Thank you very much about the help. Acctually, I have included fp-bit.c in libgcc.mk. But the order is not right, I think. Because _si_to_df.o is after the _floatdidf.o. Also, how to change _si_to_df.o to _floatsidf.o? In md file? I'm wondering that maybe I needn't to implement libgcc2.a, but that makes gcc fail to build. Eric