how to add new instruction

[James E Wilson]

apollo wrote:
> i'm afraid so. i add a new rtl expression in rtl.def. and when i add a
> new define_insn
>  section in i386.md, it said the instruction is undefined. 

You need to be much more explicit about what happened here if you want 
help.  You need to give the exact error you got, the exact command that 
was used to produce it, the exact change you made to the i386.md file, etc.
-- 
Jim Wilson, GNU Tools Support, http://www.SpecifixInc.com