Index: Makefile
===================================================================
--- Makefile	(revision 530274)
+++ Makefile	(working copy)
@@ -47,6 +47,14 @@
 CC=		clang${LLVM_VER}
 CXX=		clang++${LLVM_VER}
 
+
+.include <bsd.port.options.mk>
+
+.if ${ARCH} == powerpc && ${OSVERSION} < 1300070
+CXXFLAGS+=	-latomic
+USE_GCC=	yes
+.endif
+
 post-patch:
 	@${REINPLACE_CMD} -e 's|/usr/local/include|${PREFIX}/include|' \
 		${WRKSRC}/Jamfile