[PATCH] D138814: [InstCombine] Combine a/lshr of add -> uadd.with.overflow

[Sanjay Patel via Phabricator via llvm-commits]

spatel added a comment.

In D138814#3953729 <https://reviews.llvm.org/D138814#3953729>, @foad wrote:

>> What do you think about producing the sequence with 'not' + 'icmp' instead of the uadd + extract?
>
> The point about using uadd.with.overflow is that it also gives you the truncated 32 bit result of the add.

If we're not using that value (as shown in the first two tests), then do we still we want to canonicalize to an overflow intrinsic? That implies that we also need to transform the "not+icmp" pattern into "uadd+extract" to be consistent.


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