6 files changed, 22 insertions, 7 deletions
diff --git a/lib/CodeGen/CriticalAntiDepBreaker.cpp b/lib/CodeGen/CriticalAntiDepBreaker.cpp
index d3ffcc7..d2231ec 100644
--- a/lib/CodeGen/CriticalAntiDepBreaker.cpp
+++ b/lib/CodeGen/CriticalAntiDepBreaker.cpp
@@ -94,7 +94,14 @@ void CriticalAntiDepBreaker::FinishBlock() {
 
 void CriticalAntiDepBreaker::Observe(MachineInstr *MI, unsigned Count,
                                      unsigned InsertPosIndex) {
-  if (MI->isDebugValue())
+  // Kill instructions can define registers but are really nops, and there might
+  // be a real definition earlier that needs to be paired with uses dominated by
+  // this kill.
+
+  // FIXME: It may be possible to remove the isKill() restriction once PR18663
+  // has been properly fixed. There can be value in processing kills as seen in
+  // the AggressiveAntiDepBreaker class.
+  if (MI->isDebugValue() || MI->isKill())
     return;
   assert(Count < InsertPosIndex && "Instruction index out of expected range!");
 
@@ -237,6 +244,7 @@ void CriticalAntiDepBreaker::ScanInstruction(MachineInstr *MI,
   // Update liveness.
   // Proceeding upwards, registers that are defed but not used in this
   // instruction are now dead.
+  assert(!MI->isKill() && "Attempting to scan a kill instruction");
 
   if (!TII->isPredicated(MI)) {
     // Predicated defs are modeled as read + write, i.e. similar to two
@@ -527,7 +535,14 @@ BreakAntiDependencies(const std::vector<SUnit>& SUnits,
   unsigned Count = InsertPosIndex - 1;
   for (MachineBasicBlock::iterator I = End, E = Begin; I != E; --Count) {
     MachineInstr *MI = --I;
-    if (MI->isDebugValue())
+    // Kill instructions can define registers but are really nops, and there
+    // might be a real definition earlier that needs to be paired with uses
+    // dominated by this kill.
+    
+    // FIXME: It may be possible to remove the isKill() restriction once PR18663
+    // has been properly fixed. There can be value in processing kills as seen
+    // in the AggressiveAntiDepBreaker class.
+    if (MI->isDebugValue() || MI->isKill())
       continue;
 
     // Check if this instruction has a dependence on the critical path that
diff --git a/lib/CodeGen/LiveRangeEdit.cpp b/lib/CodeGen/LiveRangeEdit.cpp
index 431241f..c27d630 100644
--- a/lib/CodeGen/LiveRangeEdit.cpp
+++ b/lib/CodeGen/LiveRangeEdit.cpp
@@ -135,7 +135,7 @@ bool LiveRangeEdit::canRematerializeAt(Remat &RM,
   }
 
   // If only cheap remats were requested, bail out early.
-  if (cheapAsAMove && !RM.OrigMI->isAsCheapAsAMove())
+  if (cheapAsAMove && !TII.isAsCheapAsAMove(RM.OrigMI))
     return false;
 
   // Verify that all used registers are available with the same values.
diff --git a/lib/CodeGen/MachineCSE.cpp b/lib/CodeGen/MachineCSE.cpp
index 7da439c..c2ab76e 100644
--- a/lib/CodeGen/MachineCSE.cpp
+++ b/lib/CodeGen/MachineCSE.cpp
@@ -380,7 +380,7 @@ bool MachineCSE::isProfitableToCSE(unsigned CSReg, unsigned Reg,
   // Heuristics #1: Don't CSE "cheap" computation if the def is not local or in
   // an immediate predecessor. We don't want to increase register pressure and
   // end up causing other computation to be spilled.
-  if (MI->isAsCheapAsAMove()) {
+  if (TII->isAsCheapAsAMove(MI)) {
     MachineBasicBlock *CSBB = CSMI->getParent();
     MachineBasicBlock *BB = MI->getParent();
     if (CSBB != BB && !CSBB->isSuccessor(BB))
diff --git a/lib/CodeGen/MachineLICM.cpp b/lib/CodeGen/MachineLICM.cpp
index 68d2efd..94cdab5 100644
--- a/lib/CodeGen/MachineLICM.cpp
+++ b/lib/CodeGen/MachineLICM.cpp
@@ -1039,7 +1039,7 @@ bool MachineLICM::HasHighOperandLatency(MachineInstr &MI,
 /// IsCheapInstruction - Return true if the instruction is marked "cheap" or
 /// the operand latency between its def and a use is one or less.
 bool MachineLICM::IsCheapInstruction(MachineInstr &MI) const {
-  if (MI.isAsCheapAsAMove() || MI.isCopyLike())
+  if (TII->isAsCheapAsAMove(&MI) || MI.isCopyLike())
     return true;
   if (!InstrItins || InstrItins->isEmpty())
     return false;
diff --git a/lib/CodeGen/MachineSink.cpp b/lib/CodeGen/MachineSink.cpp
index f44e4d1..0ae495c 100644
--- a/lib/CodeGen/MachineSink.cpp
+++ b/lib/CodeGen/MachineSink.cpp
@@ -292,7 +292,7 @@ bool MachineSinking::isWorthBreakingCriticalEdge(MachineInstr *MI,
   if (!CEBCandidates.insert(std::make_pair(From, To)))
     return true;
 
-  if (!MI->isCopy() && !MI->isAsCheapAsAMove())
+  if (!MI->isCopy() && !TII->isAsCheapAsAMove(MI))
     return true;
 
   // MI is cheap, we probably don't want to break the critical edge for it.
diff --git a/lib/CodeGen/RegisterCoalescer.cpp b/lib/CodeGen/RegisterCoalescer.cpp
index 5aaeb87..65b0528 100644
--- a/lib/CodeGen/RegisterCoalescer.cpp
+++ b/lib/CodeGen/RegisterCoalescer.cpp
@@ -751,7 +751,7 @@ bool RegisterCoalescer::reMaterializeTrivialDef(CoalescerPair &CP,
     IsDefCopy = true;
     return false;
   }
-  if (!DefMI->isAsCheapAsAMove())
+  if (!TII->isAsCheapAsAMove(DefMI))
     return false;
   if (!TII->isTriviallyReMaterializable(DefMI, AA))
     return false;