--- a/libcpp/configure.ac	Tue May 25 18:58:51 2010 +0900
+++ b/libcpp/configure.ac	Tue Mar 22 17:18:12 2011 +0900
@@ -14,6 +14,9 @@
 AC_PROG_CXX
 AC_PROG_RANLIB
 
+AC_USE_SYSTEM_EXTENSIONS
+AC_SYS_LARGEFILE
+
 # See if we are building gcc with C++.
 # Do this early so setting lang to C++ affects following tests
 AC_ARG_ENABLE(build-with-cxx,
@@ -45,6 +48,10 @@
 if test "$ENABLE_BUILD_WITH_CXX" = "no"; then
 ZW_PROG_COMPILER_DEPENDENCIES([CC])
 else
+AC_LANG_PUSH([C++])
+AC_COMPILE_IFELSE([[int i;]], [],
+		  [AC_MSG_ERROR([C++ compiler missing or inoperational])])
+AC_LANG_POP([C++])
 ZW_PROG_COMPILER_DEPENDENCIES([CXX])
 fi
 
@@ -52,26 +59,19 @@
 AC_HEADER_TIME
 ACX_HEADER_STRING
 
-# AC_CHECK_HEADERS is repeated to work around apparent autoconf 2.59 bug.  If
-# AC_CHECK_HEADERS comes after the if clause, the last AC_LANG call gets used,
-# no matter which branch is taken.
-if test "$ENABLE_BUILD_WITH_CXX" = "no"; then
-   AC_LANG(C)
-   AC_CHECK_HEADERS(locale.h fcntl.h limits.h stddef.h \
+AC_CHECK_HEADERS(locale.h fcntl.h limits.h stddef.h \
 	stdlib.h strings.h string.h sys/file.h unistd.h)
-else
-   AC_LANG(C++)
-   AC_CHECK_HEADERS(locale.h fcntl.h limits.h stddef.h \
-	stdlib.h strings.h string.h sys/stat.h sys/file.h unistd.h)
-fi
 
 # Checks for typedefs, structures, and compiler characteristics.
+AC_C_BIGENDIAN
 AC_C_CONST
 AC_C_INLINE
 AC_FUNC_OBSTACK
 AC_TYPE_OFF_T
 AC_TYPE_SIZE_T
-AC_CHECK_TYPE(ssize_t, int)
+AC_TYPE_SSIZE_T
+AC_TYPE_UINTPTR_T
+AC_CHECK_TYPE(ptrdiff_t, int)
 AC_STRUCT_TM
 AC_CHECK_SIZEOF(int)
 AC_CHECK_SIZEOF(long)
@@ -81,8 +81,8 @@
   fread_unlocked fwrite_unlocked getchar_unlocked getc_unlocked dnl
   putchar_unlocked putc_unlocked)
 AC_CHECK_FUNCS(libcpp_UNLOCKED_FUNCS)
-AC_CHECK_DECLS(m4_split(m4_normalize(abort asprintf basename errno getopt \
-  libcpp_UNLOCKED_FUNCS vasprintf)))
+AC_CHECK_DECLS([abort, asprintf, basename(char *), errno, getopt, vasprintf])
+AC_CHECK_DECLS(m4_split(m4_normalize(libcpp_UNLOCKED_FUNCS)))
 
 # Checks for library functions.
 AC_FUNC_ALLOCA
@@ -177,6 +177,13 @@
 [Define to the widest efficient host integer type at least
    as wide as the target's size_t type.])
 
+case $target in
+  i?86-* | x86_64-*)
+    AC_TRY_COMPILE([], [asm ("pcmpestri %0, %%xmm0, %%xmm1" : : "i"(0))],
+      [AC_DEFINE([HAVE_SSE4], [1],
+		 [Define to 1 if you can assemble SSE4 insns.])])
+esac
+
 # Output.
 
 AC_CONFIG_HEADERS(config.h:config.in, [echo timestamp > stamp-h1])