[LLVMdev] DAG optimization and lowering algorithm

[Eli Friedman]

On Tue, Feb 7, 2012 at 12:38 AM, Demikhovsky, Elena
<elena.demikhovsky at intel.com> wrote:
> At the beginning, I have the following chain: LOAD -> TRUNCATE -> ZERO_EXTEND.
> After Combine(BeforeLegalizeTypes) the optimization of ZERO_EXTEND  gives me the new chain LOAD -> ANY_EXTEND -> AND.
>
> I want to optimize ANY_EXTEND but is not analyzed in the same Combine().

That sounds like it's just a matter of making sure we don't forget to
add the ANY_EXTEND to the worklist.  We don't need a whole additional
DAGCombine run for that.

-Eli