[PATCH] D21740: [InstCombine] extend matchSelectFromAndOr() to work with i1 scalar types

[Eli Friedman via llvm-commits]

eli.friedman added a comment.

Would it make sense to add "m_SExtOrBool" or something like that, which matches a value which matches either a sext or a value of boolean type?  That seems like a cleaner way to generalize the transform.

If the boolean comes from an icmp, it seems likely that you'll end up with `((X == Y) & C) | ((X != Y) & D)`.  I guess you can address that in a followup, if necessary.


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Comment at: lib/Transforms/InstCombine/InstCombineAndOrXor.cpp:1654
@@ -1653,3 +1669,1 @@
-    // The bitcasts will either all exist or all not exist. The builder will
-    // not create unnecessary casts if the types already match.
     Value *BitcastC = Builder.CreateBitCast(C, A->getType());
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Please don't get rid of this comment... you don't have any others which actually describe the transform in full.


http://reviews.llvm.org/D21740