[PATCH] D103660: [ScalarEvolution] Don't form min/max for pointer-type phi/select.

Fri Jun 4 14:54:00 PDT 2021

reames requested changes to this revision.
reames added a subscriber: nikic.
reames added a comment.
This revision now requires changes to proceed.

Can you take a step back and describe the problem you're trying to solve?  I've read through the bug, but nothing there immediately makes me think "bug in core part of SCEV" as opposed to "bug in user of SCEV".  How'd you get from there to here?

This patch as implemented seems to be a strict regression.  Without understanding what symptom you're worried about, it's hard to tell if this is a reasonable solution.

Given this seems to be related to a release regression and there may be a tendency to rush this, let me be really explicit.  This, and the change it's based on, are not okay to land without either my sign off or from someone else who regularly works on SCEV (e.g. @mkazantsev, @nikic).  This is a deep change which has non-obvious implications, with unclear motivation.  Currently, I don't think either of these changes should land at all, much less in a hurry.

JFYI, I'm going to be offline for the next two days, I'll return to this Monday.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D103660/new/

https://reviews.llvm.org/D103660