xref: /XiangShan/src/main/scala/xiangshan/backend/decode/DecodeUnit.scala (revision 5a9dd560f6f96606bf8a6d80e1e8fb55c8c0745d)

/***************************************************************************************
* Copyright (c) 2020-2021 Institute of Computing Technology, Chinese Academy of Sciences
* Copyright (c) 2020-2021 Peng Cheng Laboratory
*
* XiangShan is licensed under Mulan PSL v2.
* You can use this software according to the terms and conditions of the Mulan PSL v2.
* You may obtain a copy of Mulan PSL v2 at:
*          http://license.coscl.org.cn/MulanPSL2
*
* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
* EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
* MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
*
* See the Mulan PSL v2 for more details.
***************************************************************************************/

package xiangshan.backend.decode

import org.chipsalliance.cde.config.Parameters
import chisel3._
import chisel3.util._
import freechips.rocketchip.rocket.CSRs
import freechips.rocketchip.rocket.Instructions._
import freechips.rocketchip.util.uintToBitPat
import utility._
import utils._
import xiangshan.ExceptionNO.{EX_II, breakPoint, illegalInstr, virtualInstr}
import xiangshan._
import xiangshan.backend.fu.FuType
import xiangshan.backend.Bundles.{DecodedInst, DynInst, StaticInst}
import xiangshan.backend.decode.isa.PseudoInstructions
import xiangshan.backend.decode.isa.bitfield.{InstVType, OPCODE5Bit, XSInstBitFields}
import xiangshan.backend.fu.vector.Bundles.{VType, Vl}
import xiangshan.backend.fu.wrapper.CSRToDecode

/**
 * Abstract trait giving defaults and other relevant values to different Decode constants/
 */
abstract trait DecodeConstants {
  // This X should be used only in 1-bit signal. Otherwise, use BitPat("b???") to align with the width of UInt.
  def X = BitPat("b0")
  def N = BitPat("b0")
  def Y = BitPat("b1")
  def T = true
  def F = false

  def decodeDefault: List[BitPat] = // illegal instruction
    //   srcType(0) srcType(1) srcType(2) fuType    fuOpType    rfWen
    //   |          |          |          |         |           |  fpWen
    //   |          |          |          |         |           |  |  vecWen
    //   |          |          |          |         |           |  |  |  isXSTrap
    //   |          |          |          |         |           |  |  |  |  noSpecExec
    //   |          |          |          |         |           |  |  |  |  |  blockBackward
    //   |          |          |          |         |           |  |  |  |  |  |  flushPipe
    //   |          |          |          |         |           |  |  |  |  |  |  |  canRobCompress
    //   |          |          |          |         |           |  |  |  |  |  |  |  |  uopSplitType
    //   |          |          |          |         |           |  |  |  |  |  |  |  |  |             selImm
    List(SrcType.X, SrcType.X, SrcType.X, FuType.X, FuOpType.X, N, N, N, N, N, N, N, N, UopSplitType.X, SelImm.INVALID_INSTR) // Use SelImm to indicate invalid instr

  val decodeArray: Array[(BitPat, XSDecodeBase)]
  final def table: Array[(BitPat, List[BitPat])] = decodeArray.map(x => (x._1, x._2.generate()))
}

trait DecodeUnitConstants
{
  // abstract out instruction decode magic numbers
  val RD_MSB  = 11
  val RD_LSB  = 7
  val RS1_MSB = 19
  val RS1_LSB = 15
  val RS2_MSB = 24
  val RS2_LSB = 20
  val RS3_MSB = 31
  val RS3_LSB = 27
}

/**
 * Decoded control signals
 * See xiangshan/package.scala, xiangshan/backend/package.scala, Bundle.scala
 */

abstract class XSDecodeBase {
  def X = BitPat("b?")
  def N = BitPat("b0")
  def Y = BitPat("b1")
  def T = true
  def F = false
  def generate() : List[BitPat]
}

case class XSDecode(
  src1: BitPat, src2: BitPat, src3: BitPat,
  fu: FuType.OHType, fuOp: BitPat, selImm: BitPat,
  uopSplitType: BitPat = UopSplitType.X,
  xWen: Boolean = false,
  fWen: Boolean = false,
  vWen: Boolean = false,
  mWen: Boolean = false,
  xsTrap: Boolean = false,
  noSpec: Boolean = false,
  blockBack: Boolean = false,
  flushPipe: Boolean = false,
  canRobCompress: Boolean = false,
) extends XSDecodeBase {
  def generate() : List[BitPat] = {
    List (src1, src2, src3, BitPat(fu.U(FuType.num.W)), fuOp, xWen.B, fWen.B, (vWen || mWen).B, xsTrap.B, noSpec.B, blockBack.B, flushPipe.B, canRobCompress.B, uopSplitType, selImm)
  }
}

case class FDecode(
  src1: BitPat, src2: BitPat, src3: BitPat,
  fu: FuType.OHType, fuOp: BitPat, selImm: BitPat = SelImm.X,
  uopSplitType: BitPat = UopSplitType.X,
  xWen: Boolean = false,
  fWen: Boolean = false,
  vWen: Boolean = false,
  mWen: Boolean = false,
  xsTrap: Boolean = false,
  noSpec: Boolean = false,
  blockBack: Boolean = false,
  flushPipe: Boolean = false,
  canRobCompress: Boolean = false,
) extends XSDecodeBase {
  def generate() : List[BitPat] = {
    XSDecode(src1, src2, src3, fu, fuOp, selImm, uopSplitType, xWen, fWen, vWen, mWen, xsTrap, noSpec, blockBack, flushPipe, canRobCompress).generate()
  }
}

/**
 * Overall Decode constants
 */
object XDecode extends DecodeConstants {
  val decodeArray: Array[(BitPat, XSDecodeBase)] = Array(
    // RV32I
    LW      -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.ldu, LSUOpType.lw  , SelImm.IMM_I, xWen = T),
    LH      -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.ldu, LSUOpType.lh  , SelImm.IMM_I, xWen = T),
    LHU     -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.ldu, LSUOpType.lhu , SelImm.IMM_I, xWen = T),
    LB      -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.ldu, LSUOpType.lb  , SelImm.IMM_I, xWen = T),
    LBU     -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.ldu, LSUOpType.lbu , SelImm.IMM_I, xWen = T),
    SW      -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.stu, LSUOpType.sw  , SelImm.IMM_S          ),
    SH      -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.stu, LSUOpType.sh  , SelImm.IMM_S          ),
    SB      -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.stu, LSUOpType.sb  , SelImm.IMM_S          ),
    LUI     -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.alu, ALUOpType.add , SelImm.IMM_U, xWen = T, canRobCompress = T),
    ADDI    -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.alu, ALUOpType.add , SelImm.IMM_I, xWen = T, canRobCompress = T),
    ANDI    -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.alu, ALUOpType.and , SelImm.IMM_I, xWen = T, canRobCompress = T),
    ORI     -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.alu, ALUOpType.or  , SelImm.IMM_I, xWen = T, canRobCompress = T),
    XORI    -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.alu, ALUOpType.xor , SelImm.IMM_I, xWen = T, canRobCompress = T),
    SLTI    -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.alu, ALUOpType.slt , SelImm.IMM_I, xWen = T, canRobCompress = T),
    SLTIU   -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.alu, ALUOpType.sltu, SelImm.IMM_I, xWen = T, canRobCompress = T),
    SLL     -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.sll , SelImm.X    , xWen = T, canRobCompress = T),
    ADD     -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.add , SelImm.X    , xWen = T, canRobCompress = T),
    SUB     -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.sub , SelImm.X    , xWen = T, canRobCompress = T),
    SLT     -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.slt , SelImm.X    , xWen = T, canRobCompress = T),
    SLTU    -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.sltu, SelImm.X    , xWen = T, canRobCompress = T),
    AND     -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.and , SelImm.X    , xWen = T, canRobCompress = T),
    OR      -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.or  , SelImm.X    , xWen = T, canRobCompress = T),
    XOR     -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.xor , SelImm.X    , xWen = T, canRobCompress = T),
    SRA     -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.sra , SelImm.X    , xWen = T, canRobCompress = T),
    SRL     -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.srl , SelImm.X    , xWen = T, canRobCompress = T),

    // RV64I （extend from RV32I)
    LD      -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.ldu, LSUOpType.ld  , SelImm.IMM_I, xWen = T),
    LWU     -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.ldu, LSUOpType.lwu , SelImm.IMM_I, xWen = T),
    SD      -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.stu, LSUOpType.sd  , SelImm.IMM_S          ),

    SLLI    -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.alu, ALUOpType.sll , SelImm.IMM_I, xWen = T, canRobCompress = T),
    SRLI    -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.alu, ALUOpType.srl , SelImm.IMM_I, xWen = T, canRobCompress = T),
    SRAI    -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.alu, ALUOpType.sra , SelImm.IMM_I, xWen = T, canRobCompress = T),

    ADDIW   -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.alu, ALUOpType.addw, SelImm.IMM_I, xWen = T, canRobCompress = T),
    SLLIW   -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.alu, ALUOpType.sllw, SelImm.IMM_I, xWen = T, canRobCompress = T),
    SRAIW   -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.alu, ALUOpType.sraw, SelImm.IMM_I, xWen = T, canRobCompress = T),
    SRLIW   -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.alu, ALUOpType.srlw, SelImm.IMM_I, xWen = T, canRobCompress = T),

    ADDW    -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.addw, SelImm.X    , xWen = T, canRobCompress = T),
    SUBW    -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.subw, SelImm.X    , xWen = T, canRobCompress = T),
    SLLW    -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.sllw, SelImm.X    , xWen = T, canRobCompress = T),
    SRAW    -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.sraw, SelImm.X    , xWen = T, canRobCompress = T),
    SRLW    -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.srlw, SelImm.X    , xWen = T, canRobCompress = T),

    // RV64M
    MUL     -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.mul, MDUOpType.mul   , SelImm.X, xWen = T, canRobCompress = T),
    MULH    -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.mul, MDUOpType.mulh  , SelImm.X, xWen = T, canRobCompress = T),
    MULHU   -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.mul, MDUOpType.mulhu , SelImm.X, xWen = T, canRobCompress = T),
    MULHSU  -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.mul, MDUOpType.mulhsu, SelImm.X, xWen = T, canRobCompress = T),
    MULW    -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.mul, MDUOpType.mulw  , SelImm.X, xWen = T, canRobCompress = T),

    DIV     -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.div, MDUOpType.div   , SelImm.X, xWen = T, canRobCompress = T),
    DIVU    -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.div, MDUOpType.divu  , SelImm.X, xWen = T, canRobCompress = T),
    REM     -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.div, MDUOpType.rem   , SelImm.X, xWen = T, canRobCompress = T),
    REMU    -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.div, MDUOpType.remu  , SelImm.X, xWen = T, canRobCompress = T),
    DIVW    -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.div, MDUOpType.divw  , SelImm.X, xWen = T, canRobCompress = T),
    DIVUW   -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.div, MDUOpType.divuw , SelImm.X, xWen = T, canRobCompress = T),
    REMW    -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.div, MDUOpType.remw  , SelImm.X, xWen = T, canRobCompress = T),
    REMUW   -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.div, MDUOpType.remuw , SelImm.X, xWen = T, canRobCompress = T),

    AUIPC   -> XSDecode(SrcType.pc , SrcType.imm, SrcType.X, FuType.jmp, JumpOpType.auipc, SelImm.IMM_U , xWen = T),
    JAL     -> XSDecode(SrcType.pc , SrcType.imm, SrcType.X, FuType.jmp, JumpOpType.jal  , SelImm.IMM_UJ, xWen = T),
    JALR    -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.jmp, JumpOpType.jalr , SelImm.IMM_I , xWen = T),
    BEQ     -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.brh, BRUOpType.beq   , SelImm.IMM_SB          ),
    BNE     -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.brh, BRUOpType.bne   , SelImm.IMM_SB          ),
    BGE     -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.brh, BRUOpType.bge   , SelImm.IMM_SB          ),
    BGEU    -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.brh, BRUOpType.bgeu  , SelImm.IMM_SB          ),
    BLT     -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.brh, BRUOpType.blt   , SelImm.IMM_SB          ),
    BLTU    -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.brh, BRUOpType.bltu  , SelImm.IMM_SB          ),

    // System, the immediate12 holds the CSR register.

    CSRRW   -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.csr, CSROpType.wrt , SelImm.IMM_Z, xWen = T, noSpec = T, blockBack = T),
    CSRRS   -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.csr, CSROpType.set , SelImm.IMM_Z, xWen = T, noSpec = T, blockBack = T),
    CSRRC   -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.csr, CSROpType.clr , SelImm.IMM_Z, xWen = T, noSpec = T, blockBack = T),

    CSRRWI  -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.csr, CSROpType.wrti, SelImm.IMM_Z, xWen = T, noSpec = T, blockBack = T),
    CSRRSI  -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.csr, CSROpType.seti, SelImm.IMM_Z, xWen = T, noSpec = T, blockBack = T),
    CSRRCI  -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.csr, CSROpType.clri, SelImm.IMM_Z, xWen = T, noSpec = T, blockBack = T),

    EBREAK  -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.csr, CSROpType.jmp, SelImm.IMM_I, xWen = T, noSpec = T, blockBack = T),
    ECALL   -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.csr, CSROpType.jmp, SelImm.IMM_I, xWen = T, noSpec = T, blockBack = T),
    SRET    -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.csr, CSROpType.jmp, SelImm.IMM_I, xWen = T, noSpec = T, blockBack = T),
    MRET    -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.csr, CSROpType.jmp, SelImm.IMM_I, xWen = T, noSpec = T, blockBack = T),
    DRET    -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.csr, CSROpType.jmp, SelImm.IMM_I, xWen = T, noSpec = T, blockBack = T),
    WFI     -> XSDecode(SrcType.pc , SrcType.imm, SrcType.X, FuType.csr, CSROpType.wfi, SelImm.X    , xWen = T, noSpec = T, blockBack = T),

    SFENCE_VMA -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.fence, FenceOpType.sfence, SelImm.X, noSpec = T, blockBack = T, flushPipe = T),
    FENCE_I    -> XSDecode(SrcType.pc , SrcType.imm, SrcType.X, FuType.fence, FenceOpType.fencei, SelImm.X, noSpec = T, blockBack = T, flushPipe = T),
    FENCE      -> XSDecode(SrcType.pc , SrcType.imm, SrcType.X, FuType.fence, FenceOpType.fence , SelImm.X, noSpec = T, blockBack = T, flushPipe = T),

    // RV64A
    AMOADD_W  -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.mou, LSUOpType.amoadd_w , SelImm.X, xWen = T, noSpec = T, blockBack = T),
    AMOXOR_W  -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.mou, LSUOpType.amoxor_w , SelImm.X, xWen = T, noSpec = T, blockBack = T),
    AMOSWAP_W -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.mou, LSUOpType.amoswap_w, SelImm.X, xWen = T, noSpec = T, blockBack = T),
    AMOAND_W  -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.mou, LSUOpType.amoand_w , SelImm.X, xWen = T, noSpec = T, blockBack = T),
    AMOOR_W   -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.mou, LSUOpType.amoor_w  , SelImm.X, xWen = T, noSpec = T, blockBack = T),
    AMOMIN_W  -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.mou, LSUOpType.amomin_w , SelImm.X, xWen = T, noSpec = T, blockBack = T),
    AMOMINU_W -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.mou, LSUOpType.amominu_w, SelImm.X, xWen = T, noSpec = T, blockBack = T),
    AMOMAX_W  -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.mou, LSUOpType.amomax_w , SelImm.X, xWen = T, noSpec = T, blockBack = T),
    AMOMAXU_W -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.mou, LSUOpType.amomaxu_w, SelImm.X, xWen = T, noSpec = T, blockBack = T),

    AMOADD_D  -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.mou, LSUOpType.amoadd_d , SelImm.X, xWen = T, noSpec = T, blockBack = T),
    AMOXOR_D  -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.mou, LSUOpType.amoxor_d , SelImm.X, xWen = T, noSpec = T, blockBack = T),
    AMOSWAP_D -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.mou, LSUOpType.amoswap_d, SelImm.X, xWen = T, noSpec = T, blockBack = T),
    AMOAND_D  -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.mou, LSUOpType.amoand_d , SelImm.X, xWen = T, noSpec = T, blockBack = T),
    AMOOR_D   -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.mou, LSUOpType.amoor_d  , SelImm.X, xWen = T, noSpec = T, blockBack = T),
    AMOMIN_D  -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.mou, LSUOpType.amomin_d , SelImm.X, xWen = T, noSpec = T, blockBack = T),
    AMOMINU_D -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.mou, LSUOpType.amominu_d, SelImm.X, xWen = T, noSpec = T, blockBack = T),
    AMOMAX_D  -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.mou, LSUOpType.amomax_d , SelImm.X, xWen = T, noSpec = T, blockBack = T),
    AMOMAXU_D -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.mou, LSUOpType.amomaxu_d, SelImm.X, xWen = T, noSpec = T, blockBack = T),

    LR_W    -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.mou, LSUOpType.lr_w, SelImm.X, xWen = T, noSpec = T, blockBack = T),
    LR_D    -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.mou, LSUOpType.lr_d, SelImm.X, xWen = T, noSpec = T, blockBack = T),
    SC_W    -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.mou, LSUOpType.sc_w, SelImm.X, xWen = T, noSpec = T, blockBack = T),
    SC_D    -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.mou, LSUOpType.sc_d, SelImm.X, xWen = T, noSpec = T, blockBack = T),
  )
}

object BitmanipDecode extends DecodeConstants{
  /*
    Note: Some Bitmanip instruction may have different OP code between rv32 and rv64.
    Including pseudo instruction like zext.h, and different funct12 like rev8.
    If some day we need to support change XLEN via CSR, we should care about this.
   */
  val decodeArray: Array[(BitPat, XSDecodeBase)] = Array(
    // Zba
    ADD_UW    -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.adduw   , SelImm.X    , xWen = T, canRobCompress = T),
    SH1ADD    -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.sh1add  , SelImm.X    , xWen = T, canRobCompress = T),
    SH1ADD_UW -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.sh1adduw, SelImm.X    , xWen = T, canRobCompress = T),
    SH2ADD    -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.sh2add  , SelImm.X    , xWen = T, canRobCompress = T),
    SH2ADD_UW -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.sh2adduw, SelImm.X    , xWen = T, canRobCompress = T),
    SH3ADD    -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.sh3add  , SelImm.X    , xWen = T, canRobCompress = T),
    SH3ADD_UW -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.sh3adduw, SelImm.X    , xWen = T, canRobCompress = T),
    SLLI_UW   -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.alu, ALUOpType.slliuw  , SelImm.IMM_I, xWen = T, canRobCompress = T),

    // Zbb
    ANDN      -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.andn    , SelImm.X    , xWen = T, canRobCompress = T),
    ORN       -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.orn     , SelImm.X    , xWen = T, canRobCompress = T),
    XNOR      -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.xnor    , SelImm.X    , xWen = T, canRobCompress = T),

    CLZ       -> XSDecode(SrcType.reg, SrcType.DC , SrcType.X, FuType.bku, BKUOpType.clz     , SelImm.X    , xWen = T, canRobCompress = T),
    CLZW      -> XSDecode(SrcType.reg, SrcType.DC , SrcType.X, FuType.bku, BKUOpType.clzw    , SelImm.X    , xWen = T, canRobCompress = T),
    CTZ       -> XSDecode(SrcType.reg, SrcType.DC , SrcType.X, FuType.bku, BKUOpType.ctz     , SelImm.X    , xWen = T, canRobCompress = T),
    CTZW      -> XSDecode(SrcType.reg, SrcType.DC , SrcType.X, FuType.bku, BKUOpType.ctzw    , SelImm.X    , xWen = T, canRobCompress = T),

    CPOP      -> XSDecode(SrcType.reg, SrcType.DC,  SrcType.X, FuType.bku, BKUOpType.cpop    , SelImm.X    , xWen = T, canRobCompress = T),
    CPOPW     -> XSDecode(SrcType.reg, SrcType.DC,  SrcType.X, FuType.bku, BKUOpType.cpopw   , SelImm.X    , xWen = T, canRobCompress = T),

    MAX       -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.max     , SelImm.X    , xWen = T, canRobCompress = T),
    MAXU      -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.maxu    , SelImm.X    , xWen = T, canRobCompress = T),
    MIN       -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.min     , SelImm.X    , xWen = T, canRobCompress = T),
    MINU      -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.minu    , SelImm.X    , xWen = T, canRobCompress = T),

    SEXT_B    -> XSDecode(SrcType.reg, SrcType.DC,  SrcType.X, FuType.alu, ALUOpType.sextb   , SelImm.X    , xWen = T, canRobCompress = T),
    SEXT_H    -> XSDecode(SrcType.reg, SrcType.DC,  SrcType.X, FuType.alu, ALUOpType.sexth   , SelImm.X    , xWen = T, canRobCompress = T),
    // zext.h in rv64 is shared with packw in Zbkb with rs2 = $0.
    // If we configured to have no Zbkb, we should add zext.h here.

    ROL       -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.rol     , SelImm.X    , xWen = T, canRobCompress = T),
    ROLW      -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.rolw    , SelImm.X    , xWen = T, canRobCompress = T),
    ROR       -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.ror     , SelImm.X    , xWen = T, canRobCompress = T),
    RORI      -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.alu, ALUOpType.ror     , SelImm.IMM_I, xWen = T, canRobCompress = T),
    RORIW     -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.alu, ALUOpType.rorw    , SelImm.IMM_I, xWen = T, canRobCompress = T),
    RORW      -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.rorw    , SelImm.X    , xWen = T, canRobCompress = T),

    ORC_B     -> XSDecode(SrcType.reg, SrcType.DC,  SrcType.X, FuType.alu, ALUOpType.orcb    , SelImm.X    , xWen = T, canRobCompress = T),

    REV8      -> XSDecode(SrcType.reg, SrcType.DC,  SrcType.X, FuType.alu, ALUOpType.rev8    , SelImm.X    , xWen = T, canRobCompress = T),

    // Zbc
    CLMUL     -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.bku, BKUOpType.clmul   , SelImm.X    , xWen = T, canRobCompress = T),
    CLMULH    -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.bku, BKUOpType.clmulh  , SelImm.X    , xWen = T, canRobCompress = T),
    CLMULR    -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.bku, BKUOpType.clmulr  , SelImm.X    , xWen = T, canRobCompress = T),

    // Zbs
    BCLR      -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.bclr    , SelImm.X    , xWen = T, canRobCompress = T),
    BCLRI     -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.alu, ALUOpType.bclr    , SelImm.IMM_I, xWen = T, canRobCompress = T),
    BEXT      -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.bext    , SelImm.X    , xWen = T, canRobCompress = T),
    BEXTI     -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.alu, ALUOpType.bext    , SelImm.IMM_I, xWen = T, canRobCompress = T),
    BINV      -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.binv    , SelImm.X    , xWen = T, canRobCompress = T),
    BINVI     -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.alu, ALUOpType.binv    , SelImm.IMM_I, xWen = T, canRobCompress = T),
    BSET      -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.bset    , SelImm.X    , xWen = T, canRobCompress = T),
    BSETI     -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.alu, ALUOpType.bset    , SelImm.IMM_I, xWen = T, canRobCompress = T),

    // Zbkb
    // rol, rolw, ror,rori, roriw, rorw, andn, orn, xnor, rev8 is in Zbb
    PACK      -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.pack    , SelImm.X    , xWen = T, canRobCompress = T),
    PACKH     -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.packh   , SelImm.X    , xWen = T, canRobCompress = T),
    PACKW     -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.packw   , SelImm.X    , xWen = T, canRobCompress = T),
    BREV8     -> XSDecode(SrcType.reg, SrcType.DC,  SrcType.X, FuType.alu, ALUOpType.revb    , SelImm.X    , xWen = T, canRobCompress = T),
    // If configured to RV32, we should add zip and unzip.

    // Zbkc
    // clmul, clmulh is in Zbc

    // Zbkx
    XPERM4    -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.bku, BKUOpType.xpermn  , SelImm.X    , xWen = T, canRobCompress = T),
    XPERM8    -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.bku, BKUOpType.xpermb  , SelImm.X    , xWen = T, canRobCompress = T),
  )
}

object ScalarCryptoDecode extends DecodeConstants {
  val decodeArray: Array[(BitPat, XSDecodeBase)] = Array(
    // Zknd: NIST Suite: AES Decryption
    AES64DS    -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.bku, BKUOpType.aes64ds   , SelImm.X    , xWen = T, canRobCompress = T),
    AES64DSM   -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.bku, BKUOpType.aes64dsm  , SelImm.X    , xWen = T, canRobCompress = T),
    AES64IM    -> XSDecode(SrcType.reg, SrcType.DC,  SrcType.X, FuType.bku, BKUOpType.aes64im   , SelImm.X    , xWen = T, canRobCompress = T),
    AES64KS1I  -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.bku, BKUOpType.aes64ks1i , SelImm.IMM_I, xWen = T, canRobCompress = T),
    AES64KS2   -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.bku, BKUOpType.aes64ks2  , SelImm.X    , xWen = T, canRobCompress = T),

    // Zkne: NIST Suite: AES Encryption
    // aes64ks1i, aes64ks2 is in Zknd
    AES64ES    -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.bku, BKUOpType.aes64es   , SelImm.X    , xWen = T, canRobCompress = T),
    AES64ESM   -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.bku, BKUOpType.aes64esm  , SelImm.X    , xWen = T, canRobCompress = T),

    // Zknh: NIST Suite: Hash Function Instructions
    SHA256SIG0 -> XSDecode(SrcType.reg, SrcType.DC,  SrcType.X, FuType.bku, BKUOpType.sha256sig0, SelImm.X    , xWen = T, canRobCompress = T),
    SHA256SIG1 -> XSDecode(SrcType.reg, SrcType.DC,  SrcType.X, FuType.bku, BKUOpType.sha256sig1, SelImm.X    , xWen = T, canRobCompress = T),
    SHA256SUM0 -> XSDecode(SrcType.reg, SrcType.DC,  SrcType.X, FuType.bku, BKUOpType.sha256sum0, SelImm.X    , xWen = T, canRobCompress = T),
    SHA256SUM1 -> XSDecode(SrcType.reg, SrcType.DC,  SrcType.X, FuType.bku, BKUOpType.sha256sum1, SelImm.X    , xWen = T, canRobCompress = T),
    SHA512SIG0 -> XSDecode(SrcType.reg, SrcType.DC,  SrcType.X, FuType.bku, BKUOpType.sha512sig0, SelImm.X    , xWen = T, canRobCompress = T),
    SHA512SIG1 -> XSDecode(SrcType.reg, SrcType.DC,  SrcType.X, FuType.bku, BKUOpType.sha512sig1, SelImm.X    , xWen = T, canRobCompress = T),
    SHA512SUM0 -> XSDecode(SrcType.reg, SrcType.DC,  SrcType.X, FuType.bku, BKUOpType.sha512sum0, SelImm.X    , xWen = T, canRobCompress = T),
    SHA512SUM1 -> XSDecode(SrcType.reg, SrcType.DC,  SrcType.X, FuType.bku, BKUOpType.sha512sum1, SelImm.X    , xWen = T, canRobCompress = T),

    // Zksed: ShangMi Suite: SM4 Block Cipher Instructions
    SM4ED0     -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.bku, BKUOpType.sm4ed0    , SelImm.X    , xWen = T, canRobCompress = T),
    SM4ED1     -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.bku, BKUOpType.sm4ed1    , SelImm.X    , xWen = T, canRobCompress = T),
    SM4ED2     -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.bku, BKUOpType.sm4ed2    , SelImm.X    , xWen = T, canRobCompress = T),
    SM4ED3     -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.bku, BKUOpType.sm4ed3    , SelImm.X    , xWen = T, canRobCompress = T),
    SM4KS0     -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.bku, BKUOpType.sm4ks0    , SelImm.X    , xWen = T, canRobCompress = T),
    SM4KS1     -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.bku, BKUOpType.sm4ks1    , SelImm.X    , xWen = T, canRobCompress = T),
    SM4KS2     -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.bku, BKUOpType.sm4ks2    , SelImm.X    , xWen = T, canRobCompress = T),
    SM4KS3     -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.bku, BKUOpType.sm4ks3    , SelImm.X    , xWen = T, canRobCompress = T),

    // Zksh: ShangMi Suite: SM3 Hash Function Instructions
    SM3P0      -> XSDecode(SrcType.reg, SrcType.DC,  SrcType.X, FuType.bku, BKUOpType.sm3p0     , SelImm.X    , xWen = T, canRobCompress = T),
    SM3P1      -> XSDecode(SrcType.reg, SrcType.DC,  SrcType.X, FuType.bku, BKUOpType.sm3p1     , SelImm.X    , xWen = T, canRobCompress = T),
  )
}

/**
 * FP Decode constants
 */
object FpDecode extends DecodeConstants{
  val decodeArray: Array[(BitPat, XSDecodeBase)] = Array(
    FLH     -> FDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.ldu, LSUOpType.lh, selImm = SelImm.IMM_I, fWen = T),
    FLW     -> FDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.ldu, LSUOpType.lw, selImm = SelImm.IMM_I, fWen = T),
    FLD     -> FDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.ldu, LSUOpType.ld, selImm = SelImm.IMM_I, fWen = T),
    FSH     -> FDecode(SrcType.reg, SrcType.fp,  SrcType.X, FuType.stu, LSUOpType.sh, selImm = SelImm.IMM_S          ),
    FSW     -> FDecode(SrcType.reg, SrcType.fp,  SrcType.X, FuType.stu, LSUOpType.sw, selImm = SelImm.IMM_S          ),
    FSD     -> FDecode(SrcType.reg, SrcType.fp,  SrcType.X, FuType.stu, LSUOpType.sd, selImm = SelImm.IMM_S          ),

    FMV_D_X -> FDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.i2v, IF2VectorType.FMX_D_X, fWen = T, canRobCompress = T),
    FMV_W_X -> FDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.i2v, IF2VectorType.FMX_W_X, fWen = T, canRobCompress = T),
    FMV_H_X -> FDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.i2v, IF2VectorType.FMX_H_X, fWen = T, canRobCompress = T),

    // Int to FP
    FCVT_S_W  -> FDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.i2f, FuOpType.X, fWen = T, canRobCompress = T),
    FCVT_S_WU -> FDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.i2f, FuOpType.X, fWen = T, canRobCompress = T),
    FCVT_S_L  -> FDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.i2f, FuOpType.X, fWen = T, canRobCompress = T),
    FCVT_S_LU -> FDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.i2f, FuOpType.X, fWen = T, canRobCompress = T),

    FCVT_D_W  -> FDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.i2f, FuOpType.X, fWen = T, canRobCompress = T),
    FCVT_D_WU -> FDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.i2f, FuOpType.X, fWen = T, canRobCompress = T),
    FCVT_D_L  -> FDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.i2f, FuOpType.X, fWen = T, canRobCompress = T),
    FCVT_D_LU -> FDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.i2f, FuOpType.X, fWen = T, canRobCompress = T),

  )
}

/**
 * FP Divide SquareRoot Constants
 */
object FDivSqrtDecode extends DecodeConstants {
  val decodeArray: Array[(BitPat, XSDecodeBase)] = Array(
    FDIV_S  -> FDecode(SrcType.fp,  SrcType.fp,  SrcType.X, FuType.fDivSqrt, FuOpType.X, fWen = T, canRobCompress = T),
    FDIV_D  -> FDecode(SrcType.fp,  SrcType.fp,  SrcType.X, FuType.fDivSqrt, FuOpType.X, fWen = T, canRobCompress = T),
    FSQRT_S -> FDecode(SrcType.fp,  SrcType.imm, SrcType.X, FuType.fDivSqrt, FuOpType.X, fWen = T, canRobCompress = T),
    FSQRT_D -> FDecode(SrcType.fp,  SrcType.imm, SrcType.X, FuType.fDivSqrt, FuOpType.X, fWen = T, canRobCompress = T),
  )
}

/**
 * Svinval extension Constants
 */
object SvinvalDecode extends DecodeConstants {
  val decodeArray: Array[(BitPat, XSDecodeBase)] = Array(
    /* sinval_vma is like sfence.vma , but sinval_vma can be dispatched and issued like normal instructions while sfence.vma
     * must assure it is the ONLY instrucion executing in backend.
     */
    SINVAL_VMA        -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.fence, FenceOpType.sfence, SelImm.X),
    /* sfecne.w.inval is the begin instrucion of a TLB flush which set *noSpecExec* and *blockBackward* signals
     * so when it comes to dispatch , it will block all instruction after itself until all instrucions ahead of it in rob commit
     * then dispatch and issue this instrucion to flush sbuffer to dcache
     * after this instrucion commits , issue following sinval_vma instructions (out of order) to flush TLB
     */
    SFENCE_W_INVAL    -> XSDecode(SrcType.DC, SrcType.DC, SrcType.X, FuType.fence, FenceOpType.nofence, SelImm.X, noSpec = T, blockBack = T),
    /* sfecne.inval.ir is the end instrucion of a TLB flush which set *noSpecExec* *blockBackward* and *flushPipe* signals
     * so when it comes to dispatch , it will wait until all sinval_vma ahead of it in rob commit
     * then dispatch and issue this instrucion
     * when it commit at the head of rob , flush the pipeline since some instrucions have been fetched to ibuffer using old TLB map
     */
    SFENCE_INVAL_IR   -> XSDecode(SrcType.DC, SrcType.DC, SrcType.X, FuType.fence, FenceOpType.nofence, SelImm.X, noSpec = T, blockBack = T, flushPipe = T)
    /* what is Svinval extension ?
     *                       ----->             sfecne.w.inval
     * sfence.vma   vpn1     ----->             sinval_vma   vpn1
     * sfence.vma   vpn2     ----->             sinval_vma   vpn2
     *                       ----->             sfecne.inval.ir
     *
     * sfence.vma should be executed in-order and it flushes the pipeline after committing
     * we can parallel sfence instrucions with this extension
     */
  )
}

/*
 * CBO decode
 */
object CBODecode extends DecodeConstants {
  val decodeArray: Array[(BitPat, XSDecodeBase)] = Array(
    CBO_ZERO  -> XSDecode(SrcType.reg, SrcType.DC, SrcType.X, FuType.stu, LSUOpType.cbo_zero , SelImm.IMM_S),
    CBO_CLEAN -> XSDecode(SrcType.reg, SrcType.DC, SrcType.X, FuType.stu, LSUOpType.cbo_clean, SelImm.IMM_S),
    CBO_FLUSH -> XSDecode(SrcType.reg, SrcType.DC, SrcType.X, FuType.stu, LSUOpType.cbo_flush, SelImm.IMM_S),
    CBO_INVAL -> XSDecode(SrcType.reg, SrcType.DC, SrcType.X, FuType.stu, LSUOpType.cbo_inval, SelImm.IMM_S)
  )
}

/*
 * Hypervisor decode
 */
object HypervisorDecode extends DecodeConstants {
  override val decodeArray: Array[(BitPat, XSDecodeBase)] = Array(
    HFENCE_GVMA -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.fence, FenceOpType.hfence_g, SelImm.X, noSpec = T, blockBack = T, flushPipe = T),
    HFENCE_VVMA -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.fence, FenceOpType.hfence_v, SelImm.X, noSpec = T, blockBack = T, flushPipe = T),
    HINVAL_GVMA -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.fence, FenceOpType.hfence_g, SelImm.X),
    HINVAL_VVMA -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.fence, FenceOpType.hfence_v, SelImm.X),
    HLV_B       -> XSDecode(SrcType.reg, SrcType.X,   SrcType.X, FuType.ldu,   LSUOpType.hlvb,       SelImm.X, xWen = T),
    HLV_BU      -> XSDecode(SrcType.reg, SrcType.X,   SrcType.X, FuType.ldu,   LSUOpType.hlvbu,      SelImm.X, xWen = T),
    HLV_D       -> XSDecode(SrcType.reg, SrcType.X,   SrcType.X, FuType.ldu,   LSUOpType.hlvd,       SelImm.X, xWen = T),
    HLV_H       -> XSDecode(SrcType.reg, SrcType.X,   SrcType.X, FuType.ldu,   LSUOpType.hlvh,       SelImm.X, xWen = T),
    HLV_HU      -> XSDecode(SrcType.reg, SrcType.X,   SrcType.X, FuType.ldu,   LSUOpType.hlvhu,      SelImm.X, xWen = T),
    HLV_W       -> XSDecode(SrcType.reg, SrcType.X,   SrcType.X, FuType.ldu,   LSUOpType.hlvw,       SelImm.X, xWen = T),
    HLV_WU      -> XSDecode(SrcType.reg, SrcType.X,   SrcType.X, FuType.ldu,   LSUOpType.hlvwu,      SelImm.X, xWen = T),
    HLVX_HU     -> XSDecode(SrcType.reg, SrcType.X,   SrcType.X, FuType.ldu,   LSUOpType.hlvxhu,     SelImm.X, xWen = T),
    HLVX_WU     -> XSDecode(SrcType.reg, SrcType.X,   SrcType.X, FuType.ldu,   LSUOpType.hlvxwu,     SelImm.X, xWen = T),
    HSV_B       -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.stu,   LSUOpType.hsvb,       SelImm.X),
    HSV_D       -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.stu,   LSUOpType.hsvd,       SelImm.X),
    HSV_H       -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.stu,   LSUOpType.hsvh,       SelImm.X),
    HSV_W       -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.stu,   LSUOpType.hsvw,       SelImm.X),
  )
}

object ZicondDecode extends DecodeConstants {
  override val decodeArray: Array[(BitPat, XSDecodeBase)] = Array(
    CZERO_EQZ   -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.czero_eqz, SelImm.X, xWen = T, canRobCompress = T),
    CZERO_NEZ   -> XSDecode(SrcType.reg, SrcType.reg, SrcType.X, FuType.alu, ALUOpType.czero_nez, SelImm.X, xWen = T, canRobCompress = T),
  )
}

/**
 * XiangShan Trap Decode constants
 */
object XSTrapDecode extends DecodeConstants {
  def TRAP = BitPat("b000000000000?????000000001101011")
  val decodeArray: Array[(BitPat, XSDecodeBase)] = Array(
    TRAP    -> XSDecode(SrcType.reg, SrcType.imm, SrcType.X, FuType.alu, ALUOpType.add, SelImm.IMM_I, xWen = T, xsTrap = T, noSpec = T, blockBack = T)
  )
}

abstract class Imm(val len: Int) {
  def toImm32(minBits: UInt): UInt = do_toImm32(minBits(len - 1, 0))
  def do_toImm32(minBits: UInt): UInt
  def minBitsFromInstr(instr: UInt): UInt
}

case class Imm_I() extends Imm(12) {
  override def do_toImm32(minBits: UInt): UInt = SignExt(minBits(len - 1, 0), 32)

  override def minBitsFromInstr(instr: UInt): UInt =
    Cat(instr(31, 20))
}

case class Imm_S() extends Imm(12) {
  override def do_toImm32(minBits: UInt): UInt = SignExt(minBits, 32)

  override def minBitsFromInstr(instr: UInt): UInt =
    Cat(instr(31, 25), instr(11, 7))
}

case class Imm_B() extends Imm(12) {
  override def do_toImm32(minBits: UInt): UInt = SignExt(Cat(minBits, 0.U(1.W)), 32)

  override def minBitsFromInstr(instr: UInt): UInt =
    Cat(instr(31), instr(7), instr(30, 25), instr(11, 8))
}

case class Imm_U() extends Imm(20){
  override def do_toImm32(minBits: UInt): UInt = Cat(minBits(len - 1, 0), 0.U(12.W))

  override def minBitsFromInstr(instr: UInt): UInt = {
    instr(31, 12)
  }
}

case class Imm_J() extends Imm(20){
  override def do_toImm32(minBits: UInt): UInt = SignExt(Cat(minBits, 0.U(1.W)), 32)

  override def minBitsFromInstr(instr: UInt): UInt = {
    Cat(instr(31), instr(19, 12), instr(20), instr(30, 25), instr(24, 21))
  }
}

case class Imm_Z() extends Imm(12 + 5 + 5){
  override def do_toImm32(minBits: UInt): UInt = minBits

  override def minBitsFromInstr(instr: UInt): UInt = {
    Cat(instr(11, 7), instr(19, 15), instr(31, 20))
  }

  def getCSRAddr(imm: UInt): UInt = {
    require(imm.getWidth == this.len)
    imm(11, 0)
  }

  def getRS1(imm: UInt): UInt = {
    require(imm.getWidth == this.len)
    imm(16, 12)
  }

  def getRD(imm: UInt): UInt = {
    require(imm.getWidth == this.len)
    imm(21, 17)
  }

  def getImm5(imm: UInt): UInt = {
    require(imm.getWidth == this.len)
    imm(16, 12)
  }
}

case class Imm_B6() extends Imm(6){
  override def do_toImm32(minBits: UInt): UInt = ZeroExt(minBits, 32)

  override def minBitsFromInstr(instr: UInt): UInt = {
    instr(25, 20)
  }
}

case class Imm_OPIVIS() extends Imm(5){
  override def do_toImm32(minBits: UInt): UInt = SignExt(minBits, 32)

  override def minBitsFromInstr(instr: UInt): UInt = {
    instr(19, 15)
  }
}

case class Imm_OPIVIU() extends Imm(5){
  override def do_toImm32(minBits: UInt): UInt = ZeroExt(minBits, 32)

  override def minBitsFromInstr(instr: UInt): UInt = {
    instr(19, 15)
  }
}

case class Imm_VSETVLI() extends Imm(11){
  override def do_toImm32(minBits: UInt): UInt = SignExt(minBits, 32)

  override def minBitsFromInstr(instr: UInt): UInt = {
    instr(30, 20)
  }
  /**
    * get VType from extended imm
    * @param extedImm
    * @return VType
    */
  def getVType(extedImm: UInt): InstVType = {
    val vtype = Wire(new InstVType)
    vtype := extedImm(10, 0).asTypeOf(new InstVType)
    vtype
  }
}

case class Imm_VSETIVLI() extends Imm(15){
  override def do_toImm32(minBits: UInt): UInt = SignExt(minBits, 32)

  override def minBitsFromInstr(instr: UInt): UInt = {
    val rvInst: XSInstBitFields = instr.asTypeOf(new XSInstBitFields)
    val uimm5 = rvInst.UIMM_VSETIVLI
    val vtype8 = rvInst.ZIMM_VSETIVLI
    Cat(uimm5, vtype8)
  }
  /**
    * get VType from extended imm
    * @param extedImm
    * @return VType
    */
  def getVType(extedImm: UInt): InstVType = {
    val vtype = Wire(new InstVType)
    vtype := extedImm(9, 0).asTypeOf(new InstVType)
    vtype
  }

  def getAvl(extedImm: UInt): UInt = {
    extedImm(14, 10)
  }
}

case class Imm_LUI32() extends Imm(32){
  override def do_toImm32(minBits: UInt): UInt = minBits(31, 0)

  override def minBitsFromInstr(instr: UInt): UInt = {
    instr(31, 0)
  }
}

case class Imm_VRORVI() extends Imm(6){
  override def do_toImm32(minBits: UInt): UInt = ZeroExt(minBits, 32)

  override def minBitsFromInstr(instr: UInt): UInt = {
    Cat(instr(26), instr(19, 15))
  }
}

object ImmUnion {
  val I = Imm_I()
  val S = Imm_S()
  val B = Imm_B()
  val U = Imm_U()
  val J = Imm_J()
  val Z = Imm_Z()
  val B6 = Imm_B6()
  val OPIVIS = Imm_OPIVIS()
  val OPIVIU = Imm_OPIVIU()
  val VSETVLI = Imm_VSETVLI()
  val VSETIVLI = Imm_VSETIVLI()
  val LUI32 = Imm_LUI32()
  val VRORVI = Imm_VRORVI()

  // do not add special type lui32 to this, keep ImmUnion max len being 20.
  val imms = Seq(I, S, B, U, J, Z, B6, OPIVIS, OPIVIU, VSETVLI, VSETIVLI, VRORVI)
  val maxLen = imms.maxBy(_.len).len
  val immSelMap = Seq(
    SelImm.IMM_I,
    SelImm.IMM_S,
    SelImm.IMM_SB,
    SelImm.IMM_U,
    SelImm.IMM_UJ,
    SelImm.IMM_Z,
    SelImm.IMM_B6,
    SelImm.IMM_OPIVIS,
    SelImm.IMM_OPIVIU,
    SelImm.IMM_VSETVLI,
    SelImm.IMM_VSETIVLI,
    SelImm.IMM_VRORVI,
  ).zip(imms)
  println(s"ImmUnion max len: $maxLen")
}

case class Imm_LUI_LOAD() {
  def immFromLuiLoad(lui_imm: UInt, load_imm: UInt): UInt = {
    val loadImm = load_imm(Imm_I().len - 1, 0)
    Cat(lui_imm(ImmUnion.maxLen - loadImm.getWidth - 1, 0), loadImm)
  }
  def getLuiImm(uop: DynInst): UInt = {
    val loadImmLen = Imm_I().len
    val imm_u = Cat(uop.psrc(1), uop.psrc(0), uop.imm(ImmUnion.maxLen - 1, loadImmLen))
    Cat(Imm_U().toImm32(imm_u)(31, loadImmLen), uop.imm(loadImmLen - 1, 0))
  }
}

/**
 * IO bundle for the Decode unit
 */
class DecodeUnitDeqIO(implicit p: Parameters) extends XSBundle {
  val decodedInst = Output(new DecodedInst)
  val isComplex = Output(Bool())
  val uopInfo = Output(new UopInfo)
}
class DecodeUnitIO(implicit p: Parameters) extends XSBundle {
  val enq = new Bundle {
    val ctrlFlow = Input(new StaticInst)
    val vtype = Input(new VType)
    val vstart = Input(Vl())
  }
//  val vconfig = Input(UInt(XLEN.W))
  val deq = new DecodeUnitDeqIO
  val csrCtrl = Input(new CustomCSRCtrlIO)
  val fromCSR = Input(new CSRToDecode)
}

/**
 * Decode unit that takes in a single CtrlFlow and generates a CfCtrl.
 */
class DecodeUnit(implicit p: Parameters) extends XSModule with DecodeUnitConstants {
  val io = IO(new DecodeUnitIO)

  val ctrl_flow = io.enq.ctrlFlow // input with RVC Expanded

  private val inst: XSInstBitFields = io.enq.ctrlFlow.instr.asTypeOf(new XSInstBitFields)

  val decode_table: Array[(BitPat, List[BitPat])] = XDecode.table ++
    FpDecode.table ++
//    FDivSqrtDecode.table ++
    BitmanipDecode.table ++
    ScalarCryptoDecode.table ++
    XSTrapDecode.table ++
    CBODecode.table ++
    SvinvalDecode.table ++
    HypervisorDecode.table ++
    VecDecoder.table ++
    ZicondDecode.table

  require(decode_table.map(_._2.length == 15).reduce(_ && _), "Decode tables have different column size")
  // assertion for LUI: only LUI should be assigned `selImm === SelImm.IMM_U && fuType === FuType.alu`
  val luiMatch = (t: Seq[BitPat]) => t(3).value == FuType.alu.ohid && t.reverse.head.value == SelImm.IMM_U.litValue
  val luiTable = decode_table.filter(t => luiMatch(t._2)).map(_._1).distinct
  assert(luiTable.length == 1 && luiTable.head == LUI, "Conflicts: LUI is determined by FuType and SelImm in Dispatch")

  // output
  val decodedInst: DecodedInst = Wire(new DecodedInst()).decode(ctrl_flow.instr, decode_table)

  val fpDecoder = Module(new FPDecoder)
  fpDecoder.io.instr := ctrl_flow.instr
  decodedInst.fpu := fpDecoder.io.fpCtrl
  decodedInst.fpu.wflags := fpDecoder.io.fpCtrl.wflags || decodedInst.wfflags

  decodedInst.connectStaticInst(io.enq.ctrlFlow)

  decodedInst.uopIdx := 0.U
  decodedInst.firstUop := true.B
  decodedInst.lastUop := true.B
  decodedInst.numUops := 1.U
  decodedInst.numWB   := 1.U

  val isMove = BitPat("b000000000000_?????_000_?????_0010011") === ctrl_flow.instr
  decodedInst.isMove := isMove && ctrl_flow.instr(RD_MSB, RD_LSB) =/= 0.U && !io.csrCtrl.singlestep

  // fmadd - b1000011
  // fmsub - b1000111
  // fnmsub- b1001011
  // fnmadd- b1001111
  private val isFMA = inst.OPCODE === BitPat("b100??11")
  private val isVppu = FuType.isVppu(decodedInst.fuType)
  private val isVecOPF = FuType.isVecOPF(decodedInst.fuType)

  // read src1~3 location
  decodedInst.lsrc(0) := inst.RS1
  decodedInst.lsrc(1) := inst.RS2
  // src(2) of fma is fs3, src(2) of vector inst is old vd
  decodedInst.lsrc(2) := Mux(isFMA, inst.FS3, inst.VD)
  decodedInst.lsrc(3) := V0_IDX.U
  decodedInst.lsrc(4) := Vl_IDX.U

  // read dest location
  decodedInst.ldest := inst.RD

  // init v0Wen vlWen
  decodedInst.v0Wen := false.B
  decodedInst.vlWen := false.B

  // fill in exception vector
  val vecException = Module(new VecExceptionGen)
  vecException.io.inst := io.enq.ctrlFlow.instr
  vecException.io.decodedInst := decodedInst
  vecException.io.vtype := decodedInst.vpu.vtype
  vecException.io.vstart := decodedInst.vpu.vstart

  private val exceptionII =
    decodedInst.selImm === SelImm.INVALID_INSTR ||
    vecException.io.illegalInst ||
    io.fromCSR.illegalInst.sfenceVMA  && FuType.FuTypeOrR(decodedInst.fuType, FuType.fence) && decodedInst.fuOpType === FenceOpType.sfence  ||
    io.fromCSR.illegalInst.sfencePart && FuType.FuTypeOrR(decodedInst.fuType, FuType.fence) && decodedInst.fuOpType === FenceOpType.nofence ||
    io.fromCSR.illegalInst.hfenceGVMA && FuType.FuTypeOrR(decodedInst.fuType, FuType.fence) && decodedInst.fuOpType === FenceOpType.hfence_g ||
    io.fromCSR.illegalInst.hfenceVVMA && FuType.FuTypeOrR(decodedInst.fuType, FuType.fence) && decodedInst.fuOpType === FenceOpType.hfence_v ||
    io.fromCSR.illegalInst.hlsv       && FuType.FuTypeOrR(decodedInst.fuType, FuType.ldu)   && (LSUOpType.isHlv(decodedInst.fuOpType) || LSUOpType.isHlvx(decodedInst.fuOpType)) ||
    io.fromCSR.illegalInst.hlsv       && FuType.FuTypeOrR(decodedInst.fuType, FuType.stu)   && LSUOpType.isHsv(decodedInst.fuOpType) ||
    io.fromCSR.illegalInst.fsIsOff    && (FuType.FuTypeOrR(decodedInst.fuType, FuType.fpOP ++ Seq(FuType.f2v)) ||
                                          (FuType.FuTypeOrR(decodedInst.fuType, FuType.ldu) && (decodedInst.fuOpType === LSUOpType.lw || decodedInst.fuOpType === LSUOpType.ld) ||
                                           FuType.FuTypeOrR(decodedInst.fuType, FuType.stu) && (decodedInst.fuOpType === LSUOpType.sw || decodedInst.fuOpType === LSUOpType.sd)) && decodedInst.instr(2) ||
                                           isVecOPF) ||
    io.fromCSR.illegalInst.vsIsOff    && FuType.FuTypeOrR(decodedInst.fuType, FuType.vecAll) ||
    io.fromCSR.illegalInst.wfi        && FuType.FuTypeOrR(decodedInst.fuType, FuType.csr)   && CSROpType.isWfi(decodedInst.fuOpType) ||
    (decodedInst.needFrm.scalaNeedFrm || FuType.isScalaNeedFrm(decodedInst.fuType)) && (((decodedInst.fpu.rm === 5.U) || (decodedInst.fpu.rm === 6.U)) || ((decodedInst.fpu.rm === 7.U) && io.fromCSR.illegalInst.frm)) ||
    (decodedInst.needFrm.vectorNeedFrm || FuType.isVectorNeedFrm(decodedInst.fuType)) && io.fromCSR.illegalInst.frm

  private val exceptionVI =
    io.fromCSR.virtualInst.sfenceVMA  && FuType.FuTypeOrR(decodedInst.fuType, FuType.fence) && decodedInst.fuOpType === FenceOpType.sfence ||
    io.fromCSR.virtualInst.sfencePart && FuType.FuTypeOrR(decodedInst.fuType, FuType.fence) && decodedInst.fuOpType === FenceOpType.nofence ||
    io.fromCSR.virtualInst.hfence     && FuType.FuTypeOrR(decodedInst.fuType, FuType.fence) && (decodedInst.fuOpType === FenceOpType.hfence_g || decodedInst.fuOpType === FenceOpType.hfence_v) ||
    io.fromCSR.virtualInst.hlsv       && FuType.FuTypeOrR(decodedInst.fuType, FuType.ldu)   && (LSUOpType.isHlv(decodedInst.fuOpType) || LSUOpType.isHlvx(decodedInst.fuOpType)) ||
    io.fromCSR.virtualInst.hlsv       && FuType.FuTypeOrR(decodedInst.fuType, FuType.stu)   && LSUOpType.isHsv(decodedInst.fuOpType) ||
    io.fromCSR.virtualInst.wfi        && FuType.FuTypeOrR(decodedInst.fuType, FuType.csr)   && CSROpType.isWfi(decodedInst.fuOpType)

  decodedInst.exceptionVec(illegalInstr) := exceptionII || io.enq.ctrlFlow.exceptionVec(EX_II)
  decodedInst.exceptionVec(virtualInstr) := exceptionVI

  //update exceptionVec: from frontend trigger's breakpoint exception. To reduce 1 bit of overhead in ibuffer entry.
  decodedInst.exceptionVec(breakPoint) := TriggerAction.isExp(ctrl_flow.trigger)

  decodedInst.imm := LookupTree(decodedInst.selImm, ImmUnion.immSelMap.map(
    x => {
      val minBits = x._2.minBitsFromInstr(ctrl_flow.instr)
      require(minBits.getWidth == x._2.len)
      x._1 -> minBits
    }
  ))

  private val isLs = FuType.isLoadStore(decodedInst.fuType)
  private val isVls = FuType.isVls(decodedInst.fuType)
  private val isStore = FuType.isStore(decodedInst.fuType)
  private val isAMO = FuType.isAMO(decodedInst.fuType)
  private val isVStore = FuType.isVStore(decodedInst.fuType)
  private val isBranch = !decodedInst.preDecodeInfo.notCFI || FuType.isJump(decodedInst.fuType)

  decodedInst.commitType := Cat(isLs | isVls, (isStore && !isAMO) | isVStore | isBranch)

  decodedInst.isVset := FuType.isVset(decodedInst.fuType)

  private val needReverseInsts = Seq(VRSUB_VI, VRSUB_VX, VFRDIV_VF, VFRSUB_VF, VFMV_F_S)
  private val vextInsts = Seq(VZEXT_VF2, VZEXT_VF4, VZEXT_VF8, VSEXT_VF2, VSEXT_VF4, VSEXT_VF8)
  private val narrowInsts = Seq(
    VNSRA_WV, VNSRA_WX, VNSRA_WI, VNSRL_WV, VNSRL_WX, VNSRL_WI,
    VNCLIP_WV, VNCLIP_WX, VNCLIP_WI, VNCLIPU_WV, VNCLIPU_WX, VNCLIPU_WI,
  )
  private val maskDstInsts = Seq(
    VMADC_VV, VMADC_VX,  VMADC_VI,  VMADC_VVM, VMADC_VXM, VMADC_VIM,
    VMSBC_VV, VMSBC_VX,  VMSBC_VVM, VMSBC_VXM,
    VMAND_MM, VMNAND_MM, VMANDN_MM, VMXOR_MM, VMOR_MM, VMNOR_MM, VMORN_MM, VMXNOR_MM,
    VMSEQ_VV, VMSEQ_VX, VMSEQ_VI, VMSNE_VV, VMSNE_VX, VMSNE_VI,
    VMSLE_VV, VMSLE_VX, VMSLE_VI, VMSLEU_VV, VMSLEU_VX, VMSLEU_VI,
    VMSLT_VV, VMSLT_VX, VMSLTU_VV, VMSLTU_VX,
    VMSGT_VX, VMSGT_VI, VMSGTU_VX, VMSGTU_VI,
    VMFEQ_VV, VMFEQ_VF, VMFNE_VV, VMFNE_VF, VMFLT_VV, VMFLT_VF, VMFLE_VV, VMFLE_VF, VMFGT_VF, VMFGE_VF,
  )
  private val maskOpInsts = Seq(
    VMAND_MM, VMNAND_MM, VMANDN_MM, VMXOR_MM, VMOR_MM, VMNOR_MM, VMORN_MM, VMXNOR_MM,
  )
  private val vmaInsts = Seq(
    VMACC_VV, VMACC_VX, VNMSAC_VV, VNMSAC_VX, VMADD_VV, VMADD_VX, VNMSUB_VV, VNMSUB_VX,
    VWMACCU_VV, VWMACCU_VX, VWMACC_VV, VWMACC_VX, VWMACCSU_VV, VWMACCSU_VX, VWMACCUS_VX,
  )
  private val wfflagsInsts = Seq(
    // opfff
    FADD_S, FSUB_S, FADD_D, FSUB_D,
    FEQ_S, FLT_S, FLE_S, FEQ_D, FLT_D, FLE_D,
    FMIN_S, FMAX_S, FMIN_D, FMAX_D,
    FMUL_S, FMUL_D,
    FDIV_S, FDIV_D, FSQRT_S, FSQRT_D,
    FMADD_S, FMSUB_S, FNMADD_S, FNMSUB_S, FMADD_D, FMSUB_D, FNMADD_D, FNMSUB_D,
    FSGNJ_S, FSGNJN_S, FSGNJX_S,
    // opfvv
    VFADD_VV, VFSUB_VV, VFWADD_VV, VFWSUB_VV, VFWADD_WV, VFWSUB_WV,
    VFMUL_VV, VFDIV_VV, VFWMUL_VV,
    VFMACC_VV, VFNMACC_VV, VFMSAC_VV, VFNMSAC_VV, VFMADD_VV, VFNMADD_VV, VFMSUB_VV, VFNMSUB_VV,
    VFWMACC_VV, VFWNMACC_VV, VFWMSAC_VV, VFWNMSAC_VV,
    VFSQRT_V,
    VFMIN_VV, VFMAX_VV,
    VMFEQ_VV, VMFNE_VV, VMFLT_VV, VMFLE_VV,
    VFSGNJ_VV, VFSGNJN_VV, VFSGNJX_VV,
    // opfvf
    VFADD_VF, VFSUB_VF, VFRSUB_VF, VFWADD_VF, VFWSUB_VF, VFWADD_WF, VFWSUB_WF,
    VFMUL_VF, VFDIV_VF, VFRDIV_VF, VFWMUL_VF,
    VFMACC_VF, VFNMACC_VF, VFMSAC_VF, VFNMSAC_VF, VFMADD_VF, VFNMADD_VF, VFMSUB_VF, VFNMSUB_VF,
    VFWMACC_VF, VFWNMACC_VF, VFWMSAC_VF, VFWNMSAC_VF,
    VFMIN_VF, VFMAX_VF,
    VMFEQ_VF, VMFNE_VF, VMFLT_VF, VMFLE_VF, VMFGT_VF, VMFGE_VF,
    VFSGNJ_VF, VFSGNJN_VF, VFSGNJX_VF,
    // vfred
    VFREDOSUM_VS, VFREDUSUM_VS, VFREDMAX_VS, VFREDMIN_VS, VFWREDOSUM_VS, VFWREDUSUM_VS,
    // fcvt & vfcvt
    FCVT_S_W, FCVT_S_WU, FCVT_S_L, FCVT_S_LU,
    FCVT_W_S, FCVT_WU_S, FCVT_L_S, FCVT_LU_S,
    FCVT_D_W, FCVT_D_WU, FCVT_D_L, FCVT_D_LU,
    FCVT_W_D, FCVT_WU_D, FCVT_L_D, FCVT_LU_D, FCVT_S_D, FCVT_D_S,
    FCVT_S_H, FCVT_H_S, FCVT_H_D, FCVT_D_H,
    VFCVT_XU_F_V, VFCVT_X_F_V, VFCVT_RTZ_XU_F_V, VFCVT_RTZ_X_F_V, VFCVT_F_XU_V, VFCVT_F_X_V,
    VFWCVT_XU_F_V, VFWCVT_X_F_V, VFWCVT_RTZ_XU_F_V, VFWCVT_RTZ_X_F_V, VFWCVT_F_XU_V, VFWCVT_F_X_V, VFWCVT_F_F_V,
    VFNCVT_XU_F_W, VFNCVT_X_F_W, VFNCVT_RTZ_XU_F_W, VFNCVT_RTZ_X_F_W, VFNCVT_F_XU_W, VFNCVT_F_X_W, VFNCVT_F_F_W,
    VFNCVT_ROD_F_F_W, VFRSQRT7_V, VFREC7_V,
  )

  private val scalaNeedFrmInsts = Seq(
    FADD_S, FSUB_S, FADD_D, FSUB_D,
    FCVT_W_S, FCVT_WU_S, FCVT_L_S, FCVT_LU_S,
    FCVT_W_D, FCVT_WU_D, FCVT_L_D, FCVT_LU_D, FCVT_S_D, FCVT_D_S,
  )

  private val vectorNeedFrmInsts = Seq (
    VFSLIDE1UP_VF, VFSLIDE1DOWN_VF,
  )

  decodedInst.wfflags := wfflagsInsts.map(_ === inst.ALL).reduce(_ || _)
  decodedInst.needFrm.scalaNeedFrm := scalaNeedFrmInsts.map(_ === inst.ALL).reduce(_ || _)
  decodedInst.needFrm.vectorNeedFrm := vectorNeedFrmInsts.map(_ === inst.ALL).reduce(_ || _)
  val fpToVecDecoder = Module(new FPToVecDecoder())
  fpToVecDecoder.io.instr := inst.asUInt
  val isFpToVecInst = fpToVecDecoder.io.vpuCtrl.fpu.isFpToVecInst
  decodedInst.vpu := 0.U.asTypeOf(decodedInst.vpu) // Todo: Connect vpu decoder
  when(isFpToVecInst){
    decodedInst.vpu := fpToVecDecoder.io.vpuCtrl
  }.otherwise{
    decodedInst.vpu.vill := io.enq.vtype.illegal
    decodedInst.vpu.vma := io.enq.vtype.vma
    decodedInst.vpu.vta := io.enq.vtype.vta
    decodedInst.vpu.vsew := io.enq.vtype.vsew
    decodedInst.vpu.vlmul := io.enq.vtype.vlmul
    decodedInst.vpu.vm := inst.VM
    decodedInst.vpu.nf := inst.NF
    decodedInst.vpu.veew := inst.WIDTH
    decodedInst.vpu.isReverse := needReverseInsts.map(_ === inst.ALL).reduce(_ || _)
    decodedInst.vpu.isExt := vextInsts.map(_ === inst.ALL).reduce(_ || _)
    val isNarrow = narrowInsts.map(_ === inst.ALL).reduce(_ || _)
    val isDstMask = maskDstInsts.map(_ === inst.ALL).reduce(_ || _)
    val isOpMask = maskOpInsts.map(_ === inst.ALL).reduce(_ || _)
    val isVlx = decodedInst.fuOpType === VlduType.vloxe || decodedInst.fuOpType === VlduType.vluxe
    val isVle = decodedInst.fuOpType === VlduType.vle || decodedInst.fuOpType === VlduType.vleff || decodedInst.fuOpType === VlduType.vlse
    val isVlm = decodedInst.fuOpType === VlduType.vlm
    val isWritePartVd = decodedInst.uopSplitType === UopSplitType.VEC_VRED || decodedInst.uopSplitType === UopSplitType.VEC_0XV
    val isVma = vmaInsts.map(_ === inst.ALL).reduce(_ || _)
    val emulIsFrac = Cat(~decodedInst.vpu.vlmul(2), decodedInst.vpu.vlmul(1, 0)) +& decodedInst.vpu.veew < 4.U +& decodedInst.vpu.vsew
    decodedInst.vpu.isNarrow := isNarrow
    decodedInst.vpu.isDstMask := isDstMask
    decodedInst.vpu.isOpMask := isOpMask
    decodedInst.vpu.isDependOldvd := isVppu || isVecOPF || isVStore || (isDstMask && !isOpMask) || isNarrow || isVlx || isVma
    decodedInst.vpu.isWritePartVd := isWritePartVd || isVlm || isVle && emulIsFrac
    decodedInst.vpu.vstart := io.enq.vstart
  }
  decodedInst.vpu.specVill := io.enq.vtype.illegal
  decodedInst.vpu.specVma := io.enq.vtype.vma
  decodedInst.vpu.specVta := io.enq.vtype.vta
  decodedInst.vpu.specVsew := io.enq.vtype.vsew
  decodedInst.vpu.specVlmul := io.enq.vtype.vlmul

  decodedInst.vlsInstr := isVls

  decodedInst.srcType(3) := Mux(inst.VM === 0.U && !isFpToVecInst, SrcType.vp, SrcType.DC) // mask src
  decodedInst.srcType(4) := Mux(!isFpToVecInst, SrcType.vp, SrcType.DC) // vconfig

  val uopInfoGen = Module(new UopInfoGen)
  uopInfoGen.io.in.preInfo.typeOfSplit := decodedInst.uopSplitType
  uopInfoGen.io.in.preInfo.vsew := decodedInst.vpu.vsew
  uopInfoGen.io.in.preInfo.vlmul := decodedInst.vpu.vlmul
  uopInfoGen.io.in.preInfo.vwidth := inst.RM
  uopInfoGen.io.in.preInfo.vmvn := inst.IMM5_OPIVI(2, 0)
  uopInfoGen.io.in.preInfo.nf := inst.NF
  uopInfoGen.io.in.preInfo.isVlsr := decodedInst.fuOpType === VlduType.vlr || decodedInst.fuOpType === VstuType.vsr
  uopInfoGen.io.in.preInfo.isVlsm := decodedInst.fuOpType === VlduType.vlm || decodedInst.fuOpType === VstuType.vsm
  io.deq.isComplex := uopInfoGen.io.out.isComplex
  // numOfUop should be 1 when vector instruction is illegalInst
  io.deq.uopInfo.numOfUop := Mux(vecException.io.illegalInst, 1.U, uopInfoGen.io.out.uopInfo.numOfUop)
  io.deq.uopInfo.numOfWB := uopInfoGen.io.out.uopInfo.numOfWB
  io.deq.uopInfo.lmul := uopInfoGen.io.out.uopInfo.lmul

  val isCSR = inst.OPCODE5Bit === OPCODE5Bit.SYSTEM && inst.FUNCT3(1, 0) =/= 0.U
  val isCSRR = isCSR && inst.FUNCT3 === BitPat("b?1?") && inst.RS1 === 0.U
  val isCSRW = isCSR && inst.FUNCT3 === BitPat("b?10") && inst.RD  === 0.U
  dontTouch(isCSRR)
  dontTouch(isCSRW)

  // for csrr vl instruction, convert to vsetvl
  val isCsrrVlenb = isCSRR && inst.CSRIDX === CSRs.vlenb.U
  val isCsrrVl    = isCSRR && inst.CSRIDX === CSRs.vl.U

  // decode for SoftPrefetch instructions (prefetch.w / prefetch.r / prefetch.i)
  val isSoftPrefetch = inst.OPCODE === BitPat("b0010011") && inst.FUNCT3 === BitPat("b110") && inst.RD === 0.U
  val isPreW = isSoftPrefetch && inst.RS2 === 3.U(5.W)
  val isPreR = isSoftPrefetch && inst.RS2 === 1.U(5.W)
  val isPreI = isSoftPrefetch && inst.RS2 === 0.U(5.W)

  when (isCsrrVl) {
    // convert to vsetvl instruction
    decodedInst.srcType(0) := SrcType.no
    decodedInst.srcType(1) := SrcType.no
    decodedInst.srcType(2) := SrcType.no
    decodedInst.srcType(3) := SrcType.no
    decodedInst.srcType(4) := SrcType.vp
    decodedInst.lsrc(4)    := Vl_IDX.U
    decodedInst.waitForward   := false.B
    decodedInst.blockBackward := false.B
    decodedInst.exceptionVec(illegalInstr) := io.fromCSR.illegalInst.vsIsOff
  }.elsewhen(isCsrrVlenb){
    // convert to addi instruction
    decodedInst.srcType(0) := SrcType.reg
    decodedInst.srcType(1) := SrcType.imm
    decodedInst.srcType(2) := SrcType.no
    decodedInst.srcType(3) := SrcType.no
    decodedInst.srcType(4) := SrcType.no
    decodedInst.selImm := SelImm.IMM_I
    decodedInst.waitForward := false.B
    decodedInst.blockBackward := false.B
    decodedInst.canRobCompress := true.B
    decodedInst.exceptionVec(illegalInstr) := io.fromCSR.illegalInst.vsIsOff
  }.elsewhen(isPreW || isPreR || isPreI){
    decodedInst.selImm := SelImm.IMM_S
    decodedInst.fuType := FuType.ldu.U
    decodedInst.canRobCompress := false.B
    decodedInst.fuOpType := Mux1H(Seq(
      isPreW -> LSUOpType.prefetch_w,
      isPreR -> LSUOpType.prefetch_r,
      isPreI -> LSUOpType.prefetch_i,
    ))

  }

  io.deq.decodedInst := decodedInst
  io.deq.decodedInst.rfWen := (decodedInst.ldest =/= 0.U) && decodedInst.rfWen
  io.deq.decodedInst.fuType := Mux1H(Seq(
    // keep condition
    (!FuType.FuTypeOrR(decodedInst.fuType, FuType.vldu, FuType.vstu) && !isCsrrVl && !isCsrrVlenb) -> decodedInst.fuType,
    (isCsrrVl) -> FuType.vsetfwf.U,
    (isCsrrVlenb) -> FuType.alu.U,

    // change vlsu to vseglsu when NF =/= 0.U
    ( FuType.FuTypeOrR(decodedInst.fuType, FuType.vldu, FuType.vstu) && inst.NF === 0.U || (inst.NF =/= 0.U && (inst.MOP === "b00".U && inst.SUMOP === "b01000".U))) -> decodedInst.fuType,
    // MOP === b00 && SUMOP === b01000: unit-stride whole register store
    // MOP =/= b00                    : strided and indexed store
    ( FuType.FuTypeOrR(decodedInst.fuType, FuType.vstu)              && inst.NF =/= 0.U && ((inst.MOP === "b00".U && inst.SUMOP =/= "b01000".U) || inst.MOP =/= "b00".U)) -> FuType.vsegstu.U,
    // MOP === b00 && LUMOP === b01000: unit-stride whole register load
    // MOP =/= b00                    : strided and indexed load
    ( FuType.FuTypeOrR(decodedInst.fuType, FuType.vldu)              && inst.NF =/= 0.U && ((inst.MOP === "b00".U && inst.LUMOP =/= "b01000".U) || inst.MOP =/= "b00".U)) -> FuType.vsegldu.U,
  ))
  io.deq.decodedInst.imm := Mux(isCsrrVlenb, (VLEN / 8).U, decodedInst.imm)

  io.deq.decodedInst.fuOpType := MuxCase(decodedInst.fuOpType, Seq(
    isCsrrVl    -> VSETOpType.csrrvl,
    isCsrrVlenb -> ALUOpType.add,
  ))

  io.deq.decodedInst.blockBackward := MuxCase(decodedInst.blockBackward, Seq(
    isCSRR -> false.B,
  ))
  //-------------------------------------------------------------
  // Debug Info
//  XSDebug("in:  instr=%x pc=%x excepVec=%b crossPageIPFFix=%d\n",
//    io.enq.ctrl_flow.instr, io.enq.ctrl_flow.pc, io.enq.ctrl_flow.exceptionVec.asUInt,
//    io.enq.ctrl_flow.crossPageIPFFix)
//  XSDebug("out: srcType(0)=%b srcType(1)=%b srcType(2)=%b lsrc(0)=%d lsrc(1)=%d lsrc(2)=%d ldest=%d fuType=%b fuOpType=%b\n",
//    io.deq.cf_ctrl.ctrl.srcType(0), io.deq.cf_ctrl.ctrl.srcType(1), io.deq.cf_ctrl.ctrl.srcType(2),
//    io.deq.cf_ctrl.ctrl.lsrc(0), io.deq.cf_ctrl.ctrl.lsrc(1), io.deq.cf_ctrl.ctrl.lsrc(2),
//    io.deq.cf_ctrl.ctrl.ldest, io.deq.cf_ctrl.ctrl.fuType, io.deq.cf_ctrl.ctrl.fuOpType)
//  XSDebug("out: rfWen=%d fpWen=%d isXSTrap=%d noSpecExec=%d isBlocked=%d flushPipe=%d imm=%x\n",
//    io.deq.cf_ctrl.ctrl.rfWen, io.deq.cf_ctrl.ctrl.fpWen, io.deq.cf_ctrl.ctrl.isXSTrap,
//    io.deq.cf_ctrl.ctrl.noSpecExec, io.deq.cf_ctrl.ctrl.blockBackward, io.deq.cf_ctrl.ctrl.flushPipe,
//    io.deq.cf_ctrl.ctrl.imm)
//  XSDebug("out: excepVec=%b\n", io.deq.cf_ctrl.cf.exceptionVec.asUInt)
}