[PATCH] D106745: [DAG] DAGCombiner::useDivRem - recognise sub(X,mul(div(X,Y),Y)) as a rem(X,Y)

Sat Jul 24 10:14:25 PDT 2021

lebedev.ri added a comment.

In D106745#2902526 <https://reviews.llvm.org/D106745#2902526>, @RKSimon wrote:

> I'm so sorry, this was chasing what I thought was a bug in PR51014 but was just a screwup on my part - sorry for wasting your time

I do not follow.
It *is* an expanded rem: https://alive2.llvm.org/ce/z/oYT73P
And the divrempairs pass actively fights against it: https://godbolt.org/z/9P7qeqb9E
Because `TargetTransformInfo::hasDivRemOp()` said that there is no divrem for i8.

Repository:
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https://reviews.llvm.org/D106745