--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/acinclude.m4	Thu Dec 11 23:28:50 2008 +0000
@@ -0,0 +1,20 @@
+# AC_CHECK_FASTCALL([if-ok],[if-notok])
+# Test if the compiler recognizes __attribute__((regparm(3))) - we don't 
+# currently check if it actually works correctly, but probably should...
+# -----------------------
+AC_DEFUN([AC_CHECK_FASTCALL], [
+AC_MSG_CHECKING([support for fastcall calling conventions]);
+AC_RUN_IFELSE([
+  AC_LANG_SOURCE([[
+int __attribute__((regparm(3))) foo(int a, int b) { return a+b; }
+
+int main(int argc, char *argv[])
+{
+   return foo( 1, 2 ) == 3 ? 0 : 1;
+}]])], [ 
+   AC_MSG_RESULT([yes])
+   $1 ], [ 
+   AC_MSG_RESULT([no])
+   $2 ])
+])
+