xref: /XiangShan/src/main/scala/xiangshan/backend/rename/Rename.scala (revision fa7f2c2660816d7244ad7e2262d26ca447d0b18e)
1c6d43980SLemover/***************************************************************************************
2c6d43980SLemover* Copyright (c) 2020-2021 Institute of Computing Technology, Chinese Academy of Sciences
3f320e0f0SYinan Xu* Copyright (c) 2020-2021 Peng Cheng Laboratory
4c6d43980SLemover*
5c6d43980SLemover* XiangShan is licensed under Mulan PSL v2.
6c6d43980SLemover* You can use this software according to the terms and conditions of the Mulan PSL v2.
7c6d43980SLemover* You may obtain a copy of Mulan PSL v2 at:
8c6d43980SLemover*          http://license.coscl.org.cn/MulanPSL2
9c6d43980SLemover*
10c6d43980SLemover* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
11c6d43980SLemover* EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
12c6d43980SLemover* MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
13c6d43980SLemover*
14c6d43980SLemover* See the Mulan PSL v2 for more details.
15c6d43980SLemover***************************************************************************************/
16c6d43980SLemover
175844fcf0SLinJiaweipackage xiangshan.backend.rename
185844fcf0SLinJiawei
192225d46eSJiawei Linimport chipsalliance.rocketchip.config.Parameters
205844fcf0SLinJiaweiimport chisel3._
215844fcf0SLinJiaweiimport chisel3.util._
225844fcf0SLinJiaweiimport xiangshan._
237cef916fSYinan Xuimport utils._
243c02ee8fSwakafaimport utility._
25a0db5a4bSYinan Xuimport xiangshan.backend.decode.{FusionDecodeInfo, Imm_I, Imm_LUI_LOAD, Imm_U}
269aca92b9SYinan Xuimport xiangshan.backend.rob.RobPtr
2770224bf6SYinan Xuimport xiangshan.backend.rename.freelist._
28980c1bc3SWilliam Wangimport xiangshan.mem.mdp._
2999b8dc2cSYinan Xu
30ccfddc82SHaojin Tangclass Rename(implicit p: Parameters) extends XSModule with HasCircularQueuePtrHelper with HasPerfEvents {
315844fcf0SLinJiawei  val io = IO(new Bundle() {
325844fcf0SLinJiawei    val redirect = Flipped(ValidIO(new Redirect))
33ccfddc82SHaojin Tang    val robCommits = Input(new RobCommitIO)
347fa2c198SYinan Xu    // from decode
359a2e6b8aSLinJiawei    val in = Vec(RenameWidth, Flipped(DecoupledIO(new CfCtrl)))
36a0db5a4bSYinan Xu    val fusionInfo = Vec(DecodeWidth - 1, Flipped(new FusionDecodeInfo))
37980c1bc3SWilliam Wang    // ssit read result
38980c1bc3SWilliam Wang    val ssit = Flipped(Vec(RenameWidth, Output(new SSITEntry)))
39980c1bc3SWilliam Wang    // waittable read result
40980c1bc3SWilliam Wang    val waittable = Flipped(Vec(RenameWidth, Output(Bool())))
417fa2c198SYinan Xu    // to rename table
427fa2c198SYinan Xu    val intReadPorts = Vec(RenameWidth, Vec(3, Input(UInt(PhyRegIdxWidth.W))))
437fa2c198SYinan Xu    val fpReadPorts = Vec(RenameWidth, Vec(4, Input(UInt(PhyRegIdxWidth.W))))
447fa2c198SYinan Xu    val intRenamePorts = Vec(RenameWidth, Output(new RatWritePort))
457fa2c198SYinan Xu    val fpRenamePorts = Vec(RenameWidth, Output(new RatWritePort))
46dcf3a679STang Haojin    // from rename table
47dcf3a679STang Haojin    val int_old_pdest = Vec(CommitWidth, Input(UInt(PhyRegIdxWidth.W)))
48dcf3a679STang Haojin    val fp_old_pdest = Vec(CommitWidth, Input(UInt(PhyRegIdxWidth.W)))
49dcf3a679STang Haojin    val int_need_free = Vec(CommitWidth, Input(Bool()))
5057c4f8d6SLinJiawei    // to dispatch1
519a2e6b8aSLinJiawei    val out = Vec(RenameWidth, DecoupledIO(new MicroOp))
52*fa7f2c26STang Haojin    // for snapshots
53*fa7f2c26STang Haojin    val snpt = Input(new SnapshotPort)
54ccfddc82SHaojin Tang    // debug arch ports
55ccfddc82SHaojin Tang    val debug_int_rat = Vec(32, Input(UInt(PhyRegIdxWidth.W)))
56ccfddc82SHaojin Tang    val debug_fp_rat = Vec(32, Input(UInt(PhyRegIdxWidth.W)))
57d2b20d1aSTang Haojin    // perf only
58d2b20d1aSTang Haojin    val stallReason = new Bundle {
59d2b20d1aSTang Haojin      val in = Flipped(new StallReasonIO(RenameWidth))
60d2b20d1aSTang Haojin      val out = new StallReasonIO(RenameWidth)
61d2b20d1aSTang Haojin    }
625844fcf0SLinJiawei  })
63b034d3b9SLinJiawei
648b8e745dSYikeZhou  // create free list and rat
65459d1caeSYinan Xu  val intFreeList = Module(new MEFreeList(NRPhyRegs))
66459d1caeSYinan Xu  val fpFreeList = Module(new StdFreeList(NRPhyRegs - 32))
678b8e745dSYikeZhou
68ccfddc82SHaojin Tang  intFreeList.io.commit    <> io.robCommits
69ccfddc82SHaojin Tang  intFreeList.io.debug_rat <> io.debug_int_rat
70ccfddc82SHaojin Tang  fpFreeList.io.commit     <> io.robCommits
71ccfddc82SHaojin Tang  fpFreeList.io.debug_rat  <> io.debug_fp_rat
72ccfddc82SHaojin Tang
739aca92b9SYinan Xu  // decide if given instruction needs allocating a new physical register (CfCtrl: from decode; RobCommitInfo: from rob)
74b034d3b9SLinJiawei  def needDestReg[T <: CfCtrl](fp: Boolean, x: T): Bool = {
75b034d3b9SLinJiawei    {if(fp) x.ctrl.fpWen else x.ctrl.rfWen && (x.ctrl.ldest =/= 0.U)}
76b034d3b9SLinJiawei  }
779aca92b9SYinan Xu  def needDestRegCommit[T <: RobCommitInfo](fp: Boolean, x: T): Bool = {
78c3abb8b6SYinan Xu    if(fp) x.fpWen else x.rfWen
79fe6452fcSYinan Xu  }
80ccfddc82SHaojin Tang  def needDestRegWalk[T <: RobCommitInfo](fp: Boolean, x: T): Bool = {
81ccfddc82SHaojin Tang    if(fp) x.fpWen else x.rfWen && x.ldest =/= 0.U
82ccfddc82SHaojin Tang  }
838b8e745dSYikeZhou
84f4b2089aSYinan Xu  // connect [redirect + walk] ports for __float point__ & __integer__ free list
855eb4af5bSYikeZhou  Seq((fpFreeList, true), (intFreeList, false)).foreach{ case (fl, isFp) =>
8670224bf6SYinan Xu    fl.io.redirect := io.redirect.valid
8770224bf6SYinan Xu    fl.io.walk := io.robCommits.isWalk
884efb89cbSYikeZhou  }
895eb4af5bSYikeZhou  // only when both fp and int free list and dispatch1 has enough space can we do allocation
90ccfddc82SHaojin Tang  // when isWalk, freelist can definitely allocate
91ccfddc82SHaojin Tang  intFreeList.io.doAllocate := fpFreeList.io.canAllocate && io.out(0).ready || io.robCommits.isWalk
92ccfddc82SHaojin Tang  fpFreeList.io.doAllocate := intFreeList.io.canAllocate && io.out(0).ready || io.robCommits.isWalk
935eb4af5bSYikeZhou
945eb4af5bSYikeZhou  //           dispatch1 ready ++ float point free list ready ++ int free list ready      ++ not walk
9570224bf6SYinan Xu  val canOut = io.out(0).ready && fpFreeList.io.canAllocate && intFreeList.io.canAllocate && !io.robCommits.isWalk
965eb4af5bSYikeZhou
97b034d3b9SLinJiawei
989aca92b9SYinan Xu  // speculatively assign the instruction with an robIdx
999aca92b9SYinan Xu  val validCount = PopCount(io.in.map(_.valid)) // number of instructions waiting to enter rob (from decode)
1009aca92b9SYinan Xu  val robIdxHead = RegInit(0.U.asTypeOf(new RobPtr))
1018f77f081SYinan Xu  val lastCycleMisprediction = RegNext(io.redirect.valid && !io.redirect.bits.flushItself())
102f4b2089aSYinan Xu  val robIdxHeadNext = Mux(io.redirect.valid, io.redirect.bits.robIdx, // redirect: move ptr to given rob index
1039aca92b9SYinan Xu         Mux(lastCycleMisprediction, robIdxHead + 1.U, // mis-predict: not flush robIdx itself
1049aca92b9SYinan Xu                         Mux(canOut, robIdxHead + validCount, // instructions successfully entered next stage: increase robIdx
105f4b2089aSYinan Xu                      /* default */  robIdxHead))) // no instructions passed by this cycle: stick to old value
1069aca92b9SYinan Xu  robIdxHead := robIdxHeadNext
107588ceab5SYinan Xu
10800ad41d0SYinan Xu  /**
10900ad41d0SYinan Xu    * Rename: allocate free physical register and update rename table
11000ad41d0SYinan Xu    */
111b034d3b9SLinJiawei  val uops = Wire(Vec(RenameWidth, new MicroOp))
112b034d3b9SLinJiawei  uops.foreach( uop => {
11320e31bd1SYinan Xu    uop.srcState(0) := DontCare
11420e31bd1SYinan Xu    uop.srcState(1) := DontCare
11520e31bd1SYinan Xu    uop.srcState(2) := DontCare
1169aca92b9SYinan Xu    uop.robIdx := DontCare
1177cef916fSYinan Xu    uop.debugInfo := DontCare
118bc86598fSWilliam Wang    uop.lqIdx := DontCare
119bc86598fSWilliam Wang    uop.sqIdx := DontCare
120*fa7f2c26STang Haojin    uop.snapshot := DontCare
121b034d3b9SLinJiawei  })
122b034d3b9SLinJiawei
123ccfddc82SHaojin Tang  require(RenameWidth >= CommitWidth)
124ccfddc82SHaojin Tang
12599b8dc2cSYinan Xu  val needFpDest = Wire(Vec(RenameWidth, Bool()))
12699b8dc2cSYinan Xu  val needIntDest = Wire(Vec(RenameWidth, Bool()))
127b424051cSYinan Xu  val hasValid = Cat(io.in.map(_.valid)).orR
1288b8e745dSYikeZhou
1298b8e745dSYikeZhou  val isMove = io.in.map(_.bits.ctrl.isMove)
1308b8e745dSYikeZhou
131ccfddc82SHaojin Tang  val walkNeedFpDest = WireDefault(VecInit(Seq.fill(RenameWidth)(false.B)))
132ccfddc82SHaojin Tang  val walkNeedIntDest = WireDefault(VecInit(Seq.fill(RenameWidth)(false.B)))
133ccfddc82SHaojin Tang  val walkIsMove = WireDefault(VecInit(Seq.fill(RenameWidth)(false.B)))
134ccfddc82SHaojin Tang
1358b8e745dSYikeZhou  val intSpecWen = Wire(Vec(RenameWidth, Bool()))
1368b8e745dSYikeZhou  val fpSpecWen = Wire(Vec(RenameWidth, Bool()))
1378b8e745dSYikeZhou
138ccfddc82SHaojin Tang  val walkIntSpecWen = WireDefault(VecInit(Seq.fill(RenameWidth)(false.B)))
139ccfddc82SHaojin Tang
140ccfddc82SHaojin Tang  val walkPdest = Wire(Vec(RenameWidth, UInt(PhyRegIdxWidth.W)))
141ccfddc82SHaojin Tang
1428b8e745dSYikeZhou  // uop calculation
143b034d3b9SLinJiawei  for (i <- 0 until RenameWidth) {
144b034d3b9SLinJiawei    uops(i).cf := io.in(i).bits.cf
145b034d3b9SLinJiawei    uops(i).ctrl := io.in(i).bits.ctrl
146b034d3b9SLinJiawei
147980c1bc3SWilliam Wang    // update cf according to ssit result
148980c1bc3SWilliam Wang    uops(i).cf.storeSetHit := io.ssit(i).valid
149980c1bc3SWilliam Wang    uops(i).cf.loadWaitStrict := io.ssit(i).strict && io.ssit(i).valid
150980c1bc3SWilliam Wang    uops(i).cf.ssid := io.ssit(i).ssid
151980c1bc3SWilliam Wang
152980c1bc3SWilliam Wang    // update cf according to waittable result
153980c1bc3SWilliam Wang    uops(i).cf.loadWaitBit := io.waittable(i)
154980c1bc3SWilliam Wang
155b034d3b9SLinJiawei    // alloc a new phy reg
1560febc381SYinan Xu    needFpDest(i) := io.in(i).valid && needDestReg(fp = true, io.in(i).bits)
1570febc381SYinan Xu    needIntDest(i) := io.in(i).valid && needDestReg(fp = false, io.in(i).bits)
158ccfddc82SHaojin Tang    if (i < CommitWidth) {
159ccfddc82SHaojin Tang      walkNeedFpDest(i) := io.robCommits.walkValid(i) && needDestRegWalk(fp = true, io.robCommits.info(i))
160ccfddc82SHaojin Tang      walkNeedIntDest(i) := io.robCommits.walkValid(i) && needDestRegWalk(fp = false, io.robCommits.info(i))
161ccfddc82SHaojin Tang      walkIsMove(i) := io.robCommits.info(i).isMove
162ccfddc82SHaojin Tang    }
163dcf3a679STang Haojin    fpFreeList.io.allocateReq(i) := needFpDest(i)
164dcf3a679STang Haojin    fpFreeList.io.walkReq(i) := walkNeedFpDest(i)
165dcf3a679STang Haojin    intFreeList.io.allocateReq(i) := needIntDest(i) && !isMove(i)
166dcf3a679STang Haojin    intFreeList.io.walkReq(i) := walkNeedIntDest(i) && !walkIsMove(i)
1672438f9ebSYinan Xu
1688b8e745dSYikeZhou    // no valid instruction from decode stage || all resources (dispatch1 + both free lists) ready
169b424051cSYinan Xu    io.in(i).ready := !hasValid || canOut
17058e06390SLinJiawei
1719aca92b9SYinan Xu    uops(i).robIdx := robIdxHead + PopCount(io.in.take(i).map(_.valid))
172588ceab5SYinan Xu
173a0db5a4bSYinan Xu    uops(i).psrc(0) := Mux(uops(i).ctrl.srcType(0) === SrcType.reg, io.intReadPorts(i)(0), io.fpReadPorts(i)(0))
174a0db5a4bSYinan Xu    uops(i).psrc(1) := Mux(uops(i).ctrl.srcType(1) === SrcType.reg, io.intReadPorts(i)(1), io.fpReadPorts(i)(1))
175a0db5a4bSYinan Xu    // int psrc2 should be bypassed from next instruction if it is fused
176a0db5a4bSYinan Xu    if (i < RenameWidth - 1) {
177a0db5a4bSYinan Xu      when (io.fusionInfo(i).rs2FromRs2 || io.fusionInfo(i).rs2FromRs1) {
178a0db5a4bSYinan Xu        uops(i).psrc(1) := Mux(io.fusionInfo(i).rs2FromRs2, io.intReadPorts(i + 1)(1), io.intReadPorts(i + 1)(0))
179a0db5a4bSYinan Xu      }.elsewhen(io.fusionInfo(i).rs2FromZero) {
180a0db5a4bSYinan Xu        uops(i).psrc(1) := 0.U
181a0db5a4bSYinan Xu      }
182a0db5a4bSYinan Xu    }
183a0db5a4bSYinan Xu    uops(i).psrc(2) := io.fpReadPorts(i)(2)
18470224bf6SYinan Xu    uops(i).eliminatedMove := isMove(i)
1858b8e745dSYikeZhou
1868b8e745dSYikeZhou    // update pdest
18770224bf6SYinan Xu    uops(i).pdest := Mux(needIntDest(i), intFreeList.io.allocatePhyReg(i), // normal int inst
18870224bf6SYinan Xu      // normal fp inst
18970224bf6SYinan Xu      Mux(needFpDest(i), fpFreeList.io.allocatePhyReg(i),
19070224bf6SYinan Xu        /* default */0.U))
1918b8e745dSYikeZhou
192ebb8ebf8SYinan Xu    // Assign performance counters
193ebb8ebf8SYinan Xu    uops(i).debugInfo.renameTime := GTimer()
194ebb8ebf8SYinan Xu
19570224bf6SYinan Xu    io.out(i).valid := io.in(i).valid && intFreeList.io.canAllocate && fpFreeList.io.canAllocate && !io.robCommits.isWalk
196ebb8ebf8SYinan Xu    io.out(i).bits := uops(i)
197f025d715SYinan Xu    // dirty code for fence. The lsrc is passed by imm.
198a020ce37SYinan Xu    when (io.out(i).bits.ctrl.fuType === FuType.fence) {
199a020ce37SYinan Xu      io.out(i).bits.ctrl.imm := Cat(io.in(i).bits.ctrl.lsrc(1), io.in(i).bits.ctrl.lsrc(0))
200a020ce37SYinan Xu    }
201f025d715SYinan Xu    // dirty code for SoftPrefetch (prefetch.r/prefetch.w)
202f025d715SYinan Xu    when (io.in(i).bits.ctrl.isSoftPrefetch) {
203f025d715SYinan Xu      io.out(i).bits.ctrl.fuType := FuType.ldu
204f025d715SYinan Xu      io.out(i).bits.ctrl.fuOpType := Mux(io.in(i).bits.ctrl.lsrc(1) === 1.U, LSUOpType.prefetch_r, LSUOpType.prefetch_w)
205f025d715SYinan Xu      io.out(i).bits.ctrl.selImm := SelImm.IMM_S
206f025d715SYinan Xu      io.out(i).bits.ctrl.imm := Cat(io.in(i).bits.ctrl.imm(io.in(i).bits.ctrl.imm.getWidth - 1, 5), 0.U(5.W))
207f025d715SYinan Xu    }
208ebb8ebf8SYinan Xu
2098b8e745dSYikeZhou    // write speculative rename table
21039d3280eSYikeZhou    // we update rat later inside commit code
21170224bf6SYinan Xu    intSpecWen(i) := needIntDest(i) && intFreeList.io.canAllocate && intFreeList.io.doAllocate && !io.robCommits.isWalk && !io.redirect.valid
21270224bf6SYinan Xu    fpSpecWen(i) := needFpDest(i) && fpFreeList.io.canAllocate && fpFreeList.io.doAllocate && !io.robCommits.isWalk && !io.redirect.valid
21370224bf6SYinan Xu
214ccfddc82SHaojin Tang    if (i < CommitWidth) {
215ccfddc82SHaojin Tang      walkIntSpecWen(i) := walkNeedIntDest(i) && !io.redirect.valid
216ccfddc82SHaojin Tang      walkPdest(i) := io.robCommits.info(i).pdest
217ccfddc82SHaojin Tang    } else {
218ccfddc82SHaojin Tang      walkPdest(i) := io.out(i).bits.pdest
219ccfddc82SHaojin Tang    }
220b034d3b9SLinJiawei  }
221b034d3b9SLinJiawei
22270224bf6SYinan Xu  /**
22370224bf6SYinan Xu    * How to set psrc:
22470224bf6SYinan Xu    * - bypass the pdest to psrc if previous instructions write to the same ldest as lsrc
22570224bf6SYinan Xu    * - default: psrc from RAT
22670224bf6SYinan Xu    * How to set pdest:
22770224bf6SYinan Xu    * - Mux(isMove, psrc, pdest_from_freelist).
22870224bf6SYinan Xu    *
22970224bf6SYinan Xu    * The critical path of rename lies here:
23070224bf6SYinan Xu    * When move elimination is enabled, we need to update the rat with psrc.
23170224bf6SYinan Xu    * However, psrc maybe comes from previous instructions' pdest, which comes from freelist.
23270224bf6SYinan Xu    *
23370224bf6SYinan Xu    * If we expand these logic for pdest(N):
23470224bf6SYinan Xu    * pdest(N) = Mux(isMove(N), psrc(N), freelist_out(N))
23570224bf6SYinan Xu    *          = Mux(isMove(N), Mux(bypass(N, N - 1), pdest(N - 1),
23670224bf6SYinan Xu    *                           Mux(bypass(N, N - 2), pdest(N - 2),
23770224bf6SYinan Xu    *                           ...
23870224bf6SYinan Xu    *                           Mux(bypass(N, 0),     pdest(0),
23970224bf6SYinan Xu    *                                                 rat_out(N))...)),
24070224bf6SYinan Xu    *                           freelist_out(N))
24170224bf6SYinan Xu    */
24270224bf6SYinan Xu  // a simple functional model for now
24370224bf6SYinan Xu  io.out(0).bits.pdest := Mux(isMove(0), uops(0).psrc.head, uops(0).pdest)
24470224bf6SYinan Xu  val bypassCond = Wire(Vec(4, MixedVec(List.tabulate(RenameWidth-1)(i => UInt((i+1).W)))))
24599b8dc2cSYinan Xu  for (i <- 1 until RenameWidth) {
24670224bf6SYinan Xu    val fpCond = io.in(i).bits.ctrl.srcType.map(_ === SrcType.fp) :+ needFpDest(i)
24770224bf6SYinan Xu    val intCond = io.in(i).bits.ctrl.srcType.map(_ === SrcType.reg) :+ needIntDest(i)
24870224bf6SYinan Xu    val target = io.in(i).bits.ctrl.lsrc :+ io.in(i).bits.ctrl.ldest
24970224bf6SYinan Xu    for ((((cond1, cond2), t), j) <- fpCond.zip(intCond).zip(target).zipWithIndex) {
25070224bf6SYinan Xu      val destToSrc = io.in.take(i).zipWithIndex.map { case (in, j) =>
25170224bf6SYinan Xu        val indexMatch = in.bits.ctrl.ldest === t
25270224bf6SYinan Xu        val writeMatch =  cond2 && needIntDest(j) || cond1 && needFpDest(j)
25370224bf6SYinan Xu        indexMatch && writeMatch
25470224bf6SYinan Xu      }
25570224bf6SYinan Xu      bypassCond(j)(i - 1) := VecInit(destToSrc).asUInt
25670224bf6SYinan Xu    }
25770224bf6SYinan Xu    io.out(i).bits.psrc(0) := io.out.take(i).map(_.bits.pdest).zip(bypassCond(0)(i-1).asBools).foldLeft(uops(i).psrc(0)) {
25870224bf6SYinan Xu      (z, next) => Mux(next._2, next._1, z)
25970224bf6SYinan Xu    }
26070224bf6SYinan Xu    io.out(i).bits.psrc(1) := io.out.take(i).map(_.bits.pdest).zip(bypassCond(1)(i-1).asBools).foldLeft(uops(i).psrc(1)) {
26170224bf6SYinan Xu      (z, next) => Mux(next._2, next._1, z)
26270224bf6SYinan Xu    }
26370224bf6SYinan Xu    io.out(i).bits.psrc(2) := io.out.take(i).map(_.bits.pdest).zip(bypassCond(2)(i-1).asBools).foldLeft(uops(i).psrc(2)) {
26470224bf6SYinan Xu      (z, next) => Mux(next._2, next._1, z)
26570224bf6SYinan Xu    }
26670224bf6SYinan Xu    io.out(i).bits.pdest := Mux(isMove(i), io.out(i).bits.psrc(0), uops(i).pdest)
267fd7603d9SYinan Xu
268fd7603d9SYinan Xu    // For fused-lui-load, load.src(0) is replaced by the imm.
269fd7603d9SYinan Xu    val last_is_lui = io.in(i - 1).bits.ctrl.selImm === SelImm.IMM_U && io.in(i - 1).bits.ctrl.srcType(0) =/= SrcType.pc
270f025d715SYinan Xu    val this_is_load = io.in(i).bits.ctrl.fuType === FuType.ldu
27189c0fb0aSYinan Xu    val lui_to_load = io.in(i - 1).valid && io.in(i - 1).bits.ctrl.ldest === io.in(i).bits.ctrl.lsrc(0)
272fd7603d9SYinan Xu    val fused_lui_load = last_is_lui && this_is_load && lui_to_load
273fd7603d9SYinan Xu    when (fused_lui_load) {
274fd7603d9SYinan Xu      // The first LOAD operand (base address) is replaced by LUI-imm and stored in {psrc, imm}
275fd7603d9SYinan Xu      val lui_imm = io.in(i - 1).bits.ctrl.imm
276fd7603d9SYinan Xu      val ld_imm = io.in(i).bits.ctrl.imm
277fd7603d9SYinan Xu      io.out(i).bits.ctrl.srcType(0) := SrcType.imm
278fd7603d9SYinan Xu      io.out(i).bits.ctrl.imm := Imm_LUI_LOAD().immFromLuiLoad(lui_imm, ld_imm)
279fd7603d9SYinan Xu      val psrcWidth = uops(i).psrc.head.getWidth
280fd7603d9SYinan Xu      val lui_imm_in_imm = uops(i).ctrl.imm.getWidth - Imm_I().len
281fd7603d9SYinan Xu      val left_lui_imm = Imm_U().len - lui_imm_in_imm
282fd7603d9SYinan Xu      require(2 * psrcWidth >= left_lui_imm, "cannot fused lui and load with psrc")
283fd7603d9SYinan Xu      io.out(i).bits.psrc(0) := lui_imm(lui_imm_in_imm + psrcWidth - 1, lui_imm_in_imm)
284fd7603d9SYinan Xu      io.out(i).bits.psrc(1) := lui_imm(lui_imm.getWidth - 1, lui_imm_in_imm + psrcWidth)
285fd7603d9SYinan Xu    }
286fd7603d9SYinan Xu
287b034d3b9SLinJiawei  }
28800ad41d0SYinan Xu
289*fa7f2c26STang Haojin  val hasCFI = VecInit(io.in.map(in => (!in.bits.cf.pd.notCFI || FuType.isJumpExu(in.bits.ctrl.fuType)) && in.fire)).asUInt.orR
290*fa7f2c26STang Haojin  val snapshotCtr = RegInit((4 * CommitWidth).U)
291*fa7f2c26STang Haojin  val allowSnpt = if (EnableRenameSnapshot) !snapshotCtr.orR else false.B
292*fa7f2c26STang Haojin  io.out.head.bits.snapshot := hasCFI && allowSnpt
293*fa7f2c26STang Haojin  when(io.out.head.fire && io.out.head.bits.snapshot) {
294*fa7f2c26STang Haojin    snapshotCtr := (4 * CommitWidth).U - PopCount(io.out.map(_.fire))
295*fa7f2c26STang Haojin  }.elsewhen(io.out.head.fire) {
296*fa7f2c26STang Haojin    snapshotCtr := Mux(snapshotCtr < PopCount(io.out.map(_.fire)), 0.U, snapshotCtr - PopCount(io.out.map(_.fire)))
297*fa7f2c26STang Haojin  }
298*fa7f2c26STang Haojin
299*fa7f2c26STang Haojin  intFreeList.io.snpt := io.snpt
300*fa7f2c26STang Haojin  fpFreeList.io.snpt := io.snpt
301*fa7f2c26STang Haojin  intFreeList.io.snpt.snptEnq := io.out.head.fire && io.out.head.bits.snapshot
302*fa7f2c26STang Haojin  fpFreeList.io.snpt.snptEnq := io.out.head.fire && io.out.head.bits.snapshot
303*fa7f2c26STang Haojin
30400ad41d0SYinan Xu  /**
30500ad41d0SYinan Xu    * Instructions commit: update freelist and rename table
30600ad41d0SYinan Xu    */
30700ad41d0SYinan Xu  for (i <- 0 until CommitWidth) {
3086474c47fSYinan Xu    val commitValid = io.robCommits.isCommit && io.robCommits.commitValid(i)
3096474c47fSYinan Xu    val walkValid = io.robCommits.isWalk && io.robCommits.walkValid(i)
31000ad41d0SYinan Xu
3117fa2c198SYinan Xu    Seq((io.intRenamePorts, false), (io.fpRenamePorts, true)) foreach { case (rat, fp) =>
3128b8e745dSYikeZhou      /*
3138b8e745dSYikeZhou      I. RAT Update
3148b8e745dSYikeZhou       */
3158b8e745dSYikeZhou
3168b8e745dSYikeZhou      // walk back write - restore spec state : ldest => old_pdest
3178b8e745dSYikeZhou      if (fp && i < RenameWidth) {
3187fa2c198SYinan Xu        // When redirect happens (mis-prediction), don't update the rename table
31970224bf6SYinan Xu        rat(i).wen := fpSpecWen(i)
3207fa2c198SYinan Xu        rat(i).addr := uops(i).ctrl.ldest
32170224bf6SYinan Xu        rat(i).data := fpFreeList.io.allocatePhyReg(i)
3228b8e745dSYikeZhou      } else if (!fp && i < RenameWidth) {
32370224bf6SYinan Xu        rat(i).wen := intSpecWen(i)
3247fa2c198SYinan Xu        rat(i).addr := uops(i).ctrl.ldest
32570224bf6SYinan Xu        rat(i).data := io.out(i).bits.pdest
32639d3280eSYikeZhou      }
3278b8e745dSYikeZhou
3288b8e745dSYikeZhou      /*
3298b8e745dSYikeZhou      II. Free List Update
3308b8e745dSYikeZhou       */
3318b8e745dSYikeZhou      if (fp) { // Float Point free list
332dcf3a679STang Haojin        fpFreeList.io.freeReq(i)  := RegNext(commitValid && needDestRegCommit(fp, io.robCommits.info(i)), false.B)
333dcf3a679STang Haojin        fpFreeList.io.freePhyReg(i) := io.fp_old_pdest(i)
3347fa2c198SYinan Xu      } else { // Integer free list
335dcf3a679STang Haojin        intFreeList.io.freeReq(i) := io.int_need_free(i)
336dcf3a679STang Haojin        intFreeList.io.freePhyReg(i) := RegNext(io.int_old_pdest(i))
337ccfddc82SHaojin Tang      }
338ccfddc82SHaojin Tang    }
3398b8e745dSYikeZhou  }
3408b8e745dSYikeZhou
3418b8e745dSYikeZhou  /*
34270224bf6SYinan Xu  Debug and performance counters
3438b8e745dSYikeZhou   */
3448b8e745dSYikeZhou  def printRenameInfo(in: DecoupledIO[CfCtrl], out: DecoupledIO[MicroOp]) = {
34570224bf6SYinan Xu    XSInfo(out.fire, p"pc:${Hexadecimal(in.bits.cf.pc)} in(${in.valid},${in.ready}) " +
3468b8e745dSYikeZhou      p"lsrc(0):${in.bits.ctrl.lsrc(0)} -> psrc(0):${out.bits.psrc(0)} " +
3478b8e745dSYikeZhou      p"lsrc(1):${in.bits.ctrl.lsrc(1)} -> psrc(1):${out.bits.psrc(1)} " +
3488b8e745dSYikeZhou      p"lsrc(2):${in.bits.ctrl.lsrc(2)} -> psrc(2):${out.bits.psrc(2)} " +
349dcf3a679STang Haojin      p"ldest:${in.bits.ctrl.ldest} -> pdest:${out.bits.pdest} "
3508b8e745dSYikeZhou    )
3518b8e745dSYikeZhou  }
3528b8e745dSYikeZhou
3538b8e745dSYikeZhou  for((x,y) <- io.in.zip(io.out)){
3548b8e745dSYikeZhou    printRenameInfo(x, y)
3558b8e745dSYikeZhou  }
3568b8e745dSYikeZhou
357d2b20d1aSTang Haojin  val debugRedirect = RegEnable(io.redirect.bits, io.redirect.valid)
358d2b20d1aSTang Haojin  // bad speculation
359d2b20d1aSTang Haojin  val recStall = io.redirect.valid || io.robCommits.isWalk
360d2b20d1aSTang Haojin  val ctrlRecStall = Mux(io.redirect.valid, io.redirect.bits.debugIsCtrl, io.robCommits.isWalk && debugRedirect.debugIsCtrl)
361d2b20d1aSTang Haojin  val mvioRecStall = Mux(io.redirect.valid, io.redirect.bits.debugIsMemVio, io.robCommits.isWalk && debugRedirect.debugIsMemVio)
362d2b20d1aSTang Haojin  val otherRecStall = recStall && !(ctrlRecStall || mvioRecStall)
363d2b20d1aSTang Haojin  XSPerfAccumulate("recovery_stall", recStall)
364d2b20d1aSTang Haojin  XSPerfAccumulate("control_recovery_stall", ctrlRecStall)
365d2b20d1aSTang Haojin  XSPerfAccumulate("mem_violation_recovery_stall", mvioRecStall)
366d2b20d1aSTang Haojin  XSPerfAccumulate("other_recovery_stall", otherRecStall)
367d2b20d1aSTang Haojin  // freelist stall
368d2b20d1aSTang Haojin  val notRecStall = !io.out.head.valid && !recStall
369d2b20d1aSTang Haojin  val intFlStall = notRecStall && hasValid && !intFreeList.io.canAllocate
370d2b20d1aSTang Haojin  val fpFlStall = notRecStall && hasValid && !fpFreeList.io.canAllocate
371d2b20d1aSTang Haojin  // other stall
372d2b20d1aSTang Haojin  val otherStall = notRecStall && !intFlStall && !fpFlStall
373d2b20d1aSTang Haojin
374d2b20d1aSTang Haojin  io.stallReason.in.backReason.valid := io.stallReason.out.backReason.valid || !io.in.head.ready
375d2b20d1aSTang Haojin  io.stallReason.in.backReason.bits := Mux(io.stallReason.out.backReason.valid, io.stallReason.out.backReason.bits,
376d2b20d1aSTang Haojin    MuxCase(TopDownCounters.OtherCoreStall.id.U, Seq(
377d2b20d1aSTang Haojin      ctrlRecStall  -> TopDownCounters.ControlRecoveryStall.id.U,
378d2b20d1aSTang Haojin      mvioRecStall  -> TopDownCounters.MemVioRecoveryStall.id.U,
379d2b20d1aSTang Haojin      otherRecStall -> TopDownCounters.OtherRecoveryStall.id.U,
380d2b20d1aSTang Haojin      intFlStall    -> TopDownCounters.IntFlStall.id.U,
381d2b20d1aSTang Haojin      fpFlStall     -> TopDownCounters.FpFlStall.id.U
382d2b20d1aSTang Haojin    )
383d2b20d1aSTang Haojin  ))
384d2b20d1aSTang Haojin  io.stallReason.out.reason.zip(io.stallReason.in.reason).zip(io.in.map(_.valid)).foreach { case ((out, in), valid) =>
385d2b20d1aSTang Haojin    out := Mux(io.stallReason.in.backReason.valid,
386d2b20d1aSTang Haojin               io.stallReason.in.backReason.bits,
387d2b20d1aSTang Haojin               Mux(valid, TopDownCounters.NoStall.id.U, in))
388d2b20d1aSTang Haojin  }
389d2b20d1aSTang Haojin
3909aca92b9SYinan Xu  XSDebug(io.robCommits.isWalk, p"Walk Recovery Enabled\n")
3916474c47fSYinan Xu  XSDebug(io.robCommits.isWalk, p"validVec:${Binary(io.robCommits.walkValid.asUInt)}\n")
3928b8e745dSYikeZhou  for (i <- 0 until CommitWidth) {
3939aca92b9SYinan Xu    val info = io.robCommits.info(i)
3946474c47fSYinan Xu    XSDebug(io.robCommits.isWalk && io.robCommits.walkValid(i), p"[#$i walk info] pc:${Hexadecimal(info.pc)} " +
395dcf3a679STang Haojin      p"ldest:${info.ldest} rfWen:${info.rfWen} fpWen:${info.fpWen} ")
3968b8e745dSYikeZhou  }
3978b8e745dSYikeZhou
3988b8e745dSYikeZhou  XSDebug(p"inValidVec: ${Binary(Cat(io.in.map(_.valid)))}\n")
3998b8e745dSYikeZhou
400408a32b7SAllen  XSPerfAccumulate("in", Mux(RegNext(io.in(0).ready), PopCount(io.in.map(_.valid)), 0.U))
401408a32b7SAllen  XSPerfAccumulate("utilization", PopCount(io.in.map(_.valid)))
402408a32b7SAllen  XSPerfAccumulate("waitInstr", PopCount((0 until RenameWidth).map(i => io.in(i).valid && !io.in(i).ready)))
40370224bf6SYinan Xu  XSPerfAccumulate("stall_cycle_dispatch", hasValid && !io.out(0).ready && fpFreeList.io.canAllocate && intFreeList.io.canAllocate && !io.robCommits.isWalk)
40470224bf6SYinan Xu  XSPerfAccumulate("stall_cycle_fp", hasValid && io.out(0).ready && !fpFreeList.io.canAllocate && intFreeList.io.canAllocate && !io.robCommits.isWalk)
40570224bf6SYinan Xu  XSPerfAccumulate("stall_cycle_int", hasValid && io.out(0).ready && fpFreeList.io.canAllocate && !intFreeList.io.canAllocate && !io.robCommits.isWalk)
40670224bf6SYinan Xu  XSPerfAccumulate("stall_cycle_walk", hasValid && io.out(0).ready && fpFreeList.io.canAllocate && intFreeList.io.canAllocate && io.robCommits.isWalk)
4075eb4af5bSYikeZhou
408d8aa3d57SbugGenerator  XSPerfHistogram("slots_fire", PopCount(io.out.map(_.fire)), true.B, 0, RenameWidth+1, 1)
409d8aa3d57SbugGenerator  // Explaination: when out(0) not fire, PopCount(valid) is not meaningfull
410d8aa3d57SbugGenerator  XSPerfHistogram("slots_valid_pure", PopCount(io.in.map(_.valid)), io.out(0).fire, 0, RenameWidth+1, 1)
411d8aa3d57SbugGenerator  XSPerfHistogram("slots_valid_rough", PopCount(io.in.map(_.valid)), true.B, 0, RenameWidth+1, 1)
412d8aa3d57SbugGenerator
413f025d715SYinan Xu  XSPerfAccumulate("move_instr_count", PopCount(io.out.map(out => out.fire && out.bits.ctrl.isMove)))
414f025d715SYinan Xu  val is_fused_lui_load = io.out.map(o => o.fire && o.bits.ctrl.fuType === FuType.ldu && o.bits.ctrl.srcType(0) === SrcType.imm)
415fd7603d9SYinan Xu  XSPerfAccumulate("fused_lui_load_instr_count", PopCount(is_fused_lui_load))
416cd365d4cSrvcoresjw
417cd365d4cSrvcoresjw
4181ca0e4f3SYinan Xu  val renamePerf = Seq(
419cd365d4cSrvcoresjw    ("rename_in                  ", PopCount(io.in.map(_.valid & io.in(0).ready ))                                                               ),
420cd365d4cSrvcoresjw    ("rename_waitinstr           ", PopCount((0 until RenameWidth).map(i => io.in(i).valid && !io.in(i).ready))                                  ),
421cd365d4cSrvcoresjw    ("rename_stall_cycle_dispatch", hasValid && !io.out(0).ready &&  fpFreeList.io.canAllocate &&  intFreeList.io.canAllocate && !io.robCommits.isWalk),
422cd365d4cSrvcoresjw    ("rename_stall_cycle_fp      ", hasValid &&  io.out(0).ready && !fpFreeList.io.canAllocate &&  intFreeList.io.canAllocate && !io.robCommits.isWalk),
423cd365d4cSrvcoresjw    ("rename_stall_cycle_int     ", hasValid &&  io.out(0).ready &&  fpFreeList.io.canAllocate && !intFreeList.io.canAllocate && !io.robCommits.isWalk),
4241ca0e4f3SYinan Xu    ("rename_stall_cycle_walk    ", hasValid &&  io.out(0).ready &&  fpFreeList.io.canAllocate &&  intFreeList.io.canAllocate &&  io.robCommits.isWalk)
425cd365d4cSrvcoresjw  )
4261ca0e4f3SYinan Xu  val intFlPerf = intFreeList.getPerfEvents
4271ca0e4f3SYinan Xu  val fpFlPerf = fpFreeList.getPerfEvents
4281ca0e4f3SYinan Xu  val perfEvents = renamePerf ++ intFlPerf ++ fpFlPerf
4291ca0e4f3SYinan Xu  generatePerfEvent()
4305eb4af5bSYikeZhou}
431