diff -Naurd mpfr-3.1.2-a/PATCHES mpfr-3.1.2-b/PATCHES
--- mpfr-3.1.2-a/PATCHES	2013-09-26 10:52:52.000000000 +0000
+++ mpfr-3.1.2-b/PATCHES	2013-09-26 10:52:52.000000000 +0000
@@ -0,0 +1 @@
+exp_2
diff -Naurd mpfr-3.1.2-a/VERSION mpfr-3.1.2-b/VERSION
--- mpfr-3.1.2-a/VERSION	2013-03-13 15:37:28.000000000 +0000
+++ mpfr-3.1.2-b/VERSION	2013-09-26 10:52:52.000000000 +0000
@@ -1 +1 @@
-3.1.2
+3.1.2-p1
diff -Naurd mpfr-3.1.2-a/src/exp_2.c mpfr-3.1.2-b/src/exp_2.c
--- mpfr-3.1.2-a/src/exp_2.c	2013-03-13 15:37:28.000000000 +0000
+++ mpfr-3.1.2-b/src/exp_2.c	2013-09-26 10:52:52.000000000 +0000
@@ -204,7 +204,7 @@
           for (k = 0; k < K; k++)
             {
               mpz_mul (ss, ss, ss);
-              exps <<= 1;
+              exps *= 2;
               exps += mpz_normalize (ss, ss, q);
             }
           mpfr_set_z (s, ss, MPFR_RNDN);
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	2013-03-13 15:37:37.000000000 +0000
+++ mpfr-3.1.2-b/src/mpfr.h	2013-09-26 10:52:52.000000000 +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"
+#define MPFR_VERSION_STRING "3.1.2-p1"
 
 /* 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/version.c mpfr-3.1.2-b/src/version.c
--- mpfr-3.1.2-a/src/version.c	2013-03-13 15:37:34.000000000 +0000
+++ mpfr-3.1.2-b/src/version.c	2013-09-26 10:52:52.000000000 +0000
@@ -25,5 +25,5 @@
 const char *
 mpfr_get_version (void)
 {
-  return "3.1.2";
+  return "3.1.2-p1";
 }