[SCCP] Mark CFG as preserved.

SCCP does not change the CFG, so we can mark it as preserved.

Reviewers: dberlin, efriedma, davide

Reviewed By: davide

Differential Revision: https://reviews.llvm.org/D47149

llvm-svn: 335820

1 files changed, 2 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/Scalar/SCCP.cpp b/llvm/lib/Transforms/Scalar/SCCP.cpp
index 33eb80734d1..af201257135 100644
--- a/llvm/lib/Transforms/Scalar/SCCP.cpp
+++ b/llvm/lib/Transforms/Scalar/SCCP.cpp
@@ -1777,6 +1777,7 @@ PreservedAnalyses SCCPPass::run(Function &F, FunctionAnalysisManager &AM) {
 
   auto PA = PreservedAnalyses();
   PA.preserve<GlobalsAA>();
+  PA.preserveSet<CFGAnalyses>();
   return PA;
 }
 
@@ -1799,6 +1800,7 @@ public:
   void getAnalysisUsage(AnalysisUsage &AU) const override {
     AU.addRequired<TargetLibraryInfoWrapperPass>();
     AU.addPreserved<GlobalsAAWrapperPass>();
+    AU.setPreservesCFG();
   }
 
   // runOnFunction - Run the Sparse Conditional Constant Propagation