diff --git a/llvm/Makefile.config.in b/llvm/Makefile.config.in
index c88bf88340b9..73659cfb8459 100644
--- a/llvm/Makefile.config.in
+++ b/llvm/Makefile.config.in
@@ -11,6 +11,9 @@ OS=@OS@
 # Target hardware architecture
 ARCH=@ARCH@
 
+# Endian-ness of the target
+ENDIAN=@ENDIAN@
+
 # Path to the C++ compiler to use.  This is an optional setting, which defaults
 # to whatever your gmake defaults to.
 #
diff --git a/llvm/autoconf/configure.ac b/llvm/autoconf/configure.ac
index e0012759b201..8333333047d6 100644
--- a/llvm/autoconf/configure.ac
+++ b/llvm/autoconf/configure.ac
@@ -244,6 +244,9 @@ AC_STRUCT_TM
 dnl Check for various C features
 AC_C_PRINTF_A
 
+dnl Check for the endianness of the target
+AC_C_BIGENDIAN(AC_SUBST([ENDIAN],[big]),AC_SUBST([ENDIAN],[little]))
+
 dnl Check for C++ extensions
 AC_CXX_HAVE_HASH_MAP
 AC_CXX_HAVE_HASH_SET
diff --git a/llvm/configure b/llvm/configure
index f26e0a35726a..c504f4c7e631 100755
--- a/llvm/configure
+++ b/llvm/configure
@@ -465,7 +465,7 @@ ac_includes_default="\
 #endif"
 
 ac_unique_file=""Makefile.config.in""
-ac_subst_vars='SHELL PATH_SEPARATOR PACKAGE_NAME PACKAGE_TARNAME PACKAGE_VERSION PACKAGE_STRING PACKAGE_BUGREPORT exec_prefix prefix program_transform_name bindir sbindir libexecdir datadir sysconfdir sharedstatedir localstatedir libdir includedir oldincludedir infodir mandir build_alias host_alias target_alias DEFS ECHO_C ECHO_N ECHO_T LIBS subdirs INSTALL_PROGRAM INSTALL_SCRIPT INSTALL_DATA build build_cpu build_vendor build_os host host_cpu host_vendor host_os target target_cpu target_vendor target_os OS LLVMGCCDIR ARCH CXX CXXFLAGS LDFLAGS CPPFLAGS ac_ct_CXX EXEEXT OBJEXT CC CFLAGS ac_ct_CC CPP ifGNUmake LEX LEXLIB LEX_OUTPUT_ROOT YACC BISON EGREP LN_S ECHO AR ac_ct_AR RANLIB ac_ct_RANLIB STRIP ac_ct_STRIP CXXCPP F77 FFLAGS ac_ct_F77 LIBTOOL DOT ETAGS ETAGSFLAGS PYTHON QMTEST ALLOCA MMAP_FILE ENABLE_OPTIMIZED SPEC_ROOT USE_SPEC SPEC95_ROOT USE_SPEC95 UPB DISABLE_LLC_DIFFS JIT LLVMCC1 LLVMCC1PLUS BCR PAPIDIR SHLIBEXT LIBOBJS LTLIBOBJS'
+ac_subst_vars='SHELL PATH_SEPARATOR PACKAGE_NAME PACKAGE_TARNAME PACKAGE_VERSION PACKAGE_STRING PACKAGE_BUGREPORT exec_prefix prefix program_transform_name bindir sbindir libexecdir datadir sysconfdir sharedstatedir localstatedir libdir includedir oldincludedir infodir mandir build_alias host_alias target_alias DEFS ECHO_C ECHO_N ECHO_T LIBS subdirs INSTALL_PROGRAM INSTALL_SCRIPT INSTALL_DATA build build_cpu build_vendor build_os host host_cpu host_vendor host_os target target_cpu target_vendor target_os OS LLVMGCCDIR ARCH CXX CXXFLAGS LDFLAGS CPPFLAGS ac_ct_CXX EXEEXT OBJEXT CC CFLAGS ac_ct_CC CPP ifGNUmake LEX LEXLIB LEX_OUTPUT_ROOT YACC BISON EGREP LN_S ECHO AR ac_ct_AR RANLIB ac_ct_RANLIB STRIP ac_ct_STRIP CXXCPP F77 FFLAGS ac_ct_F77 LIBTOOL DOT ETAGS ETAGSFLAGS PYTHON QMTEST ENDIAN ALLOCA MMAP_FILE ENABLE_OPTIMIZED SPEC_ROOT USE_SPEC SPEC95_ROOT USE_SPEC95 UPB DISABLE_LLC_DIFFS JIT LLVMCC1 LLVMCC1PLUS BCR PAPIDIR SHLIBEXT LIBOBJS LTLIBOBJS'
 ac_subst_files=''
 
 # Initialize some variables set by options.
@@ -19481,6 +19481,209 @@ _ACEOF
 	fi
 
 
+echo "$as_me:$LINENO: checking whether byte ordering is bigendian" >&5
+echo $ECHO_N "checking whether byte ordering is bigendian... $ECHO_C" >&6
+if test "${ac_cv_c_bigendian+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  # See if sys/param.h defines the BYTE_ORDER macro.
+cat >conftest.$ac_ext <<_ACEOF
+#line $LINENO "configure"
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+#include <sys/types.h>
+#include <sys/param.h>
+
+int
+main ()
+{
+#if !BYTE_ORDER || !BIG_ENDIAN || !LITTLE_ENDIAN
+ bogus endian macros
+#endif
+
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
+  (eval $ac_compile) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+         { ac_try='test -s conftest.$ac_objext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  # It does; now see whether it defined to BIG_ENDIAN or not.
+cat >conftest.$ac_ext <<_ACEOF
+#line $LINENO "configure"
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+#include <sys/types.h>
+#include <sys/param.h>
+
+int
+main ()
+{
+#if BYTE_ORDER != BIG_ENDIAN
+ not big endian
+#endif
+
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
+  (eval $ac_compile) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+         { ac_try='test -s conftest.$ac_objext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  ac_cv_c_bigendian=yes
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+ac_cv_c_bigendian=no
+fi
+rm -f conftest.$ac_objext conftest.$ac_ext
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+# It does not; compile a test program.
+if test "$cross_compiling" = yes; then
+  # try to guess the endianness by grepping values into an object file
+  ac_cv_c_bigendian=unknown
+  cat >conftest.$ac_ext <<_ACEOF
+#line $LINENO "configure"
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+short ascii_mm[] = { 0x4249, 0x4765, 0x6E44, 0x6961, 0x6E53, 0x7953, 0 };
+short ascii_ii[] = { 0x694C, 0x5454, 0x656C, 0x6E45, 0x6944, 0x6E61, 0 };
+void _ascii () { char *s = (char *) ascii_mm; s = (char *) ascii_ii; }
+short ebcdic_ii[] = { 0x89D3, 0xE3E3, 0x8593, 0x95C5, 0x89C4, 0x9581, 0 };
+short ebcdic_mm[] = { 0xC2C9, 0xC785, 0x95C4, 0x8981, 0x95E2, 0xA8E2, 0 };
+void _ebcdic () { char *s = (char *) ebcdic_mm; s = (char *) ebcdic_ii; }
+int
+main ()
+{
+ _ascii (); _ebcdic ();
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
+  (eval $ac_compile) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+         { ac_try='test -s conftest.$ac_objext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  if grep BIGenDianSyS conftest.$ac_objext >/dev/null ; then
+  ac_cv_c_bigendian=yes
+fi
+if grep LiTTleEnDian conftest.$ac_objext >/dev/null ; then
+  if test "$ac_cv_c_bigendian" = unknown; then
+    ac_cv_c_bigendian=no
+  else
+    # finding both strings is unlikely to happen, but who knows?
+    ac_cv_c_bigendian=unknown
+  fi
+fi
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+fi
+rm -f conftest.$ac_objext conftest.$ac_ext
+else
+  cat >conftest.$ac_ext <<_ACEOF
+#line $LINENO "configure"
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+int
+main ()
+{
+  /* Are we little or big endian?  From Harbison&Steele.  */
+  union
+  {
+    long l;
+    char c[sizeof (long)];
+  } u;
+  u.l = 1;
+  exit (u.c[sizeof (long) - 1] == 1);
+}
+_ACEOF
+rm -f conftest$ac_exeext
+if { (eval echo "$as_me:$LINENO: \"$ac_link\"") >&5
+  (eval $ac_link) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } && { ac_try='./conftest$ac_exeext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  ac_cv_c_bigendian=no
+else
+  echo "$as_me: program exited with status $ac_status" >&5
+echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+( exit $ac_status )
+ac_cv_c_bigendian=yes
+fi
+rm -f core core.* *.core gmon.out bb.out conftest$ac_exeext conftest.$ac_objext conftest.$ac_ext
+fi
+fi
+rm -f conftest.$ac_objext conftest.$ac_ext
+fi
+echo "$as_me:$LINENO: result: $ac_cv_c_bigendian" >&5
+echo "${ECHO_T}$ac_cv_c_bigendian" >&6
+case $ac_cv_c_bigendian in
+  yes)
+    ENDIAN=big
+ ;;
+  no)
+    ENDIAN=little
+ ;;
+  *)
+    { { echo "$as_me:$LINENO: error: unknown endianness
+presetting ac_cv_c_bigendian=no (or yes) will help" >&5
+echo "$as_me: error: unknown endianness
+presetting ac_cv_c_bigendian=no (or yes) will help" >&2;}
+   { (exit 1); exit 1; }; } ;;
+esac
+
+
 echo "$as_me:$LINENO: checking whether the compiler implements namespaces" >&5
 echo $ECHO_N "checking whether the compiler implements namespaces... $ECHO_C" >&6
 if test "${ac_cv_cxx_namespaces+set}" = set; then
@@ -22460,6 +22663,7 @@ s,@ETAGS@,$ETAGS,;t t
 s,@ETAGSFLAGS@,$ETAGSFLAGS,;t t
 s,@PYTHON@,$PYTHON,;t t
 s,@QMTEST@,$QMTEST,;t t
+s,@ENDIAN@,$ENDIAN,;t t
 s,@ALLOCA@,$ALLOCA,;t t
 s,@MMAP_FILE@,$MMAP_FILE,;t t
 s,@ENABLE_OPTIMIZED@,$ENABLE_OPTIMIZED,;t t