Can c1 be built for 64-bit?

[Ao Qi]

Hi, all
I try to build a 64-bit c1, however, in hotspot/make/Makefile, I found:

  ifeq ($(ARCH_DATA_MODEL), 32)
	$(CD) $(OUTPUTDIR); \
	    $(MAKE) -f $(ABS_OS_MAKEFILE) \
		      $(MAKE_ARGS) $(VM_TARGET)
  else
	@$(ECHO) "No compiler1 ($(VM_TARGET)) for ARCH_DATA_MODEL=$(ARCH_DATA_MODEL)"
  endif

So I wonder why compiler1 can not be built for a 64-bit version?

Thanks,
Ao Qi