[PATCH] D63065: [InstSimplify] Fix addo/subo undef folds (PR42209)

[Nikita Popov via Phabricator via llvm-commits]

nikic added a comment.

@lebedev.ri It's not possible to fold to `{ i8 undef, i1 false }`. As a counter-example `uaddo(1, undef)` can never have the value `{ 0, false }`. Reaching the zero value would have required overflow, which is precluded by the overflow result. Similar cases exist for the other intrinsics as well.


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  rL LLVM

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