From f4fda804038e8f98b597e82a8df607321369db2b Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Thu, 3 Aug 2006 17:02:20 +0000
Subject: [PATCH] add and use ARMISD::RET_FLAG

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29499 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/ARM/ARMISelDAGToDAG.cpp | 15 +++++++--------
 lib/Target/ARM/ARMInstrInfo.td     |  4 +++-
 2 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/lib/Target/ARM/ARMISelDAGToDAG.cpp b/lib/Target/ARM/ARMISelDAGToDAG.cpp
index 1f75cff7ffb..b299f81c01b 100644
--- a/lib/Target/ARM/ARMISelDAGToDAG.cpp
+++ b/lib/Target/ARM/ARMISelDAGToDAG.cpp
@@ -52,7 +52,10 @@ namespace llvm {
       // Start the numbering where the builting ops and target ops leave off.
       FIRST_NUMBER = ISD::BUILTIN_OP_END+ARM::INSTRUCTION_LIST_END,
       /// CALL - A direct function call.
-      CALL
+      CALL,
+
+      /// Return with a flag operand.
+      RET_FLAG
     };
   }
 }
@@ -61,6 +64,7 @@ const char *ARMTargetLowering::getTargetNodeName(unsigned Opcode) const {
   switch (Opcode) {
   default: return 0;
   case ARMISD::CALL:          return "ARMISD::CALL";
+  case ARMISD::RET_FLAG:      return "ARMISD::RET_FLAG";
   }
 }
 
@@ -175,13 +179,8 @@ static SDOperand LowerRET(SDOperand Op, SelectionDAG &DAG) {
     break;
   }
 
-  SDOperand LR = DAG.getRegister(ARM::R14, MVT::i32);
-
-  //bug: the copy and branch should be linked with a flag so that the
-  //scheduller can't move an instruction that destroys R0 in between them
-  //return DAG.getNode(ISD::BRIND, MVT::Other, Copy, LR, Copy.getValue(1));
-
-  return DAG.getNode(ISD::BRIND, MVT::Other, Copy, LR);
+  //We must use RET_FLAG instead of BRIND because BRIND doesn't have a flag
+  return DAG.getNode(ARMISD::RET_FLAG, MVT::Other, Copy, Copy.getValue(1));
 }
 
 static SDOperand LowerFORMAL_ARGUMENT(SDOperand Op, SelectionDAG &DAG,
diff --git a/lib/Target/ARM/ARMInstrInfo.td b/lib/Target/ARM/ARMInstrInfo.td
index a749aa00721..5ba4deba2e0 100644
--- a/lib/Target/ARM/ARMInstrInfo.td
+++ b/lib/Target/ARM/ARMInstrInfo.td
@@ -44,6 +44,8 @@ def callseq_end    : SDNode<"ISD::CALLSEQ_END",   SDT_ARMCallSeq, [SDNPHasChain]
 def SDT_ARMcall    : SDTypeProfile<0, -1, [SDTCisInt<0>]>;
 def ARMcall        : SDNode<"ARMISD::CALL", SDT_ARMcall,
                            [SDNPHasChain, SDNPOptInFlag, SDNPOutFlag]>;
+def retflag        : SDNode<"ARMISD::RET_FLAG", SDTRet,
+	                   [SDNPHasChain, SDNPOptInFlag]>;
 
 def ADJCALLSTACKUP : InstARM<(ops i32imm:$amt),
                             "!ADJCALLSTACKUP $amt",
@@ -54,7 +56,7 @@ def ADJCALLSTACKDOWN : InstARM<(ops i32imm:$amt),
                                [(callseq_start imm:$amt)]>;
 
 let isReturn = 1 in {
-  def bx: InstARM<(ops IntRegs:$dst), "bx $dst", [(brind IntRegs:$dst)]>;
+  def bx: InstARM<(ops), "bx r14", [(retflag)]>;
 }
 
 let  Defs = [R0, R1, R2, R3] in {
-- 
2.34.1