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Hi!

I started writing a LLVM backend for a custom architecture. I have some register and instruction .td files and some other files/classes like a MCStreamer for assembler output. At the moment I can compile some empty programs so far.

I implemented the method ::eliminateFrameIndex() similar to the Sparc and ARM backend. The method looks like this:

// frame pointer is in reg of class mytarget::ARegsRegClass
unsigned ScratchReg = MF.getRegInfo().createVirtualRegister(&mytarget::ARegsRegClass);
const TargetInstrInfo &TII = \*MF.getTarget().getInstrInfo();
BuildMI(\*MI.getParent(), II, dl, TII.get(mytarget::ADD\_AReg), ScratchReg).addReg(FramePtr).addImm(Offset);
// Update the original instruction to use the scratch register.
MI.getOperand(FIOperandNum).ChangeToRegister(ScratchReg, false);

But for the test case

int foo(void)
{
int a = 43;
return(41);
}

I get the error message "Remaining virtual register operands".

Is something wrong with my method? Did I miss to implement some more methods?

Thanks in advance,
Boris