- 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59971 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 44 insertions, 18 deletions

diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index 0e926adc31..972e4ae8c2 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/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/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
index f3948f9ee8..41d4425cc5 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
+++ b/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 =
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 9c5458d54a..efe7bac72e 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -780,6 +780,12 @@ X86TargetLowering::X86TargetLowering(X86TargetMachine &TM)
   // We want to custom lower some of our intrinsics.
   setOperationAction(ISD::INTRINSIC_WO_CHAIN, MVT::Other, Custom);
 
+  // Add with overflow operations are custom lowered.
+  setOperationAction(ISD::SADDO, MVT::i32, Custom);
+  setOperationAction(ISD::SADDO, MVT::i64, Custom);
+  setOperationAction(ISD::UADDO, MVT::i32, Custom);
+  setOperationAction(ISD::UADDO, MVT::i64, Custom);
+
   // We have target-specific dag combine patterns for the following nodes:
   setTargetDAGCombine(ISD::VECTOR_SHUFFLE);
   setTargetDAGCombine(ISD::BUILD_VECTOR);
@@ -6142,6 +6148,11 @@ SDValue X86TargetLowering::LowerCTTZ(SDValue Op, SelectionDAG &DAG) {
   return Op;
 }
 
+SDValue X86TargetLowering::LowerXADDO(SDValue Op, SelectionDAG &DAG,
+                                      ISD::NodeType NTy) {
+  return SDValue();
+}
+
 SDValue X86TargetLowering::LowerCMP_SWAP(SDValue Op, SelectionDAG &DAG) {
   MVT T = Op.getValueType();
   unsigned Reg = 0;
@@ -6321,6 +6332,8 @@ SDValue X86TargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) {
   case ISD::FLT_ROUNDS_:        return LowerFLT_ROUNDS_(Op, DAG);
   case ISD::CTLZ:               return LowerCTLZ(Op, DAG);
   case ISD::CTTZ:               return LowerCTTZ(Op, DAG);
+  case ISD::SADDO:              return LowerXADDO(Op, DAG, ISD::SADDO);
+  case ISD::UADDO:              return LowerXADDO(Op, DAG, ISD::UADDO);
       
   // FIXME: REMOVE THIS WHEN LegalizeDAGTypes lands.
   case ISD::READCYCLECOUNTER:
diff --git a/lib/Target/X86/X86ISelLowering.h b/lib/Target/X86/X86ISelLowering.h
index 2358889fda..e9d8e55e10 100644
--- a/lib/Target/X86/X86ISelLowering.h
+++ b/lib/Target/X86/X86ISelLowering.h
@@ -592,6 +592,8 @@ namespace llvm {
     SDValue LowerFLT_ROUNDS_(SDValue Op, SelectionDAG &DAG);
     SDValue LowerCTLZ(SDValue Op, SelectionDAG &DAG);
     SDValue LowerCTTZ(SDValue Op, SelectionDAG &DAG);
+    SDValue LowerXADDO(SDValue Op, SelectionDAG &DAG, ISD::NodeType NTy);
+
     SDValue LowerCMP_SWAP(SDValue Op, SelectionDAG &DAG);
     SDValue LowerLOAD_SUB(SDValue Op, SelectionDAG &DAG);
     SDValue LowerATOMIC_BINARY_64(SDValue Op, SelectionDAG &DAG,