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.)



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136457 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 41 insertions, 2 deletions

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 498e1d3740..7d45d29996 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -3257,9 +3257,46 @@ void SelectionDAGBuilder::visitStore(const StoreInst &I) {
 }
 
 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 @@ SelectionDAGBuilder::implVisitBinaryAtomic(const CallInst& I,
                   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 @@ SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I, unsigned Intrinsic) {
                     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;