diff --git a/gas/ChangeLog b/gas/ChangeLog
index 1bc25c8bd7..595cbfb51a 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,11 @@
+2009-12-15  H.J. Lu  <hongjiu.lu@intel.com>
+
+	* as.h (mempcpy): New.
+
+	* configure.in: Check if mempcpy is declared.
+	* configure: Regenerated.
+	* config.in: Likewise.
+
 2009-12-15  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* config/tc-i386.c (build_vex_prefix): Use VEX256.
diff --git a/gas/as.h b/gas/as.h
index 1d1d97e5a0..c670536b9f 100644
--- a/gas/as.h
+++ b/gas/as.h
@@ -149,6 +149,10 @@ extern void *realloc ();
 extern char *strstr ();
 #endif
 
+#if !HAVE_DECL_MEMPCPY
+void *mempcpy(void *, const void *, size_t);
+#endif
+
 #if !HAVE_DECL_VSNPRINTF
 extern int vsnprintf(char *, size_t, const char *, va_list);
 #endif
diff --git a/gas/config.in b/gas/config.in
index 9493de7242..9f4c746c22 100644
--- a/gas/config.in
+++ b/gas/config.in
@@ -49,6 +49,10 @@
 /* Is the prototype for getopt in <unistd.h> in the expected format? */
 #undef HAVE_DECL_GETOPT
 
+/* Define to 1 if you have the declaration of `mempcpy', and to 0 if you
+   don't. */
+#undef HAVE_DECL_MEMPCPY
+
 /* Define to 1 if you have the declaration of `vsnprintf', and to 0 if you
    don't. */
 #undef HAVE_DECL_VSNPRINTF
diff --git a/gas/configure b/gas/configure
index cbcffc7dcc..86ae97484a 100755
--- a/gas/configure
+++ b/gas/configure
@@ -13820,6 +13820,17 @@ $as_echo "#define NEED_DECLARATION_STRSTR 1" >>confdefs.h
 fi
 
 
+ac_fn_c_check_decl "$LINENO" "mempcpy" "ac_cv_have_decl_mempcpy" "$ac_includes_default"
+if test "x$ac_cv_have_decl_mempcpy" = x""yes; then :
+  ac_have_decl=1
+else
+  ac_have_decl=0
+fi
+
+cat >>confdefs.h <<_ACEOF
+#define HAVE_DECL_MEMPCPY $ac_have_decl
+_ACEOF
+
 ac_fn_c_check_decl "$LINENO" "vsnprintf" "ac_cv_have_decl_vsnprintf" "$ac_includes_default"
 if test "x$ac_cv_have_decl_vsnprintf" = x""yes; then :
   ac_have_decl=1
diff --git a/gas/configure.in b/gas/configure.in
index 455b8ee177..d21b124d77 100644
--- a/gas/configure.in
+++ b/gas/configure.in
@@ -704,6 +704,7 @@ GAS_CHECK_DECL_NEEDED(malloc, f, char *(*f)(), $gas_test_headers)
 GAS_CHECK_DECL_NEEDED(sbrk, f, char *(*f)(), $gas_test_headers)
 GAS_CHECK_DECL_NEEDED(strstr, f, char *(*f)(), $gas_test_headers)
 
+AC_CHECK_DECLS([mempcpy])
 AC_CHECK_DECLS([vsnprintf])
 
 BFD_BINARY_FOPEN