How to add new library into GCC source

[Le Ton Chanh]

Hi all,
I added a new C library (*.h file) into GCC source in directory $(GCC_ROOT)/gcc and it is used in haifa-sched.c and final.c. But when I built GCC, it warmed "undefined reference to ...". How can I fix this?

The second question, I want to add 'nop' instruction after an instruction in assembly source file generated by cc1 when the schedule queued for 1 cycles for the insn respectively. Does GCC support that?

I am using GCC 3.3.4. Thanks in advance.

Le Ton Chanh 
email:letonchanh at yahoo dot com