allow custom lowering to return null for legal results

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25007 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 15 insertions, 17 deletions

diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index 1d68419121..1d9dd5c2c8 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -1956,11 +1956,6 @@ SDOperand SelectionDAGLegalize::LegalizeOp(SDOperand Op) {
       break;
     }
     switch (TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0))) {
-    case TargetLowering::Legal:
-      if (Tmp1 != Node->getOperand(0) ||
-	  Tmp2 != Node->getOperand(1))
-	Result = DAG.getNode(Node->getOpcode(), Node->getValueType(0), Tmp1,Tmp2);
-      break;
     case TargetLowering::Custom: {
       Result = DAG.getNode(Node->getOpcode(), Node->getValueType(0), Tmp1, Tmp2);
       SDOperand Tmp = TLI.LowerOperation(Result, DAG);
@@ -1968,9 +1963,13 @@ SDOperand SelectionDAGLegalize::LegalizeOp(SDOperand Op) {
 	Tmp = LegalizeOp(Tmp);  // Relegalize input.
 	AddLegalizedOperand(Op, Tmp);
 	return Tmp;
-      }
-      break;
+      } //else it was considered legal and we fall through
     }
+    case TargetLowering::Legal:
+      if (Tmp1 != Node->getOperand(0) ||
+	  Tmp2 != Node->getOperand(1))
+	Result = DAG.getNode(Node->getOpcode(), Node->getValueType(0), Tmp1,Tmp2);
+      break;
     default:
       assert(0 && "Operation not supported");
     }
@@ -2007,14 +2006,6 @@ SDOperand SelectionDAGLegalize::LegalizeOp(SDOperand Op) {
     Tmp1 = LegalizeOp(Node->getOperand(0));   // LHS
     Tmp2 = LegalizeOp(Node->getOperand(1));   // RHS
     switch (TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0))) {
-    case TargetLowering::Legal:
-      if (Tmp1 != Node->getOperand(0) ||
-          Tmp2 != Node->getOperand(1))
-        Result = DAG.getNode(Node->getOpcode(), Node->getValueType(0), Tmp1,
-                             Tmp2);
-      break;
-    case TargetLowering::Promote:
-      assert(0 && "Cannot promote handle this yet!");
     case TargetLowering::Custom: {
       Result = DAG.getNode(Node->getOpcode(), Node->getValueType(0), Tmp1, Tmp2);
       SDOperand Tmp = TLI.LowerOperation(Result, DAG);
@@ -2022,9 +2013,16 @@ SDOperand SelectionDAGLegalize::LegalizeOp(SDOperand Op) {
 	Tmp = LegalizeOp(Tmp);  // Relegalize input.
 	AddLegalizedOperand(Op, Tmp);
 	return Tmp;
-      }
-      break;
+      } //else it was considered legal and we fall through
     }
+    case TargetLowering::Legal:
+      if (Tmp1 != Node->getOperand(0) ||
+          Tmp2 != Node->getOperand(1))
+        Result = DAG.getNode(Node->getOpcode(), Node->getValueType(0), Tmp1,
+                             Tmp2);
+      break;
+    case TargetLowering::Promote:
+      assert(0 && "Cannot promote handle this yet!");
     case TargetLowering::Expand:
       if (MVT::isInteger(Node->getValueType(0))) {
         MVT::ValueType VT = Node->getValueType(0);