From 50d2d2143ed2b16bba4056b604dd3ebc5ee378d2 Mon Sep 17 00:00:00 2001
From: Davide Italiano <davide@freebsd.org>
Date: Sun, 29 May 2016 00:41:17 +0000
Subject: [PATCH] [PM] Reassociate: cache analyses more aggressively.

While here, add a FIXME for setPreserveCFG().

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@271159 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Scalar/Reassociate.cpp | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/lib/Transforms/Scalar/Reassociate.cpp b/lib/Transforms/Scalar/Reassociate.cpp
index 6b761c5bec7..75f646d1d43 100644
--- a/lib/Transforms/Scalar/Reassociate.cpp
+++ b/lib/Transforms/Scalar/Reassociate.cpp
@@ -2227,8 +2227,13 @@ PreservedAnalyses ReassociatePass::run(Function &F) {
   RankMap.clear();
   ValueRankMap.clear();
 
-  if (MadeChange)
-    return PreservedAnalyses::none();
+  if (MadeChange) {
+    // FIXME: Reassociate should also 'preserve the CFG'.
+    // The new pass manager has currently no way to do it.
+    auto PA = PreservedAnalyses();
+    PA.preserve<GlobalsAA>();
+    return PA;
+  }
 
   return PreservedAnalyses::all();
 }