From d07359667118ab1e889c3b9163b5e6a12414c38b Mon Sep 17 00:00:00 2001
From: Jakob Stoklund Olesen <stoklund@2pi.dk>
Date: Tue, 5 Feb 2013 18:12:03 +0000
Subject: [PATCH] Move MRI liveouts to Mips return instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174410 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/Mips/MipsISelLowering.cpp | 25 ++++++++++---------------
 lib/Target/Mips/MipsInstrInfo.td     |  3 ++-
 2 files changed, 12 insertions(+), 16 deletions(-)

diff --git a/lib/Target/Mips/MipsISelLowering.cpp b/lib/Target/Mips/MipsISelLowering.cpp
index cf8ed35b03f..ff0064e68c8 100644
--- a/lib/Target/Mips/MipsISelLowering.cpp
+++ b/lib/Target/Mips/MipsISelLowering.cpp
@@ -3454,15 +3454,8 @@ MipsTargetLowering::LowerReturn(SDValue Chain,
   // Analize return values.
   CCInfo.AnalyzeReturn(Outs, RetCC_Mips);
 
-  // If this is the first return lowered for this function, add
-  // the regs to the liveout set for the function.
-  if (DAG.getMachineFunction().getRegInfo().liveout_empty()) {
-    for (unsigned i = 0; i != RVLocs.size(); ++i)
-      if (RVLocs[i].isRegLoc())
-        DAG.getMachineFunction().getRegInfo().addLiveOut(RVLocs[i].getLocReg());
-  }
-
   SDValue Flag;
+  SmallVector<SDValue, 4> RetOps(1, Chain);
 
   // Copy the result values into the output registers.
   for (unsigned i = 0; i != RVLocs.size(); ++i) {
@@ -3471,9 +3464,9 @@ MipsTargetLowering::LowerReturn(SDValue Chain,
 
     Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(), OutVals[i], Flag);
 
-    // guarantee that all emitted copies are
-    // stuck together, avoiding something bad
+    // Guarantee that all emitted copies are stuck together with flags.
     Flag = Chain.getValue(1);
+    RetOps.push_back(DAG.getRegister(VA.getLocReg(), VA.getLocVT()));
   }
 
   // The mips ABIs for returning structs by value requires that we copy
@@ -3492,15 +3485,17 @@ MipsTargetLowering::LowerReturn(SDValue Chain,
 
     Chain = DAG.getCopyToReg(Chain, dl, V0, Val, Flag);
     Flag = Chain.getValue(1);
-    MF.getRegInfo().addLiveOut(V0);
+    RetOps.push_back(DAG.getRegister(V0, getPointerTy()));
   }
 
-  // Return on Mips is always a "jr $ra"
+  RetOps[0] = Chain;  // Update chain.
+
+  // Add the flag if we have it.
   if (Flag.getNode())
-    return DAG.getNode(MipsISD::Ret, dl, MVT::Other, Chain, Flag);
+    RetOps.push_back(Flag);
 
-  // Return Void
-  return DAG.getNode(MipsISD::Ret, dl, MVT::Other, Chain);
+  // Return on Mips is always a "jr $ra"
+  return DAG.getNode(MipsISD::Ret, dl, MVT::Other, &RetOps[0], RetOps.size());
 }
 
 //===----------------------------------------------------------------------===//
diff --git a/lib/Target/Mips/MipsInstrInfo.td b/lib/Target/Mips/MipsInstrInfo.td
index b563b8fca13..f9e3af517b7 100644
--- a/lib/Target/Mips/MipsInstrInfo.td
+++ b/lib/Target/Mips/MipsInstrInfo.td
@@ -72,7 +72,8 @@ def MipsTprelLo    : SDNode<"MipsISD::TprelLo", SDTIntUnaryOp>;
 def MipsThreadPointer: SDNode<"MipsISD::ThreadPointer", SDT_MipsThreadPointer>;
 
 // Return
-def MipsRet : SDNode<"MipsISD::Ret", SDTNone, [SDNPHasChain, SDNPOptInGlue]>;
+def MipsRet : SDNode<"MipsISD::Ret", SDTNone,
+                     [SDNPHasChain, SDNPOptInGlue, SDNPVariadic]>;
 
 // These are target-independent nodes, but have target-specific formats.
 def callseq_start : SDNode<"ISD::CALLSEQ_START", SDT_MipsCallSeqStart,
-- 
2.34.1