[PATCH] Propagate DAG node ordering during legalization and instruction selection

[Jakob Stoklund Olesen]

On Mar 18, 2013, at 2:02 PM, Justin Holewinski <justin.holewinski at gmail.com> wrote:

> Compile-time impact is negligible for a release build on the unit tests.  There is about an 8% impact with assertions enabled.
> 
> I'm not sure how CSE factors in here.  This propagation happens during legalization.  I agree that it should be addressed, but I see it as a separate issue.  Unless I'm missing some instance of CSE being performed during legalization?

CSE is continuous in SelectionDAG. Whenever you create a new SDNode, you may actually get an existing node if an identical one happens to exist.

/jakob