[PATCH] D15559: [SCEVExpander] Make findExistingExpansion smarter

[Michael Zolotukhin via llvm-commits]

mzolotukhin accepted this revision.
mzolotukhin added a comment.

> Attached Wei's comment in r259815

> 

>   Fix a regression for r259736.

>   

>   When SCEV expansion tries to reuse an existing value, it is needed to ensure

>   that using the Value at the InsertPt will not break LCSSA. The fix adds a

>   check that InsertPt is either inside the candidate Value's parent loop, or

>   the candidate Value's parent loop is nullptr.

> 


Oh, I see, makes sense. The patch LGTM, thanks for your patience:)

Michael


================
Comment at: include/llvm/Analysis/ScalarEvolutionExpander.h:266
@@ -265,1 +265,3 @@
 
+    Value *FindValueInExprValueMap(const SCEV *S, const Instruction *InsertPt);
+
----------------
Please add a comment for the new function.


http://reviews.llvm.org/D15559