[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

3 files changed, 7 insertions, 4 deletions

diff --git a/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp b/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
index 64a97f86a21..0e672f1449a 100644
--- a/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
+++ b/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
@@ -1545,7 +1545,7 @@ bool LoopConstrainer::run() {
   // This function canonicalizes the loop into Loop-Simplify and LCSSA forms.
   auto CanonicalizeLoop = [&] (Loop *L, bool IsOriginalLoop) {
     formLCSSARecursively(*L, DT, &LI, &SE);
-    simplifyLoop(L, &DT, &LI, &SE, nullptr, true);
+    simplifyLoop(L, &DT, &LI, &SE, nullptr, nullptr, true);
     // Pre/post loops are slow paths, we do not need to perform any loop
     // optimizations on them.
     if (!IsOriginalLoop)
diff --git a/llvm/lib/Transforms/Scalar/LoopInterchange.cpp b/llvm/lib/Transforms/Scalar/LoopInterchange.cpp
index bde4ecaaa6c..bec5af584f4 100644
--- a/llvm/lib/Transforms/Scalar/LoopInterchange.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopInterchange.cpp
@@ -1362,9 +1362,11 @@ bool LoopInterchangeTransform::adjustLoopBranches() {
   // preheaders do not satisfy those conditions.
   if (isa<PHINode>(OuterLoopPreHeader->begin()) ||
       !OuterLoopPreHeader->getUniquePredecessor())
-    OuterLoopPreHeader = InsertPreheaderForLoop(OuterLoop, DT, LI, true);
+    OuterLoopPreHeader =
+        InsertPreheaderForLoop(OuterLoop, DT, LI, nullptr, true);
   if (InnerLoopPreHeader == OuterLoop->getHeader())
-    InnerLoopPreHeader = InsertPreheaderForLoop(InnerLoop, DT, LI, true);
+    InnerLoopPreHeader =
+        InsertPreheaderForLoop(InnerLoop, DT, LI, nullptr, true);
 
   // Adjust the loop preheader
   BasicBlock *InnerLoopHeader = InnerLoop->getHeader();
diff --git a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
index 0aeaabcbba4..7e9daf0b1fb 100644
--- a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
@@ -1393,7 +1393,8 @@ PreservedAnalyses LoopUnrollPass::run(Function &F,
   // will simplify all loops, regardless of whether anything end up being
   // unrolled.
   for (auto &L : LI) {
-    Changed |= simplifyLoop(L, &DT, &LI, &SE, &AC, false /* PreserveLCSSA */);
+    Changed |=
+        simplifyLoop(L, &DT, &LI, &SE, &AC, nullptr, false /* PreserveLCSSA */);
     Changed |= formLCSSARecursively(*L, DT, &LI, &SE);
   }