George Burgess IV 94c82b281d [MSSA] Add logic for special handling of atomics/volatiles.
This patch makes MemorySSA recognize atomic/volatile loads, and makes
MSSA treat said loads specially. This allows us to be a bit more
aggressive in some cases.

Administrative note: Revision was LGTM'ed by reames in person.
Additionally, this doesn't include the `invariant.load` recognition in
the differential revision, because I feel it's better to commit that
separately. Will commit soon.

Differential Revision: https://reviews.llvm.org/D16875


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277637 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-03 19:39:54 +00:00
..
2016-08-02 23:25:59 +00:00