[LLVMdev] building an ARM backend

[Rafael Espíndola]

The company I work for uses quiet some ARM processors and I am trying
to convince them to let me spend some company time building an llvm
back end :-)

I have read the documentation and taken a look on the X86 back end. It
looks quiet simple to get a very minimal back end working. I am
considering for a first version:

1) only support the 32 bits ABI
2) Ignore the shifter (i.e use only 8 bits immediates)
3) Ignore the fancier addressing modes

Without this, the generated code with not be very good but the back
end will be very simple. The only part that appears to require more
work is describing the instructions set.

Am I underestimating how hard it is? How much work do you thing is
required to have this minimal back end working?

PS.: What is the getRARegister method for?
PS.: Once I have a small back end working I will try to improve it :-)

Thanks,
Rafael