Code generation for 'fence' instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136283 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 3996eeb..903efd7 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -601,9 +601,11 @@
// membarrier needs custom lowering; the rest are legal and handled
// normally.
setOperationAction(ISD::MEMBARRIER, MVT::Other, Custom);
+ setOperationAction(ISD::ATOMIC_FENCE, MVT::Other, Custom);
} else {
// Set them all for expansion, which will force libcalls.
setOperationAction(ISD::MEMBARRIER, MVT::Other, Expand);
+ setOperationAction(ISD::ATOMIC_FENCE, MVT::Other, Expand);
setOperationAction(ISD::ATOMIC_CMP_SWAP, MVT::i8, Expand);
setOperationAction(ISD::ATOMIC_CMP_SWAP, MVT::i16, Expand);
setOperationAction(ISD::ATOMIC_CMP_SWAP, MVT::i32, Expand);
@@ -2277,6 +2279,33 @@
DAG.getConstant(DMBOpt, MVT::i32));
}
+
+static SDValue LowerATOMIC_FENCE(SDValue Op, SelectionDAG &DAG,
+ const ARMSubtarget *Subtarget) {
+ // FIXME: handle "fence singlethread" more efficiently.
+ DebugLoc dl = Op.getDebugLoc();
+ if (!Subtarget->hasDataBarrier()) {
+ // Some ARMv6 cpus can support data barriers with an mcr instruction.
+ // Thumb1 and pre-v6 ARM mode use a libcall instead and should never get
+ // here.
+ assert(Subtarget->hasV6Ops() && !Subtarget->isThumb() &&
+ "Unexpected ISD::MEMBARRIER encountered. Should be libcall!");
+ return DAG.getNode(ARMISD::MEMBARRIER_MCR, dl, MVT::Other, Op.getOperand(0),
+ DAG.getConstant(0, MVT::i32));
+ }
+
+ AtomicOrdering FenceOrdering = static_cast<AtomicOrdering>(
+ cast<ConstantSDNode>(Op.getOperand(1))->getZExtValue());
+
+ ARM_MB::MemBOpt DMBOpt;
+ if (FenceOrdering == Release)
+ DMBOpt = ARM_MB::ISHST;
+ else
+ DMBOpt = ARM_MB::ISH;
+ return DAG.getNode(ARMISD::MEMBARRIER, dl, MVT::Other, Op.getOperand(0),
+ DAG.getConstant(DMBOpt, MVT::i32));
+}
+
static SDValue LowerPREFETCH(SDValue Op, SelectionDAG &DAG,
const ARMSubtarget *Subtarget) {
// ARM pre v5TE and Thumb1 does not have preload instructions.
@@ -4834,6 +4863,7 @@
case ISD::BR_JT: return LowerBR_JT(Op, DAG);
case ISD::VASTART: return LowerVASTART(Op, DAG);
case ISD::MEMBARRIER: return LowerMEMBARRIER(Op, DAG, Subtarget);
+ case ISD::ATOMIC_FENCE: return LowerATOMIC_FENCE(Op, DAG, Subtarget);
case ISD::PREFETCH: return LowerPREFETCH(Op, DAG, Subtarget);
case ISD::SINT_TO_FP:
case ISD::UINT_TO_FP: return LowerINT_TO_FP(Op, DAG);