[PATCH] D15146: [InstCombine] Look through PHIs, GEPs, IntToPtrs and PtrToInts to expose more constants when comparing GEPs

[hfinkel@anl.gov via llvm-commits]

hfinkel added a subscriber: hfinkel.

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Comment at: lib/Transforms/InstCombine/InstCombineCompares.cpp:920
@@ +919,3 @@
+  //   OFFSET1 cmp OFFSET2
+  Value *NewRHS = rewriteAsOffsetGEP(RHS, PtrBase, DL, Nodes);
+  return new ICmpInst(ICmpInst::getSignedPredicate(Cond), Index, NewRHS);
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For the particular ICmpInst you've creating here, is this `((gep Ptr, OFFSET1) cmp (gep Ptr, OFFSET2)` or `OFFSET1 cmp OFFSET2`? Given that rewriteAsOffsetGEP returns a GEP that uses PtrBase as its base address, it looks like for former. I see no reason it should not be the latter, however.

I think this would be clearer if you used the same names in your comments as you did names for the local variables.



http://reviews.llvm.org/D15146