[PATCH] D41689: [SCEVAA] Don't crash on pointers with no dominance relationship.

Dan Gohman via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Thu Jan 4 17:14:09 PST 2018


sunfish added a comment.

I haven't thought about this in depth, but it seems like SCEV theoretically should be able to cope under such circumstances.

>From the comments in PR33761, SCEV is being asked to compute the difference between `((8 * %tmp2) + %tmp)` and `{%tmp,+,64}<%bb4>`, where `%tmp2` doesn't dominate the loop. It seems the result should be something like `{0,+,64}<%bb4> + (-8 * %tmp2)`, and there is even a point in the program where the expression can be computed -- immediately after %tmp2.


Repository:
  rL LLVM

https://reviews.llvm.org/D41689





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