Index: Mk/bsd.xorg.mk
===================================================================
--- Mk/bsd.xorg.mk	(revision 312060)
+++ Mk/bsd.xorg.mk	(working copy)
@@ -49,6 +49,11 @@
 . if ${XORG_CAT} == "driver"
 USE_GNOME+=	pkgconfig
 USE_XORG+=	xorg-server xproto randrproto xi
+# work around a llvm bug on i386, llvm bug #15806 
+# reproduced with clang 3.2 (current release) and 3.1
+.  if ${ARCH} == i386
+CFLAGS+=	-fno-optimize-sibling-calls
+.  endif
 CONFIGURE_ENV+=	DRIVER_MAN_SUFFIX=4x DRIVER_MAN_DIR='$$(mandir)/man4'
 .  if ${PORTNAME:M*input*}x != x
 USE_XORG+=	inputproto renderproto