PowerPc extended instruction

[kanishk rastogi]

sir,
i have cross compiled gcc on my x86_64 pc for Powerpc.
on compiling my assembly program it gives error for some instructions
like mftbu,mftb....
I checked for these on net and found that these are some extended
instructions for powerPC. What do i need to do so that the assembler
understands the instuction.
thanks in advance .
i configures bin utils with
--target=powerpc-elf



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