1 files changed, 61 insertions, 0 deletions
diff --git a/lib/Target/X86/InstSelectSimple.cpp b/lib/Target/X86/InstSelectSimple.cpp
index 4a04b2910f..4988a0dc4c 100644
--- a/lib/Target/X86/InstSelectSimple.cpp
+++ b/lib/Target/X86/InstSelectSimple.cpp
@@ -1502,6 +1502,8 @@ void ISel::LowerUnknownIntrinsicFunctionCalls(Function &F) {
           case Intrinsic::frameaddress:
           case Intrinsic::memcpy:
           case Intrinsic::memset:
+          case Intrinsic::readport:
+          case Intrinsic::writeport:
             // We directly implement these intrinsics
             break;
           default:
@@ -1663,6 +1665,65 @@ void ISel::visitIntrinsicCall(Intrinsic::ID ID, CallInst &CI) {
     return;
   }
 
+  case Intrinsic::readport:
+    //
+    // First, determine that the size of the operand falls within the
+    // acceptable range for this architecture.
+    //
+    assert (((CI.getOperand(1)->getType()->getPrimitiveSize()) == 2) &&
+            "llvm.readport operand size is not a 16 bit value!");
+
+    //
+    // Now, move the I/O port address into the DX register and use the IN
+    // instruction to get the input data.
+    //
+    BuildMI(BB, X86::MOV16rr, 1, X86::DX).addReg(getReg(CI.getOperand(1)));
+    switch (CI.getCalledFunction()->getReturnType()->getPrimitiveSize()) {
+      case 1:
+        BuildMI(BB, X86::IN8, 1);
+        break;
+      case 2:
+        BuildMI(BB, X86::IN16, 1);
+        break;
+      case 4:
+        BuildMI(BB, X86::IN32, 1);
+        break;
+      default:
+        assert (0 && "Cannot do input on this data type");
+    }
+    return;
+
+  case Intrinsic::writeport:
+    //
+    // First, determine that the size of the operand falls within the
+    // acceptable range for this architecture.
+    //
+    assert (((CI.getOperand(1)->getType()->getPrimitiveSize()) == 2) &&
+            "llvm.readport operand size is not a 16 bit value!");
+
+    //
+    // Now, move the I/O port address into the DX register and the value to
+    // write into the AL/AX/EAX register.
+    //
+    BuildMI(BB, X86::MOV16rr, 1, X86::DX).addReg(getReg(CI.getOperand(1)));
+    switch (CI.getOperand(2)->getType()->getPrimitiveSize()) {
+      case 1:
+        BuildMI(BB, X86::MOV8rr, 1, X86::AL).addReg(getReg(CI.getOperand(2)));
+        BuildMI(BB, X86::OUT8, 1);
+        break;
+      case 2:
+        BuildMI(BB, X86::MOV16rr, 1, X86::AX).addReg(getReg(CI.getOperand(2)));
+        BuildMI(BB, X86::OUT16, 1);
+        break;
+      case 4:
+        BuildMI(BB, X86::MOV32rr, 1, X86::EAX).addReg(getReg(CI.getOperand(2)));
+        BuildMI(BB, X86::OUT32, 1);
+        break;
+      default:
+        assert (0 && "Cannot do input on this data type");
+    }
+    return;
+
   default: assert(0 && "Error: unknown intrinsics should have been lowered!");
   }
 }