$(AM_V_at)$(MAKE) -f Makefile.qsbr clean
$(AM_V_at)$(MAKE) -f Makefile.mb clean
$(AM_V_at)$(MAKE) -f Makefile.membarrier clean
$(AM_V_at)$(MAKE) -f Makefile.qsbr clean
$(AM_V_at)$(MAKE) -f Makefile.mb clean
$(AM_V_at)$(MAKE) -f Makefile.membarrier clean