[MemorySSA] Use GraphDiff info when computing IDF.

Summary:
When computing IDF for insert updates, ensure we use the snapshot CFG offered by GraphDiff.
Caught by D63389.

Reviewers: kuhar, george.burgess.iv

Subscribers: jlebar, Prazek, llvm-commits, Szelethus

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D63443

llvm-svn: 363879

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/Analysis/MemorySSAUpdater.cpp b/llvm/lib/Analysis/MemorySSAUpdater.cpp
index 02588931061..b2ae26412b3 100644
--- a/llvm/lib/Analysis/MemorySSAUpdater.cpp
+++ b/llvm/lib/Analysis/MemorySSAUpdater.cpp
@@ -963,7 +963,7 @@ void MemorySSAUpdater::applyInsertUpdates(ArrayRef<CFGUpdate> Updates,
   // Compute IDF and add Phis in all IDF blocks that do not have one.
   SmallVector<BasicBlock *, 32> IDFBlocks;
   if (!BlocksToProcess.empty()) {
-    ForwardIDFCalculator IDFs(DT);
+    ForwardIDFCalculator IDFs(DT, GD);
     SmallPtrSet<BasicBlock *, 16> DefiningBlocks(BlocksToProcess.begin(),
                                                  BlocksToProcess.end());
     IDFs.setDefiningBlocks(DefiningBlocks);