[LLVMdev] Initial cut at a instruction raising patch

[Richard Pennington]

Chris Lattner wrote:
> How do you plan to handle things like arbitrary precision integers,  
> etc?  It seems like you'll end up duplicating a ton of codegen logic  
> to handle this.

Maybe I'm not being very clear. I want this replacement to be done at 
the very last minute (before unreferenced functions are removed, of 
course).

I only want to catch libgcc-ish functions.

For example on the x86 (32) a function containing prinf() only needs 
__divdi3 and __moddi3.

I'd like the code generator to do its magic until there is no more magic 
to do, and then replace any 64 bit divides with the function call, for 
example.

Make sense?

-Rich