ARM: fix assertion failure on -O0 cmpxchg.

Because lowering of CMP_SWAP_64 occurs during type legalization, there can be
i64 types produced by more than just a BUILD_PAIR or similar. My initial tests
used just incoming function args.

llvm-svn: 266828

1 files changed, 9 insertions, 7 deletions

diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp
index f240dca1b07..febe58b8fa7 100644
--- a/llvm/lib/Target/ARM/ARMISelLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp
@@ -6971,13 +6971,17 @@ static void ReplaceREADCYCLECOUNTER(SDNode *N,
   Results.push_back(Cycles32.getValue(1));
 }
 
-static SDValue createGPRPairNode(SelectionDAG &DAG, SDValue V0, SDValue V1) {
-  SDLoc dl(V0.getNode());
+static SDValue createGPRPairNode(SelectionDAG &DAG, SDValue V) {
+  SDLoc dl(V.getNode());
+  SDValue VLo = DAG.getAnyExtOrTrunc(V, dl, MVT::i32);
+  SDValue VHi = DAG.getAnyExtOrTrunc(
+      DAG.getNode(ISD::SRL, dl, MVT::i64, V, DAG.getConstant(32, dl, MVT::i32)),
+      dl, MVT::i32);
   SDValue RegClass =
       DAG.getTargetConstant(ARM::GPRPairRegClassID, dl, MVT::i32);
   SDValue SubReg0 = DAG.getTargetConstant(ARM::gsub_0, dl, MVT::i32);
   SDValue SubReg1 = DAG.getTargetConstant(ARM::gsub_1, dl, MVT::i32);
-  const SDValue Ops[] = { RegClass, V0, SubReg0, V1, SubReg1 };
+  const SDValue Ops[] = { RegClass, VLo, SubReg0, VHi, SubReg1 };
   return SDValue(
       DAG.getMachineNode(TargetOpcode::REG_SEQUENCE, dl, MVT::Untyped, Ops), 0);
 }
@@ -6988,10 +6992,8 @@ static void ReplaceCMP_SWAP_64Results(SDNode *N,
   assert(N->getValueType(0) == MVT::i64 &&
          "AtomicCmpSwap on types less than 64 should be legal");
   SDValue Ops[] = {N->getOperand(1),
-                   createGPRPairNode(DAG, N->getOperand(2)->getOperand(0),
-                                     N->getOperand(2)->getOperand(1)),
-                   createGPRPairNode(DAG, N->getOperand(3)->getOperand(0),
-                                     N->getOperand(3)->getOperand(1)),
+                   createGPRPairNode(DAG, N->getOperand(2)),
+                   createGPRPairNode(DAG, N->getOperand(3)),
                    N->getOperand(0)};
   SDNode *CmpSwap = DAG.getMachineNode(
       ARM::CMP_SWAP_64, SDLoc(N),