1 files changed, 442 insertions, 0 deletions
diff --git a/lib/Target/Mips/MipsSEISelLowering.cpp b/lib/Target/Mips/MipsSEISelLowering.cpp
new file mode 100644
index 0000000000..4f219218d3
--- /dev/null
+++ b/lib/Target/Mips/MipsSEISelLowering.cpp
@@ -0,0 +1,442 @@
+//===-- MipsSEISelLowering.cpp - MipsSE DAG Lowering Interface --*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Subclass of MipsTargetLowering specialized for mips32/64.
+//
+//===----------------------------------------------------------------------===//
+#include "MipsSEISelLowering.h"
+#include "MipsRegisterInfo.h"
+#include "MipsTargetMachine.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Target/TargetInstrInfo.h"
+
+using namespace llvm;
+
+static cl::opt<bool>
+EnableMipsTailCalls("enable-mips-tail-calls", cl::Hidden,
+                    cl::desc("MIPS: Enable tail calls."), cl::init(false));
+
+MipsSETargetLowering::MipsSETargetLowering(MipsTargetMachine &TM)
+  : MipsTargetLowering(TM) {
+  // Set up the register classes
+  addRegisterClass(MVT::i32, &Mips::CPURegsRegClass);
+
+  if (HasMips64)
+    addRegisterClass(MVT::i64, &Mips::CPU64RegsRegClass);
+
+  if (Subtarget->hasDSP()) {
+    MVT::SimpleValueType VecTys[2] = {MVT::v2i16, MVT::v4i8};
+
+    for (unsigned i = 0; i < array_lengthof(VecTys); ++i) {
+      addRegisterClass(VecTys[i], &Mips::DSPRegsRegClass);
+
+      // Expand all builtin opcodes.
+      for (unsigned Opc = 0; Opc < ISD::BUILTIN_OP_END; ++Opc)
+        setOperationAction(Opc, VecTys[i], Expand);
+
+      setOperationAction(ISD::LOAD, VecTys[i], Legal);
+      setOperationAction(ISD::STORE, VecTys[i], Legal);
+      setOperationAction(ISD::BITCAST, VecTys[i], Legal);
+    }
+  }
+
+  if (!TM.Options.UseSoftFloat) {
+    addRegisterClass(MVT::f32, &Mips::FGR32RegClass);
+
+    // When dealing with single precision only, use libcalls
+    if (!Subtarget->isSingleFloat()) {
+      if (HasMips64)
+        addRegisterClass(MVT::f64, &Mips::FGR64RegClass);
+      else
+        addRegisterClass(MVT::f64, &Mips::AFGR64RegClass);
+    }
+  }
+
+  setOperationAction(ISD::SMUL_LOHI,          MVT::i32, Custom);
+  setOperationAction(ISD::UMUL_LOHI,          MVT::i32, Custom);
+  setOperationAction(ISD::MULHS,              MVT::i32, Custom);
+  setOperationAction(ISD::MULHU,              MVT::i32, Custom);
+
+  if (HasMips64)
+    setOperationAction(ISD::MUL,              MVT::i64, Custom);
+
+  setOperationAction(ISD::SDIVREM, MVT::i32, Custom);
+  setOperationAction(ISD::UDIVREM, MVT::i32, Custom);
+  setOperationAction(ISD::SDIVREM, MVT::i64, Custom);
+  setOperationAction(ISD::UDIVREM, MVT::i64, Custom);
+  setOperationAction(ISD::MEMBARRIER,         MVT::Other, Custom);
+  setOperationAction(ISD::ATOMIC_FENCE,       MVT::Other, Custom);
+  setOperationAction(ISD::LOAD,               MVT::i32, Custom);
+  setOperationAction(ISD::STORE,              MVT::i32, Custom);
+
+  setTargetDAGCombine(ISD::ADDE);
+  setTargetDAGCombine(ISD::SUBE);
+
+  computeRegisterProperties();
+}
+
+const MipsTargetLowering *
+llvm::createMipsSETargetLowering(MipsTargetMachine &TM) {
+  return new MipsSETargetLowering(TM);
+}
+
+
+bool
+MipsSETargetLowering::allowsUnalignedMemoryAccesses(EVT VT, bool *Fast) const {
+  MVT::SimpleValueType SVT = VT.getSimpleVT().SimpleTy;
+
+  switch (SVT) {
+  case MVT::i64:
+  case MVT::i32:
+    if (Fast)
+      *Fast = true;
+    return true;
+  default:
+    return false;
+  }
+}
+
+SDValue MipsSETargetLowering::LowerOperation(SDValue Op,
+                                             SelectionDAG &DAG) const {
+  switch(Op.getOpcode()) {
+  case ISD::SMUL_LOHI: return lowerMulDiv(Op, MipsISD::Mult, true, true, DAG);
+  case ISD::UMUL_LOHI: return lowerMulDiv(Op, MipsISD::Multu, true, true, DAG);
+  case ISD::MULHS:     return lowerMulDiv(Op, MipsISD::Mult, false, true, DAG);
+  case ISD::MULHU:     return lowerMulDiv(Op, MipsISD::Multu, false, true, DAG);
+  case ISD::MUL:       return lowerMulDiv(Op, MipsISD::Mult, true, false, DAG);
+  case ISD::SDIVREM:   return lowerMulDiv(Op, MipsISD::DivRem, true, true, DAG);
+  case ISD::UDIVREM:   return lowerMulDiv(Op, MipsISD::DivRemU, true, true, DAG);
+  }
+
+  return MipsTargetLowering::LowerOperation(Op, DAG);
+}
+
+// selectMADD -
+// Transforms a subgraph in CurDAG if the following pattern is found:
+//  (addc multLo, Lo0), (adde multHi, Hi0),
+// where,
+//  multHi/Lo: product of multiplication
+//  Lo0: initial value of Lo register
+//  Hi0: initial value of Hi register
+// Return true if pattern matching was successful.
+static bool selectMADD(SDNode *ADDENode, SelectionDAG *CurDAG) {
+  // ADDENode's second operand must be a flag output of an ADDC node in order
+  // for the matching to be successful.
+  SDNode *ADDCNode = ADDENode->getOperand(2).getNode();
+
+  if (ADDCNode->getOpcode() != ISD::ADDC)
+    return false;
+
+  SDValue MultHi = ADDENode->getOperand(0);
+  SDValue MultLo = ADDCNode->getOperand(0);
+  SDNode *MultNode = MultHi.getNode();
+  unsigned MultOpc = MultHi.getOpcode();
+
+  // MultHi and MultLo must be generated by the same node,
+  if (MultLo.getNode() != MultNode)
+    return false;
+
+  // and it must be a multiplication.
+  if (MultOpc != ISD::SMUL_LOHI && MultOpc != ISD::UMUL_LOHI)
+    return false;
+
+  // MultLo amd MultHi must be the first and second output of MultNode
+  // respectively.
+  if (MultHi.getResNo() != 1 || MultLo.getResNo() != 0)
+    return false;
+
+  // Transform this to a MADD only if ADDENode and ADDCNode are the only users
+  // of the values of MultNode, in which case MultNode will be removed in later
+  // phases.
+  // If there exist users other than ADDENode or ADDCNode, this function returns
+  // here, which will result in MultNode being mapped to a single MULT
+  // instruction node rather than a pair of MULT and MADD instructions being
+  // produced.
+  if (!MultHi.hasOneUse() || !MultLo.hasOneUse())
+    return false;
+
+  DebugLoc DL = ADDENode->getDebugLoc();
+
+  // Initialize accumulator.
+  SDValue ACCIn = CurDAG->getNode(MipsISD::InsertLOHI, DL, MVT::Untyped,
+                                  ADDCNode->getOperand(1),
+                                  ADDENode->getOperand(1));
+
+  // create MipsMAdd(u) node
+  MultOpc = MultOpc == ISD::UMUL_LOHI ? MipsISD::MAddu : MipsISD::MAdd;
+
+  SDValue MAdd = CurDAG->getNode(MultOpc, DL, MVT::Untyped,
+                                 MultNode->getOperand(0),// Factor 0
+                                 MultNode->getOperand(1),// Factor 1
+                                 ACCIn);
+
+  // replace uses of adde and addc here
+  if (!SDValue(ADDCNode, 0).use_empty()) {
+    SDValue LoIdx = CurDAG->getConstant(Mips::sub_lo, MVT::i32);
+    SDValue LoOut = CurDAG->getNode(MipsISD::ExtractLOHI, DL, MVT::i32, MAdd,
+                                    LoIdx);
+    CurDAG->ReplaceAllUsesOfValueWith(SDValue(ADDCNode, 0), LoOut);
+  }
+  if (!SDValue(ADDENode, 0).use_empty()) {
+    SDValue HiIdx = CurDAG->getConstant(Mips::sub_hi, MVT::i32);
+    SDValue HiOut = CurDAG->getNode(MipsISD::ExtractLOHI, DL, MVT::i32, MAdd,
+                                    HiIdx);
+    CurDAG->ReplaceAllUsesOfValueWith(SDValue(ADDENode, 0), HiOut);
+  }
+
+  return true;
+}
+
+// selectMSUB -
+// Transforms a subgraph in CurDAG if the following pattern is found:
+//  (addc Lo0, multLo), (sube Hi0, multHi),
+// where,
+//  multHi/Lo: product of multiplication
+//  Lo0: initial value of Lo register
+//  Hi0: initial value of Hi register
+// Return true if pattern matching was successful.
+static bool selectMSUB(SDNode *SUBENode, SelectionDAG *CurDAG) {
+  // SUBENode's second operand must be a flag output of an SUBC node in order
+  // for the matching to be successful.
+  SDNode *SUBCNode = SUBENode->getOperand(2).getNode();
+
+  if (SUBCNode->getOpcode() != ISD::SUBC)
+    return false;
+
+  SDValue MultHi = SUBENode->getOperand(1);
+  SDValue MultLo = SUBCNode->getOperand(1);
+  SDNode *MultNode = MultHi.getNode();
+  unsigned MultOpc = MultHi.getOpcode();
+
+  // MultHi and MultLo must be generated by the same node,
+  if (MultLo.getNode() != MultNode)
+    return false;
+
+  // and it must be a multiplication.
+  if (MultOpc != ISD::SMUL_LOHI && MultOpc != ISD::UMUL_LOHI)
+    return false;
+
+  // MultLo amd MultHi must be the first and second output of MultNode
+  // respectively.
+  if (MultHi.getResNo() != 1 || MultLo.getResNo() != 0)
+    return false;
+
+  // Transform this to a MSUB only if SUBENode and SUBCNode are the only users
+  // of the values of MultNode, in which case MultNode will be removed in later
+  // phases.
+  // If there exist users other than SUBENode or SUBCNode, this function returns
+  // here, which will result in MultNode being mapped to a single MULT
+  // instruction node rather than a pair of MULT and MSUB instructions being
+  // produced.
+  if (!MultHi.hasOneUse() || !MultLo.hasOneUse())
+    return false;
+
+  DebugLoc DL = SUBENode->getDebugLoc();
+
+  // Initialize accumulator.
+  SDValue ACCIn = CurDAG->getNode(MipsISD::InsertLOHI, DL, MVT::Untyped,
+                                  SUBCNode->getOperand(0),
+                                  SUBENode->getOperand(0));
+
+  // create MipsSub(u) node
+  MultOpc = MultOpc == ISD::UMUL_LOHI ? MipsISD::MSubu : MipsISD::MSub;
+
+  SDValue MSub = CurDAG->getNode(MultOpc, DL, MVT::Glue,
+                                 MultNode->getOperand(0),// Factor 0
+                                 MultNode->getOperand(1),// Factor 1
+                                 ACCIn);
+
+  // replace uses of sube and subc here
+  if (!SDValue(SUBCNode, 0).use_empty()) {
+    SDValue LoIdx = CurDAG->getConstant(Mips::sub_lo, MVT::i32);
+    SDValue LoOut = CurDAG->getNode(MipsISD::ExtractLOHI, DL, MVT::i32, MSub,
+                                    LoIdx);
+    CurDAG->ReplaceAllUsesOfValueWith(SDValue(SUBCNode, 0), LoOut);
+  }
+  if (!SDValue(SUBENode, 0).use_empty()) {
+    SDValue HiIdx = CurDAG->getConstant(Mips::sub_hi, MVT::i32);
+    SDValue HiOut = CurDAG->getNode(MipsISD::ExtractLOHI, DL, MVT::i32, MSub,
+                                    HiIdx);
+    CurDAG->ReplaceAllUsesOfValueWith(SDValue(SUBENode, 0), HiOut);
+  }
+
+  return true;
+}
+
+static SDValue performADDECombine(SDNode *N, SelectionDAG &DAG,
+                                  TargetLowering::DAGCombinerInfo &DCI,
+                                  const MipsSubtarget *Subtarget) {
+  if (DCI.isBeforeLegalize())
+    return SDValue();
+
+  if (Subtarget->hasMips32() && N->getValueType(0) == MVT::i32 &&
+      selectMADD(N, &DAG))
+    return SDValue(N, 0);
+
+  return SDValue();
+}
+
+static SDValue performSUBECombine(SDNode *N, SelectionDAG &DAG,
+                                  TargetLowering::DAGCombinerInfo &DCI,
+                                  const MipsSubtarget *Subtarget) {
+  if (DCI.isBeforeLegalize())
+    return SDValue();
+
+  if (Subtarget->hasMips32() && N->getValueType(0) == MVT::i32 &&
+      selectMSUB(N, &DAG))
+    return SDValue(N, 0);
+
+  return SDValue();
+}
+
+SDValue
+MipsSETargetLowering::PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const {
+  SelectionDAG &DAG = DCI.DAG;
+
+  switch (N->getOpcode()) {
+  case ISD::ADDE:
+    return performADDECombine(N, DAG, DCI, Subtarget);
+  case ISD::SUBE:
+    return performSUBECombine(N, DAG, DCI, Subtarget);
+  default:
+    return MipsTargetLowering::PerformDAGCombine(N, DCI);
+  }
+}
+
+MachineBasicBlock *
+MipsSETargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
+                                                  MachineBasicBlock *BB) const {
+  switch (MI->getOpcode()) {
+  default:
+    return MipsTargetLowering::EmitInstrWithCustomInserter(MI, BB);
+  case Mips::BPOSGE32_PSEUDO:
+    return emitBPOSGE32(MI, BB);
+  }
+}
+
+bool MipsSETargetLowering::
+isEligibleForTailCallOptimization(const MipsCC &MipsCCInfo,
+                                  unsigned NextStackOffset,
+                                  const MipsFunctionInfo& FI) const {
+  if (!EnableMipsTailCalls)
+    return false;
+
+  // Return false if either the callee or caller has a byval argument.
+  if (MipsCCInfo.hasByValArg() || FI.hasByvalArg())
+    return false;
+
+  // Return true if the callee's argument area is no larger than the
+  // caller's.
+  return NextStackOffset <= FI.getIncomingArgSize();
+}
+
+void MipsSETargetLowering::
+getOpndList(SmallVectorImpl<SDValue> &Ops,
+            std::deque< std::pair<unsigned, SDValue> > &RegsToPass,
+            bool IsPICCall, bool GlobalOrExternal, bool InternalLinkage,
+            CallLoweringInfo &CLI, SDValue Callee, SDValue Chain) const {
+  // T9 should contain the address of the callee function if
+  // -reloction-model=pic or it is an indirect call.
+  if (IsPICCall || !GlobalOrExternal) {
+    unsigned T9Reg = IsN64 ? Mips::T9_64 : Mips::T9;
+    RegsToPass.push_front(std::make_pair(T9Reg, Callee));
+  } else
+    Ops.push_back(Callee);
+
+  MipsTargetLowering::getOpndList(Ops, RegsToPass, IsPICCall, GlobalOrExternal,
+                                  InternalLinkage, CLI, Callee, Chain);
+}
+
+SDValue MipsSETargetLowering::lowerMulDiv(SDValue Op, unsigned NewOpc,
+                                          bool HasLo, bool HasHi,
+                                          SelectionDAG &DAG) const {
+  EVT Ty = Op.getOperand(0).getValueType();
+  DebugLoc DL = Op.getDebugLoc();
+  SDValue Mult = DAG.getNode(NewOpc, DL, MVT::Untyped,
+                             Op.getOperand(0), Op.getOperand(1));
+  SDValue Lo, Hi;
+
+  if (HasLo)
+    Lo = DAG.getNode(MipsISD::ExtractLOHI, DL, Ty, Mult,
+                     DAG.getConstant(Mips::sub_lo, MVT::i32));
+  if (HasHi)
+    Hi = DAG.getNode(MipsISD::ExtractLOHI, DL, Ty, Mult,
+                     DAG.getConstant(Mips::sub_hi, MVT::i32));
+
+  if (!HasLo || !HasHi)
+    return HasLo ? Lo : Hi;
+
+  SDValue Vals[] = { Lo, Hi };
+  return DAG.getMergeValues(Vals, 2, DL);
+}
+
+MachineBasicBlock * MipsSETargetLowering::
+emitBPOSGE32(MachineInstr *MI, MachineBasicBlock *BB) const{
+  // $bb:
+  //  bposge32_pseudo $vr0
+  //  =>
+  // $bb:
+  //  bposge32 $tbb
+  // $fbb:
+  //  li $vr2, 0
+  //  b $sink
+  // $tbb:
+  //  li $vr1, 1
+  // $sink:
+  //  $vr0 = phi($vr2, $fbb, $vr1, $tbb)
+
+  MachineRegisterInfo &RegInfo = BB->getParent()->getRegInfo();
+  const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
+  const TargetRegisterClass *RC = &Mips::CPURegsRegClass;
+  DebugLoc DL = MI->getDebugLoc();
+  const BasicBlock *LLVM_BB = BB->getBasicBlock();
+  MachineFunction::iterator It = llvm::next(MachineFunction::iterator(BB));
+  MachineFunction *F = BB->getParent();
+  MachineBasicBlock *FBB = F->CreateMachineBasicBlock(LLVM_BB);
+  MachineBasicBlock *TBB = F->CreateMachineBasicBlock(LLVM_BB);
+  MachineBasicBlock *Sink  = F->CreateMachineBasicBlock(LLVM_BB);
+  F->insert(It, FBB);
+  F->insert(It, TBB);
+  F->insert(It, Sink);
+
+  // Transfer the remainder of BB and its successor edges to Sink.
+  Sink->splice(Sink->begin(), BB, llvm::next(MachineBasicBlock::iterator(MI)),
+               BB->end());
+  Sink->transferSuccessorsAndUpdatePHIs(BB);
+
+  // Add successors.
+  BB->addSuccessor(FBB);
+  BB->addSuccessor(TBB);
+  FBB->addSuccessor(Sink);
+  TBB->addSuccessor(Sink);
+
+  // Insert the real bposge32 instruction to $BB.
+  BuildMI(BB, DL, TII->get(Mips::BPOSGE32)).addMBB(TBB);
+
+  // Fill $FBB.
+  unsigned VR2 = RegInfo.createVirtualRegister(RC);
+  BuildMI(*FBB, FBB->end(), DL, TII->get(Mips::ADDiu), VR2)
+    .addReg(Mips::ZERO).addImm(0);
+  BuildMI(*FBB, FBB->end(), DL, TII->get(Mips::B)).addMBB(Sink);
+
+  // Fill $TBB.
+  unsigned VR1 = RegInfo.createVirtualRegister(RC);
+  BuildMI(*TBB, TBB->end(), DL, TII->get(Mips::ADDiu), VR1)
+    .addReg(Mips::ZERO).addImm(1);
+
+  // Insert phi function to $Sink.
+  BuildMI(*Sink, Sink->begin(), DL, TII->get(Mips::PHI),
+          MI->getOperand(0).getReg())
+    .addReg(VR2).addMBB(FBB).addReg(VR1).addMBB(TBB);
+
+  MI->eraseFromParent();   // The pseudo instruction is gone now.
+  return Sink;
+}