[LLVMdev] ISel Pattern Preferences

David Greene dag at cray.com
Mon Apr 6 11:31:48 PDT 2009

What's a reliable way to prefer one patterns over another?  I have two 
patterns with different predicates.  Pattern A has a very general predicate 
to catch a wide variety of store instructions.  Pattern B has a narrower 
predicate meant to catch very specific store instructions that would also 
satisfy the predicate for Pattern A.

We used to match Pattern B just fine but after changing .td files a bit the 
selector is always picking Pattern A.

Setting AddedComplexity doesn't seem to help.


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