compiler/dex/quick/mips/utility_mips.cc

/*
 * Copyright (C) 2012 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "codegen_mips.h"

#include "arch/mips/instruction_set_features_mips.h"
#include "arch/mips/entrypoints_direct_mips.h"
#include "base/logging.h"
#include "dex/quick/mir_to_lir-inl.h"
#include "dex/reg_storage_eq.h"
#include "dex/mir_graph.h"
#include "driver/compiler_driver.h"
#include "driver/compiler_options.h"
#include "mips_lir.h"

namespace art {

/* This file contains codegen for the Mips ISA */
LIR* MipsMir2Lir::OpFpRegCopy(RegStorage r_dest, RegStorage r_src) {
  int opcode;
  if (cu_->target64) {
    DCHECK_EQ(r_dest.Is64Bit(), r_src.Is64Bit());
    if (r_dest.Is64Bit()) {
      if (r_dest.IsDouble()) {
        if (r_src.IsDouble()) {
          opcode = kMipsFmovd;
        } else {
          // Note the operands are swapped for the dmtc1 instr.
          RegStorage t_opnd = r_src;
          r_src = r_dest;
          r_dest = t_opnd;
          opcode = kMips64Dmtc1;
        }
      } else {
        DCHECK(r_src.IsDouble());
        opcode = kMips64Dmfc1;
      }
    } else {
      if (r_dest.IsSingle()) {
        if (r_src.IsSingle()) {
          opcode = kMipsFmovs;
        } else {
          // Note the operands are swapped for the mtc1 instr.
          RegStorage t_opnd = r_src;
          r_src = r_dest;
          r_dest = t_opnd;
          opcode = kMipsMtc1;
        }
      } else {
        DCHECK(r_src.IsSingle());
        opcode = kMipsMfc1;
      }
    }
  } else {
    // Must be both DOUBLE or both not DOUBLE.
    DCHECK_EQ(r_dest.IsDouble(), r_src.IsDouble());
    if (r_dest.IsDouble()) {
      opcode = kMipsFmovd;
    } else {
      if (r_dest.IsSingle()) {
        if (r_src.IsSingle()) {
          opcode = kMipsFmovs;
        } else {
          // Note the operands are swapped for the mtc1 instr.
          RegStorage t_opnd = r_src;
          r_src = r_dest;
          r_dest = t_opnd;
          opcode = kMipsMtc1;
        }
      } else {
        DCHECK(r_src.IsSingle());
        opcode = kMipsMfc1;
      }
    }
  }
  LIR* res;
  if (cu_->target64) {
    res = RawLIR(current_dalvik_offset_, opcode, r_dest.GetReg(), r_src.GetReg());
  } else {
    res = RawLIR(current_dalvik_offset_, opcode, r_src.GetReg(), r_dest.GetReg());
  }
  if (!(cu_->disable_opt & (1 << kSafeOptimizations)) && r_dest == r_src) {
    res->flags.is_nop = true;
  }
  return res;
}

bool MipsMir2Lir::InexpensiveConstantInt(int32_t value) {
  // For encodings, see LoadConstantNoClobber below.
  return ((value == 0) || IsUint<16>(value) || IsInt<16>(value));
}

bool MipsMir2Lir::InexpensiveConstantFloat(int32_t value ATTRIBUTE_UNUSED) {
  return false;  // TUNING
}

bool MipsMir2Lir::InexpensiveConstantLong(int64_t value ATTRIBUTE_UNUSED) {
  return false;  // TUNING
}

bool MipsMir2Lir::InexpensiveConstantDouble(int64_t value ATTRIBUTE_UNUSED) {
  return false;  // TUNING
}

/*
 * Load a immediate using a shortcut if possible; otherwise
 * grab from the per-translation literal pool.  If target is
 * a high register, build constant into a low register and copy.
 *
 * No additional register clobbering operation performed. Use this version when
 * 1) r_dest is freshly returned from AllocTemp or
 * 2) The codegen is under fixed register usage
 */
LIR* MipsMir2Lir::LoadConstantNoClobber(RegStorage r_dest, int value) {
  LIR *res;

  RegStorage r_dest_save = r_dest;
  int is_fp_reg = r_dest.IsFloat();
  if (is_fp_reg) {
    DCHECK(r_dest.IsSingle());
    r_dest = AllocTemp();
  }

  // See if the value can be constructed cheaply.
  if (value == 0) {
    res = NewLIR2(kMipsMove, r_dest.GetReg(), rZERO);
  } else if (IsUint<16>(value)) {
    // Use OR with (unsigned) immediate to encode 16b unsigned int.
    res = NewLIR3(kMipsOri, r_dest.GetReg(), rZERO, value);
  } else if (IsInt<16>(value)) {
    // Use ADD with (signed) immediate to encode 16b signed int.
    res = NewLIR3(kMipsAddiu, r_dest.GetReg(), rZERO, value);
  } else {
    res = NewLIR2(kMipsLui, r_dest.GetReg(), value >> 16);
    if (value & 0xffff)
      NewLIR3(kMipsOri, r_dest.GetReg(), r_dest.GetReg(), value);
  }

  if (is_fp_reg) {
    NewLIR2(kMipsMtc1, r_dest.GetReg(), r_dest_save.GetReg());
    FreeTemp(r_dest);
  }

  return res;
}

LIR* MipsMir2Lir::LoadConstantWideNoClobber(RegStorage r_dest, int64_t value) {
  LIR* res = nullptr;
  DCHECK(r_dest.Is64Bit());
  RegStorage r_dest_save = r_dest;
  int is_fp_reg = r_dest.IsFloat();
  if (is_fp_reg) {
    DCHECK(r_dest.IsDouble());
    r_dest = AllocTemp();
  }

  int bit31 = (value & UINT64_C(0x80000000)) != 0;

  // Loads with 1 instruction.
  if (IsUint<16>(value)) {
    res = NewLIR3(kMipsOri, r_dest.GetReg(), rZEROd, value);
  } else if (IsInt<16>(value)) {
    res = NewLIR3(kMips64Daddiu, r_dest.GetReg(), rZEROd, value);
  } else if ((value & 0xFFFF) == 0 && IsInt<16>(value >> 16)) {
    res = NewLIR2(kMipsLui, r_dest.GetReg(), value >> 16);
  } else if (IsInt<32>(value)) {
    // Loads with 2 instructions.
    res = NewLIR2(kMipsLui, r_dest.GetReg(), value >> 16);
    NewLIR3(kMipsOri, r_dest.GetReg(), r_dest.GetReg(), value);
  } else if ((value & 0xFFFF0000) == 0 && IsInt<16>(value >> 32)) {
    res = NewLIR3(kMipsOri, r_dest.GetReg(), rZEROd, value);
    NewLIR2(kMips64Dahi, r_dest.GetReg(), value >> 32);
  } else if ((value & UINT64_C(0xFFFFFFFF0000)) == 0) {
    res = NewLIR3(kMipsOri, r_dest.GetReg(), rZEROd, value);
    NewLIR2(kMips64Dati, r_dest.GetReg(), value >> 48);
  } else if ((value & 0xFFFF) == 0 && (value >> 32) >= (-32768 - bit31) &&
             (value >> 32) <= (32767 - bit31)) {
    res = NewLIR2(kMipsLui, r_dest.GetReg(), value >> 16);
    NewLIR2(kMips64Dahi, r_dest.GetReg(), (value >> 32) + bit31);
  } else if ((value & 0xFFFF) == 0 && ((value >> 31) & 0x1FFFF) == ((0x20000 - bit31) & 0x1FFFF)) {
    res = NewLIR2(kMipsLui, r_dest.GetReg(), value >> 16);
    NewLIR2(kMips64Dati, r_dest.GetReg(), (value >> 48) + bit31);
  } else {
    int64_t tmp = value;
    int shift_cnt = 0;
    while ((tmp & 1) == 0) {
      tmp >>= 1;
      shift_cnt++;
    }

    if (IsUint<16>(tmp)) {
      res = NewLIR3(kMipsOri, r_dest.GetReg(), rZEROd, tmp);
      NewLIR3((shift_cnt < 32) ? kMips64Dsll : kMips64Dsll32, r_dest.GetReg(), r_dest.GetReg(),
              shift_cnt & 0x1F);
    } else if (IsInt<16>(tmp)) {
      res = NewLIR3(kMips64Daddiu, r_dest.GetReg(), rZEROd, tmp);
      NewLIR3((shift_cnt < 32) ? kMips64Dsll : kMips64Dsll32, r_dest.GetReg(), r_dest.GetReg(),
              shift_cnt & 0x1F);
    } else if (IsInt<32>(tmp)) {
      // Loads with 3 instructions.
      res = NewLIR2(kMipsLui, r_dest.GetReg(), tmp >> 16);
      NewLIR3(kMipsOri, r_dest.GetReg(), r_dest.GetReg(), tmp);
      NewLIR3((shift_cnt < 32) ? kMips64Dsll : kMips64Dsll32, r_dest.GetReg(), r_dest.GetReg(),
              shift_cnt & 0x1F);
    } else {
      tmp = value >> 16;
      shift_cnt = 16;
      while ((tmp & 1) == 0) {
        tmp >>= 1;
        shift_cnt++;
      }

      if (IsUint<16>(tmp)) {
        res = NewLIR3(kMipsOri, r_dest.GetReg(), rZEROd, tmp);
        NewLIR3((shift_cnt < 32) ? kMips64Dsll : kMips64Dsll32, r_dest.GetReg(), r_dest.GetReg(),
                shift_cnt & 0x1F);
        NewLIR3(kMipsOri, r_dest.GetReg(), r_dest.GetReg(), value);
      } else if (IsInt<16>(tmp)) {
        res = NewLIR3(kMips64Daddiu, r_dest.GetReg(), rZEROd, tmp);
        NewLIR3((shift_cnt < 32) ? kMips64Dsll : kMips64Dsll32, r_dest.GetReg(), r_dest.GetReg(),
                shift_cnt & 0x1F);
        NewLIR3(kMipsOri, r_dest.GetReg(), r_dest.GetReg(), value);
      } else {
        // Loads with 3-4 instructions.
        uint64_t tmp2 = value;
        if (((tmp2 >> 16) & 0xFFFF) != 0 || (tmp2 & 0xFFFFFFFF) == 0) {
          res = NewLIR2(kMipsLui, r_dest.GetReg(), tmp2 >> 16);
        }
        if ((tmp2 & 0xFFFF) != 0) {
          if (res)
            NewLIR3(kMipsOri, r_dest.GetReg(), r_dest.GetReg(), tmp2);
          else
            res = NewLIR3(kMipsOri, r_dest.GetReg(), rZEROd, tmp2);
        }
        if (bit31) {
          tmp2 += UINT64_C(0x100000000);
        }
        if (((tmp2 >> 32) & 0xFFFF) != 0) {
          NewLIR2(kMips64Dahi, r_dest.GetReg(), tmp2 >> 32);
        }
        if (tmp2 & UINT64_C(0x800000000000)) {
          tmp2 += UINT64_C(0x1000000000000);
        }
        if ((tmp2 >> 48) != 0) {
          NewLIR2(kMips64Dati, r_dest.GetReg(), tmp2 >> 48);
        }
      }
    }
  }

  if (is_fp_reg) {
    NewLIR2(kMips64Dmtc1, r_dest.GetReg(), r_dest_save.GetReg());
    FreeTemp(r_dest);
  }
  return res;
}

LIR* MipsMir2Lir::OpUnconditionalBranch(LIR* target) {
  LIR* res = NewLIR1(kMipsB, 0 /* offset to be patched during assembly*/);
  res->target = target;
  return res;
}

LIR* MipsMir2Lir::OpReg(OpKind op, RegStorage r_dest_src) {
  MipsOpCode opcode = kMipsNop;
  switch (op) {
    case kOpBlx:
      opcode = kMipsJalr;
      break;
    case kOpBx:
      return NewLIR2(kMipsJalr, rZERO, r_dest_src.GetReg());
    default:
      LOG(FATAL) << "Bad case in OpReg";
      UNREACHABLE();
  }
  return NewLIR2(opcode, cu_->target64 ? rRAd : rRA, r_dest_src.GetReg());
}

LIR* MipsMir2Lir::OpRegImm(OpKind op, RegStorage r_dest_src1, int value) {
  if ((op == kOpAdd) || (op == kOpSub)) {
    return OpRegRegImm(op, r_dest_src1, r_dest_src1, value);
  } else {
    LOG(FATAL) << "Bad case in OpRegImm";
    UNREACHABLE();
  }
}

LIR* MipsMir2Lir::OpRegRegReg(OpKind op, RegStorage r_dest, RegStorage r_src1, RegStorage r_src2) {
  MipsOpCode opcode = kMipsNop;
  bool is64bit = cu_->target64 && (r_dest.Is64Bit() || r_src1.Is64Bit() || r_src2.Is64Bit());
  switch (op) {
    case kOpAdd:
      opcode = is64bit ? kMips64Daddu : kMipsAddu;
      break;
    case kOpSub:
      opcode = is64bit ? kMips64Dsubu : kMipsSubu;
      break;
    case kOpAnd:
      opcode = kMipsAnd;
      break;
    case kOpMul:
      opcode = isaIsR6_ ? kMipsR6Mul : kMipsR2Mul;
      break;
    case kOpOr:
      opcode = kMipsOr;
      break;
    case kOpXor:
      opcode = kMipsXor;
      break;
    case kOpLsl:
      opcode = is64bit ? kMips64Dsllv : kMipsSllv;
      break;
    case kOpLsr:
      opcode = is64bit ? kMips64Dsrlv : kMipsSrlv;
      break;
    case kOpAsr:
      opcode = is64bit ? kMips64Dsrav : kMipsSrav;
      break;
    case kOpAdc:
    case kOpSbc:
      LOG(FATAL) << "No carry bit on MIPS";
      break;
    default:
      LOG(FATAL) << "Bad case in OpRegRegReg";
      break;
  }
  return NewLIR3(opcode, r_dest.GetReg(), r_src1.GetReg(), r_src2.GetReg());
}

LIR* MipsMir2Lir::OpRegRegImm(OpKind op, RegStorage r_dest, RegStorage r_src1, int value) {
  LIR *res;
  MipsOpCode opcode = kMipsNop;
  bool short_form = true;
  bool is64bit = cu_->target64 && (r_dest.Is64Bit() || r_src1.Is64Bit());

  switch (op) {
    case kOpAdd:
      if (IS_SIMM16(value)) {
        opcode = is64bit ? kMips64Daddiu : kMipsAddiu;
      } else {
        short_form = false;
        opcode = is64bit ? kMips64Daddu : kMipsAddu;
      }
      break;
    case kOpSub:
      if (IS_SIMM16((-value))) {
        value = -value;
        opcode = is64bit ? kMips64Daddiu : kMipsAddiu;
      } else {
        short_form = false;
        opcode = is64bit ? kMips64Dsubu : kMipsSubu;
      }
      break;
    case kOpLsl:
      if (is64bit) {
        DCHECK(value >= 0 && value <= 63);
        if (value >= 0 && value <= 31) {
          opcode = kMips64Dsll;
        } else {
          opcode = kMips64Dsll32;
          value = value - 32;
        }
      } else {
        DCHECK(value >= 0 && value <= 31);
        opcode = kMipsSll;
      }
      break;
    case kOpLsr:
      if (is64bit) {
        DCHECK(value >= 0 && value <= 63);
        if (value >= 0 && value <= 31) {
          opcode = kMips64Dsrl;
        } else {
          opcode = kMips64Dsrl32;
          value = value - 32;
        }
      } else {
        DCHECK(value >= 0 && value <= 31);
        opcode = kMipsSrl;
      }
      break;
    case kOpAsr:
      if (is64bit) {
        DCHECK(value >= 0 && value <= 63);
        if (value >= 0 && value <= 31) {
          opcode = kMips64Dsra;
        } else {
          opcode = kMips64Dsra32;
          value = value - 32;
        }
      } else {
        DCHECK(value >= 0 && value <= 31);
        opcode = kMipsSra;
      }
      break;
    case kOpAnd:
      if (IS_UIMM16((value))) {
        opcode = kMipsAndi;
      } else {
        short_form = false;
        opcode = kMipsAnd;
      }
      break;
    case kOpOr:
      if (IS_UIMM16((value))) {
        opcode = kMipsOri;
      } else {
        short_form = false;
        opcode = kMipsOr;
      }
      break;
    case kOpXor:
      if (IS_UIMM16((value))) {
        opcode = kMipsXori;
      } else {
        short_form = false;
        opcode = kMipsXor;
      }
      break;
    case kOpMul:
      short_form = false;
      opcode = isaIsR6_ ? kMipsR6Mul : kMipsR2Mul;
      break;
    default:
      LOG(FATAL) << "Bad case in OpRegRegImm";
      break;
  }

  if (short_form) {
    res = NewLIR3(opcode, r_dest.GetReg(), r_src1.GetReg(), value);
  } else {
    if (r_dest != r_src1) {
      res = LoadConstant(r_dest, value);
      NewLIR3(opcode, r_dest.GetReg(), r_src1.GetReg(), r_dest.GetReg());
    } else {
      RegStorage r_scratch;
      if (is64bit) {
        r_scratch = AllocTempWide();
        res = LoadConstantWide(r_scratch, value);
      } else {
        r_scratch = AllocTemp();
        res = LoadConstant(r_scratch, value);
      }
      NewLIR3(opcode, r_dest.GetReg(), r_src1.GetReg(), r_scratch.GetReg());
    }
  }
  return res;
}

LIR* MipsMir2Lir::OpRegReg(OpKind op, RegStorage r_dest_src1, RegStorage r_src2) {
  MipsOpCode opcode = kMipsNop;
  LIR *res;
  switch (op) {
    case kOpMov:
      opcode = kMipsMove;
      break;
    case kOpMvn:
      return NewLIR3(kMipsNor, r_dest_src1.GetReg(), r_src2.GetReg(), rZERO);
    case kOpNeg:
      if (cu_->target64 && r_dest_src1.Is64Bit()) {
        return NewLIR3(kMips64Dsubu, r_dest_src1.GetReg(), rZEROd, r_src2.GetReg());
      } else {
        return NewLIR3(kMipsSubu, r_dest_src1.GetReg(), rZERO, r_src2.GetReg());
      }
    case kOpAdd:
    case kOpAnd:
    case kOpMul:
    case kOpOr:
    case kOpSub:
    case kOpXor:
      return OpRegRegReg(op, r_dest_src1, r_dest_src1, r_src2);
    case kOp2Byte:
      if (cu_->target64) {
        res = NewLIR2(kMipsSeb, r_dest_src1.GetReg(), r_src2.GetReg());
      } else {
        if (cu_->compiler_driver->GetInstructionSetFeatures()->AsMipsInstructionSetFeatures()
            ->IsMipsIsaRevGreaterThanEqual2()) {
          res = NewLIR2(kMipsSeb, r_dest_src1.GetReg(), r_src2.GetReg());
        } else {
          res = OpRegRegImm(kOpLsl, r_dest_src1, r_src2, 24);
          OpRegRegImm(kOpAsr, r_dest_src1, r_dest_src1, 24);
        }
      }
      return res;
    case kOp2Short:
      if (cu_->target64) {
        res = NewLIR2(kMipsSeh, r_dest_src1.GetReg(), r_src2.GetReg());
      } else {
        if (cu_->compiler_driver->GetInstructionSetFeatures()->AsMipsInstructionSetFeatures()
            ->IsMipsIsaRevGreaterThanEqual2()) {
          res = NewLIR2(kMipsSeh, r_dest_src1.GetReg(), r_src2.GetReg());
        } else {
          res = OpRegRegImm(kOpLsl, r_dest_src1, r_src2, 16);
          OpRegRegImm(kOpAsr, r_dest_src1, r_dest_src1, 16);
        }
      }
      return res;
    case kOp2Char:
      return NewLIR3(kMipsAndi, r_dest_src1.GetReg(), r_src2.GetReg(), 0xFFFF);
    default:
      LOG(FATAL) << "Bad case in OpRegReg";
      UNREACHABLE();
  }
  return NewLIR2(opcode, r_dest_src1.GetReg(), r_src2.GetReg());
}

LIR* MipsMir2Lir::OpMovRegMem(RegStorage r_dest ATTRIBUTE_UNUSED,
                              RegStorage r_base ATTRIBUTE_UNUSED,
                              int offset ATTRIBUTE_UNUSED,
                              MoveType move_type ATTRIBUTE_UNUSED) {
  UNIMPLEMENTED(FATAL);
  UNREACHABLE();
}

LIR* MipsMir2Lir::OpMovMemReg(RegStorage r_base ATTRIBUTE_UNUSED,
                              int offset ATTRIBUTE_UNUSED,
                              RegStorage r_src ATTRIBUTE_UNUSED,
                              MoveType move_type ATTRIBUTE_UNUSED) {
  UNIMPLEMENTED(FATAL);
  UNREACHABLE();
}

LIR* MipsMir2Lir::OpCondRegReg(OpKind op ATTRIBUTE_UNUSED,
                               ConditionCode cc ATTRIBUTE_UNUSED,
                               RegStorage r_dest ATTRIBUTE_UNUSED,
                               RegStorage r_src ATTRIBUTE_UNUSED) {
  LOG(FATAL) << "Unexpected use of OpCondRegReg for MIPS";
  UNREACHABLE();
}

LIR* MipsMir2Lir::LoadConstantWide(RegStorage r_dest, int64_t value) {
  LIR *res;
  if (cu_->target64) {
    res = LoadConstantWideNoClobber(r_dest, value);
    return res;
  }
  if (fpuIs32Bit_ || !r_dest.IsFloat()) {
    // 32bit FPU (pairs) or loading into GPR.
    if (!r_dest.IsPair()) {
      // Form 64-bit pair.
      r_dest = Solo64ToPair64(r_dest);
    }
    res = LoadConstantNoClobber(r_dest.GetLow(), Low32Bits(value));
    LoadConstantNoClobber(r_dest.GetHigh(), High32Bits(value));
  } else {
    // Here if we have a 64bit FPU and loading into FPR.
    RegStorage r_temp = AllocTemp();
    r_dest = Fp64ToSolo32(r_dest);
    res = LoadConstantNoClobber(r_dest, Low32Bits(value));
    LoadConstantNoClobber(r_temp, High32Bits(value));
    NewLIR2(kMipsMthc1, r_temp.GetReg(), r_dest.GetReg());
    FreeTemp(r_temp);
  }
  return res;
}

/* Load value from base + scaled index. */
LIR* MipsMir2Lir::LoadBaseIndexed(RegStorage r_base, RegStorage r_index, RegStorage r_dest,
                                  int scale, OpSize size) {
  LIR *first = nullptr;
  LIR *res;
  MipsOpCode opcode = kMipsNop;
  bool is64bit = cu_->target64 && r_dest.Is64Bit();
  RegStorage t_reg = is64bit ? AllocTempWide() : AllocTemp();

  if (r_dest.IsFloat()) {
    DCHECK(r_dest.IsSingle());
    DCHECK((size == k32) || (size == kSingle) || (size == kReference));
    size = kSingle;
  } else {
    if (size == kSingle)
      size = k32;
  }

  if (cu_->target64) {
    if (!scale) {
      if (is64bit) {
        first = NewLIR3(kMips64Daddu, t_reg.GetReg() , r_base.GetReg(), r_index.GetReg());
      } else {
        first = NewLIR3(kMipsAddu, t_reg.GetReg() , r_base.GetReg(), r_index.GetReg());
      }
    } else {
      first = OpRegRegImm(kOpLsl, t_reg, r_index, scale);
      NewLIR3(kMips64Daddu, t_reg.GetReg() , r_base.GetReg(), t_reg.GetReg());
    }
  } else {
    if (!scale) {
      first = NewLIR3(kMipsAddu, t_reg.GetReg() , r_base.GetReg(), r_index.GetReg());
    } else {
      first = OpRegRegImm(kOpLsl, t_reg, r_index, scale);
      NewLIR3(kMipsAddu, t_reg.GetReg() , r_base.GetReg(), t_reg.GetReg());
    }
  }

  switch (size) {
    case k64:
      if (cu_->target64) {
        opcode = kMips64Ld;
      } else {
        LOG(FATAL) << "Bad case in LoadBaseIndexed";
      }
      break;
    case kSingle:
      opcode = kMipsFlwc1;
      break;
    case k32:
    case kReference:
      opcode = kMipsLw;
      break;
    case kUnsignedHalf:
      opcode = kMipsLhu;
      break;
    case kSignedHalf:
      opcode = kMipsLh;
      break;
    case kUnsignedByte:
      opcode = kMipsLbu;
      break;
    case kSignedByte:
      opcode = kMipsLb;
      break;
    default:
      LOG(FATAL) << "Bad case in LoadBaseIndexed";
  }

  res = NewLIR3(opcode, r_dest.GetReg(), 0, t_reg.GetReg());
  FreeTemp(t_reg);
  return (first) ? first : res;
}

// Store value base base + scaled index.
LIR* MipsMir2Lir::StoreBaseIndexed(RegStorage r_base, RegStorage r_index, RegStorage r_src,
                                   int scale, OpSize size) {
  LIR *first = nullptr;
  MipsOpCode opcode = kMipsNop;
  RegStorage t_reg = AllocTemp();

  if (r_src.IsFloat()) {
    DCHECK(r_src.IsSingle());
    DCHECK((size == k32) || (size == kSingle) || (size == kReference));
    size = kSingle;
  } else {
    if (size == kSingle)
      size = k32;
  }

  MipsOpCode add_opcode = cu_->target64 ? kMips64Daddu : kMipsAddu;
  if (!scale) {
    first = NewLIR3(add_opcode, t_reg.GetReg() , r_base.GetReg(), r_index.GetReg());
  } else {
    first = OpRegRegImm(kOpLsl, t_reg, r_index, scale);
    NewLIR3(add_opcode, t_reg.GetReg() , r_base.GetReg(), t_reg.GetReg());
  }

  switch (size) {
    case kSingle:
      opcode = kMipsFswc1;
      break;
    case k32:
    case kReference:
      opcode = kMipsSw;
      break;
    case kUnsignedHalf:
    case kSignedHalf:
      opcode = kMipsSh;
      break;
    case kUnsignedByte:
    case kSignedByte:
      opcode = kMipsSb;
      break;
    default:
      LOG(FATAL) << "Bad case in StoreBaseIndexed";
  }
  NewLIR3(opcode, r_src.GetReg(), 0, t_reg.GetReg());
  return first;
}

// FIXME: don't split r_dest into 2 containers.
LIR* MipsMir2Lir::LoadBaseDispBody(RegStorage r_base, int displacement, RegStorage r_dest,
                                   OpSize size) {
/*
 * Load value from base + displacement.  Optionally perform null check
 * on base (which must have an associated s_reg and MIR).  If not
 * performing null check, incoming MIR can be null. IMPORTANT: this
 * code must not allocate any new temps.  If a new register is needed
 * and base and dest are the same, spill some other register to
 * rlp and then restore.
 */
  LIR *res;
  LIR *load = nullptr;
  LIR *load2 = nullptr;
  MipsOpCode opcode = kMipsNop;
  bool short_form = IS_SIMM16(displacement);
  bool is64bit = false;

  switch (size) {
    case k64:
    case kDouble:
      if (cu_->target64) {
        r_dest = Check64BitReg(r_dest);
        if (!r_dest.IsFloat()) {
          opcode = kMips64Ld;
        } else {
          opcode = kMipsFldc1;
        }
        DCHECK_ALIGNED(displacement, 4);
        break;
      }
      is64bit = true;
      if (fpuIs32Bit_ && !r_dest.IsPair()) {
        // Form 64-bit pair.
        r_dest = Solo64ToPair64(r_dest);
      }
      short_form = IS_SIMM16_2WORD(displacement);
      FALLTHROUGH_INTENDED;
    case k32:
    case kSingle:
    case kReference:
      opcode = kMipsLw;
      if (r_dest.IsFloat()) {
        opcode = kMipsFlwc1;
        if (!is64bit) {
          DCHECK(r_dest.IsSingle());
        } else {
          DCHECK(r_dest.IsDouble());
        }
      }
      DCHECK_ALIGNED(displacement, 4);
      break;
    case kUnsignedHalf:
      opcode = kMipsLhu;
      DCHECK_ALIGNED(displacement, 2);
      break;
    case kSignedHalf:
      opcode = kMipsLh;
      DCHECK_ALIGNED(displacement, 2);
      break;
    case kUnsignedByte:
      opcode = kMipsLbu;
      break;
    case kSignedByte:
      opcode = kMipsLb;
      break;
    default:
      LOG(FATAL) << "Bad case in LoadBaseIndexedBody";
  }

  if (cu_->target64) {
    if (short_form) {
      load = res = NewLIR3(opcode, r_dest.GetReg(), displacement, r_base.GetReg());
    } else {
      RegStorage r_tmp = (r_base == r_dest) ? AllocTemp() : r_dest;
      res = OpRegRegImm(kOpAdd, r_tmp, r_base, displacement);
      load = NewLIR3(opcode, r_dest.GetReg(), 0, r_tmp.GetReg());
      if (r_tmp != r_dest)
        FreeTemp(r_tmp);
    }

    if (mem_ref_type_ == ResourceMask::kDalvikReg) {
      DCHECK_EQ(r_base, TargetPtrReg(kSp));
      AnnotateDalvikRegAccess(load, displacement >> 2, true /* is_load */, r_dest.Is64Bit());
    }
    return res;
  }

  if (short_form) {
    if (!is64bit) {
      load = res = NewLIR3(opcode, r_dest.GetReg(), displacement, r_base.GetReg());
    } else {
      if (fpuIs32Bit_ || !r_dest.IsFloat()) {
        DCHECK(r_dest.IsPair());
        load = res = NewLIR3(opcode, r_dest.GetLowReg(), displacement + LOWORD_OFFSET,
                             r_base.GetReg());
        load2 = NewLIR3(opcode, r_dest.GetHighReg(), displacement + HIWORD_OFFSET, r_base.GetReg());
      } else {
        // Here if 64bit fpu and r_dest is a 64bit fp register.
        RegStorage r_tmp = AllocTemp();
        // FIXME: why is r_dest a 64BitPair here???
        r_dest = Fp64ToSolo32(r_dest);
        load = res = NewLIR3(kMipsFlwc1, r_dest.GetReg(), displacement + LOWORD_OFFSET,
                             r_base.GetReg());
        load2 = NewLIR3(kMipsLw, r_tmp.GetReg(), displacement + HIWORD_OFFSET, r_base.GetReg());
        NewLIR2(kMipsMthc1, r_tmp.GetReg(), r_dest.GetReg());
        FreeTemp(r_tmp);
      }
    }
  } else {
    if (!is64bit) {
      RegStorage r_tmp = (r_base == r_dest || r_dest.IsFloat()) ? AllocTemp() : r_dest;
      res = OpRegRegImm(kOpAdd, r_tmp, r_base, displacement);
      load = NewLIR3(opcode, r_dest.GetReg(), 0, r_tmp.GetReg());
      if (r_tmp != r_dest)
        FreeTemp(r_tmp);
    } else {
      RegStorage r_tmp = AllocTemp();
      res = OpRegRegImm(kOpAdd, r_tmp, r_base, displacement);
      if (fpuIs32Bit_ || !r_dest.IsFloat()) {
        DCHECK(r_dest.IsPair());
        load = NewLIR3(opcode, r_dest.GetLowReg(), LOWORD_OFFSET, r_tmp.GetReg());
        load2 = NewLIR3(opcode, r_dest.GetHighReg(), HIWORD_OFFSET, r_tmp.GetReg());
      } else {
        // Here if 64bit fpu and r_dest is a 64bit fp register
        r_dest = Fp64ToSolo32(r_dest);
        load = res = NewLIR3(kMipsFlwc1, r_dest.GetReg(), LOWORD_OFFSET, r_tmp.GetReg());
        load2 = NewLIR3(kMipsLw, r_tmp.GetReg(), HIWORD_OFFSET, r_tmp.GetReg());
        NewLIR2(kMipsMthc1, r_tmp.GetReg(), r_dest.GetReg());
      }
      FreeTemp(r_tmp);
    }
  }

  if (mem_ref_type_ == ResourceMask::kDalvikReg) {
    DCHECK_EQ(r_base, TargetPtrReg(kSp));
    AnnotateDalvikRegAccess(load, (displacement + (is64bit ? LOWORD_OFFSET : 0)) >> 2,
                            true /* is_load */, is64bit /* is64bit */);
    if (is64bit) {
      AnnotateDalvikRegAccess(load2, (displacement + HIWORD_OFFSET) >> 2,
                              true /* is_load */, is64bit /* is64bit */);
    }
  }
  return res;
}

void MipsMir2Lir::ForceImplicitNullCheck(RegStorage reg, int opt_flags, bool is_wide) {
  if (cu_->compiler_driver->GetCompilerOptions().GetImplicitNullChecks()) {
    if (!(cu_->disable_opt & (1 << kNullCheckElimination)) && (opt_flags & MIR_IGNORE_NULL_CHECK)) {
      return;
    }
    // Force an implicit null check by performing a memory operation (load) from the given
    // register with offset 0.  This will cause a signal if the register contains 0 (null).
    LIR* load = Load32Disp(reg, LOWORD_OFFSET, rs_rZERO);
    MarkSafepointPC(load);
    if (is_wide) {
      load = Load32Disp(reg, HIWORD_OFFSET, rs_rZERO);
      MarkSafepointPC(load);
    }
  }
}

LIR* MipsMir2Lir::LoadBaseDisp(RegStorage r_base, int displacement, RegStorage r_dest, OpSize size,
                               VolatileKind is_volatile) {
  if (UNLIKELY(is_volatile == kVolatile && (size == k64 || size == kDouble))
      && (!cu_->target64 || displacement & 0x7)) {
    // TODO: use lld/scd instructions for Mips64.
    // Do atomic 64-bit load.
    return GenAtomic64Load(r_base, displacement, r_dest);
  }

  // TODO: base this on target.
  if (size == kWord) {
    size = cu_->target64 ? k64 : k32;
  }
  LIR* load;
  load = LoadBaseDispBody(r_base, displacement, r_dest, size);

  if (UNLIKELY(is_volatile == kVolatile)) {
    GenMemBarrier(kLoadAny);
  }

  return load;
}

// FIXME: don't split r_dest into 2 containers.
LIR* MipsMir2Lir::StoreBaseDispBody(RegStorage r_base, int displacement, RegStorage r_src,
                                    OpSize size) {
  LIR *res;
  LIR *store = nullptr;
  LIR *store2 = nullptr;
  MipsOpCode opcode = kMipsNop;
  bool short_form = IS_SIMM16(displacement);
  bool is64bit = false;

  switch (size) {
    case k64:
    case kDouble:
      if (cu_->target64) {
        r_src = Check64BitReg(r_src);
        if (!r_src.IsFloat()) {
          opcode = kMips64Sd;
        } else {
          opcode = kMipsFsdc1;
        }
        DCHECK_ALIGNED(displacement, 4);
        break;
      }
      is64bit = true;
      if (fpuIs32Bit_ && !r_src.IsPair()) {
        // Form 64-bit pair.
        r_src = Solo64ToPair64(r_src);
      }
      short_form = IS_SIMM16_2WORD(displacement);
      FALLTHROUGH_INTENDED;
    case k32:
    case kSingle:
    case kReference:
      opcode = kMipsSw;
      if (r_src.IsFloat()) {
        opcode = kMipsFswc1;
        if (!is64bit) {
          DCHECK(r_src.IsSingle());
        } else {
          DCHECK(r_src.IsDouble());
        }
      }
      DCHECK_ALIGNED(displacement, 4);
      break;
    case kUnsignedHalf:
    case kSignedHalf:
      opcode = kMipsSh;
      DCHECK_ALIGNED(displacement, 2);
      break;
    case kUnsignedByte:
    case kSignedByte:
      opcode = kMipsSb;
      break;
    default:
      LOG(FATAL) << "Bad case in StoreBaseDispBody";
  }

  if (cu_->target64) {
    if (short_form) {
      store = res = NewLIR3(opcode, r_src.GetReg(), displacement, r_base.GetReg());
    } else {
      RegStorage r_scratch = AllocTemp();
      res = OpRegRegImm(kOpAdd, r_scratch, r_base, displacement);
      store = NewLIR3(opcode, r_src.GetReg(), 0, r_scratch.GetReg());
      FreeTemp(r_scratch);
    }

    if (mem_ref_type_ == ResourceMask::kDalvikReg) {
      DCHECK_EQ(r_base, TargetPtrReg(kSp));
      AnnotateDalvikRegAccess(store, displacement >> 2, false /* is_load */, r_src.Is64Bit());
    }
    return res;
  }

  if (short_form) {
    if (!is64bit) {
      store = res = NewLIR3(opcode, r_src.GetReg(), displacement, r_base.GetReg());
    } else {
      if (fpuIs32Bit_ || !r_src.IsFloat()) {
        DCHECK(r_src.IsPair());
        store = res = NewLIR3(opcode, r_src.GetLowReg(), displacement + LOWORD_OFFSET,
                              r_base.GetReg());
        store2 = NewLIR3(opcode, r_src.GetHighReg(), displacement + HIWORD_OFFSET, r_base.GetReg());
      } else {
        // Here if 64bit fpu and r_src is a 64bit fp register
        RegStorage r_tmp = AllocTemp();
        r_src = Fp64ToSolo32(r_src);
        store = res = NewLIR3(kMipsFswc1, r_src.GetReg(), displacement + LOWORD_OFFSET,
                              r_base.GetReg());
        NewLIR2(kMipsMfhc1, r_tmp.GetReg(), r_src.GetReg());
        store2 = NewLIR3(kMipsSw, r_tmp.GetReg(), displacement + HIWORD_OFFSET, r_base.GetReg());
        FreeTemp(r_tmp);
      }
    }
  } else {
    RegStorage r_scratch = AllocTemp();
    res = OpRegRegImm(kOpAdd, r_scratch, r_base, displacement);
    if (!is64bit) {
      store =  NewLIR3(opcode, r_src.GetReg(), 0, r_scratch.GetReg());
    } else {
      if (fpuIs32Bit_ || !r_src.IsFloat()) {
        DCHECK(r_src.IsPair());
        store = NewLIR3(opcode, r_src.GetLowReg(), LOWORD_OFFSET, r_scratch.GetReg());
        store2 = NewLIR3(opcode, r_src.GetHighReg(), HIWORD_OFFSET, r_scratch.GetReg());
      } else {
        // Here if 64bit fpu and r_src is a 64bit fp register
        RegStorage r_tmp = AllocTemp();
        r_src = Fp64ToSolo32(r_src);
        store = NewLIR3(kMipsFswc1, r_src.GetReg(), LOWORD_OFFSET, r_scratch.GetReg());
        NewLIR2(kMipsMfhc1, r_tmp.GetReg(), r_src.GetReg());
        store2 = NewLIR3(kMipsSw, r_tmp.GetReg(), HIWORD_OFFSET, r_scratch.GetReg());
        FreeTemp(r_tmp);
      }
    }
    FreeTemp(r_scratch);
  }

  if (mem_ref_type_ == ResourceMask::kDalvikReg) {
    DCHECK_EQ(r_base, TargetPtrReg(kSp));
    AnnotateDalvikRegAccess(store, (displacement + (is64bit ? LOWORD_OFFSET : 0)) >> 2,
                            false /* is_load */, is64bit /* is64bit */);
    if (is64bit) {
      AnnotateDalvikRegAccess(store2, (displacement + HIWORD_OFFSET) >> 2,
                              false /* is_load */, is64bit /* is64bit */);
    }
  }

  return res;
}

LIR* MipsMir2Lir::StoreBaseDisp(RegStorage r_base, int displacement, RegStorage r_src, OpSize size,
                                VolatileKind is_volatile) {
  if (is_volatile == kVolatile) {
    // Ensure that prior accesses become visible to other threads first.
    GenMemBarrier(kAnyStore);
  }

  LIR* store;
  if (UNLIKELY(is_volatile == kVolatile && (size == k64 || size == kDouble) &&
      (!cu_->target64 || displacement & 0x7))) {
    // TODO: use lld/scd instructions for Mips64.
    // Do atomic 64-bit load.
    store = GenAtomic64Store(r_base, displacement, r_src);
  } else {
    // TODO: base this on target.
    if (size == kWord) {
      size = cu_->target64 ? k64 : k32;
    }
    store = StoreBaseDispBody(r_base, displacement, r_src, size);
  }

  if (UNLIKELY(is_volatile == kVolatile)) {
    // Preserve order with respect to any subsequent volatile loads.
    // We need StoreLoad, but that generally requires the most expensive barrier.
    GenMemBarrier(kAnyAny);
  }

  return store;
}

LIR* MipsMir2Lir::OpMem(OpKind op ATTRIBUTE_UNUSED,
                        RegStorage r_base ATTRIBUTE_UNUSED,
                        int disp ATTRIBUTE_UNUSED) {
  LOG(FATAL) << "Unexpected use of OpMem for MIPS";
  UNREACHABLE();
}

LIR* MipsMir2Lir::OpCondBranch(ConditionCode cc ATTRIBUTE_UNUSED, LIR* target ATTRIBUTE_UNUSED) {
  LOG(FATAL) << "Unexpected use of OpCondBranch for MIPS";
  UNREACHABLE();
}

LIR* MipsMir2Lir::InvokeTrampoline(OpKind op, RegStorage r_tgt, QuickEntrypointEnum trampoline) {
  if (!cu_->target64 && IsDirectEntrypoint(trampoline)) {
    // Reserve argument space on stack (for $a0-$a3) for
    // entrypoints that directly reference native implementations.
    // This is not safe in general, as it violates the frame size
    // of the Quick method, but it is used here only for calling
    // native functions, outside of the runtime.
    OpRegImm(kOpSub, rs_rSP, 16);
    LIR* retVal = OpReg(op, r_tgt);
    OpRegImm(kOpAdd, rs_rSP, 16);
    return retVal;
  }

  return OpReg(op, r_tgt);
}

RegStorage MipsMir2Lir::AllocPtrSizeTemp(bool required) {
  return cu_->target64 ? AllocTempWide(required) : AllocTemp(required);
}

}  // namespace art