[LLVMdev] The order of GVN and IndVarSimplify

[Richard Sandiford]

Andrew Trick <atrick at apple.com> writes:
> - I think GVN should run earlier, before most of the loop opts, and I
> think IndVars should run much later. I filed a bug for this. See
> PR17809: Reordering IR-level optimization passes. It’s hard to make
> progress on a major pass pipeline change because it requires a lot of
> investment in performance analysis. If you could file a bug for your
> test case and relate it to that bug it would be great. It can’t hurt,
> and may motivate someone to get around to fixing it sooner.

Thanks for the pointer.  I've attached the testcase and a summary
of the thread.  Like you say, it sounds like major work, but should
definitely help with this sort of situtation.

Richard