| AC_DEFUN([ACX_64BIT],[ |
| AC_ARG_ENABLE( |
| [64bit], |
| [AS_HELP_STRING([--enable-64bit],[enable 64-bit compiling @<:@disabled@:>@])], |
| [enable_64bit="${enableval}"], |
| [enable_64bit="no"]) |
| |
| if test "x$enable_64bit" = "xyes" |
| then |
| AC_MSG_CHECKING(if we can compile in 64-bit mode) |
| tmp_CFLAGS=$CFLAGS |
| CFLAGS="-m64" |
| AC_RUN_IFELSE( |
| [ |
| AC_LANG_PROGRAM([],[return sizeof(void*) == 8 ? 0 : 1;]) |
| ], [ |
| AC_MSG_RESULT(yes) |
| CXXFLAGS="-m64 $CXXFLAGS" |
| LDFLAGS="-m64 $LDFLAGS" |
| CFLAGS="-m64 $tmp_CFLAGS" |
| ],[ |
| AC_MSG_RESULT(no) |
| AC_MSG_ERROR([Don't know how to compile in 64-bit mode.]) |
| CFLAGS=$tmp_CFLAGS |
| ] |
| ) |
| fi |
| |
| ]) |