1 files changed, 55 insertions, 0 deletions
diff --git a/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp b/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
index 8d18a1f8138..272be22996f 100644
--- a/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
+++ b/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
@@ -3420,6 +3420,61 @@ void X86DAGToDAGISel::Select(SDNode *Node) {
 
   switch (Opcode) {
   default: break;
+  case ISD::INTRINSIC_VOID: {
+    unsigned IntNo = Node->getConstantOperandVal(1);
+    switch (IntNo) {
+    default: break;
+    case Intrinsic::x86_sse3_monitor:
+    case Intrinsic::x86_monitorx:
+    case Intrinsic::x86_clzero: {
+      bool Use64BitPtr = Node->getOperand(2).getValueType() == MVT::i64;
+
+      unsigned Opc = 0;
+      switch (IntNo) {
+      case Intrinsic::x86_sse3_monitor:
+        if (!Subtarget->hasSSE3())
+          break;
+        Opc = Use64BitPtr ? X86::MONITOR64rrr : X86::MONITOR32rrr;
+        break;
+      case Intrinsic::x86_monitorx:
+        if (!Subtarget->hasMWAITX())
+          break;
+        Opc = Use64BitPtr ? X86::MONITORX64rrr : X86::MONITORX32rrr;
+        break;
+      case Intrinsic::x86_clzero:
+        if (!Subtarget->hasCLZERO())
+          break;
+        Opc = Use64BitPtr ? X86::CLZERO64r : X86::CLZERO32r;
+        break;
+      }
+
+      if (Opc) {
+        unsigned PtrReg = Use64BitPtr ? X86::RAX : X86::EAX;
+        SDValue Chain = CurDAG->getCopyToReg(Node->getOperand(0), dl, PtrReg,
+                                             Node->getOperand(2), SDValue());
+        SDValue InFlag = Chain.getValue(1);
+
+        if (IntNo == Intrinsic::x86_sse3_monitor ||
+            IntNo == Intrinsic::x86_monitorx) {
+          // Copy the other two operands to ECX and EDX.
+          Chain = CurDAG->getCopyToReg(Chain, dl, X86::ECX, Node->getOperand(3),
+                                       InFlag);
+          InFlag = Chain.getValue(1);
+          Chain = CurDAG->getCopyToReg(Chain, dl, X86::EDX, Node->getOperand(4),
+                                       InFlag);
+          InFlag = Chain.getValue(1);
+        }
+
+        MachineSDNode *CNode = CurDAG->getMachineNode(Opc, dl, MVT::Other,
+                                                      { Chain, InFlag});
+        ReplaceNode(Node, CNode);
+        return;
+      }
+    }
+    }
+
+    break;
+  }
   case ISD::BRIND: {
     if (Subtarget->isTargetNaCl())
       // NaCl has its own pass where jmp %r32 are converted to jmp %r64. We