[llvm-dev] SCEVUDiv simplification

[Hongbin Zheng via llvm-dev]

Maybe because when n is 0, it trap? And you simplification get rid of the
trap?

On Thu, Aug 2, 2018 at 10:03 AM Alexandre Isoard via llvm-dev <
llvm-dev at lists.llvm.org> wrote:

> Hello,
>
> I noticed that our SCEVUDiv does not simplify anything when the RHS is not
> a constant.
> Is that because there is a potential issue with division by zero being
> simplified?
>
> For instance, would it be okay to simplify:
>
> ((%i * %n)<nuw> /u %n)
>
> into: %i
>
> The way I see it, if %n is 0, then that division is undefined and we can
> "define it", at will, as being %i.
>
> Would that make sense in SCEV world?
>
>
> --
> *Alexandre Isoard*
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