[PATCH] D145510: [SCEV] Fix finite loop non-strict predicate simplification (PR60944)

[Philip Reames via Phabricator via llvm-commits]

reames added a comment.

In D145510#4259519 <https://reviews.llvm.org/D145510#4259519>, @efriedma wrote:

> We used to produce a backedge-taken count of `%m`, but now we produce `(-1 + (1 umax (1 + %m)))`.

On your reduced example, it's interesting the the loop backedge is guaranteed to execute when %m is defined.  This might be an over-reduction, but we might be able to do a corrected version of D148107 <https://reviews.llvm.org/D148107> based on the defining scope bound of RHS being guaranteed to reach the backedge test.  I'm a bit worried about both the compile time of that, and that I'm over specializing for your possible over-reduced example.


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