[all-commits] [llvm/llvm-project] 61d4b3: [test][NewPM] Make dead-uses.ll work under NPM

[aeubanks via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 61d4b342d15a82d5e841d9e72a52d77eaa5b5097
      https://github.com/llvm/llvm-project/commit/61d4b342d15a82d5e841d9e72a52d77eaa5b5097
  Author: Arthur Eubanks <aeubanks at google.com>
  Date:   2020-10-06 (Tue, 06 Oct 2020)

  Changed paths:
    M llvm/test/Analysis/GlobalsModRef/dead-uses.ll

  Log Message:
  -----------
  [test][NewPM] Make dead-uses.ll work under NPM

This one is weird...

globals-aa needs to be already computed at licm, or else a function pass
can't run a module analysis and won't have access to globals-aa.
But the globals-aa result is impacted by instcombine in a way that
affects what the test is expecting. If globals-aa is computed before
instcombine, it is cached and globals-aa used in licm won't contain the
necessary info provided by instcombine.
Another catch is that if we don't invalidate AAManager, it will use the
cached AAManager that instcombine requested, which may not contain
globals-aa. So we have to invalidate<aa> so that licm can recompute
an AAManager with the globals-aa created by the require<globals-aa>.

This is essentially the problem described in https://reviews.llvm.org/D84259.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D88118