- Make lowering of "add with overflow" customizable by back-ends.

- Mark "add with overflow" as having a custom lowering for X86. Give it a null
  lowering representation for now.

llvm-svn: 59971

2 files changed, 29 insertions, 18 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index 0e926adc312..972e4ae8c28 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -4172,22 +4172,34 @@ SDValue SelectionDAGLegalize::LegalizeOp(SDValue Op) {
 
   case ISD::SADDO:
   case ISD::UADDO: {
-    SDValue LHS = LegalizeOp(Node->getOperand(0));
-    SDValue RHS = LegalizeOp(Node->getOperand(1));
-
-    SDValue Sum = DAG.getNode(ISD::ADD, LHS.getValueType(), LHS, RHS);
-    MVT OType = SDValue(Node, 1).getValueType();
-    SDValue Cmp = DAG.getSetCC(OType, Sum, LHS,
-                               (Node->getOpcode() == ISD::SADDO) ?
-                               ISD::SETLT : ISD::SETULT);
-
-    MVT ValueVTs[] = { LHS.getValueType(), OType };
-    SDValue Ops[] = { Sum, Cmp };
-
-    Result = DAG.getMergeValues(DAG.getVTList(&ValueVTs[0], 2), &Ops[0], 2);
-    SDNode *RNode = Result.getNode();
-    DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), SDValue(RNode, 0));
-    DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), SDValue(RNode, 1));
+    MVT VT = Node->getValueType(0);
+    switch (TLI.getOperationAction(Node->getOpcode(), VT)) {
+    default: assert(0 && "This action not supported for this op yet!");
+    case TargetLowering::Custom:
+      Result = TLI.LowerOperation(Op, DAG);
+      if (Result.getNode()) break;
+      // FALLTHROUGH
+    case TargetLowering::Legal: {
+      SDValue LHS = LegalizeOp(Node->getOperand(0));
+      SDValue RHS = LegalizeOp(Node->getOperand(1));
+
+      SDValue Sum = DAG.getNode(ISD::ADD, LHS.getValueType(), LHS, RHS);
+      MVT OType = Node->getValueType(1);
+      SDValue Cmp = DAG.getSetCC(OType, Sum, LHS,
+                                 (Node->getOpcode() == ISD::SADDO) ?
+                                 ISD::SETLT : ISD::SETULT);
+
+      MVT ValueVTs[] = { LHS.getValueType(), OType };
+      SDValue Ops[] = { Sum, Cmp };
+
+      Result = DAG.getMergeValues(DAG.getVTList(&ValueVTs[0], 2), &Ops[0], 2);
+      SDNode *RNode = Result.getNode();
+      DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), SDValue(RNode, 0));
+      DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), SDValue(RNode, 1));
+      break;
+    }
+    }
+
     break;
   }
   }
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
index f3948f9ee8a..41d4425cc5b 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
@@ -4096,9 +4096,8 @@ SelectionDAGLowering::visitIntrinsicCall(CallInst &I, unsigned Intrinsic) {
   case Intrinsic::sadd_with_overflow: {
     SDValue Op1 = getValue(I.getOperand(1));
     SDValue Op2 = getValue(I.getOperand(2));
-    MVT Ty = Op1.getValueType();
 
-    MVT ValueVTs[] = { Ty, MVT::i1 };
+    MVT ValueVTs[] = { Op1.getValueType(), MVT::i1 };
     SDValue Ops[] = { Op1, Op2 };
 
     SDValue Result =