[LLVMdev] Variable length condition code for SETCC and SELECT?

[B. Scott Michel]

B. Scott Michel wrote:
> It'd be easy to hack PromoteOp to make a pass to determine all operands' 
> promoted value types, take the max, then figure out some way to 
> re-promote them to maximal promoted value type. Except that this is a 
> non-optimal solution requiring PromoteOp to potentially traverse the 
> operand tree twice.
>
> Any suggestions or ideas?
>   
Not many suggestions or ideas, given the feedback so far. I'm not sure 
that two passes down a Node's Operand DAG can be avoided. The first pass 
would determine the maximal MVT needed, the second pass would generate 
the promoted Nodes.

In the absence of any suggestions or ideas, it's off to begging 
forgiveness if the patch confuses people and code. :-)


-scooter