1 files changed, 19 insertions, 9 deletions

diff --git a/contrib/llvm/lib/CodeGen/TwoAddressInstructionPass.cpp b/contrib/llvm/lib/CodeGen/TwoAddressInstructionPass.cpp
index 0f1b2ed..83c00e2 100644
--- a/contrib/llvm/lib/CodeGen/TwoAddressInstructionPass.cpp
+++ b/contrib/llvm/lib/CodeGen/TwoAddressInstructionPass.cpp
@@ -52,7 +52,7 @@
 
 using namespace llvm;
 
-#define DEBUG_TYPE "twoaddrinstr"
+#define DEBUG_TYPE "twoaddressinstruction"
 
 STATISTIC(NumTwoAddressInstrs, "Number of two-address instructions");
 STATISTIC(NumCommuted        , "Number of instructions commuted to coalesce");
@@ -68,6 +68,13 @@ EnableRescheduling("twoaddr-reschedule",
                    cl::desc("Coalesce copies by rescheduling (default=true)"),
                    cl::init(true), cl::Hidden);
 
+// Limit the number of dataflow edges to traverse when evaluating the benefit
+// of commuting operands.
+static cl::opt<unsigned> MaxDataFlowEdge(
+    "dataflow-edge-limit", cl::Hidden, cl::init(3),
+    cl::desc("Maximum number of dataflow edges to traverse when evaluating "
+             "the benefit of commuting operands"));
+
 namespace {
 class TwoAddressInstructionPass : public MachineFunctionPass {
   MachineFunction *MF;
@@ -155,7 +162,7 @@ public:
 
   void getAnalysisUsage(AnalysisUsage &AU) const override {
     AU.setPreservesCFG();
-    AU.addRequired<AAResultsWrapperPass>();
+    AU.addUsedIfAvailable<AAResultsWrapperPass>();
     AU.addUsedIfAvailable<LiveVariables>();
     AU.addPreserved<LiveVariables>();
     AU.addPreserved<SlotIndexes>();
@@ -171,10 +178,10 @@ public:
 } // end anonymous namespace
 
 char TwoAddressInstructionPass::ID = 0;
-INITIALIZE_PASS_BEGIN(TwoAddressInstructionPass, "twoaddressinstruction",
+INITIALIZE_PASS_BEGIN(TwoAddressInstructionPass, DEBUG_TYPE,
                 "Two-Address instruction pass", false, false)
 INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)
-INITIALIZE_PASS_END(TwoAddressInstructionPass, "twoaddressinstruction",
+INITIALIZE_PASS_END(TwoAddressInstructionPass, DEBUG_TYPE,
                 "Two-Address instruction pass", false, false)
 
 char &llvm::TwoAddressInstructionPassID = TwoAddressInstructionPass::ID;
@@ -637,10 +644,10 @@ isProfitableToCommute(unsigned regA, unsigned regB, unsigned regC,
   // To more generally minimize register copies, ideally the logic of two addr
   // instruction pass should be integrated with register allocation pass where
   // interference graph is available.
-  if (isRevCopyChain(regC, regA, 3))
+  if (isRevCopyChain(regC, regA, MaxDataFlowEdge))
     return true;
 
-  if (isRevCopyChain(regB, regA, 3))
+  if (isRevCopyChain(regB, regA, MaxDataFlowEdge))
     return false;
 
   // Since there are no intervening uses for both registers, then commute
@@ -905,7 +912,7 @@ rescheduleMIBelowKill(MachineBasicBlock::iterator &mi,
     ++End;
   }
 
-  // Check if the reschedule will not break depedencies.
+  // Check if the reschedule will not break dependencies.
   unsigned NumVisited = 0;
   MachineBasicBlock::iterator KillPos = KillMI;
   ++KillPos;
@@ -1627,7 +1634,10 @@ bool TwoAddressInstructionPass::runOnMachineFunction(MachineFunction &Func) {
   InstrItins = MF->getSubtarget().getInstrItineraryData();
   LV = getAnalysisIfAvailable<LiveVariables>();
   LIS = getAnalysisIfAvailable<LiveIntervals>();
-  AA = &getAnalysis<AAResultsWrapperPass>().getAAResults();
+  if (auto *AAPass = getAnalysisIfAvailable<AAResultsWrapperPass>())
+    AA = &AAPass->getAAResults();
+  else
+    AA = nullptr;
   OptLevel = TM.getOptLevel();
 
   bool MadeChange = false;
@@ -1785,7 +1795,7 @@ eliminateRegSequence(MachineBasicBlock::iterator &MBBI) {
     MachineInstr *CopyMI = BuildMI(*MI.getParent(), MI, MI.getDebugLoc(),
                                    TII->get(TargetOpcode::COPY))
                                .addReg(DstReg, RegState::Define, SubIdx)
-                               .addOperand(UseMO);
+                               .add(UseMO);
 
     // The first def needs an <undef> flag because there is no live register
     // before it.