Improve MachineMemOperand handling.

 - Allocate MachineMemOperands and MachineMemOperand lists in MachineFunctions.
   This eliminates MachineInstr's std::list member and allows the data to be
   created by isel and live for the remainder of codegen, avoiding a lot of
   copying and unnecessary translation. This also shrinks MemSDNode.
 - Delete MemOperandSDNode. Introduce MachineSDNode which has dedicated
   fields for MachineMemOperands.
 - Change MemSDNode to have a MachineMemOperand member instead of its own
   fields with the same information. This introduces some redundancy, but
   it's more consistent with what MachineInstr will eventually want.
 - Ignore alignment when searching for redundant loads for CSE, but remember
   the greatest alignment.

Target-specific code which previously used MemOperandSDNodes with generic
SDNodes now use MemIntrinsicSDNodes, with opcodes in a designated range
so that the SelectionDAG framework knows that MachineMemOperand information
is available.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82794 91177308-0d34-0410-b5e6-96231b3b80d8

11 files changed, 435 insertions, 316 deletions

diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index 825cf39..e1b23fd 100644
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -25,6 +25,7 @@
 #include "llvm/CodeGen/MachineInstr.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
 #include "llvm/CodeGen/MachineLoopInfo.h"
+#include "llvm/CodeGen/MachineMemOperand.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/CodeGen/Passes.h"
 #include "llvm/CodeGen/PseudoSourceValue.h"
@@ -1443,12 +1444,12 @@ bool LiveIntervals::isReMaterializable(const LiveInterval &li,
 
     // If the instruction accesses memory and the memory could be non-constant,
     // assume the instruction is not rematerializable.
-    for (std::list<MachineMemOperand>::const_iterator
-           I = MI->memoperands_begin(), E = MI->memoperands_end(); I != E; ++I){
-      const MachineMemOperand &MMO = *I;
-      if (MMO.isVolatile() || MMO.isStore())
+    for (MachineInstr::mmo_iterator I = MI->memoperands_begin(),
+         E = MI->memoperands_end(); I != E; ++I){
+      const MachineMemOperand *MMO = *I;
+      if (MMO->isVolatile() || MMO->isStore())
         return false;
-      const Value *V = MMO.getValue();
+      const Value *V = MMO->getValue();
       if (!V)
         return false;
       if (const PseudoSourceValue *PSV = dyn_cast<PseudoSourceValue>(V)) {
diff --git a/lib/CodeGen/MachineFunction.cpp b/lib/CodeGen/MachineFunction.cpp
index d0773ff..3a47265 100644
--- a/lib/CodeGen/MachineFunction.cpp
+++ b/lib/CodeGen/MachineFunction.cpp
@@ -190,11 +190,6 @@ MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
 ///
 void
 MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
-  // Clear the instructions memoperands. This must be done manually because
-  // the instruction's parent pointer is now null, so it can't properly
-  // deallocate them on its own.
-  MI->clearMemOperands(*this);
-
   MI->~MachineInstr();
   InstructionRecycler.Deallocate(Allocator, MI);
 }
@@ -217,6 +212,29 @@ MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
   BasicBlockRecycler.Deallocate(Allocator, MBB);
 }
 
+MachineMemOperand *
+MachineFunction::getMachineMemOperand(const Value *v, unsigned f,
+                                      int64_t o, uint64_t s,
+                                      unsigned base_alignment) {
+  return new (Allocator.Allocate<MachineMemOperand>())
+             MachineMemOperand(v, f, o, s, base_alignment);
+}
+
+MachineMemOperand *
+MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
+                                      int64_t Offset, uint64_t Size) {
+  return new (Allocator.Allocate<MachineMemOperand>())
+             MachineMemOperand(MMO->getValue(), MMO->getFlags(),
+                               int64_t(uint64_t(MMO->getOffset()) +
+                                       uint64_t(Offset)),
+                               Size, MMO->getBaseAlignment());
+}
+
+MachineInstr::mmo_iterator
+MachineFunction::allocateMemRefsArray(unsigned long Num) {
+  return Allocator.Allocate<MachineMemOperand *>(Num);
+}
+
 void MachineFunction::dump() const {
   print(errs());
 }
diff --git a/lib/CodeGen/MachineInstr.cpp b/lib/CodeGen/MachineInstr.cpp
index baab120..2d06aa4 100644
--- a/lib/CodeGen/MachineInstr.cpp
+++ b/lib/CodeGen/MachineInstr.cpp
@@ -17,6 +17,7 @@
 #include "llvm/Value.h"
 #include "llvm/Assembly/Writer.h"
 #include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineMemOperand.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/CodeGen/PseudoSourceValue.h"
 #include "llvm/Target/TargetMachine.h"
@@ -298,40 +299,56 @@ void MachineMemOperand::Profile(FoldingSetNodeID &ID) const {
   ID.AddInteger(Flags);
 }
 
-raw_ostream &llvm::operator<<(raw_ostream &OS, const MachineMemOperand &MRO) {
-  assert((MRO.isLoad() || MRO.isStore()) &&
+void MachineMemOperand::refineAlignment(const MachineMemOperand *MMO) {
+  // The Value and Offset may differ due to CSE. But the flags and size
+  // should be the same.
+  assert(MMO->getFlags() == getFlags() && "Flags mismatch!");
+  assert(MMO->getSize() == getSize() && "Size mismatch!");
+
+  if (MMO->getBaseAlignment() >= getBaseAlignment()) {
+    // Update the alignment value.
+    Flags = (Flags & 7) | ((Log2_32(MMO->getBaseAlignment()) + 1) << 3);
+    // Also update the base and offset, because the new alignment may
+    // not be applicable with the old ones.
+    V = MMO->getValue();
+    Offset = MMO->getOffset();
+  }
+}
+
+raw_ostream &llvm::operator<<(raw_ostream &OS, const MachineMemOperand &MMO) {
+  assert((MMO.isLoad() || MMO.isStore()) &&
          "SV has to be a load, store or both.");
   
-  if (MRO.isVolatile())
+  if (MMO.isVolatile())
     OS << "Volatile ";
 
-  if (MRO.isLoad())
+  if (MMO.isLoad())
     OS << "LD";
-  if (MRO.isStore())
+  if (MMO.isStore())
     OS << "ST";
-  OS << MRO.getSize();
+  OS << MMO.getSize();
   
   // Print the address information.
   OS << "[";
-  if (!MRO.getValue())
+  if (!MMO.getValue())
     OS << "<unknown>";
   else
-    WriteAsOperand(OS, MRO.getValue(), /*PrintType=*/false);
+    WriteAsOperand(OS, MMO.getValue(), /*PrintType=*/false);
 
   // If the alignment of the memory reference itself differs from the alignment
   // of the base pointer, print the base alignment explicitly, next to the base
   // pointer.
-  if (MRO.getBaseAlignment() != MRO.getAlignment())
-    OS << "(align=" << MRO.getBaseAlignment() << ")";
+  if (MMO.getBaseAlignment() != MMO.getAlignment())
+    OS << "(align=" << MMO.getBaseAlignment() << ")";
 
-  if (MRO.getOffset() != 0)
-    OS << "+" << MRO.getOffset();
+  if (MMO.getOffset() != 0)
+    OS << "+" << MMO.getOffset();
   OS << "]";
 
   // Print the alignment of the reference.
-  if (MRO.getBaseAlignment() != MRO.getAlignment() ||
-      MRO.getBaseAlignment() != MRO.getSize())
-    OS << "(align=" << MRO.getAlignment() << ")";
+  if (MMO.getBaseAlignment() != MMO.getAlignment() ||
+      MMO.getBaseAlignment() != MMO.getSize())
+    OS << "(align=" << MMO.getAlignment() << ")";
 
   return OS;
 }
@@ -343,7 +360,8 @@ raw_ostream &llvm::operator<<(raw_ostream &OS, const MachineMemOperand &MRO) {
 /// MachineInstr ctor - This constructor creates a dummy MachineInstr with
 /// TID NULL and no operands.
 MachineInstr::MachineInstr()
-  : TID(0), NumImplicitOps(0), Parent(0), debugLoc(DebugLoc::getUnknownLoc()) {
+  : TID(0), NumImplicitOps(0), MemRefs(0), MemRefsEnd(0),
+    Parent(0), debugLoc(DebugLoc::getUnknownLoc()) {
   // Make sure that we get added to a machine basicblock
   LeakDetector::addGarbageObject(this);
 }
@@ -362,7 +380,7 @@ void MachineInstr::addImplicitDefUseOperands() {
 /// TargetInstrDesc or the numOperands if it is not zero. (for
 /// instructions with variable number of operands).
 MachineInstr::MachineInstr(const TargetInstrDesc &tid, bool NoImp)
-  : TID(&tid), NumImplicitOps(0), Parent(0), 
+  : TID(&tid), NumImplicitOps(0), MemRefs(0), MemRefsEnd(0), Parent(0),
     debugLoc(DebugLoc::getUnknownLoc()) {
   if (!NoImp && TID->getImplicitDefs())
     for (const unsigned *ImpDefs = TID->getImplicitDefs(); *ImpDefs; ++ImpDefs)
@@ -380,7 +398,8 @@ MachineInstr::MachineInstr(const TargetInstrDesc &tid, bool NoImp)
 /// MachineInstr ctor - As above, but with a DebugLoc.
 MachineInstr::MachineInstr(const TargetInstrDesc &tid, const DebugLoc dl,
                            bool NoImp)
-  : TID(&tid), NumImplicitOps(0), Parent(0), debugLoc(dl) {
+  : TID(&tid), NumImplicitOps(0), MemRefs(0), MemRefsEnd(0),
+    Parent(0), debugLoc(dl) {
   if (!NoImp && TID->getImplicitDefs())
     for (const unsigned *ImpDefs = TID->getImplicitDefs(); *ImpDefs; ++ImpDefs)
       NumImplicitOps++;
@@ -399,7 +418,7 @@ MachineInstr::MachineInstr(const TargetInstrDesc &tid, const DebugLoc dl,
 /// basic block.
 ///
 MachineInstr::MachineInstr(MachineBasicBlock *MBB, const TargetInstrDesc &tid)
-  : TID(&tid), NumImplicitOps(0), Parent(0), 
+  : TID(&tid), NumImplicitOps(0), MemRefs(0), MemRefsEnd(0), Parent(0), 
     debugLoc(DebugLoc::getUnknownLoc()) {
   assert(MBB && "Cannot use inserting ctor with null basic block!");
   if (TID->ImplicitDefs)
@@ -419,7 +438,8 @@ MachineInstr::MachineInstr(MachineBasicBlock *MBB, const TargetInstrDesc &tid)
 ///
 MachineInstr::MachineInstr(MachineBasicBlock *MBB, const DebugLoc dl,
                            const TargetInstrDesc &tid)
-  : TID(&tid), NumImplicitOps(0), Parent(0), debugLoc(dl) {
+  : TID(&tid), NumImplicitOps(0), MemRefs(0), MemRefsEnd(0),
+    Parent(0), debugLoc(dl) {
   assert(MBB && "Cannot use inserting ctor with null basic block!");
   if (TID->ImplicitDefs)
     for (const unsigned *ImpDefs = TID->getImplicitDefs(); *ImpDefs; ++ImpDefs)
@@ -437,8 +457,9 @@ MachineInstr::MachineInstr(MachineBasicBlock *MBB, const DebugLoc dl,
 /// MachineInstr ctor - Copies MachineInstr arg exactly
 ///
 MachineInstr::MachineInstr(MachineFunction &MF, const MachineInstr &MI)
-  : TID(&MI.getDesc()), NumImplicitOps(0), Parent(0), 
-        debugLoc(MI.getDebugLoc()) {
+  : TID(&MI.getDesc()), NumImplicitOps(0),
+    MemRefs(MI.MemRefs), MemRefsEnd(MI.MemRefsEnd),
+    Parent(0), debugLoc(MI.getDebugLoc()) {
   Operands.reserve(MI.getNumOperands());
 
   // Add operands
@@ -446,11 +467,6 @@ MachineInstr::MachineInstr(MachineFunction &MF, const MachineInstr &MI)
     addOperand(MI.getOperand(i));
   NumImplicitOps = MI.NumImplicitOps;
 
-  // Add memory operands.
-  for (std::list<MachineMemOperand>::const_iterator i = MI.memoperands_begin(),
-       j = MI.memoperands_end(); i != j; ++i)
-    addMemOperand(MF, *i);
-
   // Set parent to null.
   Parent = 0;
 
@@ -459,8 +475,6 @@ MachineInstr::MachineInstr(MachineFunction &MF, const MachineInstr &MI)
 
 MachineInstr::~MachineInstr() {
   LeakDetector::removeGarbageObject(this);
-  assert(MemOperands.empty() &&
-         "MachineInstr being deleted with live memoperands!");
 #ifndef NDEBUG
   for (unsigned i = 0, e = Operands.size(); i != e; ++i) {
     assert(Operands[i].ParentMI == this && "ParentMI mismatch!");
@@ -621,18 +635,24 @@ void MachineInstr::RemoveOperand(unsigned OpNo) {
   }
 }
 
-/// addMemOperand - Add a MachineMemOperand to the machine instruction,
-/// referencing arbitrary storage.
+/// addMemOperand - Add a MachineMemOperand to the machine instruction.
+/// This function should be used only occasionally. The setMemRefs function
+/// is the primary method for setting up a MachineInstr's MemRefs list.
 void MachineInstr::addMemOperand(MachineFunction &MF,
-                                 const MachineMemOperand &MO) {
-  MemOperands.push_back(MO);
-}
+                                 MachineMemOperand *MO) {
+  mmo_iterator OldMemRefs = MemRefs;
+  mmo_iterator OldMemRefsEnd = MemRefsEnd;
 
-/// clearMemOperands - Erase all of this MachineInstr's MachineMemOperands.
-void MachineInstr::clearMemOperands(MachineFunction &MF) {
-  MemOperands.clear();
-}
+  size_t NewNum = (MemRefsEnd - MemRefs) + 1;
+  mmo_iterator NewMemRefs = MF.allocateMemRefsArray(NewNum);
+  mmo_iterator NewMemRefsEnd = NewMemRefs + NewNum;
 
+  std::copy(OldMemRefs, OldMemRefsEnd, NewMemRefs);
+  NewMemRefs[NewNum - 1] = MO;
+
+  MemRefs = NewMemRefs;
+  MemRefsEnd = NewMemRefsEnd;
+}
 
 /// removeFromParent - This method unlinks 'this' from the containing basic
 /// block, and returns it, but does not delete it.
@@ -972,9 +992,8 @@ bool MachineInstr::hasVolatileMemoryRef() const {
     return true;
   
   // Check the memory reference information for volatile references.
-  for (std::list<MachineMemOperand>::const_iterator I = memoperands_begin(),
-       E = memoperands_end(); I != E; ++I)
-    if (I->isVolatile())
+  for (mmo_iterator I = memoperands_begin(), E = memoperands_end(); I != E; ++I)
+    if ((*I)->isVolatile())
       return true;
 
   return false;
@@ -1004,9 +1023,9 @@ void MachineInstr::print(raw_ostream &OS, const TargetMachine *TM) const {
 
   if (!memoperands_empty()) {
     OS << ", Mem:";
-    for (std::list<MachineMemOperand>::const_iterator i = memoperands_begin(),
-         e = memoperands_end(); i != e; ++i) {
-      OS << *i;
+    for (mmo_iterator i = memoperands_begin(), e = memoperands_end();
+         i != e; ++i) {
+      OS << **i;
       if (next(i) != e)
         OS << " ";
     }
diff --git a/lib/CodeGen/ScheduleDAGEmit.cpp b/lib/CodeGen/ScheduleDAGEmit.cpp
index 770f5bb..0d15c02 100644
--- a/lib/CodeGen/ScheduleDAGEmit.cpp
+++ b/lib/CodeGen/ScheduleDAGEmit.cpp
@@ -28,10 +28,6 @@
 #include "llvm/Support/MathExtras.h"
 using namespace llvm;
 
-void ScheduleDAG::AddMemOperand(MachineInstr *MI, const MachineMemOperand &MO) {
-  MI->addMemOperand(MF, MO);
-}
-
 void ScheduleDAG::EmitNoop() {
   TII->insertNoop(*BB, InsertPos);
 }
diff --git a/lib/CodeGen/ScheduleDAGInstrs.cpp b/lib/CodeGen/ScheduleDAGInstrs.cpp
index b065d60..b55e606 100644
--- a/lib/CodeGen/ScheduleDAGInstrs.cpp
+++ b/lib/CodeGen/ScheduleDAGInstrs.cpp
@@ -17,6 +17,7 @@
 #include "llvm/Operator.h"
 #include "llvm/Analysis/AliasAnalysis.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineMemOperand.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/CodeGen/PseudoSourceValue.h"
 #include "llvm/Target/TargetMachine.h"
@@ -96,11 +97,11 @@ static const Value *getUnderlyingObject(const Value *V) {
 /// object, return the Value for that object. Otherwise return null.
 static const Value *getUnderlyingObjectForInstr(const MachineInstr *MI) {
   if (!MI->hasOneMemOperand() ||
-      !MI->memoperands_begin()->getValue() ||
-      MI->memoperands_begin()->isVolatile())
+      !(*MI->memoperands_begin())->getValue() ||
+      (*MI->memoperands_begin())->isVolatile())
     return 0;
 
-  const Value *V = MI->memoperands_begin()->getValue();
+  const Value *V = (*MI->memoperands_begin())->getValue();
   if (!V)
     return 0;
 
@@ -335,10 +336,10 @@ void ScheduleDAGInstrs::BuildSchedGraph() {
       if (!ChainTID.isCall() &&
           !ChainTID.hasUnmodeledSideEffects() &&
           ChainMI->hasOneMemOperand() &&
-          !ChainMI->memoperands_begin()->isVolatile() &&
-          ChainMI->memoperands_begin()->getValue())
+          !(*ChainMI->memoperands_begin())->isVolatile() &&
+          (*ChainMI->memoperands_begin())->getValue())
         // We know that the Chain accesses one specific memory location.
-        ChainMMO = &*ChainMI->memoperands_begin();
+        ChainMMO = *ChainMI->memoperands_begin();
       else
         // Unknown memory accesses. Assume the worst.
         ChainMMO = 0;
diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
index 6c6e96a..3e2101a 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
@@ -263,19 +263,10 @@ unsigned ScheduleDAGSDNodes::CountResults(SDNode *Node) {
 }
 
 /// CountOperands - The inputs to target nodes have any actual inputs first,
-/// followed by special operands that describe memory references, then an
-/// optional chain operand, then an optional flag operand.  Compute the number
-/// of actual operands that will go into the resulting MachineInstr.
+/// followed by an optional chain operand, then an optional flag operand.
+/// Compute the number of actual operands that will go into the resulting
+/// MachineInstr.
 unsigned ScheduleDAGSDNodes::CountOperands(SDNode *Node) {
-  unsigned N = ComputeMemOperandsEnd(Node);
-  while (N && isa<MemOperandSDNode>(Node->getOperand(N - 1).getNode()))
-    --N; // Ignore MEMOPERAND nodes
-  return N;
-}
-
-/// ComputeMemOperandsEnd - Find the index one past the last MemOperandSDNode
-/// operand
-unsigned ScheduleDAGSDNodes::ComputeMemOperandsEnd(SDNode *Node) {
   unsigned N = Node->getNumOperands();
   while (N && Node->getOperand(N - 1).getValueType() == MVT::Flag)
     --N;
@@ -284,7 +275,6 @@ unsigned ScheduleDAGSDNodes::ComputeMemOperandsEnd(SDNode *Node) {
   return N;
 }
 
-
 void ScheduleDAGSDNodes::dumpNode(const SUnit *SU) const {
   if (!SU->getNode()) {
     errs() << "PHYS REG COPY\n";
diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.h b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.h
index 51041ef..0a6816a 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.h
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.h
@@ -58,7 +58,6 @@ namespace llvm {
       if (isa<ConstantPoolSDNode>(Node))   return true;
       if (isa<JumpTableSDNode>(Node))      return true;
       if (isa<ExternalSymbolSDNode>(Node)) return true;
-      if (isa<MemOperandSDNode>(Node))     return true;
       if (Node->getOpcode() == ISD::EntryToken) return true;
       return false;
     }
@@ -99,15 +98,11 @@ namespace llvm {
     static unsigned CountResults(SDNode *Node);
 
     /// CountOperands - The inputs to target nodes have any actual inputs first,
-    /// followed by special operands that describe memory references, then an
-    /// optional chain operand, then flag operands.  Compute the number of
-    /// actual operands that will go into the resulting MachineInstr.
+    /// followed by an optional chain operand, then flag operands.  Compute
+    /// the number of actual operands that will go into the resulting
+    /// MachineInstr.
     static unsigned CountOperands(SDNode *Node);
 
-    /// ComputeMemOperandsEnd - Find the index one past the last
-    /// MemOperandSDNode operand
-    static unsigned ComputeMemOperandsEnd(SDNode *Node);
-
     /// EmitNode - Generate machine code for an node and needed dependencies.
     /// VRBaseMap contains, for each already emitted node, the first virtual
     /// register number for the results of the node.
diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodesEmit.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodesEmit.cpp
index c404873..c9e40ff 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodesEmit.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodesEmit.cpp
@@ -497,7 +497,6 @@ void ScheduleDAGSDNodes::EmitNode(SDNode *Node, bool IsClone, bool IsCloned,
     const TargetInstrDesc &II = TII->get(Opc);
     unsigned NumResults = CountResults(Node);
     unsigned NodeOperands = CountOperands(Node);
-    unsigned MemOperandsEnd = ComputeMemOperandsEnd(Node);
     bool HasPhysRegOuts = (NumResults > II.getNumDefs()) &&
                           II.getImplicitDefs() != 0;
 #ifndef NDEBUG
@@ -525,9 +524,9 @@ void ScheduleDAGSDNodes::EmitNode(SDNode *Node, bool IsClone, bool IsCloned,
       AddOperand(MI, Node->getOperand(i), i-NumSkip+II.getNumDefs(), &II,
                  VRBaseMap);
 
-    // Emit all of the memory operands of this instruction
-    for (unsigned i = NodeOperands; i != MemOperandsEnd; ++i)
-      AddMemOperand(MI,cast<MemOperandSDNode>(Node->getOperand(i+NumSkip))->MO);
+    // Transfer all of the memory reference descriptions of this instruction.
+    MI->setMemRefs(cast<MachineSDNode>(Node)->memoperands_begin(),
+                   cast<MachineSDNode>(Node)->memoperands_end());
 
     if (II.usesCustomDAGSchedInsertionHook()) {
       // Insert this instruction into the basic block using a target
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 2b2e911..f6fed21 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -402,11 +402,6 @@ static void AddNodeIDCustom(FoldingSetNodeID &ID, const SDNode *N) {
   case ISD::SRCVALUE:
     ID.AddPointer(cast<SrcValueSDNode>(N)->getValue());
     break;
-  case ISD::MEMOPERAND: {
-    const MachineMemOperand &MO = cast<MemOperandSDNode>(N)->MO;
-    MO.Profile(ID);
-    break;
-  }
   case ISD::FrameIndex:
   case ISD::TargetFrameIndex:
     ID.AddInteger(cast<FrameIndexSDNode>(N)->getIndex());
@@ -481,20 +476,18 @@ static void AddNodeIDNode(FoldingSetNodeID &ID, const SDNode *N) {
 }
 
 /// encodeMemSDNodeFlags - Generic routine for computing a value for use in
-/// the CSE map that carries alignment, volatility, indexing mode, and
+/// the CSE map that carries volatility, indexing mode, and
 /// extension/truncation information.
 ///
 static inline unsigned
-encodeMemSDNodeFlags(int ConvType, ISD::MemIndexedMode AM,
-                     bool isVolatile, unsigned Alignment) {
+encodeMemSDNodeFlags(int ConvType, ISD::MemIndexedMode AM, bool isVolatile) {
   assert((ConvType & 3) == ConvType &&
          "ConvType may not require more than 2 bits!");
   assert((AM & 7) == AM &&
          "AM may not require more than 3 bits!");
   return ConvType |
          (AM << 2) |
-         (isVolatile << 5) |
-         ((Log2_32(Alignment) + 1) << 6);
+         (isVolatile << 5);
 }
 
 //===----------------------------------------------------------------------===//
@@ -1330,28 +1323,6 @@ SDValue SelectionDAG::getSrcValue(const Value *V) {
   return SDValue(N, 0);
 }
 
-SDValue SelectionDAG::getMemOperand(const MachineMemOperand &MO) {
-#ifndef NDEBUG
-  const Value *v = MO.getValue();
-  assert((!v || isa<PointerType>(v->getType())) &&
-         "SrcValue is not a pointer?");
-#endif
-
-  FoldingSetNodeID ID;
-  AddNodeIDNode(ID, ISD::MEMOPERAND, getVTList(MVT::Other), 0, 0);
-  MO.Profile(ID);
-
-  void *IP = 0;
-  if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
-    return SDValue(E, 0);
-
-  SDNode *N = NodeAllocator.Allocate<MemOperandSDNode>();
-  new (N) MemOperandSDNode(MO);
-  CSEMap.InsertNode(N, IP);
-  AllNodes.push_back(N);
-  return SDValue(N, 0);
-}
-
 /// getShiftAmountOperand - Return the specified value casted to
 /// the target's desired shift amount type.
 SDValue SelectionDAG::getShiftAmountOperand(SDValue Op) {
@@ -3523,25 +3494,49 @@ SDValue SelectionDAG::getAtomic(unsigned Opcode, DebugLoc dl, EVT MemVT,
                                 SDValue Ptr, SDValue Cmp,
                                 SDValue Swp, const Value* PtrVal,
                                 unsigned Alignment) {
+  if (Alignment == 0)  // Ensure that codegen never sees alignment 0
+    Alignment = getEVTAlignment(MemVT);
+
+  // Check if the memory reference references a frame index
+  if (!PtrVal)
+    if (const FrameIndexSDNode *FI =
+          dyn_cast<const FrameIndexSDNode>(Ptr.getNode()))
+      PtrVal = PseudoSourceValue::getFixedStack(FI->getIndex());
+
+  MachineFunction &MF = getMachineFunction();
+  unsigned Flags = MachineMemOperand::MOLoad | MachineMemOperand::MOStore;
+
+  // For now, atomics are considered to be volatile always.
+  Flags |= MachineMemOperand::MOVolatile;
+
+  MachineMemOperand *MMO =
+    MF.getMachineMemOperand(PtrVal, Flags, 0,
+                            MemVT.getStoreSize(), Alignment);
+
+  return getAtomic(Opcode, dl, MemVT, Chain, Ptr, Cmp, Swp, MMO);
+}
+
+SDValue SelectionDAG::getAtomic(unsigned Opcode, DebugLoc dl, EVT MemVT,
+                                SDValue Chain,
+                                SDValue Ptr, SDValue Cmp,
+                                SDValue Swp, MachineMemOperand *MMO) {
   assert(Opcode == ISD::ATOMIC_CMP_SWAP && "Invalid Atomic Op");
   assert(Cmp.getValueType() == Swp.getValueType() && "Invalid Atomic Op Types");
 
   EVT VT = Cmp.getValueType();
 
-  if (Alignment == 0)  // Ensure that codegen never sees alignment 0
-    Alignment = getEVTAlignment(MemVT);
-
   SDVTList VTs = getVTList(VT, MVT::Other);
   FoldingSetNodeID ID;
   ID.AddInteger(MemVT.getRawBits());
   SDValue Ops[] = {Chain, Ptr, Cmp, Swp};
   AddNodeIDNode(ID, Opcode, VTs, Ops, 4);
   void* IP = 0;
-  if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+  if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP)) {
+    cast<AtomicSDNode>(E)->refineAlignment(MMO);
     return SDValue(E, 0);
+  }
   SDNode* N = NodeAllocator.Allocate<AtomicSDNode>();
-  new (N) AtomicSDNode(Opcode, dl, VTs, MemVT,
-                       Chain, Ptr, Cmp, Swp, PtrVal, Alignment);
+  new (N) AtomicSDNode(Opcode, dl, VTs, MemVT, Chain, Ptr, Cmp, Swp, MMO);
   CSEMap.InsertNode(N, IP);
   AllNodes.push_back(N);
   return SDValue(N, 0);
@@ -3552,6 +3547,32 @@ SDValue SelectionDAG::getAtomic(unsigned Opcode, DebugLoc dl, EVT MemVT,
                                 SDValue Ptr, SDValue Val,
                                 const Value* PtrVal,
                                 unsigned Alignment) {
+  if (Alignment == 0)  // Ensure that codegen never sees alignment 0
+    Alignment = getEVTAlignment(MemVT);
+
+  // Check if the memory reference references a frame index
+  if (!PtrVal)
+    if (const FrameIndexSDNode *FI =
+          dyn_cast<const FrameIndexSDNode>(Ptr.getNode()))
+      PtrVal = PseudoSourceValue::getFixedStack(FI->getIndex());
+
+  MachineFunction &MF = getMachineFunction();
+  unsigned Flags = MachineMemOperand::MOLoad | MachineMemOperand::MOStore;
+
+  // For now, atomics are considered to be volatile always.
+  Flags |= MachineMemOperand::MOVolatile;
+
+  MachineMemOperand *MMO =
+    MF.getMachineMemOperand(PtrVal, Flags, 0,
+                            MemVT.getStoreSize(), Alignment);
+
+  return getAtomic(Opcode, dl, MemVT, Chain, Ptr, Val, MMO);
+}
+
+SDValue SelectionDAG::getAtomic(unsigned Opcode, DebugLoc dl, EVT MemVT,
+                                SDValue Chain,
+                                SDValue Ptr, SDValue Val,
+                                MachineMemOperand *MMO) {
   assert((Opcode == ISD::ATOMIC_LOAD_ADD ||
           Opcode == ISD::ATOMIC_LOAD_SUB ||
           Opcode == ISD::ATOMIC_LOAD_AND ||
@@ -3567,20 +3588,18 @@ SDValue SelectionDAG::getAtomic(unsigned Opcode, DebugLoc dl, EVT MemVT,
 
   EVT VT = Val.getValueType();
 
-  if (Alignment == 0)  // Ensure that codegen never sees alignment 0
-    Alignment = getEVTAlignment(MemVT);
-
   SDVTList VTs = getVTList(VT, MVT::Other);
   FoldingSetNodeID ID;
   ID.AddInteger(MemVT.getRawBits());
   SDValue Ops[] = {Chain, Ptr, Val};
   AddNodeIDNode(ID, Opcode, VTs, Ops, 3);
   void* IP = 0;
-  if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+  if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP)) {
+    cast<AtomicSDNode>(E)->refineAlignment(MMO);
     return SDValue(E, 0);
+  }
   SDNode* N = NodeAllocator.Allocate<AtomicSDNode>();
-  new (N) AtomicSDNode(Opcode, dl, VTs, MemVT,
-                       Chain, Ptr, Val, PtrVal, Alignment);
+  new (N) AtomicSDNode(Opcode, dl, VTs, MemVT, Chain, Ptr, Val, MMO);
   CSEMap.InsertNode(N, IP);
   AllNodes.push_back(N);
   return SDValue(N, 0);
@@ -3619,23 +3638,51 @@ SelectionDAG::getMemIntrinsicNode(unsigned Opcode, DebugLoc dl, SDVTList VTList,
                                   EVT MemVT, const Value *srcValue, int SVOff,
                                   unsigned Align, bool Vol,
                                   bool ReadMem, bool WriteMem) {
+  if (Align == 0)  // Ensure that codegen never sees alignment 0
+    Align = getEVTAlignment(MemVT);
+
+  MachineFunction &MF = getMachineFunction();
+  unsigned Flags = 0;
+  if (WriteMem)
+    Flags |= MachineMemOperand::MOStore;
+  if (ReadMem)
+    Flags |= MachineMemOperand::MOLoad;
+  if (Vol)
+    Flags |= MachineMemOperand::MOVolatile;
+  MachineMemOperand *MMO =
+    MF.getMachineMemOperand(srcValue, Flags, SVOff,
+                            MemVT.getStoreSize(), Align);
+
+  return getMemIntrinsicNode(Opcode, dl, VTList, Ops, NumOps, MemVT, MMO);
+}
+
+SDValue
+SelectionDAG::getMemIntrinsicNode(unsigned Opcode, DebugLoc dl, SDVTList VTList,
+                                  const SDValue *Ops, unsigned NumOps,
+                                  EVT MemVT, MachineMemOperand *MMO) {
+  assert((Opcode == ISD::INTRINSIC_VOID ||
+          Opcode == ISD::INTRINSIC_W_CHAIN ||
+          (Opcode <= INT_MAX &&
+           (int)Opcode >= ISD::FIRST_TARGET_MEMORY_OPCODE)) &&
+         "Opcode is not a memory-accessing opcode!");
+
   // Memoize the node unless it returns a flag.
   MemIntrinsicSDNode *N;
   if (VTList.VTs[VTList.NumVTs-1] != MVT::Flag) {
     FoldingSetNodeID ID;
     AddNodeIDNode(ID, Opcode, VTList, Ops, NumOps);
     void *IP = 0;
-    if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+    if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP)) {
+      cast<MemIntrinsicSDNode>(E)->refineAlignment(MMO);
       return SDValue(E, 0);
+    }
 
     N = NodeAllocator.Allocate<MemIntrinsicSDNode>();
-    new (N) MemIntrinsicSDNode(Opcode, dl, VTList, Ops, NumOps, MemVT,
-                               srcValue, SVOff, Align, Vol, ReadMem, WriteMem);
+    new (N) MemIntrinsicSDNode(Opcode, dl, VTList, Ops, NumOps, MemVT, MMO);
     CSEMap.InsertNode(N, IP);
   } else {
     N = NodeAllocator.Allocate<MemIntrinsicSDNode>();
-    new (N) MemIntrinsicSDNode(Opcode, dl, VTList, Ops, NumOps, MemVT,
-                               srcValue, SVOff, Align, Vol, ReadMem, WriteMem);
+    new (N) MemIntrinsicSDNode(Opcode, dl, VTList, Ops, NumOps, MemVT, MMO);
   }
   AllNodes.push_back(N);
   return SDValue(N, 0);
@@ -3650,6 +3697,27 @@ SelectionDAG::getLoad(ISD::MemIndexedMode AM, DebugLoc dl,
   if (Alignment == 0)  // Ensure that codegen never sees alignment 0
     Alignment = getEVTAlignment(VT);
 
+  // Check if the memory reference references a frame index
+  if (!SV)
+    if (const FrameIndexSDNode *FI =
+          dyn_cast<const FrameIndexSDNode>(Ptr.getNode()))
+      SV = PseudoSourceValue::getFixedStack(FI->getIndex());
+
+  MachineFunction &MF = getMachineFunction();
+  unsigned Flags = MachineMemOperand::MOLoad;
+  if (isVolatile)
+    Flags |= MachineMemOperand::MOVolatile;
+  MachineMemOperand *MMO =
+    MF.getMachineMemOperand(SV, Flags, SVOffset,
+                            MemVT.getStoreSize(), Alignment);
+  return getLoad(AM, dl, ExtType, VT, Chain, Ptr, Offset, MemVT, MMO);
+}
+
+SDValue
+SelectionDAG::getLoad(ISD::MemIndexedMode AM, DebugLoc dl,
+                      ISD::LoadExtType ExtType, EVT VT, SDValue Chain,
+                      SDValue Ptr, SDValue Offset, EVT MemVT,
+                      MachineMemOperand *MMO) {
   if (VT == MemVT) {
     ExtType = ISD::NON_EXTLOAD;
   } else if (ExtType == ISD::NON_EXTLOAD) {
@@ -3678,13 +3746,14 @@ SelectionDAG::getLoad(ISD::MemIndexedMode AM, DebugLoc dl,
   FoldingSetNodeID ID;
   AddNodeIDNode(ID, ISD::LOAD, VTs, Ops, 3);
   ID.AddInteger(MemVT.getRawBits());
-  ID.AddInteger(encodeMemSDNodeFlags(ExtType, AM, isVolatile, Alignment));
+  ID.AddInteger(encodeMemSDNodeFlags(ExtType, AM, MMO->isVolatile()));
   void *IP = 0;
-  if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+  if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP)) {
+    cast<LoadSDNode>(E)->refineAlignment(MMO);
     return SDValue(E, 0);
+  }
   SDNode *N = NodeAllocator.Allocate<LoadSDNode>();
-  new (N) LoadSDNode(Ops, dl, VTs, AM, ExtType, MemVT, SV, SVOffset,
-                     Alignment, isVolatile);
+  new (N) LoadSDNode(Ops, dl, VTs, AM, ExtType, MemVT, MMO);
   CSEMap.InsertNode(N, IP);
   AllNodes.push_back(N);
   return SDValue(N, 0);
@@ -3724,25 +3793,43 @@ SelectionDAG::getIndexedLoad(SDValue OrigLoad, DebugLoc dl, SDValue Base,
 SDValue SelectionDAG::getStore(SDValue Chain, DebugLoc dl, SDValue Val,
                                SDValue Ptr, const Value *SV, int SVOffset,
                                bool isVolatile, unsigned Alignment) {
-  EVT VT = Val.getValueType();
-
   if (Alignment == 0)  // Ensure that codegen never sees alignment 0
-    Alignment = getEVTAlignment(VT);
+    Alignment = getEVTAlignment(Val.getValueType());
+
+  // Check if the memory reference references a frame index
+  if (!SV)
+    if (const FrameIndexSDNode *FI =
+          dyn_cast<const FrameIndexSDNode>(Ptr.getNode()))
+      SV = PseudoSourceValue::getFixedStack(FI->getIndex());
+
+  MachineFunction &MF = getMachineFunction();
+  unsigned Flags = MachineMemOperand::MOStore;
+  if (isVolatile)
+    Flags |= MachineMemOperand::MOVolatile;
+  MachineMemOperand *MMO =
+    MF.getMachineMemOperand(SV, Flags, SVOffset,
+                            Val.getValueType().getStoreSize(), Alignment);
 
+  return getStore(Chain, dl, Val, Ptr, MMO);
+}
+
+SDValue SelectionDAG::getStore(SDValue Chain, DebugLoc dl, SDValue Val,
+                               SDValue Ptr, MachineMemOperand *MMO) {
+  EVT VT = Val.getValueType();
   SDVTList VTs = getVTList(MVT::Other);
   SDValue Undef = getUNDEF(Ptr.getValueType());
   SDValue Ops[] = { Chain, Val, Ptr, Undef };
   FoldingSetNodeID ID;
   AddNodeIDNode(ID, ISD::STORE, VTs, Ops, 4);
   ID.AddInteger(VT.getRawBits());
-  ID.AddInteger(encodeMemSDNodeFlags(false, ISD::UNINDEXED,
-                                     isVolatile, Alignment));
+  ID.AddInteger(encodeMemSDNodeFlags(false, ISD::UNINDEXED, MMO->isVolatile()));
   void *IP = 0;
-  if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+  if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP)) {
+    cast<StoreSDNode>(E)->refineAlignment(MMO);
     return SDValue(E, 0);
+  }
   SDNode *N = NodeAllocator.Allocate<StoreSDNode>();
-  new (N) StoreSDNode(Ops, dl, VTs, ISD::UNINDEXED, false,
-                      VT, SV, SVOffset, Alignment, isVolatile);
+  new (N) StoreSDNode(Ops, dl, VTs, ISD::UNINDEXED, false, VT, MMO);
   CSEMap.InsertNode(N, IP);
   AllNodes.push_back(N);
   return SDValue(N, 0);
@@ -3752,17 +3839,37 @@ SDValue SelectionDAG::getTruncStore(SDValue Chain, DebugLoc dl, SDValue Val,
                                     SDValue Ptr, const Value *SV,
                                     int SVOffset, EVT SVT,
                                     bool isVolatile, unsigned Alignment) {
+  if (Alignment == 0)  // Ensure that codegen never sees alignment 0
+    Alignment = getEVTAlignment(SVT);
+
+  // Check if the memory reference references a frame index
+  if (!SV)
+    if (const FrameIndexSDNode *FI =
+          dyn_cast<const FrameIndexSDNode>(Ptr.getNode()))
+      SV = PseudoSourceValue::getFixedStack(FI->getIndex());
+
+  MachineFunction &MF = getMachineFunction();
+  unsigned Flags = MachineMemOperand::MOStore;
+  if (isVolatile)
+    Flags |= MachineMemOperand::MOVolatile;
+  MachineMemOperand *MMO =
+    MF.getMachineMemOperand(SV, Flags, SVOffset, SVT.getStoreSize(), Alignment);
+
+  return getTruncStore(Chain, dl, Val, Ptr, SVT, MMO);
+}
+
+SDValue SelectionDAG::getTruncStore(SDValue Chain, DebugLoc dl, SDValue Val,
+                                    SDValue Ptr, EVT SVT,
+                                    MachineMemOperand *MMO) {
   EVT VT = Val.getValueType();
 
   if (VT == SVT)
-    return getStore(Chain, dl, Val, Ptr, SV, SVOffset, isVolatile, Alignment);
+    return getStore(Chain, dl, Val, Ptr, MMO);
 
   assert(VT.bitsGT(SVT) && "Not a truncation?");
   assert(VT.isInteger() == SVT.isInteger() &&
          "Can't do FP-INT conversion!");
 
-  if (Alignment == 0)  // Ensure that codegen never sees alignment 0
-    Alignment = getEVTAlignment(VT);
 
   SDVTList VTs = getVTList(MVT::Other);
   SDValue Undef = getUNDEF(Ptr.getValueType());
@@ -3770,14 +3877,14 @@ SDValue SelectionDAG::getTruncStore(SDValue Chain, DebugLoc dl, SDValue Val,
   FoldingSetNodeID ID;
   AddNodeIDNode(ID, ISD::STORE, VTs, Ops, 4);
   ID.AddInteger(SVT.getRawBits());
-  ID.AddInteger(encodeMemSDNodeFlags(true, ISD::UNINDEXED,
-                                     isVolatile, Alignment));
+  ID.AddInteger(encodeMemSDNodeFlags(true, ISD::UNINDEXED, MMO->isVolatile()));
   void *IP = 0;
-  if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+  if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP)) {
+    cast<StoreSDNode>(E)->refineAlignment(MMO);
     return SDValue(E, 0);
+  }
   SDNode *N = NodeAllocator.Allocate<StoreSDNode>();
-  new (N) StoreSDNode(Ops, dl, VTs, ISD::UNINDEXED, true,
-                      SVT, SV, SVOffset, Alignment, isVolatile);
+  new (N) StoreSDNode(Ops, dl, VTs, ISD::UNINDEXED, true, SVT, MMO);
   CSEMap.InsertNode(N, IP);
   AllNodes.push_back(N);
   return SDValue(N, 0);
@@ -3801,8 +3908,7 @@ SelectionDAG::getIndexedStore(SDValue OrigStore, DebugLoc dl, SDValue Base,
   SDNode *N = NodeAllocator.Allocate<StoreSDNode>();
   new (N) StoreSDNode(Ops, dl, VTs, AM,
                       ST->isTruncatingStore(), ST->getMemoryVT(),
-                      ST->getSrcValue(), ST->getSrcValueOffset(),
-                      ST->getAlignment(), ST->isVolatile());
+                      ST->getMemOperand());
   CSEMap.InsertNode(N, IP);
   AllNodes.push_back(N);
   return SDValue(N, 0);
@@ -4454,29 +4560,35 @@ SDNode *SelectionDAG::MorphNodeTo(SDNode *N, unsigned Opc,
       DeadNodeSet.insert(Used);
   }
 
-  // If NumOps is larger than the # of operands we currently have, reallocate
-  // the operand list.
-  if (NumOps > N->NumOperands) {
-    if (N->OperandsNeedDelete)
-      delete[] N->OperandList;
-
-    if (N->isMachineOpcode()) {
-      // We're creating a final node that will live unmorphed for the
-      // remainder of the current SelectionDAG iteration, so we can allocate
-      // the operands directly out of a pool with no recycling metadata.
-      N->OperandList = OperandAllocator.Allocate<SDUse>(NumOps);
-      N->OperandsNeedDelete = false;
-    } else {
-      N->OperandList = new SDUse[NumOps];
+  if (MachineSDNode *MN = dyn_cast<MachineSDNode>(N)) {
+    // Initialize the memory references information.
+    MN->setMemRefs(0, 0);
+    // If NumOps is larger than the # of operands we can have in a
+    // MachineSDNode, reallocate the operand list.
+    if (NumOps > MN->NumOperands || !MN->OperandsNeedDelete) {
+      if (MN->OperandsNeedDelete)
+        delete[] MN->OperandList;
+      if (NumOps > array_lengthof(MN->LocalOperands))
+        // We're creating a final node that will live unmorphed for the
+        // remainder of the current SelectionDAG iteration, so we can allocate
+        // the operands directly out of a pool with no recycling metadata.
+        MN->InitOperands(OperandAllocator.Allocate<SDUse>(NumOps),
+                        Ops, NumOps);
+      else
+        MN->InitOperands(MN->LocalOperands, Ops, NumOps);
+      MN->OperandsNeedDelete = false;
+    } else
+      MN->InitOperands(MN->OperandList, Ops, NumOps);
+  } else {
+    // If NumOps is larger than the # of operands we currently have, reallocate
+    // the operand list.
+    if (NumOps > N->NumOperands) {
+      if (N->OperandsNeedDelete)
+        delete[] N->OperandList;
+      N->InitOperands(new SDUse[NumOps], Ops, NumOps);
       N->OperandsNeedDelete = true;
-    }
-  }
-
-  // Assign the new operands.
-  N->NumOperands = NumOps;
-  for (unsigned i = 0, e = NumOps; i != e; ++i) {
-    N->OperandList[i].setUser(N);
-    N->OperandList[i].setInitial(Ops[i]);
+    } else
+      MN->InitOperands(MN->OperandList, Ops, NumOps);
   }
 
   // Delete any nodes that are still dead after adding the uses for the
@@ -4501,41 +4613,49 @@ SDNode *SelectionDAG::MorphNodeTo(SDNode *N, unsigned Opc,
 /// node of the specified opcode and operands, it returns that node instead of
 /// the current one.
 SDNode *SelectionDAG::getMachineNode(unsigned Opcode, DebugLoc dl, EVT VT) {
-  return getNode(~Opcode, dl, VT).getNode();
+  SDVTList VTs = getVTList(VT);
+  return getMachineNode(Opcode, dl, VTs, 0, 0);
 }
 
 SDNode *SelectionDAG::getMachineNode(unsigned Opcode, DebugLoc dl, EVT VT,
                                      SDValue Op1) {
-  return getNode(~Opcode, dl, VT, Op1).getNode();
+  SDVTList VTs = getVTList(VT);
+  SDValue Ops[] = { Op1 };
+  return getMachineNode(Opcode, dl, VTs, Ops, array_lengthof(Ops));
 }
 
 SDNode *SelectionDAG::getMachineNode(unsigned Opcode, DebugLoc dl, EVT VT,
                                      SDValue Op1, SDValue Op2) {
-  return getNode(~Opcode, dl, VT, Op1, Op2).getNode();
+  SDVTList VTs = getVTList(VT);
+  SDValue Ops[] = { Op1, Op2 };
+  return getMachineNode(Opcode, dl, VTs, Ops, array_lengthof(Ops));
 }
 
 SDNode *SelectionDAG::getMachineNode(unsigned Opcode, DebugLoc dl, EVT VT,
                                      SDValue Op1, SDValue Op2,
                                      SDValue Op3) {
-  return getNode(~Opcode, dl, VT, Op1, Op2, Op3).getNode();
+  SDVTList VTs = getVTList(VT);
+  SDValue Ops[] = { Op1, Op2, Op3 };
+  return getMachineNode(Opcode, dl, VTs, Ops, array_lengthof(Ops));
 }
 
 SDNode *SelectionDAG::getMachineNode(unsigned Opcode, DebugLoc dl, EVT VT,
                                      const SDValue *Ops, unsigned NumOps) {
-  return getNode(~Opcode, dl, VT, Ops, NumOps).getNode();
+  SDVTList VTs = getVTList(VT);
+  return getMachineNode(Opcode, dl, VTs, Ops, NumOps);
 }
 
 SDNode *SelectionDAG::getMachineNode(unsigned Opcode, DebugLoc dl,
                                      EVT VT1, EVT VT2) {
   SDVTList VTs = getVTList(VT1, VT2);
-  SDValue Op;
-  return getNode(~Opcode, dl, VTs, &Op, 0).getNode();
+  return getMachineNode(Opcode, dl, VTs, 0, 0);
 }
 
 SDNode *SelectionDAG::getMachineNode(unsigned Opcode, DebugLoc dl, EVT VT1,
                                      EVT VT2, SDValue Op1) {
   SDVTList VTs = getVTList(VT1, VT2);
-  return getNode(~Opcode, dl, VTs, &Op1, 1).getNode();
+  SDValue Ops[] = { Op1 };
+  return getMachineNode(Opcode, dl, VTs, Ops, array_lengthof(Ops));
 }
 
 SDNode *SelectionDAG::getMachineNode(unsigned Opcode, DebugLoc dl, EVT VT1,
@@ -4543,7 +4663,7 @@ SDNode *SelectionDAG::getMachineNode(unsigned Opcode, DebugLoc dl, EVT VT1,
                                      SDValue Op2) {
   SDVTList VTs = getVTList(VT1, VT2);
   SDValue Ops[] = { Op1, Op2 };
-  return getNode(~Opcode, dl, VTs, Ops, 2).getNode();
+  return getMachineNode(Opcode, dl, VTs, Ops, array_lengthof(Ops));
 }
 
 SDNode *SelectionDAG::getMachineNode(unsigned Opcode, DebugLoc dl, EVT VT1,
@@ -4551,14 +4671,14 @@ SDNode *SelectionDAG::getMachineNode(unsigned Opcode, DebugLoc dl, EVT VT1,
                                      SDValue Op2, SDValue Op3) {
   SDVTList VTs = getVTList(VT1, VT2);
   SDValue Ops[] = { Op1, Op2, Op3 };
-  return getNode(~Opcode, dl, VTs, Ops, 3).getNode();
+  return getMachineNode(Opcode, dl, VTs, Ops, array_lengthof(Ops));
 }
 
 SDNode *SelectionDAG::getMachineNode(unsigned Opcode, DebugLoc dl,
                                      EVT VT1, EVT VT2,
                                      const SDValue *Ops, unsigned NumOps) {
   SDVTList VTs = getVTList(VT1, VT2);
-  return getNode(~Opcode, dl, VTs, Ops, NumOps).getNode();
+  return getMachineNode(Opcode, dl, VTs, Ops, NumOps);
 }
 
 SDNode *SelectionDAG::getMachineNode(unsigned Opcode, DebugLoc dl,
@@ -4566,7 +4686,7 @@ SDNode *SelectionDAG::getMachineNode(unsigned Opcode, DebugLoc dl,
                                      SDValue Op1, SDValue Op2) {
   SDVTList VTs = getVTList(VT1, VT2, VT3);
   SDValue Ops[] = { Op1, Op2 };
-  return getNode(~Opcode, dl, VTs, Ops, 2).getNode();
+  return getMachineNode(Opcode, dl, VTs, Ops, array_lengthof(Ops));
 }
 
 SDNode *SelectionDAG::getMachineNode(unsigned Opcode, DebugLoc dl,
@@ -4575,27 +4695,67 @@ SDNode *SelectionDAG::getMachineNode(unsigned Opcode, DebugLoc dl,
                                      SDValue Op3) {
   SDVTList VTs = getVTList(VT1, VT2, VT3);
   SDValue Ops[] = { Op1, Op2, Op3 };
-  return getNode(~Opcode, dl, VTs, Ops, 3).getNode();
+  return getMachineNode(Opcode, dl, VTs, Ops, array_lengthof(Ops));
 }
 
 SDNode *SelectionDAG::getMachineNode(unsigned Opcode, DebugLoc dl,
                                      EVT VT1, EVT VT2, EVT VT3,
                                      const SDValue *Ops, unsigned NumOps) {
   SDVTList VTs = getVTList(VT1, VT2, VT3);
-  return getNode(~Opcode, dl, VTs, Ops, NumOps).getNode();
+  return getMachineNode(Opcode, dl, VTs, Ops, NumOps);
 }
 
 SDNode *SelectionDAG::getMachineNode(unsigned Opcode, DebugLoc dl, EVT VT1,
                                      EVT VT2, EVT VT3, EVT VT4,
                                      const SDValue *Ops, unsigned NumOps) {
   SDVTList VTs = getVTList(VT1, VT2, VT3, VT4);
-  return getNode(~Opcode, dl, VTs, Ops, NumOps).getNode();
+  return getMachineNode(Opcode, dl, VTs, Ops, NumOps);
 }
 
 SDNode *SelectionDAG::getMachineNode(unsigned Opcode, DebugLoc dl,
                                      const std::vector<EVT> &ResultTys,
                                      const SDValue *Ops, unsigned NumOps) {
-  return getNode(~Opcode, dl, ResultTys, Ops, NumOps).getNode();
+  SDVTList VTs = getVTList(&ResultTys[0], ResultTys.size());
+  return getMachineNode(Opcode, dl, VTs, Ops, NumOps);
+}
+
+SDNode *SelectionDAG::getMachineNode(unsigned Opcode, DebugLoc DL, SDVTList VTs,
+                                     const SDValue *Ops, unsigned NumOps) {
+  bool DoCSE = VTs.VTs[VTs.NumVTs-1] != MVT::Flag;
+  MachineSDNode *N;
+  void *IP;
+
+  if (DoCSE) {
+    FoldingSetNodeID ID;
+    AddNodeIDNode(ID, ~Opcode, VTs, Ops, NumOps);
+    IP = 0;
+    if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+      return E;
+  }
+
+  // Allocate a new MachineSDNode.
+  N = NodeAllocator.Allocate<MachineSDNode>();
+  new (N) MachineSDNode(~Opcode, DL, VTs);
+
+  // Initialize the operands list.
+  if (NumOps > array_lengthof(N->LocalOperands))
+    // We're creating a final node that will live unmorphed for the
+    // remainder of the current SelectionDAG iteration, so we can allocate
+    // the operands directly out of a pool with no recycling metadata.
+    N->InitOperands(OperandAllocator.Allocate<SDUse>(NumOps),
+                    Ops, NumOps);
+  else
+    N->InitOperands(N->LocalOperands, Ops, NumOps);
+  N->OperandsNeedDelete = false;
+
+  if (DoCSE)
+    CSEMap.InsertNode(N, IP);
+
+  AllNodes.push_back(N);
+#ifndef NDEBUG
+  VerifyNode(N);
+#endif
+  return N;
 }
 
 /// getTargetExtractSubreg - A convenience function for creating
@@ -4968,57 +5128,21 @@ GlobalAddressSDNode::GlobalAddressSDNode(unsigned Opc, const GlobalValue *GA,
 }
 
 MemSDNode::MemSDNode(unsigned Opc, DebugLoc dl, SDVTList VTs, EVT memvt,
-                     const Value *srcValue, int SVO, unsigned alignment,
-                     bool vol)
- : SDNode(Opc, dl, VTs), MemoryVT(memvt), SrcValue(srcValue), SVOffset(SVO) {
-  SubclassData = encodeMemSDNodeFlags(0, ISD::UNINDEXED, vol, alignment);
-  assert(isPowerOf2_32(alignment) && "Alignment is not a power of 2!");
-  assert(getOriginalAlignment() == alignment && "Alignment encoding error!");
-  assert(isVolatile() == vol && "Volatile encoding error!");
+                     MachineMemOperand *mmo)
+ : SDNode(Opc, dl, VTs), MemoryVT(memvt), MMO(mmo) {
+  SubclassData = encodeMemSDNodeFlags(0, ISD::UNINDEXED, MMO->isVolatile());
+  assert(isVolatile() == MMO->isVolatile() && "Volatile encoding error!");
+  assert(memvt.getStoreSize() == MMO->getSize() && "Size mismatch!");
 }
 
 MemSDNode::MemSDNode(unsigned Opc, DebugLoc dl, SDVTList VTs,
                      const SDValue *Ops, unsigned NumOps, EVT memvt, 
-                     const Value *srcValue, int SVO, unsigned alignment, 
-                     bool vol)
+                     MachineMemOperand *mmo)
    : SDNode(Opc, dl, VTs, Ops, NumOps),
-     MemoryVT(memvt), SrcValue(srcValue), SVOffset(SVO) {
-  SubclassData = encodeMemSDNodeFlags(0, ISD::UNINDEXED, vol, alignment);
-  assert(isPowerOf2_32(alignment) && "Alignment is not a power of 2!");
-  assert(getOriginalAlignment() == alignment && "Alignment encoding error!");
-  assert(isVolatile() == vol && "Volatile encoding error!");
-}
-
-/// getMemOperand - Return a MachineMemOperand object describing the memory
-/// reference performed by this memory reference.
-MachineMemOperand MemSDNode::getMemOperand() const {
-  int Flags = 0;
-  if (isa<LoadSDNode>(this))
-    Flags = MachineMemOperand::MOLoad;
-  else if (isa<StoreSDNode>(this))
-    Flags = MachineMemOperand::MOStore;
-  else if (isa<AtomicSDNode>(this)) {
-    Flags = MachineMemOperand::MOLoad | MachineMemOperand::MOStore;
-  }
-  else {
-    const MemIntrinsicSDNode* MemIntrinNode = dyn_cast<MemIntrinsicSDNode>(this);
-    assert(MemIntrinNode && "Unknown MemSDNode opcode!");
-    if (MemIntrinNode->readMem()) Flags |= MachineMemOperand::MOLoad;
-    if (MemIntrinNode->writeMem()) Flags |= MachineMemOperand::MOStore;
-  }
-
-  int Size = (getMemoryVT().getSizeInBits() + 7) >> 3;
-  if (isVolatile()) Flags |= MachineMemOperand::MOVolatile;
-
-  // Check if the memory reference references a frame index
-  const FrameIndexSDNode *FI =
-  dyn_cast<const FrameIndexSDNode>(getBasePtr().getNode());
-  if (!getSrcValue() && FI)
-    return MachineMemOperand(PseudoSourceValue::getFixedStack(FI->getIndex()),
-                             Flags, 0, Size, getOriginalAlignment());
-  else
-    return MachineMemOperand(getSrcValue(), Flags, getSrcValueOffset(),
-                             Size, getOriginalAlignment());
+     MemoryVT(memvt), MMO(mmo) {
+  SubclassData = encodeMemSDNodeFlags(0, ISD::UNINDEXED, MMO->isVolatile());
+  assert(isVolatile() == MMO->isVolatile() && "Volatile encoding error!");
+  assert(memvt.getStoreSize() == MMO->getSize() && "Size mismatch!");
 }
 
 /// Profile - Gather unique data for the node.
@@ -5221,7 +5345,6 @@ std::string SDNode::getOperationName(const SelectionDAG *G) const {
   case ISD::PCMARKER:      return "PCMarker";
   case ISD::READCYCLECOUNTER: return "ReadCycleCounter";
   case ISD::SRCVALUE:      return "SrcValue";
-  case ISD::MEMOPERAND:    return "MemOperand";
   case ISD::EntryToken:    return "EntryToken";
   case ISD::TokenFactor:   return "TokenFactor";
   case ISD::AssertSext:    return "AssertSext";
@@ -5500,8 +5623,20 @@ void SDNode::print_types(raw_ostream &OS, const SelectionDAG *G) const {
 }
 
 void SDNode::print_details(raw_ostream &OS, const SelectionDAG *G) const {
-  if (!isTargetOpcode() && getOpcode() == ISD::VECTOR_SHUFFLE) {
-    const ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(this);
+  if (const MachineSDNode *MN = dyn_cast<MachineSDNode>(this)) {
+    if (!MN->memoperands_empty()) {
+      OS << "<";
+      OS << "Mem:";
+      for (MachineSDNode::mmo_iterator i = MN->memoperands_begin(),
+           e = MN->memoperands_end(); i != e; ++i) {
+        OS << **i;
+        if (next(i) != e)
+          OS << " ";
+      }
+      OS << ">";
+    }
+  } else if (const ShuffleVectorSDNode *SVN =
+               dyn_cast<ShuffleVectorSDNode>(this)) {
     OS << "<";
     for (unsigned i = 0, e = ValueList[0].getVectorNumElements(); i != e; ++i) {
       int Idx = SVN->getMaskElt(i);
@@ -5512,9 +5647,7 @@ void SDNode::print_details(raw_ostream &OS, const SelectionDAG *G) const {
         OS << Idx;
     }
     OS << ">";
-  }
-
-  if (const ConstantSDNode *CSDN = dyn_cast<ConstantSDNode>(this)) {
+  } else if (const ConstantSDNode *CSDN = dyn_cast<ConstantSDNode>(this)) {
     OS << '<' << CSDN->getAPIntValue() << '>';
   } else if (const ConstantFPSDNode *CSDN = dyn_cast<ConstantFPSDNode>(this)) {
     if (&CSDN->getValueAPF().getSemantics()==&APFloat::IEEEsingle)
@@ -5579,68 +5712,40 @@ void SDNode::print_details(raw_ostream &OS, const SelectionDAG *G) const {
       OS << "<" << M->getValue() << ">";
     else
       OS << "<null>";
-  } else if (const MemOperandSDNode *M = dyn_cast<MemOperandSDNode>(this)) {
-    OS << ": " << M->MO;
   } else if (const VTSDNode *N = dyn_cast<VTSDNode>(this)) {
     OS << ":" << N->getVT().getEVTString();
   }
   else if (const LoadSDNode *LD = dyn_cast<LoadSDNode>(this)) {
-    const Value *SrcValue = LD->getSrcValue();
-    int SrcOffset = LD->getSrcValueOffset();
-    OS << " <";
-    if (SrcValue)
-      OS << SrcValue;
-    else
-      OS << "null";
-    OS << ":" << SrcOffset << ">";
+    OS << " <" << *LD->getMemOperand();
 
     bool doExt = true;
     switch (LD->getExtensionType()) {
     default: doExt = false; break;
-    case ISD::EXTLOAD: OS << " <anyext "; break;
-    case ISD::SEXTLOAD: OS << " <sext "; break;
-    case ISD::ZEXTLOAD: OS << " <zext "; break;
+    case ISD::EXTLOAD: OS << ", anyext"; break;
+    case ISD::SEXTLOAD: OS << ", sext"; break;
+    case ISD::ZEXTLOAD: OS << ", zext"; break;
     }
     if (doExt)
-      OS << LD->getMemoryVT().getEVTString() << ">";
+      OS << " from " << LD->getMemoryVT().getEVTString();
 
     const char *AM = getIndexedModeName(LD->getAddressingMode());
     if (*AM)
-      OS << " " << AM;
-    if (LD->isVolatile())
-      OS << " <volatile>";
-    OS << " alignment=" << LD->getAlignment();
+      OS << ", " << AM;
+
+    OS << ">";
   } else if (const StoreSDNode *ST = dyn_cast<StoreSDNode>(this)) {
-    const Value *SrcValue = ST->getSrcValue();
-    int SrcOffset = ST->getSrcValueOffset();
-    OS << " <";
-    if (SrcValue)
-      OS << SrcValue;
-    else
-      OS << "null";
-    OS << ":" << SrcOffset << ">";
+    OS << " <" << *ST->getMemOperand();
 
     if (ST->isTruncatingStore())
-      OS << " <trunc " << ST->getMemoryVT().getEVTString() << ">";
+      OS << ", trunc to " << ST->getMemoryVT().getEVTString();
 
     const char *AM = getIndexedModeName(ST->getAddressingMode());
     if (*AM)
-      OS << " " << AM;
-    if (ST->isVolatile())
-      OS << " <volatile>";
-    OS << " alignment=" << ST->getAlignment();
-  } else if (const AtomicSDNode* AT = dyn_cast<AtomicSDNode>(this)) {
-    const Value *SrcValue = AT->getSrcValue();
-    int SrcOffset = AT->getSrcValueOffset();
-    OS << " <";
-    if (SrcValue)
-      OS << SrcValue;
-    else
-      OS << "null";
-    OS << ":" << SrcOffset << ">";
-    if (AT->isVolatile())
-      OS << " <volatile>";
-    OS << " alignment=" << AT->getAlignment();
+      OS << ", " << AM;
+    
+    OS << ">";
+  } else if (const MemSDNode* M = dyn_cast<MemSDNode>(this)) {
+    OS << " <" << *M->getMemOperand() << ">";
   }
 }
 
diff --git a/lib/CodeGen/StackSlotColoring.cpp b/lib/CodeGen/StackSlotColoring.cpp
index 7d88dad..fad0808 100644
--- a/lib/CodeGen/StackSlotColoring.cpp
+++ b/lib/CodeGen/StackSlotColoring.cpp
@@ -18,6 +18,7 @@
 #include "llvm/CodeGen/LiveStackAnalysis.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineLoopInfo.h"
+#include "llvm/CodeGen/MachineMemOperand.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/CodeGen/PseudoSourceValue.h"
 #include "llvm/Support/CommandLine.h"
@@ -451,6 +452,7 @@ bool StackSlotColoring::AllMemRefsCanBeUnfolded(int SS) {
 /// to old frame index with new one.
 void StackSlotColoring::RewriteInstruction(MachineInstr *MI, int OldFI,
                                            int NewFI, MachineFunction &MF) {
+  // Update the operands.
   for (unsigned i = 0, ee = MI->getNumOperands(); i != ee; ++i) {
     MachineOperand &MO = MI->getOperand(i);
     if (!MO.isFI())
@@ -461,22 +463,15 @@ void StackSlotColoring::RewriteInstruction(MachineInstr *MI, int OldFI,
     MO.setIndex(NewFI);
   }
 
-  // Update the MachineMemOperand for the new memory location.
-  // FIXME: We need a better method of managing these too.
-  SmallVector<MachineMemOperand, 2> MMOs(MI->memoperands_begin(),
-                                         MI->memoperands_end());
-  MI->clearMemOperands(MF);
+  // Update the memory references. This changes the MachineMemOperands
+  // directly. They may be in use by multiple instructions, however all
+  // instructions using OldFI are being rewritten to use NewFI.
   const Value *OldSV = PseudoSourceValue::getFixedStack(OldFI);
-  for (unsigned i = 0, ee = MMOs.size(); i != ee; ++i) {
-    if (MMOs[i].getValue() != OldSV)
-      MI->addMemOperand(MF, MMOs[i]);
-    else {
-      MachineMemOperand MMO(PseudoSourceValue::getFixedStack(NewFI),
-                            MMOs[i].getFlags(), MMOs[i].getOffset(),
-                            MMOs[i].getSize(),  MMOs[i].getBaseAlignment());
-      MI->addMemOperand(MF, MMO);
-    }
-  }
+  const Value *NewSV = PseudoSourceValue::getFixedStack(NewFI);
+  for (MachineInstr::mmo_iterator I = MI->memoperands_begin(),
+       E = MI->memoperands_end(); I != E; ++I)
+    if ((*I)->getValue() == OldSV)
+      (*I)->setValue(NewSV);
 }
 
 /// PropagateBackward - Traverse backward and look for the definition of
diff --git a/lib/CodeGen/TargetInstrInfoImpl.cpp b/lib/CodeGen/TargetInstrInfoImpl.cpp
index f184cb7..ab67cd2 100644
--- a/lib/CodeGen/TargetInstrInfoImpl.cpp
+++ b/lib/CodeGen/TargetInstrInfoImpl.cpp
@@ -17,6 +17,7 @@
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineInstr.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineMemOperand.h"
 #include "llvm/CodeGen/PseudoSourceValue.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/raw_ostream.h"
@@ -203,11 +204,11 @@ TargetInstrInfo::foldMemoryOperand(MachineFunction &MF,
          "Folded a use to a non-load!");
   const MachineFrameInfo &MFI = *MF.getFrameInfo();
   assert(MFI.getObjectOffset(FrameIndex) != -1);
-  MachineMemOperand MMO(PseudoSourceValue::getFixedStack(FrameIndex),
-                        Flags,
-                        /*Offset=*/0,
-                        MFI.getObjectSize(FrameIndex),
-                        MFI.getObjectAlignment(FrameIndex));
+  MachineMemOperand *MMO =
+    MF.getMachineMemOperand(PseudoSourceValue::getFixedStack(FrameIndex),
+                            Flags, /*Offset=*/0,
+                            MFI.getObjectSize(FrameIndex),
+                            MFI.getObjectAlignment(FrameIndex));
   NewMI->addMemOperand(MF, MMO);
 
   return NewMI;
@@ -232,9 +233,8 @@ TargetInstrInfo::foldMemoryOperand(MachineFunction &MF,
   if (!NewMI) return 0;
 
   // Copy the memoperands from the load to the folded instruction.
-  for (std::list<MachineMemOperand>::iterator I = LoadMI->memoperands_begin(),
-       E = LoadMI->memoperands_end(); I != E; ++I)
-    NewMI->addMemOperand(MF, *I);
+  NewMI->setMemRefs(LoadMI->memoperands_begin(),
+                    LoadMI->memoperands_end());
 
   return NewMI;
 }