Some 64-bit atomic operations on ARM. 64-bit cmpxchg coming next.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138845 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 5268466..550c8da 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -611,6 +611,13 @@
// normally.
setOperationAction(ISD::MEMBARRIER, MVT::Other, Custom);
setOperationAction(ISD::ATOMIC_FENCE, MVT::Other, Custom);
+ // Custom lowering for 64-bit ops
+ setOperationAction(ISD::ATOMIC_LOAD_ADD, MVT::i64, Custom);
+ setOperationAction(ISD::ATOMIC_LOAD_SUB, MVT::i64, Custom);
+ setOperationAction(ISD::ATOMIC_LOAD_AND, MVT::i64, Custom);
+ setOperationAction(ISD::ATOMIC_LOAD_OR, MVT::i64, Custom);
+ setOperationAction(ISD::ATOMIC_LOAD_XOR, MVT::i64, Custom);
+ setOperationAction(ISD::ATOMIC_SWAP, MVT::i64, Custom);
// Automatically insert fences (dmb ist) around ATOMIC_SWAP etc.
setInsertFencesForAtomic(true);
} else {
@@ -4846,6 +4853,29 @@
Op.getOperand(1), Op.getOperand(2));
}
+static void
+ReplaceATOMIC_BINARY_64(SDNode *Node, SmallVectorImpl<SDValue>& Results,
+ SelectionDAG &DAG, unsigned NewOp) {
+ EVT T = Node->getValueType(0);
+ DebugLoc dl = Node->getDebugLoc();
+ assert (T == MVT::i64 && "Only know how to expand i64 atomics");
+
+ SDValue Chain = Node->getOperand(0);
+ SDValue In1 = Node->getOperand(1);
+ SDValue In2L = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32,
+ Node->getOperand(2), DAG.getIntPtrConstant(0));
+ SDValue In2H = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32,
+ Node->getOperand(2), DAG.getIntPtrConstant(1));
+ SDValue Ops[] = { Chain, In1, In2L, In2H };
+ SDVTList Tys = DAG.getVTList(MVT::i32, MVT::i32, MVT::Other);
+ SDValue Result =
+ DAG.getMemIntrinsicNode(NewOp, dl, Tys, Ops, 4, MVT::i64,
+ cast<MemSDNode>(Node)->getMemOperand());
+ SDValue OpsF[] = { Result.getValue(0), Result.getValue(1)};
+ Results.push_back(DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, OpsF, 2));
+ Results.push_back(Result.getValue(2));
+}
+
SDValue ARMTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const {
switch (Op.getOpcode()) {
default: llvm_unreachable("Don't know how to custom lower this!");
@@ -4918,6 +4948,29 @@
case ISD::SRA:
Res = Expand64BitShift(N, DAG, Subtarget);
break;
+ case ISD::ATOMIC_LOAD_ADD:
+ ReplaceATOMIC_BINARY_64(N, Results, DAG, ARMISD::ATOMADD64_DAG);
+ return;
+ case ISD::ATOMIC_LOAD_AND:
+ ReplaceATOMIC_BINARY_64(N, Results, DAG, ARMISD::ATOMAND64_DAG);
+ return;
+ case ISD::ATOMIC_LOAD_NAND:
+ ReplaceATOMIC_BINARY_64(N, Results, DAG, ARMISD::ATOMNAND64_DAG);
+ return;
+ case ISD::ATOMIC_LOAD_OR:
+ ReplaceATOMIC_BINARY_64(N, Results, DAG, ARMISD::ATOMOR64_DAG);
+ return;
+ case ISD::ATOMIC_LOAD_SUB:
+ ReplaceATOMIC_BINARY_64(N, Results, DAG, ARMISD::ATOMSUB64_DAG);
+ return;
+ case ISD::ATOMIC_LOAD_XOR:
+ ReplaceATOMIC_BINARY_64(N, Results, DAG, ARMISD::ATOMXOR64_DAG);
+ return;
+ case ISD::ATOMIC_SWAP:
+ ReplaceATOMIC_BINARY_64(N, Results, DAG, ARMISD::ATOMSWAP64_DAG);
+ return;
+ //case ISD::ATOMIC_CMP_SWAP:
+ // ReplaceATOMIC_CMPXCHG_64(N, Results, DAG);
}
if (Res.getNode())
Results.push_back(Res);
@@ -5237,6 +5290,113 @@
return BB;
}
+MachineBasicBlock *
+ARMTargetLowering::EmitAtomicBinary64(MachineInstr *MI, MachineBasicBlock *BB,
+ unsigned Op1, unsigned Op2,
+ bool NeedsCarry) const {
+ // This also handles ATOMIC_SWAP, indicated by Op1==0.
+ const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
+
+ const BasicBlock *LLVM_BB = BB->getBasicBlock();
+ MachineFunction *MF = BB->getParent();
+ MachineFunction::iterator It = BB;
+ ++It;
+
+ unsigned destlo = MI->getOperand(0).getReg();
+ unsigned desthi = MI->getOperand(1).getReg();
+ unsigned ptr = MI->getOperand(2).getReg();
+ unsigned vallo = MI->getOperand(3).getReg();
+ unsigned valhi = MI->getOperand(4).getReg();
+ DebugLoc dl = MI->getDebugLoc();
+ bool isThumb2 = Subtarget->isThumb2();
+
+ MachineRegisterInfo &MRI = BB->getParent()->getRegInfo();
+ if (isThumb2) {
+ MRI.constrainRegClass(destlo, ARM::rGPRRegisterClass);
+ MRI.constrainRegClass(desthi, ARM::rGPRRegisterClass);
+ MRI.constrainRegClass(ptr, ARM::rGPRRegisterClass);
+ }
+
+ unsigned ldrOpc = isThumb2 ? ARM::t2LDREXD : ARM::LDREXD;
+ unsigned strOpc = isThumb2 ? ARM::t2STREXD : ARM::STREXD;
+
+ MachineBasicBlock *loopMBB = MF->CreateMachineBasicBlock(LLVM_BB);
+ MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
+ MF->insert(It, loopMBB);
+ MF->insert(It, exitMBB);
+
+ // Transfer the remainder of BB and its successor edges to exitMBB.
+ exitMBB->splice(exitMBB->begin(), BB,
+ llvm::next(MachineBasicBlock::iterator(MI)),
+ BB->end());
+ exitMBB->transferSuccessorsAndUpdatePHIs(BB);
+
+ TargetRegisterClass *TRC =
+ isThumb2 ? ARM::tGPRRegisterClass : ARM::GPRRegisterClass;
+ unsigned storesuccess = MRI.createVirtualRegister(TRC);
+
+ // thisMBB:
+ // ...
+ // fallthrough --> loopMBB
+ BB->addSuccessor(loopMBB);
+
+ // loopMBB:
+ // ldrexd r2, r3, ptr
+ // <binopa> r0, r2, incr
+ // <binopb> r1, r3, incr
+ // strexd storesuccess, r0, r1, ptr
+ // cmp storesuccess, #0
+ // bne- loopMBB
+ // fallthrough --> exitMBB
+ //
+ // Note that the registers are explicitly specified because there is not any
+ // way to force the register allocator to allocate a register pair.
+ //
+ // FIXME: The hardcoded registers are not necessary for Thumb2, but we
+ // need to properly enforce the restriction that the two output registers
+ // for ldrexd must be different.
+ BB = loopMBB;
+ // Load
+ AddDefaultPred(BuildMI(BB, dl, TII->get(ldrOpc))
+ .addReg(ARM::R2, RegState::Define)
+ .addReg(ARM::R3, RegState::Define).addReg(ptr));
+ // Copy r2/r3 into dest. (This copy will normally be coalesced.)
+ BuildMI(BB, dl, TII->get(TargetOpcode::COPY), destlo).addReg(ARM::R2);
+ BuildMI(BB, dl, TII->get(TargetOpcode::COPY), desthi).addReg(ARM::R3);
+ if (Op1) {
+ // Perform binary operation
+ AddDefaultPred(BuildMI(BB, dl, TII->get(Op1), ARM::R0)
+ .addReg(destlo).addReg(vallo))
+ .addReg(NeedsCarry ? ARM::CPSR : 0, getDefRegState(NeedsCarry));
+ AddDefaultPred(BuildMI(BB, dl, TII->get(Op2), ARM::R1)
+ .addReg(desthi).addReg(valhi)).addReg(0);
+ } else {
+ // Copy to physregs for strexd
+ BuildMI(BB, dl, TII->get(TargetOpcode::COPY), ARM::R0).addReg(vallo);
+ BuildMI(BB, dl, TII->get(TargetOpcode::COPY), ARM::R1).addReg(valhi);
+ }
+
+ // Store
+ AddDefaultPred(BuildMI(BB, dl, TII->get(strOpc), storesuccess)
+ .addReg(ARM::R0).addReg(ARM::R1).addReg(ptr));
+ // Cmp+jump
+ AddDefaultPred(BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2CMPri : ARM::CMPri))
+ .addReg(storesuccess).addImm(0));
+ BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2Bcc : ARM::Bcc))
+ .addMBB(loopMBB).addImm(ARMCC::NE).addReg(ARM::CPSR);
+
+ BB->addSuccessor(loopMBB);
+ BB->addSuccessor(exitMBB);
+
+ // exitMBB:
+ // ...
+ BB = exitMBB;
+
+ MI->eraseFromParent(); // The instruction is gone now.
+
+ return BB;
+}
+
static
MachineBasicBlock *OtherSucc(MachineBasicBlock *MBB, MachineBasicBlock *Succ) {
for (MachineBasicBlock::succ_iterator I = MBB->succ_begin(),
@@ -5374,6 +5534,25 @@
case ARM::ATOMIC_CMP_SWAP_I16: return EmitAtomicCmpSwap(MI, BB, 2);
case ARM::ATOMIC_CMP_SWAP_I32: return EmitAtomicCmpSwap(MI, BB, 4);
+
+ case ARM::ATOMADD6432:
+ return EmitAtomicBinary64(MI, BB, isThumb2 ? ARM::t2ADDrr : ARM::ADDrr,
+ isThumb2 ? ARM::t2ADCrr : ARM::ADCrr, true);
+ case ARM::ATOMSUB6432:
+ return EmitAtomicBinary64(MI, BB, isThumb2 ? ARM::t2SUBrr : ARM::SUBrr,
+ isThumb2 ? ARM::t2SBCrr : ARM::SBCrr, true);
+ case ARM::ATOMOR6432:
+ return EmitAtomicBinary64(MI, BB, isThumb2 ? ARM::t2ORRrr : ARM::ORRrr,
+ isThumb2 ? ARM::t2ORRrr : ARM::ORRrr, false);
+ case ARM::ATOMXOR6432:
+ return EmitAtomicBinary64(MI, BB, isThumb2 ? ARM::t2EORrr : ARM::EORrr,
+ isThumb2 ? ARM::t2EORrr : ARM::EORrr, false);
+ case ARM::ATOMAND6432:
+ return EmitAtomicBinary64(MI, BB, isThumb2 ? ARM::t2ANDrr : ARM::ANDrr,
+ isThumb2 ? ARM::t2ANDrr : ARM::ANDrr, false);
+ case ARM::ATOMSWAP6432:
+ return EmitAtomicBinary64(MI, BB, 0, 0, false);
+
case ARM::tMOVCCr_pseudo: {
// To "insert" a SELECT_CC instruction, we actually have to insert the
// diamond control-flow pattern. The incoming instruction knows the