[MemorySSA] Teach LoopSimplify to preserve MemorySSA.

Summary:
Preserve MemorySSA in LoopSimplify, in the old pass manager, if the analysis is available.
Do not preserve it in the new pass manager.
Update tests.

Subscribers: nemanjai, jlebar, javed.absar, Prazek, kbarton, zzheng, jsji, llvm-commits, george.burgess.iv, chandlerc

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60833

llvm-svn: 360270

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/Target/PowerPC/PPCLoopPreIncPrep.cpp b/llvm/lib/Target/PowerPC/PPCLoopPreIncPrep.cpp
index 9689e8c590a..4d45d96d447 100644
--- a/llvm/lib/Target/PowerPC/PPCLoopPreIncPrep.cpp
+++ b/llvm/lib/Target/PowerPC/PPCLoopPreIncPrep.cpp
@@ -331,7 +331,7 @@ bool PPCLoopPreIncPrep::runOnLoop(Loop *L) {
   // iteration space), insert a new preheader for the loop.
   if (!LoopPredecessor ||
       !LoopPredecessor->getTerminator()->getType()->isVoidTy()) {
-    LoopPredecessor = InsertPreheaderForLoop(L, DT, LI, PreserveLCSSA);
+    LoopPredecessor = InsertPreheaderForLoop(L, DT, LI, nullptr, PreserveLCSSA);
     if (LoopPredecessor)
       MadeChange = true;
   }