Don't recalculate the loop info and loop dominators analyses if they're
preserved.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45596 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/TwoAddressInstructionPass.cpp b/lib/CodeGen/TwoAddressInstructionPass.cpp
index dd71bec..8f0c473 100644
--- a/lib/CodeGen/TwoAddressInstructionPass.cpp
+++ b/lib/CodeGen/TwoAddressInstructionPass.cpp
@@ -69,6 +69,8 @@
 void TwoAddressInstructionPass::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.addRequired<LiveVariables>();
   AU.addPreserved<LiveVariables>();
+  AU.addPreservedID(MachineLoopInfoID);
+  AU.addPreservedID(MachineDominatorsID);
   AU.addPreservedID(PHIEliminationID);
   MachineFunctionPass::getAnalysisUsage(AU);
 }