//===- subzero/src/IceInstMips32.cpp - Mips32 instruction implementation --===//
//
//                        The Subzero Code Generator
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
/// \file
/// \brief Implements the InstMips32 and OperandMips32 classes, primarily the
/// constructors and the dump()/emit() methods.
///
//===----------------------------------------------------------------------===//
#include "IceAssemblerMIPS32.h"
#include "IceCfg.h"
#include "IceCfgNode.h"
#include "IceInst.h"
#include "IceInstMIPS32.h"
#include "IceOperand.h"
#include "IceRegistersMIPS32.h"
#include "IceTargetLoweringMIPS32.h"
#include <limits>

namespace Ice {
namespace MIPS32 {

const struct InstMIPS32CondAttributes_ {
  CondMIPS32::Cond Opposite;
  const char *EmitString;
} InstMIPS32CondAttributes[] = {
#define X(tag, opp, emit)                                                      \
  { CondMIPS32::opp, emit }                                                    \
  ,
    ICEINSTMIPS32COND_TABLE
#undef X
};

bool OperandMIPS32Mem::canHoldOffset(Type Ty, bool SignExt, int32_t Offset) {
  (void)SignExt;
  (void)Ty;
  if ((std::numeric_limits<int16_t>::min() <= Offset) &&
      (Offset <= std::numeric_limits<int16_t>::max()))
    return true;
  return false;
}

OperandMIPS32Mem::OperandMIPS32Mem(Cfg *Func, Type Ty, Variable *Base,
                                   Operand *ImmOffset, AddrMode Mode)
    : OperandMIPS32(kMem, Ty), Base(Base), ImmOffset(ImmOffset), Mode(Mode) {
  // The Neg modes are only needed for Reg +/- Reg.
  (void)Func;
  // assert(!isNegAddrMode());
  NumVars = 1;
  Vars = &this->Base;
}

const char *InstMIPS32::getWidthString(Type Ty) {
  (void)Ty;
  return "TBD";
}

template <> const char *InstMIPS32Add::Opcode = "add";
template <> const char *InstMIPS32Add_d::Opcode = "add.d";
template <> const char *InstMIPS32Add_s::Opcode = "add.s";
template <> const char *InstMIPS32Addiu::Opcode = "addiu";
template <> const char *InstMIPS32Addu::Opcode = "addu";
template <> const char *InstMIPS32And::Opcode = "and";
template <> const char *InstMIPS32Andi::Opcode = "andi";
template <> const char *InstMIPS32Cvt_d_l::Opcode = "cvt.d.l";
template <> const char *InstMIPS32Cvt_d_s::Opcode = "cvt.d.s";
template <> const char *InstMIPS32Cvt_d_w::Opcode = "cvt.d.w";
template <> const char *InstMIPS32Cvt_s_d::Opcode = "cvt.s.d";
template <> const char *InstMIPS32Cvt_s_l::Opcode = "cvt.s.l";
template <> const char *InstMIPS32Cvt_s_w::Opcode = "cvt.s.w";
template <> const char *InstMIPS32Div::Opcode = "div";
template <> const char *InstMIPS32Div_d::Opcode = "div.d";
template <> const char *InstMIPS32Div_s::Opcode = "div.s";
template <> const char *InstMIPS32Divu::Opcode = "divu";
template <> const char *InstMIPS32La::Opcode = "la";
template <> const char *InstMIPS32Ldc1::Opcode = "ldc1";
template <> const char *InstMIPS32Lui::Opcode = "lui";
template <> const char *InstMIPS32Lw::Opcode = "lw";
template <> const char *InstMIPS32Lwc1::Opcode = "lwc1";
template <> const char *InstMIPS32Mfc1::Opcode = "mfc1";
template <> const char *InstMIPS32Mfhi::Opcode = "mfhi";
template <> const char *InstMIPS32Mflo::Opcode = "mflo";
template <> const char *InstMIPS32Mov_d::Opcode = "mov.d";
template <> const char *InstMIPS32Mov_s::Opcode = "mov.s";
template <> const char *InstMIPS32Mtc1::Opcode = "mtc1";
template <> const char *InstMIPS32Mthi::Opcode = "mthi";
template <> const char *InstMIPS32Mtlo::Opcode = "mtlo";
template <> const char *InstMIPS32Mul::Opcode = "mul";
template <> const char *InstMIPS32Mul_d::Opcode = "mul.d";
template <> const char *InstMIPS32Mul_s::Opcode = "mul.s";
template <> const char *InstMIPS32Mult::Opcode = "mult";
template <> const char *InstMIPS32Multu::Opcode = "multu";
template <> const char *InstMIPS32Or::Opcode = "or";
template <> const char *InstMIPS32Ori::Opcode = "ori";
template <> const char *InstMIPS32Sdc1::Opcode = "sdc1";
template <> const char *InstMIPS32Sll::Opcode = "sll";
template <> const char *InstMIPS32Sllv::Opcode = "sllv";
template <> const char *InstMIPS32Slt::Opcode = "slt";
template <> const char *InstMIPS32Slti::Opcode = "slti";
template <> const char *InstMIPS32Sltiu::Opcode = "sltiu";
template <> const char *InstMIPS32Sltu::Opcode = "sltu";
template <> const char *InstMIPS32Sra::Opcode = "sra";
template <> const char *InstMIPS32Srav::Opcode = "srav";
template <> const char *InstMIPS32Srl::Opcode = "srl";
template <> const char *InstMIPS32Srlv::Opcode = "srlv";
template <> const char *InstMIPS32Sub::Opcode = "sub";
template <> const char *InstMIPS32Sub_d::Opcode = "sub.d";
template <> const char *InstMIPS32Sub_s::Opcode = "sub.s";
template <> const char *InstMIPS32Subu::Opcode = "subu";
template <> const char *InstMIPS32Sw::Opcode = "sw";
template <> const char *InstMIPS32Swc1::Opcode = "swc1";
template <> const char *InstMIPS32Trunc_l_d::Opcode = "trunc.l.d";
template <> const char *InstMIPS32Trunc_l_s::Opcode = "trunc.l.s";
template <> const char *InstMIPS32Trunc_w_d::Opcode = "trunc.w.d";
template <> const char *InstMIPS32Trunc_w_s::Opcode = "trunc.w.s";
template <> const char *InstMIPS32Xor::Opcode = "xor";
template <> const char *InstMIPS32Xori::Opcode = "xori";

template <> void InstMIPS32Lui::emit(const Cfg *Func) const {
  if (!BuildDefs::dump())
    return;
  Ostream &Str = Func->getContext()->getStrEmit();
  assert(getSrcSize() == 1);
  Str << "\t" << Opcode << "\t";
  getDest()->emit(Func);
  Str << ", ";
  auto *Src0 = llvm::cast<Constant>(getSrc(0));
  if (auto *CR = llvm::dyn_cast<ConstantRelocatable>(Src0)) {
    emitRelocOp(Str, Reloc);
    Str << "(";
    CR->emitWithoutPrefix(Func->getTarget());
    Str << ")";
  } else {
    Src0->emit(Func);
  }
}

template <> void InstMIPS32Mflo::emit(const Cfg *Func) const {
  if (!BuildDefs::dump())
    return;
  emitUnaryopGPRFLoHi(Opcode, this, Func);
}

template <> void InstMIPS32Mfhi::emit(const Cfg *Func) const {
  if (!BuildDefs::dump())
    return;
  emitUnaryopGPRFLoHi(Opcode, this, Func);
}

template <> void InstMIPS32Mtlo::emit(const Cfg *Func) const {
  if (!BuildDefs::dump())
    return;
  emitUnaryopGPRTLoHi(Opcode, this, Func);
}

template <> void InstMIPS32Mthi::emit(const Cfg *Func) const {
  if (!BuildDefs::dump())
    return;
  emitUnaryopGPRTLoHi(Opcode, this, Func);
}

template <> void InstMIPS32Mult::emit(const Cfg *Func) const {
  if (!BuildDefs::dump())
    return;
  emitThreeAddrLoHi(Opcode, this, Func);
}

template <> void InstMIPS32Multu::emit(const Cfg *Func) const {
  if (!BuildDefs::dump())
    return;
  emitThreeAddrLoHi(Opcode, this, Func);
}

InstMIPS32Br::InstMIPS32Br(Cfg *Func, const CfgNode *TargetTrue,
                           const CfgNode *TargetFalse,
                           const InstMIPS32Label *Label, CondMIPS32::Cond Cond)
    : InstMIPS32(Func, InstMIPS32::Br, 0, nullptr), TargetTrue(TargetTrue),
      TargetFalse(TargetFalse), Label(Label), Predicate(Cond) {}

InstMIPS32Br::InstMIPS32Br(Cfg *Func, const CfgNode *TargetTrue,
                           const CfgNode *TargetFalse, Operand *Src0,
                           const InstMIPS32Label *Label, CondMIPS32::Cond Cond)
    : InstMIPS32(Func, InstMIPS32::Br, 1, nullptr), TargetTrue(TargetTrue),
      TargetFalse(TargetFalse), Label(Label), Predicate(Cond) {
  addSource(Src0);
}

InstMIPS32Br::InstMIPS32Br(Cfg *Func, const CfgNode *TargetTrue,
                           const CfgNode *TargetFalse, Operand *Src0,
                           Operand *Src1, const InstMIPS32Label *Label,
                           CondMIPS32::Cond Cond)
    : InstMIPS32(Func, InstMIPS32::Br, 2, nullptr), TargetTrue(TargetTrue),
      TargetFalse(TargetFalse), Label(Label), Predicate(Cond) {
  addSource(Src0);
  addSource(Src1);
}

CondMIPS32::Cond InstMIPS32::getOppositeCondition(CondMIPS32::Cond Cond) {
  return InstMIPS32CondAttributes[Cond].Opposite;
}

bool InstMIPS32Br::optimizeBranch(const CfgNode *NextNode) {
  // If there is no next block, then there can be no fallthrough to optimize.
  if (NextNode == nullptr)
    return false;
  // Intra-block conditional branches can't be optimized.
  if (Label != nullptr)
    return false;
  // Unconditional branch to the next node can be removed.
  if (isUnconditionalBranch() && getTargetFalse() == NextNode) {
    assert(getTargetTrue() == nullptr);
    setDeleted();
    return true;
  }
  // If there is no fallthrough node, such as a non-default case label for a
  // switch instruction, then there is no opportunity to optimize.
  if (getTargetTrue() == nullptr)
    return false;
  // If the fallthrough is to the next node, set fallthrough to nullptr to
  // indicate.
  if (getTargetTrue() == NextNode) {
    TargetTrue = nullptr;
    return true;
  }
  // If TargetFalse is the next node, and TargetTrue is not nullptr
  // then invert the branch condition, swap the targets, and set new
  // fallthrough to nullptr.
  if (getTargetFalse() == NextNode) {
    assert(Predicate != CondMIPS32::AL);
    setPredicate(getOppositeCondition(getPredicate()));
    TargetFalse = getTargetTrue();
    TargetTrue = nullptr;
    return true;
  }
  return false;
}

bool InstMIPS32Br::repointEdges(CfgNode *OldNode, CfgNode *NewNode) {
  bool Found = false;
  if (TargetFalse == OldNode) {
    TargetFalse = NewNode;
    Found = true;
  }
  if (TargetTrue == OldNode) {
    TargetTrue = NewNode;
    Found = true;
  }
  return Found;
}

InstMIPS32Label::InstMIPS32Label(Cfg *Func, TargetMIPS32 *Target)
    : InstMIPS32(Func, InstMIPS32::Label, 0, nullptr),
      Number(Target->makeNextLabelNumber()) {
  if (BuildDefs::dump()) {
    Name = GlobalString::createWithString(
        Func->getContext(),
        ".L" + Func->getFunctionName() + "$local$__" + std::to_string(Number));
  } else {
    Name = GlobalString::createWithoutString(Func->getContext());
  }
}

void InstMIPS32Label::dump(const Cfg *Func) const {
  if (!BuildDefs::dump())
    return;
  Ostream &Str = Func->getContext()->getStrDump();
  Str << getLabelName() << ":";
}

void InstMIPS32Label::emit(const Cfg *Func) const {
  if (!BuildDefs::dump())
    return;
  Ostream &Str = Func->getContext()->getStrEmit();
  Str << getLabelName() << ":";
}

void InstMIPS32Label::emitIAS(const Cfg *Func) const {
  (void)Func;
  llvm_unreachable("Not yet implemented");
}

InstMIPS32Call::InstMIPS32Call(Cfg *Func, Variable *Dest, Operand *CallTarget)
    : InstMIPS32(Func, InstMIPS32::Call, 1, Dest) {
  HasSideEffects = true;
  addSource(CallTarget);
}

InstMIPS32Mov::InstMIPS32Mov(Cfg *Func, Variable *Dest, Operand *Src)
    : InstMIPS32(Func, InstMIPS32::Mov, 2, Dest) {
  auto *Dest64 = llvm::dyn_cast<Variable64On32>(Dest);
  auto *Src64 = llvm::dyn_cast<Variable64On32>(Src);

  assert(Dest64 == nullptr || Src64 == nullptr);

  if (Dest64 != nullptr) {
    // this-> is needed below because there is a parameter named Dest.
    this->Dest = Dest64->getLo();
    DestHi = Dest64->getHi();
  }

  if (Src64 == nullptr) {
    addSource(Src);
  } else {
    addSource(Src64->getLo());
    addSource(Src64->getHi());
  }
}

InstMIPS32Ret::InstMIPS32Ret(Cfg *Func, Variable *RA, Variable *Source)
    : InstMIPS32(Func, InstMIPS32::Ret, Source ? 2 : 1, nullptr) {
  addSource(RA);
  if (Source)
    addSource(Source);
}

// ======================== Dump routines ======================== //

void InstMIPS32::dump(const Cfg *Func) const {
  if (!BuildDefs::dump())
    return;
  Ostream &Str = Func->getContext()->getStrDump();
  Str << "[MIPS32] ";
  Inst::dump(Func);
}

void OperandMIPS32Mem::emit(const Cfg *Func) const {
  if (!BuildDefs::dump())
    return;
  Ostream &Str = Func->getContext()->getStrEmit();
  Operand *Offset = getOffset();
  if (auto *CR = llvm::dyn_cast<ConstantRelocatable>(Offset)) {
    Str << "(";
    CR->emitWithoutPrefix(Func->getTarget());
    Str << ")";
  } else
    Offset->emit(Func);
  Str << "(";
  getBase()->emit(Func);
  Str << ")";
}

void InstMIPS32::emitUnaryopGPR(const char *Opcode, const InstMIPS32 *Inst,
                                const Cfg *Func) {
  if (!BuildDefs::dump())
    return;
  Ostream &Str = Func->getContext()->getStrEmit();
  Str << "\t" << Opcode << "\t";
  Inst->getDest()->emit(Func);
  Str << ", ";
  Inst->getSrc(0)->emit(Func);
}
void InstMIPS32::emitUnaryopGPRFLoHi(const char *Opcode, const InstMIPS32 *Inst,
                                     const Cfg *Func) {
  if (!BuildDefs::dump())
    return;
  Ostream &Str = Func->getContext()->getStrEmit();
  Str << "\t" << Opcode << "\t";
  Inst->getDest()->emit(Func);
}

void InstMIPS32::emitUnaryopGPRTLoHi(const char *Opcode, const InstMIPS32 *Inst,
                                     const Cfg *Func) {
  if (!BuildDefs::dump())
    return;
  Ostream &Str = Func->getContext()->getStrEmit();
  Str << "\t" << Opcode << "\t";
  Inst->getSrc(0)->emit(Func);
}

void InstMIPS32::emitThreeAddr(const char *Opcode, const InstMIPS32 *Inst,
                               const Cfg *Func) {
  if (!BuildDefs::dump())
    return;
  Ostream &Str = Func->getContext()->getStrEmit();
  assert(Inst->getSrcSize() == 2);
  Str << "\t" << Opcode << "\t";
  Inst->getDest()->emit(Func);
  Str << ", ";
  Inst->getSrc(0)->emit(Func);
  Str << ", ";
  Inst->getSrc(1)->emit(Func);
}

void InstMIPS32::emitTwoAddr(const char *Opcode, const InstMIPS32 *Inst,
                             const Cfg *Func) {
  if (!BuildDefs::dump())
    return;
  Ostream &Str = Func->getContext()->getStrEmit();
  assert(Inst->getSrcSize() == 1);
  Str << "\t" << Opcode << "\t";
  Inst->getDest()->emit(Func);
  Str << ", ";
  Inst->getSrc(0)->emit(Func);
}

void InstMIPS32::emitThreeAddrLoHi(const char *Opcode, const InstMIPS32 *Inst,
                                   const Cfg *Func) {
  if (!BuildDefs::dump())
    return;
  Ostream &Str = Func->getContext()->getStrEmit();
  assert(Inst->getSrcSize() == 2);
  Str << "\t" << Opcode << "\t";
  Inst->getSrc(0)->emit(Func);
  Str << ", ";
  Inst->getSrc(1)->emit(Func);
}

void InstMIPS32Ret::emit(const Cfg *Func) const {
  if (!BuildDefs::dump())
    return;
  assert(getSrcSize() > 0);
  auto *RA = llvm::cast<Variable>(getSrc(0));
  assert(RA->hasReg());
  assert(RA->getRegNum() == RegMIPS32::Reg_RA);
  Ostream &Str = Func->getContext()->getStrEmit();
  Str << "\t"
         "jr"
         "\t";
  RA->emit(Func);
}

void InstMIPS32Br::emitIAS(const Cfg *Func) const {
  auto *Asm = Func->getAssembler<MIPS32::AssemblerMIPS32>();
  if (isUnconditionalBranch()) {
    Asm->b(Asm->getOrCreateCfgNodeLabel(getTargetFalse()->getIndex()));
  } else {
    switch (Predicate) {
    default:
      break;
    case CondMIPS32::EQ:
    case CondMIPS32::NE:
      Asm->bcc(Predicate, getSrc(0), getSrc(1),
               Asm->getOrCreateCfgNodeLabel(getTargetFalse()->getIndex()));
      break;
    case CondMIPS32::EQZ:
    case CondMIPS32::NEZ:
    case CondMIPS32::LEZ:
    case CondMIPS32::LTZ:
    case CondMIPS32::GEZ:
    case CondMIPS32::GTZ:
      Asm->bzc(Predicate, getSrc(0),
               Asm->getOrCreateCfgNodeLabel(getTargetFalse()->getIndex()));
      break;
    }
  }
}

void InstMIPS32Br::emit(const Cfg *Func) const {
  if (!BuildDefs::dump())
    return;
  Ostream &Str = Func->getContext()->getStrEmit();
  Str << "\t"
         "b" << InstMIPS32CondAttributes[Predicate].EmitString << "\t";
  if (Label) {
    Str << Label->getLabelName();
  } else {
    if (isUnconditionalBranch()) {
      Str << getTargetFalse()->getAsmName();
    } else {
      switch (Predicate) {
      default:
        break;
      case CondMIPS32::EQ:
      case CondMIPS32::NE: {
        getSrc(0)->emit(Func);
        Str << ", ";
        getSrc(1)->emit(Func);
        Str << ", ";
        break;
      }
      case CondMIPS32::EQZ:
      case CondMIPS32::NEZ:
      case CondMIPS32::LEZ:
      case CondMIPS32::LTZ:
      case CondMIPS32::GEZ:
      case CondMIPS32::GTZ: {
        getSrc(0)->emit(Func);
        Str << ", ";
        break;
      }
      }
      Str << getTargetFalse()->getAsmName();
      if (getTargetTrue()) {
        Str << "\n\t"
            << "b"
            << "\t" << getTargetTrue()->getAsmName();
      }
    }
  }
}

void InstMIPS32Br::dump(const Cfg *Func) const {
  if (!BuildDefs::dump())
    return;
  Ostream &Str = Func->getContext()->getStrDump();
  Str << "\t"
         "b" << InstMIPS32CondAttributes[Predicate].EmitString << "\t";

  if (Label) {
    Str << Label->getLabelName();
  } else {
    if (isUnconditionalBranch()) {
      Str << getTargetFalse()->getAsmName();
    } else {
      dumpSources(Func);
      Str << ", ";
      Str << getTargetFalse()->getAsmName();
      if (getTargetTrue()) {
        Str << "\n\t"
            << "b"
            << "\t" << getTargetTrue()->getAsmName();
      }
    }
  }
}

void InstMIPS32Call::emit(const Cfg *Func) const {
  if (!BuildDefs::dump())
    return;
  Ostream &Str = Func->getContext()->getStrEmit();
  assert(getSrcSize() == 1);
  if (llvm::isa<ConstantInteger32>(getCallTarget())) {
    // This shouldn't happen (typically have to copy the full 32-bits to a
    // register and do an indirect jump).
    llvm::report_fatal_error("MIPS2Call to ConstantInteger32");
  } else if (const auto *CallTarget =
                 llvm::dyn_cast<ConstantRelocatable>(getCallTarget())) {
    // Calls only have 24-bits, but the linker should insert veneers to extend
    // the range if needed.
    Str << "\t"
           "jal"
           "\t";
    CallTarget->emitWithoutPrefix(Func->getTarget());
  } else {
    Str << "\t"
           "jal"
           "\t";
    getCallTarget()->emit(Func);
  }
}

void InstMIPS32Call::emitIAS(const Cfg *Func) const {
  (void)Func;
  llvm_unreachable("Not yet implemented");
}

void InstMIPS32Call::dump(const Cfg *Func) const {
  if (!BuildDefs::dump())
    return;
  Ostream &Str = Func->getContext()->getStrDump();
  if (getDest()) {
    dumpDest(Func);
    Str << " = ";
  }
  Str << "call ";
  getCallTarget()->dump(Func);
}

void InstMIPS32Ret::emitIAS(const Cfg *Func) const {
  auto *Asm = Func->getAssembler<MIPS32::AssemblerMIPS32>();
  auto *RA = llvm::cast<Variable>(getSrc(0));
  assert(RA->hasReg());
  assert(RA->getRegNum() == RegMIPS32::Reg_RA);
  (void)RA;
  Asm->ret();
}

void InstMIPS32Ret::dump(const Cfg *Func) const {
  if (!BuildDefs::dump())
    return;
  Ostream &Str = Func->getContext()->getStrDump();
  Type Ty = (getSrcSize() == 1 ? IceType_void : getSrc(0)->getType());
  Str << "ret." << Ty << " ";
  dumpSources(Func);
}

void InstMIPS32Mov::emit(const Cfg *Func) const {
  if (!BuildDefs::dump())
    return;
  assert(!(isMultiDest() && isMultiSource()) && "Invalid mov type.");
  if (isMultiDest()) {
    emitMultiDestSingleSource(Func);
    return;
  }

  if (isMultiSource()) {
    emitSingleDestMultiSource(Func);
    return;
  }

  emitSingleDestSingleSource(Func);
}

// TODO(jaydeep.patil) Handle all types of operands in mov
void InstMIPS32Mov::emitIAS(const Cfg *Func) const {
  assert(!(isMultiDest() && isMultiSource()) && "Invalid mov type.");

  if (isMultiDest()) {
    llvm_unreachable("Not yet implemented");
  }
  if (isMultiSource()) {
    llvm_unreachable("Not yet implemented");
  }

  Variable *Dest = getDest();
  Operand *Src = getSrc(0);
  auto *SrcV = llvm::dyn_cast<Variable>(Src);
  assert(!llvm::isa<Constant>(Src));
  const bool DestIsReg = Dest->hasReg();
  const bool SrcIsReg = (SrcV && SrcV->hasReg());

  // reg to reg
  if (DestIsReg && SrcIsReg) {
    switch (Dest->getType()) {
    default:
      break;
    case IceType_i1:
    case IceType_i8:
    case IceType_i16:
    case IceType_i32:
      auto *Asm = Func->getAssembler<MIPS32::AssemblerMIPS32>();
      Asm->move(getDest(), getSrc(0));
      return;
    }
  }
  llvm_unreachable("Not yet implemented");
}

void InstMIPS32Mov::dump(const Cfg *Func) const {
  if (!BuildDefs::dump())
    return;
  assert(getSrcSize() == 1 || getSrcSize() == 2);
  Ostream &Str = Func->getContext()->getStrDump();
  Variable *Dest = getDest();
  Variable *DestHi = getDestHi();
  Dest->dump(Func);
  if (DestHi) {
    Str << ", ";
    DestHi->dump(Func);
  }

  dumpOpcode(Str, " = mov", getDest()->getType());
  Str << " ";

  dumpSources(Func);
}

void InstMIPS32Mov::emitMultiDestSingleSource(const Cfg *Func) const {
  if (!BuildDefs::dump())
    return;
  Ostream &Str = Func->getContext()->getStrEmit();
  Variable *DestLo = getDest();
  Variable *DestHi = getDestHi();
  auto *Src = llvm::cast<Variable>(getSrc(0));

  assert(DestHi->hasReg());
  assert(DestLo->hasReg());
  assert(llvm::isa<Variable>(Src) && Src->hasReg());

  // Str << "\t"
  //    << "vmov" << getPredicate() << "\t";
  DestLo->emit(Func);
  Str << ", ";
  DestHi->emit(Func);
  Str << ", ";
  Src->emit(Func);
}

void InstMIPS32Mov::emitSingleDestMultiSource(const Cfg *Func) const {
  if (!BuildDefs::dump())
    return;
  Ostream &Str = Func->getContext()->getStrEmit();
  Variable *Dest = getDest();
  auto *SrcLo = llvm::cast<Variable>(getSrc(0));
  auto *SrcHi = llvm::cast<Variable>(getSrc(1));

  assert(SrcHi->hasReg());
  assert(SrcLo->hasReg());
  assert(Dest->hasReg());
  assert(getSrcSize() == 2);

  // Str << "\t"
  //    << "vmov" << getPredicate() << "\t";
  Dest->emit(Func);
  Str << ", ";
  SrcLo->emit(Func);
  Str << ", ";
  SrcHi->emit(Func);
}

void InstMIPS32Mov::emitSingleDestSingleSource(const Cfg *Func) const {
  if (!BuildDefs::dump())
    return;
  Ostream &Str = Func->getContext()->getStrEmit();
  Variable *Dest = getDest();
  Operand *Src = getSrc(0);
  auto *SrcV = llvm::dyn_cast<Variable>(Src);

  assert(!llvm::isa<Constant>(Src));

  const char *ActualOpcode = nullptr;
  const bool DestIsReg = Dest->hasReg();
  const bool DestIsMem = !Dest->hasReg();
  const bool SrcIsReg = (SrcV && SrcV->hasReg());
  const bool SrcIsMem = !(SrcV && SrcV->hasReg());

  // reg to reg
  if (DestIsReg && SrcIsReg) {
    switch (Dest->getType()) {
    case IceType_f32:
      ActualOpcode = "mov.s";
      break;
    case IceType_f64:
      ActualOpcode = "mov.d";
      break;
    case IceType_i1:
    case IceType_i8:
    case IceType_i16:
    case IceType_i32:
      Str << "\t"
             "move"
             "\t";
      getDest()->emit(Func);
      Str << ", ";
      getSrc(0)->emit(Func);
      return;
    default:
      UnimplementedError(getFlags());
      return;
    }

    assert(ActualOpcode);
    Str << "\t" << ActualOpcode << "\t";
    getDest()->emit(Func);
    Str << ", ";
    getSrc(0)->emit(Func);
    return;
  }

  // reg to stack
  if (DestIsMem && SrcIsReg) {
    switch (Dest->getType()) {
    case IceType_f32:
      ActualOpcode = "swc1";
      break;
    case IceType_f64:
      ActualOpcode = "sdc1";
      break;
    case IceType_i1:
    case IceType_i8:
    case IceType_i16:
    case IceType_i32:
      ActualOpcode = "sw";
      break;
    default:
      UnimplementedError(getFlags());
      return;
    }

    assert(ActualOpcode);
    Str << "\t" << ActualOpcode << "\t";
    getSrc(0)->emit(Func);
    Str << ", ";
    getDest()->emit(Func);
    return;
  }

  // stack to reg
  if (DestIsReg && SrcIsMem) {
    switch (Dest->getType()) {
    case IceType_f32:
      ActualOpcode = "lwc1";
      break;
    case IceType_f64:
      ActualOpcode = "ldc1";
      break;
    case IceType_i1:
    case IceType_i8:
    case IceType_i16:
    case IceType_i32:
      ActualOpcode = "lw";
      break;
    default:
      UnimplementedError(getFlags());
      return;
    }

    assert(ActualOpcode);
    Str << "\t" << ActualOpcode << "\t";
    getDest()->emit(Func);
    Str << ", ";
    getSrc(0)->emit(Func);
    return;
  }

  // stack to stack
  llvm::report_fatal_error("mov cant copy stack to stack.");
}

template <> void InstMIPS32Addiu::emitIAS(const Cfg *Func) const {
  auto *Asm = Func->getAssembler<MIPS32::AssemblerMIPS32>();
  Asm->addiu(getDest(), getSrc(0), Imm);
}

template <> void InstMIPS32Slti::emitIAS(const Cfg *Func) const {
  auto *Asm = Func->getAssembler<MIPS32::AssemblerMIPS32>();
  Asm->slti(getDest(), getSrc(0), Imm);
}

template <> void InstMIPS32Sltiu::emitIAS(const Cfg *Func) const {
  auto *Asm = Func->getAssembler<MIPS32::AssemblerMIPS32>();
  Asm->sltiu(getDest(), getSrc(0), Imm);
}

template <> void InstMIPS32And::emitIAS(const Cfg *Func) const {
  auto *Asm = Func->getAssembler<MIPS32::AssemblerMIPS32>();
  Asm->and_(getDest(), getSrc(0), getSrc(1));
}

template <> void InstMIPS32Andi::emitIAS(const Cfg *Func) const {
  auto *Asm = Func->getAssembler<MIPS32::AssemblerMIPS32>();
  Asm->andi(getDest(), getSrc(0), Imm);
}

template <> void InstMIPS32Or::emitIAS(const Cfg *Func) const {
  auto *Asm = Func->getAssembler<MIPS32::AssemblerMIPS32>();
  Asm->or_(getDest(), getSrc(0), getSrc(1));
}

template <> void InstMIPS32Ori::emitIAS(const Cfg *Func) const {
  auto *Asm = Func->getAssembler<MIPS32::AssemblerMIPS32>();
  Asm->ori(getDest(), getSrc(0), Imm);
}

template <> void InstMIPS32Xor::emitIAS(const Cfg *Func) const {
  auto *Asm = Func->getAssembler<MIPS32::AssemblerMIPS32>();
  Asm->xor_(getDest(), getSrc(0), getSrc(1));
}

template <> void InstMIPS32Xori::emitIAS(const Cfg *Func) const {
  auto *Asm = Func->getAssembler<MIPS32::AssemblerMIPS32>();
  Asm->xori(getDest(), getSrc(0), Imm);
}

template <> void InstMIPS32Sll::emitIAS(const Cfg *Func) const {
  auto *Asm = Func->getAssembler<MIPS32::AssemblerMIPS32>();
  Asm->sll(getDest(), getSrc(0), Imm);
}

template <> void InstMIPS32Srl::emitIAS(const Cfg *Func) const {
  auto *Asm = Func->getAssembler<MIPS32::AssemblerMIPS32>();
  Asm->srl(getDest(), getSrc(0), Imm);
}

template <> void InstMIPS32Sra::emitIAS(const Cfg *Func) const {
  auto *Asm = Func->getAssembler<MIPS32::AssemblerMIPS32>();
  Asm->sra(getDest(), getSrc(0), Imm);
}

template <> void InstMIPS32Addu::emitIAS(const Cfg *Func) const {
  auto *Asm = Func->getAssembler<MIPS32::AssemblerMIPS32>();
  Asm->addu(getDest(), getSrc(0), getSrc(1));
}

template <> void InstMIPS32Slt::emitIAS(const Cfg *Func) const {
  auto *Asm = Func->getAssembler<MIPS32::AssemblerMIPS32>();
  Asm->slt(getDest(), getSrc(0), getSrc(1));
}

template <> void InstMIPS32Sltu::emitIAS(const Cfg *Func) const {
  auto *Asm = Func->getAssembler<MIPS32::AssemblerMIPS32>();
  Asm->sltu(getDest(), getSrc(0), getSrc(1));
}

template <> void InstMIPS32Sw::emitIAS(const Cfg *Func) const {
  auto *Asm = Func->getAssembler<MIPS32::AssemblerMIPS32>();
  auto *Mem = llvm::dyn_cast<OperandMIPS32Mem>(getSrc(1));
  ConstantInteger32 *Offset = llvm::cast<ConstantInteger32>(Mem->getOffset());
  uint32_t Imm = static_cast<uint32_t>(Offset->getValue());
  Asm->sw(getSrc(0), Mem->getBase(), Imm);
}

template <> void InstMIPS32Lw::emitIAS(const Cfg *Func) const {
  auto *Asm = Func->getAssembler<MIPS32::AssemblerMIPS32>();
  auto *Mem = llvm::dyn_cast<OperandMIPS32Mem>(getSrc(0));
  ConstantInteger32 *Offset = llvm::cast<ConstantInteger32>(Mem->getOffset());
  uint32_t Imm = static_cast<uint32_t>(Offset->getValue());
  Asm->lw(getDest(), Mem->getBase(), Imm);
}

} // end of namespace MIPS32
} // end of namespace Ice