Add the ability to lower return instructions to TargetLowering. This

allows us to lower legal return types to something else, to meet ABI
requirements (such as that i64 be returned in two i32 regs on Darwin/ppc).

llvm-svn: 23802

1 files changed, 13 insertions, 0 deletions

diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
index 8cc538df83a..5256e4839d1 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -693,6 +693,19 @@ PPCTargetLowering::LowerCallTo(SDOperand Chain,
   return std::make_pair(RetVal, Chain);
 }
 
+SDOperand PPCTargetLowering::LowerReturnTo(SDOperand Chain, SDOperand Op,
+                                           SelectionDAG &DAG) {
+  if (Op.getValueType() == 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));
+    return DAG.getNode(ISD::RET, MVT::Other, Chain, Lo, Hi);
+  } else {
+    return DAG.getNode(ISD::RET, MVT::Other, Chain, Op);
+  }
+}
+
 SDOperand PPCTargetLowering::LowerVAStart(SDOperand Chain, SDOperand VAListP,
                                           Value *VAListV, SelectionDAG &DAG) {
   // vastart just stores the address of the VarArgsFrameIndex slot into the