diff -ur mpfr-3.1.2.orig/src/mparam_h.in mpfr-3.1.2/src/mparam_h.in
--- mpfr-3.1.2.orig/src/mparam_h.in	2013-03-13 16:37:32.000000000 +0100
+++ mpfr-3.1.2/src/mparam_h.in	2014-05-23 10:42:18.499864511 +0200
@@ -27,7 +27,9 @@
    for example with gcc -dM -E -xc /dev/null
    As of gcc 4.2, you can also use: -march=native or -mtune=native */
 
-#if defined (__tune_pentium4__) /* Threshold for Pentium 4 */
+#if 1 /* no processor specific optimization for TeX Live */
+#define MPFR_TUNE_CASE "default"
+#elif defined (__tune_pentium4__) /* Threshold for Pentium 4 */
 #define MPFR_TUNE_CASE "src/x86_64/pentium4/mparam.h"
 #include "x86_64/pentium4/mparam.h"
 
diff -ur mpfr-3.1.2.orig/src/mpfr-impl.h mpfr-3.1.2/src/mpfr-impl.h
--- mpfr-3.1.2.orig/src/mpfr-impl.h	2013-03-13 16:37:36.000000000 +0100
+++ mpfr-3.1.2/src/mpfr-impl.h	2014-05-23 10:45:48.000000000 +0200
@@ -23,6 +23,11 @@
 #ifndef __MPFR_IMPL_H__
 #define __MPFR_IMPL_H__
 
+/* Include MPFR 'config.h' before ANY system headers */
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
 /* Let's include some standard headers unconditionally as they are
    already needed by several source files or when some options are
    enabled/disabled, and it is easy to forget them (some configure
@@ -56,12 +61,6 @@
  ****************** Include files *********************
  ******************************************************/
 
-/* Include 'config.h' before using ANY configure macros if needed
-   NOTE: It isn't MPFR 'config.h', but GMP's one! */
-#ifdef HAVE_CONFIG_H
-# include "config.h"
-#endif
-
 #ifdef  MPFR_HAVE_GMP_IMPL /* Build with gmp internals*/
 
 # ifndef __GMP_H__
