[LLVMdev] localstatckallocation pass

[Reed Kotler]

I'm trying to understand how to use this.

Is it already enabled and it's just looking for the values of various 
virtual methods that can be overridden?

Mips 16 only has 8 free general registers but there are a lot of mips32 
registers that I can use in limited ways.

Some fancy schemes for addressing can cause too much register pressure 
to make it worth it.

if I want to maintain an additional pointer I can for example, using a 
pair of unused Mips32 registers, keep the value in a mips32 register and 
bring it back to live quickl.

Value is in Reg32X.

Reg32Y = Reg16Z
Reg16Z = Reg32X
... do some things with Reg16Z/Reg32X
Reg16z = Reg32Y  ; restore Reg16Z

These move instructions are both 16 bit instructions.

At some point I have think of some more formal ways to use the Mips32 
registers.