-include $(isa_src_dir)/rv64ui/Makefrag
-include $(isa_src_dir)/rv64uf/Makefrag
-include $(isa_src_dir)/rv64si/Makefrag
-include $(isa_src_dir)/rv64mi/Makefrag
-include $(isa_src_dir)/rv32ui/Makefrag
-include $(isa_src_dir)/rv32si/Makefrag
-include $(isa_src_dir)/rv32mi/Makefrag
+ifeq ($(XLEN),64)
+include $(src_dir)/rv64ui/Makefrag
+include $(src_dir)/rv64uc/Makefrag
+include $(src_dir)/rv64um/Makefrag
+include $(src_dir)/rv64ua/Makefrag
+include $(src_dir)/rv64uf/Makefrag
+include $(src_dir)/rv64ud/Makefrag
+include $(src_dir)/rv64si/Makefrag
+include $(src_dir)/rv64mi/Makefrag
+endif
+include $(src_dir)/rv32ui/Makefrag
+include $(src_dir)/rv32uc/Makefrag
+include $(src_dir)/rv32um/Makefrag
+include $(src_dir)/rv32ua/Makefrag
+include $(src_dir)/rv32uf/Makefrag
+include $(src_dir)/rv32ud/Makefrag
+include $(src_dir)/rv32si/Makefrag
+include $(src_dir)/rv32mi/Makefrag