diff -Naurd mpfr-3.1.2-a/PATCHES mpfr-3.1.2-b/PATCHES
--- mpfr-3.1.2-a/PATCHES	2014-04-15 22:20:32.243481506 +0000
+++ mpfr-3.1.2-b/PATCHES	2014-04-15 22:22:32.418722707 +0000
@@ -0,0 +1 @@
+gmp6-compat
diff -Naurd mpfr-3.1.2-a/VERSION mpfr-3.1.2-b/VERSION
--- mpfr-3.1.2-a/VERSION	2014-04-15 22:20:20.755171478 +0000
+++ mpfr-3.1.2-b/VERSION	2014-04-15 22:21:45.225450147 +0000
@@ -1 +1 @@
-3.1.2-p7
+3.1.2-p8
diff -Naurd mpfr-3.1.2-a/configure mpfr-3.1.2-b/configure
--- mpfr-3.1.2-a/configure	2013-03-13 15:38:20.000000000 +0000
+++ mpfr-3.1.2-b/configure	2014-04-15 22:21:38.821277476 +0000
@@ -14545,26 +14545,30 @@
 rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
 fi
 
-if test "$use_gmp_build" = yes ; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for valid GMP_NUMB_BITS" >&5
-$as_echo_n "checking for valid GMP_NUMB_BITS... " >&6; }
-  if test "$cross_compiling" = yes; then :
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for GMP_NUMB_BITS and sizeof(mp_limb_t) consistency" >&5
+$as_echo_n "checking for GMP_NUMB_BITS and sizeof(mp_limb_t) consistency... " >&6; }
+if test "$cross_compiling" = yes; then :
   { $as_echo "$as_me:${as_lineno-$LINENO}: result: can't test" >&5
 $as_echo "can't test" >&6; }
 else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
+#include <stdio.h>
 #include <limits.h>
 #include "gmp.h"
-#include "gmp-impl.h"
 
 int
 main ()
 {
 
-  return GMP_NUMB_BITS == BYTES_PER_MP_LIMB * CHAR_BIT
-         && sizeof(mp_limb_t) == BYTES_PER_MP_LIMB ? 0 : 1;
+  if (GMP_NUMB_BITS == sizeof(mp_limb_t) * CHAR_BIT)
+    return 0;
+  fprintf (stderr, "GMP_NUMB_BITS     = %ld\n", (long) GMP_NUMB_BITS);
+  fprintf (stderr, "sizeof(mp_limb_t) = %ld\n", (long) sizeof(mp_limb_t));
+  fprintf (stderr, "sizeof(mp_limb_t) * CHAR_BIT = %ld != GMP_NUMB_BITS\n",
+           (long) (sizeof(mp_limb_t) * CHAR_BIT));
+  return 1;
 
   ;
   return 0;
@@ -14577,14 +14581,14 @@
 
        { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
 $as_echo "no" >&6; }
-       as_fn_error $? "GMP_NUMB_BITS is incorrect.
-You probably need to change some of the GMP or MPFR compile options." "$LINENO" 5
+       as_fn_error $? "GMP_NUMB_BITS and sizeof(mp_limb_t) are not consistent.
+You probably need to change some of the GMP or MPFR compile options.
+See 'config.log' for details (search for GMP_NUMB_BITS)." "$LINENO" 5
 fi
 rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
   conftest.$ac_objext conftest.beam conftest.$ac_ext
 fi
 
-fi
 
 
 if test "$dont_link_with_gmp" = yes ; then
diff -Naurd mpfr-3.1.2-a/configure.ac mpfr-3.1.2-b/configure.ac
--- mpfr-3.1.2-a/configure.ac	2013-03-13 15:37:46.000000000 +0000
+++ mpfr-3.1.2-b/configure.ac	2013-03-13 15:37:46.000000000 +0000
@@ -435,23 +435,29 @@
    ])
 fi
 
-dnl Check for valid GMP_NUMB_BITS and BYTES_PER_MP_LIMB
+dnl Check for GMP_NUMB_BITS and sizeof(mp_limb_t) consistency.
+dnl Problems may occur if gmp.h was generated with some ABI
+dnl and is used with another ABI (or if nails are used).
 dnl This test doesn't need to link with libgmp (at least it shouldn't).
-if test "$use_gmp_build" = yes ; then
-  AC_MSG_CHECKING(for valid GMP_NUMB_BITS)
-  AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+AC_MSG_CHECKING(for GMP_NUMB_BITS and sizeof(mp_limb_t) consistency)
+AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+#include <stdio.h>
 #include <limits.h>
 #include "gmp.h"
-#include "gmp-impl.h"
 ]], [[
-  return GMP_NUMB_BITS == BYTES_PER_MP_LIMB * CHAR_BIT
-         && sizeof(mp_limb_t) == BYTES_PER_MP_LIMB ? 0 : 1;
+  if (GMP_NUMB_BITS == sizeof(mp_limb_t) * CHAR_BIT)
+    return 0;
+  fprintf (stderr, "GMP_NUMB_BITS     = %ld\n", (long) GMP_NUMB_BITS);
+  fprintf (stderr, "sizeof(mp_limb_t) = %ld\n", (long) sizeof(mp_limb_t));
+  fprintf (stderr, "sizeof(mp_limb_t) * CHAR_BIT = %ld != GMP_NUMB_BITS\n",
+           (long) (sizeof(mp_limb_t) * CHAR_BIT));
+  return 1;
 ]])], [AC_MSG_RESULT(yes)], [
        AC_MSG_RESULT(no)
-       AC_MSG_ERROR([GMP_NUMB_BITS is incorrect.
-You probably need to change some of the GMP or MPFR compile options.])],
+       AC_MSG_ERROR([GMP_NUMB_BITS and sizeof(mp_limb_t) are not consistent.
+You probably need to change some of the GMP or MPFR compile options.
+See 'config.log' for details (search for GMP_NUMB_BITS).])],
        [AC_MSG_RESULT([can't test])])
-fi
 
 
 dnl We really need to link using libtool. But it is impossible with the current
diff -Naurd mpfr-3.1.2-a/src/init2.c mpfr-3.1.2-b/src/init2.c
--- mpfr-3.1.2-a/src/init2.c	2013-03-13 15:37:32.000000000 +0000
+++ mpfr-3.1.2-b/src/init2.c	2014-04-15 22:21:06.220398489 +0000
@@ -30,11 +30,11 @@
 
   /* Check if we can represent the number of limbs
    * associated to the maximum of mpfr_prec_t*/
-  MPFR_ASSERTN( MP_SIZE_T_MAX >= (MPFR_PREC_MAX/BYTES_PER_MP_LIMB) );
+  MPFR_ASSERTN( MP_SIZE_T_MAX >= (MPFR_PREC_MAX/MPFR_BYTES_PER_MP_LIMB) );
 
-  /* Check for correct GMP_NUMB_BITS and BYTES_PER_MP_LIMB */
-  MPFR_ASSERTN( GMP_NUMB_BITS == BYTES_PER_MP_LIMB * CHAR_BIT
-                && sizeof(mp_limb_t) == BYTES_PER_MP_LIMB );
+  /* Check for correct GMP_NUMB_BITS and MPFR_BYTES_PER_MP_LIMB */
+  MPFR_ASSERTN( GMP_NUMB_BITS == MPFR_BYTES_PER_MP_LIMB * CHAR_BIT
+                && sizeof(mp_limb_t) == MPFR_BYTES_PER_MP_LIMB );
 
   MPFR_ASSERTN (mp_bits_per_limb == GMP_NUMB_BITS);
 
diff -Naurd mpfr-3.1.2-a/src/mpfr-gmp.h mpfr-3.1.2-b/src/mpfr-gmp.h
--- mpfr-3.1.2-a/src/mpfr-gmp.h	2013-03-13 15:37:32.000000000 +0000
+++ mpfr-3.1.2-b/src/mpfr-gmp.h	2014-04-15 22:21:06.220398489 +0000
@@ -72,7 +72,6 @@
 #endif
 
 /* Define some macros */
-#define BYTES_PER_MP_LIMB (GMP_NUMB_BITS/CHAR_BIT)
 
 #define MP_LIMB_T_MAX (~(mp_limb_t)0)
 
@@ -96,19 +95,19 @@
 #define SHRT_HIGHBIT       SHRT_MIN
 
 /* MP_LIMB macros */
-#define MPN_ZERO(dst, n) memset((dst), 0, (n)*BYTES_PER_MP_LIMB)
-#define MPN_COPY_DECR(dst,src,n) memmove((dst),(src),(n)*BYTES_PER_MP_LIMB)
-#define MPN_COPY_INCR(dst,src,n) memmove((dst),(src),(n)*BYTES_PER_MP_LIMB)
+#define MPN_ZERO(dst, n) memset((dst), 0, (n)*MPFR_BYTES_PER_MP_LIMB)
+#define MPN_COPY_DECR(dst,src,n) memmove((dst),(src),(n)*MPFR_BYTES_PER_MP_LIMB)
+#define MPN_COPY_INCR(dst,src,n) memmove((dst),(src),(n)*MPFR_BYTES_PER_MP_LIMB)
 #define MPN_COPY(dst,src,n) \
   do                                                                  \
     {                                                                 \
       if ((dst) != (src))                                             \
         {                                                             \
           MPFR_ASSERTD ((char *) (dst) >= (char *) (src) +            \
-                                          (n) * BYTES_PER_MP_LIMB ||  \
+                                     (n) * MPFR_BYTES_PER_MP_LIMB ||  \
                         (char *) (src) >= (char *) (dst) +            \
-                                          (n) * BYTES_PER_MP_LIMB);   \
-          memcpy ((dst), (src), (n) * BYTES_PER_MP_LIMB);             \
+                                     (n) * MPFR_BYTES_PER_MP_LIMB);   \
+          memcpy ((dst), (src), (n) * MPFR_BYTES_PER_MP_LIMB);        \
         }                                                             \
     }                                                                 \
   while (0)
diff -Naurd mpfr-3.1.2-a/src/mpfr-impl.h mpfr-3.1.2-b/src/mpfr-impl.h
--- mpfr-3.1.2-a/src/mpfr-impl.h	2013-10-09 13:34:21.000000000 +0000
+++ mpfr-3.1.2-b/src/mpfr-impl.h	2014-04-15 22:21:06.220398489 +0000
@@ -191,7 +191,7 @@
 # endif
 #endif
 
-
+#define MPFR_BYTES_PER_MP_LIMB (GMP_NUMB_BITS/CHAR_BIT)
 
 /******************************************************
  ******************** Check GMP ***********************
@@ -930,7 +930,7 @@
 #define MPFR_SET_ALLOC_SIZE(x, n) \
  ( ((mp_size_t*) MPFR_MANT(x))[-1] = n)
 #define MPFR_MALLOC_SIZE(s) \
-  ( sizeof(mpfr_size_limb_t) + BYTES_PER_MP_LIMB * ((size_t) s) )
+  ( sizeof(mpfr_size_limb_t) + MPFR_BYTES_PER_MP_LIMB * ((size_t) s) )
 #define MPFR_SET_MANT_PTR(x,p) \
    (MPFR_MANT(x) = (mp_limb_t*) ((mpfr_size_limb_t*) p + 1))
 #define MPFR_GET_REAL_PTR(x) \
@@ -964,7 +964,7 @@
 #endif
 
 #define MPFR_TMP_LIMBS_ALLOC(N) \
-  ((mp_limb_t *) MPFR_TMP_ALLOC ((size_t) (N) * BYTES_PER_MP_LIMB))
+  ((mp_limb_t *) MPFR_TMP_ALLOC ((size_t) (N) * MPFR_BYTES_PER_MP_LIMB))
 
 /* temporary allocate 1 limb at xp, and initialize mpfr variable x */
 /* The temporary var doesn't have any size field, but it doesn't matter
diff -Naurd mpfr-3.1.2-a/src/mpfr.h mpfr-3.1.2-b/src/mpfr.h
--- mpfr-3.1.2-a/src/mpfr.h	2014-04-15 22:20:20.755171478 +0000
+++ mpfr-3.1.2-b/src/mpfr.h	2014-04-15 22:21:45.225450147 +0000
@@ -27,7 +27,7 @@
 #define MPFR_VERSION_MAJOR 3
 #define MPFR_VERSION_MINOR 1
 #define MPFR_VERSION_PATCHLEVEL 2
-#define MPFR_VERSION_STRING "3.1.2-p7"
+#define MPFR_VERSION_STRING "3.1.2-p8"
 
 /* Macros dealing with MPFR VERSION */
 #define MPFR_VERSION_NUM(a,b,c) (((a) << 16L) | ((b) << 8) | (c))
diff -Naurd mpfr-3.1.2-a/src/mul.c mpfr-3.1.2-b/src/mul.c
--- mpfr-3.1.2-a/src/mul.c	2013-03-13 15:37:37.000000000 +0000
+++ mpfr-3.1.2-b/src/mul.c	2014-04-15 22:21:06.224398597 +0000
@@ -106,7 +106,7 @@
   MPFR_ASSERTD(tn <= k);
 
   /* Check for no size_t overflow*/
-  MPFR_ASSERTD((size_t) k <= ((size_t) -1) / BYTES_PER_MP_LIMB);
+  MPFR_ASSERTD((size_t) k <= ((size_t) -1) / MPFR_BYTES_PER_MP_LIMB);
   MPFR_TMP_MARK(marker);
   tmp = MPFR_TMP_LIMBS_ALLOC (k);
 
@@ -301,7 +301,7 @@
   MPFR_ASSERTD (tn <= k); /* tn <= k, thus no int overflow */
 
   /* Check for no size_t overflow*/
-  MPFR_ASSERTD ((size_t) k <= ((size_t) -1) / BYTES_PER_MP_LIMB);
+  MPFR_ASSERTD ((size_t) k <= ((size_t) -1) / MPFR_BYTES_PER_MP_LIMB);
   MPFR_TMP_MARK (marker);
   tmp = MPFR_TMP_LIMBS_ALLOC (k);
 
diff -Naurd mpfr-3.1.2-a/src/stack_interface.c mpfr-3.1.2-b/src/stack_interface.c
--- mpfr-3.1.2-a/src/stack_interface.c	2013-03-13 15:37:32.000000000 +0000
+++ mpfr-3.1.2-b/src/stack_interface.c	2014-04-15 22:21:06.220398489 +0000
@@ -26,7 +26,7 @@
 size_t
 mpfr_custom_get_size (mpfr_prec_t prec)
 {
-  return MPFR_PREC2LIMBS (prec) * BYTES_PER_MP_LIMB;
+  return MPFR_PREC2LIMBS (prec) * MPFR_BYTES_PER_MP_LIMB;
 }
 
 #undef mpfr_custom_init
diff -Naurd mpfr-3.1.2-a/src/version.c mpfr-3.1.2-b/src/version.c
--- mpfr-3.1.2-a/src/version.c	2014-04-15 22:20:20.755171478 +0000
+++ mpfr-3.1.2-b/src/version.c	2014-04-15 22:21:45.225450147 +0000
@@ -25,5 +25,5 @@
 const char *
 mpfr_get_version (void)
 {
-  return "3.1.2-p7";
+  return "3.1.2-p8";
 }