Misc optimizer+codegen work for 'cmpxchg' and 'atomicrmw'.  They appear to be
working on x86 (at least for trivial testcases); other architectures will
need more work so that they actually emit the appropriate instructions for
orderings stricter than 'monotonic'. (As far as I can tell, the ARM, PPC,
Mips, and Alpha backends need such changes.)

llvm-svn: 136457
diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
index 8c2a3cd..6e9992e 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
@@ -155,7 +155,8 @@
   SDValue Res = DAG.getAtomic(N->getOpcode(), N->getDebugLoc(),
                               N->getMemoryVT(),
                               N->getChain(), N->getBasePtr(),
-                              Op2, N->getMemOperand());
+                              Op2, N->getMemOperand(), N->getOrdering(),
+                              N->getSynchScope());
   // Legalized the chain result - switch anything that used the old chain to
   // use the new one.
   ReplaceValueWith(SDValue(N, 1), Res.getValue(1));
@@ -167,7 +168,8 @@
   SDValue Op3 = GetPromotedInteger(N->getOperand(3));
   SDValue Res = DAG.getAtomic(N->getOpcode(), N->getDebugLoc(),
                               N->getMemoryVT(), N->getChain(), N->getBasePtr(),
-                              Op2, Op3, N->getMemOperand());
+                              Op2, Op3, N->getMemOperand(), N->getOrdering(),
+                              N->getSynchScope());
   // Legalized the chain result - switch anything that used the old chain to
   // use the new one.
   ReplaceValueWith(SDValue(N, 1), Res.getValue(1));
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 9785b4c..888d8b4 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -3815,7 +3815,9 @@
 SDValue SelectionDAG::getAtomic(unsigned Opcode, DebugLoc dl, EVT MemVT,
                                 SDValue Chain, SDValue Ptr, SDValue Cmp,
                                 SDValue Swp, MachinePointerInfo PtrInfo,
-                                unsigned Alignment) {
+                                unsigned Alignment,
+                                AtomicOrdering Ordering,
+                                SynchronizationScope SynchScope) {                                
   if (Alignment == 0)  // Ensure that codegen never sees alignment 0
     Alignment = getEVTAlignment(MemVT);
 
@@ -3828,13 +3830,16 @@
   MachineMemOperand *MMO =
     MF.getMachineMemOperand(PtrInfo, Flags, MemVT.getStoreSize(), Alignment);
 
-  return getAtomic(Opcode, dl, MemVT, Chain, Ptr, Cmp, Swp, MMO);
+  return getAtomic(Opcode, dl, MemVT, Chain, Ptr, Cmp, Swp, MMO,
+                   Ordering, SynchScope);
 }
 
 SDValue SelectionDAG::getAtomic(unsigned Opcode, DebugLoc dl, EVT MemVT,
                                 SDValue Chain,
                                 SDValue Ptr, SDValue Cmp,
-                                SDValue Swp, MachineMemOperand *MMO) {
+                                SDValue Swp, MachineMemOperand *MMO,
+                                AtomicOrdering Ordering,
+                                SynchronizationScope SynchScope) {
   assert(Opcode == ISD::ATOMIC_CMP_SWAP && "Invalid Atomic Op");
   assert(Cmp.getValueType() == Swp.getValueType() && "Invalid Atomic Op Types");
 
@@ -3851,7 +3856,8 @@
     return SDValue(E, 0);
   }
   SDNode *N = new (NodeAllocator) AtomicSDNode(Opcode, dl, VTs, MemVT, Chain,
-                                               Ptr, Cmp, Swp, MMO);
+                                               Ptr, Cmp, Swp, MMO, Ordering,
+                                               SynchScope);
   CSEMap.InsertNode(N, IP);
   AllNodes.push_back(N);
   return SDValue(N, 0);
@@ -3861,7 +3867,9 @@
                                 SDValue Chain,
                                 SDValue Ptr, SDValue Val,
                                 const Value* PtrVal,
-                                unsigned Alignment) {
+                                unsigned Alignment,
+                                AtomicOrdering Ordering,
+                                SynchronizationScope SynchScope) {
   if (Alignment == 0)  // Ensure that codegen never sees alignment 0
     Alignment = getEVTAlignment(MemVT);
 
@@ -3875,13 +3883,16 @@
     MF.getMachineMemOperand(MachinePointerInfo(PtrVal), Flags,
                             MemVT.getStoreSize(), Alignment);
 
-  return getAtomic(Opcode, dl, MemVT, Chain, Ptr, Val, MMO);
+  return getAtomic(Opcode, dl, MemVT, Chain, Ptr, Val, MMO,
+                   Ordering, SynchScope);
 }
 
 SDValue SelectionDAG::getAtomic(unsigned Opcode, DebugLoc dl, EVT MemVT,
                                 SDValue Chain,
                                 SDValue Ptr, SDValue Val,
-                                MachineMemOperand *MMO) {
+                                MachineMemOperand *MMO,
+                                AtomicOrdering Ordering,
+                                SynchronizationScope SynchScope) {
   assert((Opcode == ISD::ATOMIC_LOAD_ADD ||
           Opcode == ISD::ATOMIC_LOAD_SUB ||
           Opcode == ISD::ATOMIC_LOAD_AND ||
@@ -3908,7 +3919,8 @@
     return SDValue(E, 0);
   }
   SDNode *N = new (NodeAllocator) AtomicSDNode(Opcode, dl, VTs, MemVT, Chain,
-                                               Ptr, Val, MMO);
+                                               Ptr, Val, MMO,
+                                               Ordering, SynchScope);
   CSEMap.InsertNode(N, IP);
   AllNodes.push_back(N);
   return SDValue(N, 0);
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 498e1d3..7d45d29 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -3257,9 +3257,46 @@
 }
 
 void SelectionDAGBuilder::visitAtomicCmpXchg(const AtomicCmpXchgInst &I) {
+  SDValue Root = getRoot();
+  SDValue L =
+    DAG.getAtomic(ISD::ATOMIC_CMP_SWAP, getCurDebugLoc(),
+                  getValue(I.getCompareOperand()).getValueType().getSimpleVT(),
+                  Root,
+                  getValue(I.getPointerOperand()),
+                  getValue(I.getCompareOperand()),
+                  getValue(I.getNewValOperand()),
+                  MachinePointerInfo(I.getPointerOperand()), 0 /* Alignment */,
+                  I.getOrdering(), I.getSynchScope());
+  setValue(&I, L);
+  DAG.setRoot(L.getValue(1));
 }
 
 void SelectionDAGBuilder::visitAtomicRMW(const AtomicRMWInst &I) {
+  ISD::NodeType NT;
+  switch (I.getOperation()) {
+  default: llvm_unreachable("Unknown atomicrmw operation"); return;
+  case AtomicRMWInst::Xchg: NT = ISD::ATOMIC_SWAP; break;
+  case AtomicRMWInst::Add:  NT = ISD::ATOMIC_LOAD_ADD; break;
+  case AtomicRMWInst::Sub:  NT = ISD::ATOMIC_LOAD_SUB; break;
+  case AtomicRMWInst::And:  NT = ISD::ATOMIC_LOAD_AND; break;
+  case AtomicRMWInst::Nand: NT = ISD::ATOMIC_LOAD_NAND; break;
+  case AtomicRMWInst::Or:   NT = ISD::ATOMIC_LOAD_OR; break;
+  case AtomicRMWInst::Xor:  NT = ISD::ATOMIC_LOAD_XOR; break;
+  case AtomicRMWInst::Max:  NT = ISD::ATOMIC_LOAD_MAX; break;
+  case AtomicRMWInst::Min:  NT = ISD::ATOMIC_LOAD_MIN; break;
+  case AtomicRMWInst::UMax: NT = ISD::ATOMIC_LOAD_UMAX; break;
+  case AtomicRMWInst::UMin: NT = ISD::ATOMIC_LOAD_UMIN; break;
+  }
+  SDValue L =
+    DAG.getAtomic(NT, getCurDebugLoc(),
+                  getValue(I.getValOperand()).getValueType().getSimpleVT(),
+                  getRoot(),
+                  getValue(I.getPointerOperand()),
+                  getValue(I.getValOperand()),
+                  I.getPointerOperand(), 0 /* Alignment */,
+                  I.getOrdering(), I.getSynchScope());
+  setValue(&I, L);
+  DAG.setRoot(L.getValue(1));
 }
 
 void SelectionDAGBuilder::visitFence(const FenceInst &I) {
@@ -3410,7 +3447,8 @@
                   Root,
                   getValue(I.getArgOperand(0)),
                   getValue(I.getArgOperand(1)),
-                  I.getArgOperand(0));
+                  I.getArgOperand(0), 0 /* Alignment */,
+                  Monotonic, CrossThread);
   setValue(&I, L);
   DAG.setRoot(L.getValue(1));
   return 0;
@@ -4935,7 +4973,8 @@
                     getValue(I.getArgOperand(0)),
                     getValue(I.getArgOperand(1)),
                     getValue(I.getArgOperand(2)),
-                    MachinePointerInfo(I.getArgOperand(0)));
+                    MachinePointerInfo(I.getArgOperand(0)), 0 /* Alignment */,
+                    Monotonic, CrossThread);
     setValue(&I, L);
     DAG.setRoot(L.getValue(1));
     return 0;