From: Chris Lattner <sabre@nondot.org>
Date: Fri, 27 Nov 2009 08:40:14 +0000 (+0000)
Subject: add comment.
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=9763487bd50bd9927c8bbdcc84e4f7d59b8d9cdf;p=oota-llvm.git

add comment.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90002 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Analysis/MemoryDependenceAnalysis.cpp b/lib/Analysis/MemoryDependenceAnalysis.cpp
index 0aacd1606c3..f958e75040d 100644
--- a/lib/Analysis/MemoryDependenceAnalysis.cpp
+++ b/lib/Analysis/MemoryDependenceAnalysis.cpp
@@ -1004,8 +1004,12 @@ getNonLocalPointerDepFromBB(Value *Pointer, uint64_t PointeeSize,
       Value *PredPtr = PHITranslatePointer(PtrInst, BB, Pred, TD);
       
       // If PHI translation fails, bail out.
-      if (PredPtr == 0)
+      if (PredPtr == 0) {
+        // FIXME: Instead of modelling this as a phi trans failure, we should
+        // model this as a clobber in the one predecessor.  This will allow
+        // us to PRE values that are only available in some preds but not all.
         goto PredTranslationFailure;
+      }
       
       // Check to see if we have already visited this pred block with another
       // pointer.  If so, we can't do this lookup.  This failure can occur