +104,9 @@ mpz_perfect_power_p (mpz_srcptr u)
     {
       prime = primes[i];
 
+      if (mpz_cmp_ui (u2, prime) < 0)
+	break;
+
       if (mpz_divisible_ui_p (u2, prime))	/* divisible by this prime? */
 	{
 	  rem = mpz_tdiv_q_ui (q, u2, prime * prime);
@@ -115,12 +125,6 @@ mpz_perfect_power_p (mpz_srcptr u)
 	      n++;
 	    }
 
-	  if ((n & 1) == 0 && usize < 0)
-	    {
-	      TMP_FREE;
-	      return 0;		/* even multiplicity with negative U, reject */
-	    }
-
 	  n2 = gcd (n2, n);
 	  if (n2 == 1)
 	    {
@@ -128,10 +132,11 @@ mpz_perfect_power_p (mpz_srcptr u)
 	      return 0;		/* we have multiplicity 1 of some factor */
 	    }
 
-	  if (mpz_cmpabs_ui (u2, 1) == 0)
+	  if (mpz_cmp_ui (u2, 1) == 0)
 	    {
 	      TMP_FREE;
-	      return 1;		/* factoring completed; consistent power */
+	      /* factoring completed; consistent power */
+	      return ! (usize < 0 && POW2P(n2));
 	    }
 
 	  /* As soon as n2 becomes a prime number, stop factoring.
@@ -169,6 +174,10 @@ mpz_perfect_power_p (mpz_srcptr u)
   else
     {
       unsigned long int nth;
+
+      if (usize < 0 && POW2P(n2))
+	return 0;
+
       /* We found some factors above.  We just need to consider values of n
 	 that divides n2.  */
       for (nth = 2; nth <= n2; nth++)
@@ -184,8 +193,11 @@ mpz_perfect_power_p (mpz_srcptr u)
 	    exact = mpz_root (q, u2, nth);
 	  if (exact)
 	    {
-	      TMP_FREE;
-	      return 1;
+	      if (! (usize < 0 && POW2P(nth)))
+		{
+		  TMP_FREE;
+		  return 1;
+		}
 	    }
 	  if (mpz_cmp_ui (q, SMALLEST_OMITTED_PRIME) < 0)
 	    {
@@ -199,6 +211,9 @@ mpz_perfect_power_p (mpz_srcptr u)
     }
 
 n2prime:
+  if (usize < 0 && POW2P(n2))
+    return 0;
+
   exact = mpz_root (NULL, u2, n2);
   TMP_FREE;
   return exact;
diff --git a/tests/cxx/t-prec.cc b/tests/cxx/t-prec.cc
index 160f5e6..e9f4e48 100644
--- a/tests/cxx/t-prec.cc
+++ b/tests/cxx/t-prec.cc
@@ -1,6 +1,6 @@
 /* Test precision of mpf_class expressions.
 
-Copyright 2001, 2002, 2003 Free Software Foundation, Inc.
+Copyright 2001, 2002, 2003, 2008 Free Software Foundation, Inc.
 
 This file is part of the GNU MP Library.
 
@@ -61,7 +61,7 @@ check_mpf (void)
     g = 1 / f;
     ASSERT_ALWAYS_PREC
       (g, "0.11111 11111 11111 11111 11111 11111 11111 11111 11111 11111"
-       "     11111 11111 11111 11111 11111 11", very_large_prec);
+       "     11111 11111 11111 11111 11111 111", very_large_prec);
   }
   {
     mpf_class f(15.0, large_prec);
@@ -69,7 +69,7 @@ check_mpf (void)
     g = 1 / f;
     ASSERT_ALWAYS_PREC
       (g, "0.06666 66666 66666 66666 66666 66666 66666 66666 66666 66666"
-       "     66666 66666 66666 66666 66666 67", very_large_prec);
+       "     66666 66666 66666 66666 66666 667", very_large_prec);
   }
 
   // compound expressions
@@ -94,14 +94,14 @@ check_mpf (void)
     i = f / g + h;
     ASSERT_ALWAYS_PREC
       (i, "15.33333 33333 33333 33333 33333 33333 33333 33333 33333 33333"
-       "      33333 33333 33333 333", very_large_prec);
+       "      33333 33333 33333 33333 33333 3", very_large_prec);
   }
   {
     mpf_class f(3.0, small_prec);
     mpf_class g(-(1 + f) / 3, very_large_prec);
     ASSERT_ALWAYS_PREC
       (g, "-1.33333 33333 33333 33333 33333 33333 33333 33333 33333 33333"
-       "      33333 33333 33333 333", very_large_prec);
+       "      33333 33333 33333 33333 33333 33", very_large_prec);
   }
   {
     mpf_class f(9.0, medium_prec);
@@ -117,7 +117,7 @@ check_mpf (void)
     g = hypot(1 + 5 / f, 1.0);
     ASSERT_ALWAYS_PREC
       (g, "1.66666 66666 66666 66666 66666 66666 66666 66666 66666 66666"
-       "     66666 66666 66666 667", very_large_prec);
+       "     66666 66666 66666 66666 66666 67", very_large_prec);
   }
 
   // compound assignments
@@ -142,7 +142,7 @@ check_mpf (void)
     mpf_class g(0.0, very_large_prec);
     g = mpf_class(1 / f);
     ASSERT_ALWAYS_PREC
-      (g, "0.11111 11111 11111 11111 11111 11111 11111 111", medium_prec);
+      (g, "0.11111 11111 11111 11111 11111 11111 11111 1111", medium_prec);
   }
   {
     mpf_class f(15.0, large_prec);
@@ -150,7 +150,7 @@ check_mpf (void)
     g = mpf_class(1 / f);
     ASSERT_ALWAYS_PREC
       (g, "0.06666 66666 66666 66666 66666 66666 66666 66666 66666 66666"
-       "     66666 667", large_prec);
+       "     66666 6667", large_prec);
   }
 
   {
@@ -158,7 +158,8 @@ check_mpf (void)
     mpf_class h(0.0, very_large_prec);
     h = mpf_class(f / g + 1, large_prec);
     ASSERT_ALWAYS_PREC
-      (h, "1.33333 33333 33333 33333 33333 33333 33333 33333 33333 3333",
+      (h, "1.33333 33333 33333 33333 33333 33333 33333 33333 33333 33333"
+       "     33333 333",
        large_prec);
   }
 
@@ -170,7 +171,7 @@ check_mpf (void)
     g = f - q;
     ASSERT_ALWAYS_PREC
       (g, "2.66666 66666 66666 66666 66666 66666 66666 66666 66666 66666"
-       "     66666 66666 66666 667", very_large_prec);
+       "     66666 66666 66666 66666 66666 67", very_large_prec);
   }
 
   {
@@ -179,7 +180,8 @@ check_mpf (void)
     mpf_class g(0.0, very_large_prec);
     g = mpf_class(f - q, large_prec);
     ASSERT_ALWAYS_PREC
-      (g, "2.66666 66666 66666 66666 66666 66666 66666 66666 66666 6667",
+      (g, "2.66666 66666 66666 66666 66666 66666 66666 66666 66666 66666"
+       "     66666 667",
        large_prec);
   }
   {
@@ -188,7 +190,7 @@ check_mpf (void)
     mpf_class g(0.0, very_large_prec);
     g = mpf_class(f - q);
     ASSERT_ALWAYS_PREC
-      (g, "2.66666 66666 66666 66666 66666 6667", medium_prec);
+      (g, "2.66666 66666 66666 66666 66666 66666 66666 667", medium_prec);
   }
   {
     mpf_class f(15.0, large_prec);
@@ -196,7 +198,8 @@ check_mpf (void)
     mpf_class g(0.0, very_large_prec);
     g = mpf_class(f + q);
     ASSERT_ALWAYS_PREC
-      (g, "15.33333 33333 33333 33333 33333 33333 33333 33333 33333 3333",
+      (g, "15.33333 33333 33333 33333 33333 33333 33333 33333 33333 33333"
+       "      33333 33",
        large_prec);
   }
 }