diff --git a/llvm/lib/CodeGen/MachineCombiner.cpp b/llvm/lib/CodeGen/MachineCombiner.cpp
diff --git a/llvm/lib/CodeGen/MachineTraceMetrics.cpp b/llvm/lib/CodeGen/MachineTraceMetrics.cpp
@@ -1169,6 +1169,7 @@ MachineTraceMetrics::Trace::getPHIDepth(const MachineInstr *PHI) const {
   return DepCycle;
 }
 
+/// When bottom is set include instructions in current block in estimate.
 unsigned MachineTraceMetrics::Trace::getResourceDepth(bool Bottom) const {
   // Find the limiting processor resource.
   // Numbers have been pre-scaled to be comparable.
@@ -1185,7 +1186,9 @@ unsigned MachineTraceMetrics::Trace::getResourceDepth(bool Bottom) const {
   // Convert to cycle count.
   PRMax = TE.MTM.getCycles(PRMax);
 
+  /// All instructions before current block
   unsigned Instrs = TBI.InstrDepth;
+  // plus instructions in current block
   if (Bottom)
     Instrs += TE.MTM.BlockInfo[getBlockNum()].InstrCount;
   if (unsigned IW = TE.MTM.SchedModel.getIssueWidth())
@@ -1194,44 +1197,72 @@ unsigned MachineTraceMetrics::Trace::getResourceDepth(bool Bottom) const {
   return std::max(Instrs, PRMax);
 }
 
-
-unsigned MachineTraceMetrics::Trace::
-getResourceLength(ArrayRef<const MachineBasicBlock*> Extrablocks,
-                  ArrayRef<const MCSchedClassDesc*> ExtraInstrs) const {
+unsigned MachineTraceMetrics::Trace::getResourceLength(
+    ArrayRef<const MachineBasicBlock *> Extrablocks,
+    ArrayRef<const MCSchedClassDesc *> ExtraInstrs,
+    ArrayRef<const MCSchedClassDesc *> RemoveInstrs) const {
   // Add up resources above and below the center block.
   ArrayRef<unsigned> PRDepths = TE.getProcResourceDepths(getBlockNum());
   ArrayRef<unsigned> PRHeights = TE.getProcResourceHeights(getBlockNum());
   unsigned PRMax = 0;
-  for (unsigned K = 0; K != PRDepths.size(); ++K) {
-    unsigned PRCycles = PRDepths[K] + PRHeights[K];
-    for (unsigned I = 0; I != Extrablocks.size(); ++I)
-      PRCycles += TE.MTM.getProcResourceCycles(Extrablocks[I]->getNumber())[K];
-    for (unsigned I = 0; I != ExtraInstrs.size(); ++I) {
-      const MCSchedClassDesc* SC = ExtraInstrs[I];
+
+  // Capture computing cycles from extra instructions
+  auto extraCycles = [this](ArrayRef<const MCSchedClassDesc *> Instrs,
+                            unsigned ResourceIdx)
+                         ->unsigned {
+    unsigned Cycles = 0;
+    for (unsigned I = 0; I != Instrs.size(); ++I) {
+      const MCSchedClassDesc *SC = Instrs[I];
       if (!SC->isValid())
         continue;
       for (TargetSchedModel::ProcResIter
-             PI = TE.MTM.SchedModel.getWriteProcResBegin(SC),
-             PE = TE.MTM.SchedModel.getWriteProcResEnd(SC); PI != PE; ++PI) {
-        if (PI->ProcResourceIdx != K)
+               PI = TE.MTM.SchedModel.getWriteProcResBegin(SC),
+               PE = TE.MTM.SchedModel.getWriteProcResEnd(SC);
+           PI != PE; ++PI) {
+        if (PI->ProcResourceIdx != ResourceIdx)
           continue;
-        PRCycles += (PI->Cycles * TE.MTM.SchedModel.getResourceFactor(K));
+        Cycles +=
+            (PI->Cycles * TE.MTM.SchedModel.getResourceFactor(ResourceIdx));
       }
     }
+    return Cycles;
+  };
+
+  for (unsigned K = 0; K != PRDepths.size(); ++K) {
+    unsigned PRCycles = PRDepths[K] + PRHeights[K];
+    for (unsigned I = 0; I != Extrablocks.size(); ++I)
+      PRCycles += TE.MTM.getProcResourceCycles(Extrablocks[I]->getNumber())[K];
+    PRCycles += extraCycles(ExtraInstrs, K);
+    PRCycles -= extraCycles(RemoveInstrs, K);
     PRMax = std::max(PRMax, PRCycles);
   }
   // Convert to cycle count.
   PRMax = TE.MTM.getCycles(PRMax);
 
+  // Instrs: #instructions in current trace outside current block.
   unsigned Instrs = TBI.InstrDepth + TBI.InstrHeight;
+  // Add instruction count from the extra blocks.
   for (unsigned i = 0, e = Extrablocks.size(); i != e; ++i)
     Instrs += TE.MTM.getResources(Extrablocks[i])->InstrCount;
+  Instrs += ExtraInstrs.size();
+  Instrs -= RemoveInstrs.size();
   if (unsigned IW = TE.MTM.SchedModel.getIssueWidth())
     Instrs /= IW;
   // Assume issue width 1 without a schedule model.
   return std::max(Instrs, PRMax);
 }
 
+bool MachineTraceMetrics::Trace::isDepInTrace(const MachineInstr *DefMI,
+                                              const MachineInstr *UseMI) const {
+  if (DefMI->getParent() == UseMI->getParent())
+    return true;
+
+  const TraceBlockInfo &DepTBI = TE.BlockInfo[DefMI->getParent()->getNumber()];
+  const TraceBlockInfo &TBI = TE.BlockInfo[UseMI->getParent()->getNumber()];
+
+  return DepTBI.isUsefulDominator(TBI);
+}
+
 void MachineTraceMetrics::Ensemble::print(raw_ostream &OS) const {
   OS << getName() << " ensemble:\n";
   for (unsigned i = 0, e = BlockInfo.size(); i != e; ++i) {

diff --git a/llvm/lib/CodeGen/TargetSchedule.cpp b/llvm/lib/CodeGen/TargetSchedule.cpp
@@ -225,6 +225,28 @@ unsigned TargetSchedModel::computeOperandLatency(
   return DefMI->isTransient() ? 0 : TII->defaultDefLatency(&SchedModel, DefMI);
 }
 
+unsigned TargetSchedModel::computeInstrLatency(unsigned Opcode) const {
+  assert(hasInstrSchedModel() && "Only call this function with a SchedModel");
+
+  unsigned SCIdx = TII->get(Opcode).getSchedClass();
+  const MCSchedClassDesc *SCDesc = SchedModel.getSchedClassDesc(SCIdx);
+  unsigned Latency = 0;
+
+  if (SCDesc->isValid() && !SCDesc->isVariant()) {
+    for (unsigned DefIdx = 0, DefEnd = SCDesc->NumWriteLatencyEntries;
+         DefIdx != DefEnd; ++DefIdx) {
+      // Lookup the definition's write latency in SubtargetInfo.
+      const MCWriteLatencyEntry *WLEntry =
+          STI->getWriteLatencyEntry(SCDesc, DefIdx);
+      Latency = std::max(Latency, capLatency(WLEntry->Cycles));
+    }
+    return Latency;
+  }
+
+  assert(Latency && "No MI sched latency");
+  return 0;
+}
+
 unsigned
 TargetSchedModel::computeInstrLatency(const MachineInstr *MI,
                                       bool UseDefaultDefLatency) const {