[PATCH] D63928: [ARM][SCEV][LSR] Prevent using undefined value in binops

[Sam Parker via Phabricator via llvm-commits]

samparker added a comment.

It looks like this problem is stemming from the fact that values are often cached during expansion, so even though the cast is replaced by a new value, the old value is still being used later on. Value reuse seems at important theme in this transform, so maybe we could try to introduce a map of updated values so that we don't reuse 'dead' instructions? I don't know what trade-offs we should be considering here though. This approach is certainly more simple and less likely to break again in the future.


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https://reviews.llvm.org/D63928