[llvm-commits] [llvm] r59801 - /llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

[Chris Lattner]

On Nov 20, 2008, at 11:44 PM, Bill Wendling wrote:

> Author: void
> Date: Fri Nov 21 01:44:30 2008
> New Revision: 59801
>
> URL: http://llvm.org/viewvc/llvm-project?rev=59801&view=rev
> Log:
> Default to converting UADDO to the generic form that SADDO is  
> converted to.

Hi Bill,

A couple comments.  Commonality between DAGCombine hacks is common,  
but I strongly prefer that the commonality be factored out into shared  
helper functions (e.g. SimplifySelectCC) instead of having the Visit  
methods call each other.

Second UADDO/SADDO are different operations, they shouldn't lower to  
the same code.

Third, DAG combine shouldn't do this lowering, it should go in legalize.

-Chris