[PATCH] D21776: MSSA Walker Pre-refactor

[George Burgess IV via llvm-commits]

george.burgess.iv marked an inline comment as done.

================
Comment at: lib/Transforms/Utils/MemorySSA.cpp:551
@@ -550,3 +605,1 @@
-}
-
 /// \brief Returns true if \p Replacer dominates \p Replacee .
----------------
dberlin wrote:
> I see you removed this - this is a utility being used as part of updating for another pass i haven't submitted yet.
> 
> 
Sounds good; will unremove. Thanks for the heads up.

================
Comment at: lib/Transforms/Utils/MemorySSA.cpp:856
@@ -805,1 +855,3 @@
+  // A node dominates itself, and liveOnEntry dominates everything.
+  if (Dominatee == Dominator || isLiveOnEntryDef(Dominator))
     return true;
----------------
dberlin wrote:
> This makes no sense unless the block we are talking about is the entry block.
> Otherwise, how are they in the same block?
> 
> (if it is the entry block, the loop below will give the correct answer, no?)
This is just a refactor of the old (and the new changes `locallyDominates` to `dominates`, since the only user of `locallyDominates` that I could find was the current walker, so we'd probably readd `isLiveOnEntryDef(Dominator)` anyway, since it could save domtree stuff.).

If we don't want to kill `locallyDominates`, I'm happy to remove this, because yes, the below loop should catch this case.


http://reviews.llvm.org/D21776