[PATCH] D139275: [SimplifyCFG] `FoldBranchToCommonDest()`: deal with mismatched IV's in PHI's in common successor block

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri added inline comments.


================
Comment at: llvm/lib/Transforms/Utils/SimplifyCFG.cpp:3887
+      ++NumSelectsNeeded;
+      SawVectorSelect |= PN.getType()->isVectorTy();
+    }
----------------
arsenm wrote:
> I'm not really sure what this is doing; should there be a vector variant of the fpclassify test?
These two lines are cost modelling.
We need to know how many selects we'll need,
and the cost model logic also rewards (allows bigger budget)
the cases where some of the instructions operate on vectors.


Repository:
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  https://reviews.llvm.org/D139275/new/

https://reviews.llvm.org/D139275