[PATCH] D74484: [AggressiveInstCombine] Add support for ICmp instr that feeds a select intsr's condition operand.

[Ayman Musa via Phabricator via llvm-commits]

aymanmus added a comment.

In D74484#1873705 <https://reviews.llvm.org/D74484#1873705>, @lebedev.ri wrote:

> In D74484#1872137 <https://reviews.llvm.org/D74484#1872137>, @lebedev.ri wrote:
>
> > This seems not generic enough to me, can't we not require the icmp operands to be constants/[sz]ext's,
> >  but instead try to see if it can be evaluated in smaller bitwidth (what the rest of the code here does)?
> >
> > As long as the icmp can be shrunked to at least as small bitwidth as we need there to get rid of cast,
> >  i think we can always pick the actual bitwidth we'll use, which might be wider than minimal?
>
>
> After thinking about this, i'd be okay with not doing that straight away.
>  It should be doable, but would require substantial redesign to nicely model more than one dag and their connection/dependency.


Exactly, there are many improvements that can be added to this pass in many ways.
What I add here is a small and simple improvement that doesn't need serious redesign.
It has it's added value (not a big one though) at a minimal cost.


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  https://reviews.llvm.org/D74484/new/

https://reviews.llvm.org/D74484