[PATCH] Fixing a heisenbug where the memory dependence analysis behaves differently with and without -g

[Yunzhong Gao]

  From: David Blaikie [mailto:dblaikie at gmail.com]
  Sent: Tuesday, November 12, 2013 2:26 PM

  > Are there existing test cases that ensure the threshold is respected? If you massively increase or
  > decrease the threshold, do any tests fail? If not, then it seems we're missing test coverage. We
  > should have some tests that check that, and then we could have another variant that has a trash
  > llvm.dbg.value intrinsic designed to push the block over the limit and ensure that we get the same
  > behavior as if the intrinsic is not present.
  > - David

  No existing test fails if I increase the threshold from 100 to 5000 or decrease it to 15, so it seems
  that we are missing test cases. Err I do not quite have an idea how to test the threshold directly.
  Who should I ask? The CODE_OWNERS.txt does not say who owns the analysis passes. I am
  going to cc Owen, since he seemed to have added this pass in the beginning, and Bill, since he
  changed the threshold most recently. Sorry for the spam.

http://llvm-reviews.chandlerc.com/D2141