Remove TLI.LowerReturnTo, and just let targets custom lower ISD::RET for
the same functionality.  This addresses another piece of bug 680.  Next,
on to fixing Alpha VAARG, which I broke last time.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25696 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCISelLowering.cpp b/lib/Target/PowerPC/PPCISelLowering.cpp
index b994959..f1c1735 100644
--- a/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -110,6 +110,9 @@
   setOperationAction(ISD::GlobalAddress, MVT::i32, Custom);
   setOperationAction(ISD::ConstantPool,  MVT::i32, Custom);
 
+  // RET must be custom lowered, to meet ABI requirements
+  setOperationAction(ISD::RET               , MVT::Other, Custom);
+  
   // VASTART needs to be custom lowered to use the VarArgsFrameIndex
   setOperationAction(ISD::VASTART           , MVT::Other, Custom);
   
@@ -440,6 +443,30 @@
     return DAG.getNode(ISD::STORE, MVT::Other, Op.getOperand(0), FR, 
                        Op.getOperand(1), Op.getOperand(2));
   }
+  case ISD::RET: {
+    SDOperand Copy;
+    
+    switch(Op.getNumOperands()) {
+    default:
+      assert(0 && "Do not know how to return this many arguments!");
+      abort();
+    case 1: 
+      return SDOperand(); // ret void is legal
+    case 2: {
+      MVT::ValueType ArgVT = Op.getOperand(1).getValueType();
+      unsigned ArgReg = MVT::isInteger(ArgVT) ? PPC::R3 : PPC::F1;
+      Copy = DAG.getCopyToReg(Op.getOperand(0), ArgReg, Op.getOperand(1),
+                              SDOperand());
+      break;
+    }
+    case 3:
+      Copy = DAG.getCopyToReg(Op.getOperand(0), PPC::R3, Op.getOperand(2), 
+                              SDOperand());
+      Copy = DAG.getCopyToReg(Copy, PPC::R4, Op.getOperand(1),Copy.getValue(1));
+      break;
+    }
+    return DAG.getNode(PPCISD::RET_FLAG, MVT::Other, Copy, Copy.getValue(1));
+  }
   }
   return SDOperand();
 }
@@ -835,30 +862,6 @@
   return std::make_pair(RetVal, Chain);
 }
 
-SDOperand PPCTargetLowering::LowerReturnTo(SDOperand Chain, SDOperand Op,
-                                           SelectionDAG &DAG) {
-  SDOperand Copy;
-  switch (Op.getValueType()) {
-    default: assert(0 && "Unknown type to return!");
-    case MVT::i32:
-      Copy = DAG.getCopyToReg(Chain, PPC::R3, Op, SDOperand());
-      break;
-    case MVT::f32:
-    case MVT::f64:
-      Copy = DAG.getCopyToReg(Chain, PPC::F1, Op, SDOperand());
-      break;
-    case MVT::i64:
-      SDOperand Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, Op, 
-                                 DAG.getConstant(1, MVT::i32));
-      SDOperand Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, Op,
-                                 DAG.getConstant(0, MVT::i32));
-      Copy = DAG.getCopyToReg(Chain, PPC::R3, Hi, SDOperand());
-      Copy = DAG.getCopyToReg(Copy, PPC::R4, Lo, Copy.getValue(1));
-      break;
-  }
-  return DAG.getNode(PPCISD::RET_FLAG, MVT::Other, Copy, Copy.getValue(1));
-}
-
 std::pair<SDOperand, SDOperand> PPCTargetLowering::
 LowerFrameReturnAddress(bool isFrameAddress, SDOperand Chain, unsigned Depth,
                         SelectionDAG &DAG) {