xref: /XiangShan/src/main/scala/xiangshan/backend/rename/Rename.scala (revision eb163ef08fc5ac1da1f32d948699bd6de053e444)
1/***************************************************************************************
2* Copyright (c) 2020-2021 Institute of Computing Technology, Chinese Academy of Sciences
3* Copyright (c) 2020-2021 Peng Cheng Laboratory
4*
5* XiangShan is licensed under Mulan PSL v2.
6* You can use this software according to the terms and conditions of the Mulan PSL v2.
7* You may obtain a copy of Mulan PSL v2 at:
8*          http://license.coscl.org.cn/MulanPSL2
9*
10* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
11* EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
12* MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
13*
14* See the Mulan PSL v2 for more details.
15***************************************************************************************/
16
17package xiangshan.backend.rename
18
19import chipsalliance.rocketchip.config.Parameters
20import chisel3._
21import chisel3.util._
22import xiangshan._
23import utils._
24import xiangshan.backend.decode.{FusionDecodeInfo, Imm_I, Imm_LUI_LOAD, Imm_U}
25import xiangshan.backend.rob.RobPtr
26import xiangshan.backend.rename.freelist._
27import xiangshan.mem.mdp._
28
29class Rename(implicit p: Parameters) extends XSModule with HasCircularQueuePtrHelper with HasPerfEvents {
30  val io = IO(new Bundle() {
31    val redirect = Flipped(ValidIO(new Redirect))
32    val robCommits = Input(new RobCommitIO)
33    // from decode
34    val in = Vec(RenameWidth, Flipped(DecoupledIO(new CfCtrl)))
35    val fusionInfo = Vec(DecodeWidth - 1, Flipped(new FusionDecodeInfo))
36    // ssit read result
37    val ssit = Flipped(Vec(RenameWidth, Output(new SSITEntry)))
38    // waittable read result
39    val waittable = Flipped(Vec(RenameWidth, Output(Bool())))
40    // to rename table
41    val intReadPorts = Vec(RenameWidth, Vec(3, Input(UInt(PhyRegIdxWidth.W))))
42    val fpReadPorts = Vec(RenameWidth, Vec(4, Input(UInt(PhyRegIdxWidth.W))))
43    val intRenamePorts = Vec(RenameWidth, Output(new RatWritePort))
44    val fpRenamePorts = Vec(RenameWidth, Output(new RatWritePort))
45    // to dispatch1
46    val out = Vec(RenameWidth, DecoupledIO(new MicroOp))
47    // debug arch ports
48    val debug_int_rat = Vec(32, Input(UInt(PhyRegIdxWidth.W)))
49    val debug_fp_rat = Vec(32, Input(UInt(PhyRegIdxWidth.W)))
50  })
51
52  // create free list and rat
53  val intFreeList = Module(new MEFreeList(NRPhyRegs))
54  val intRefCounter = Module(new RefCounter(NRPhyRegs))
55  val fpFreeList = Module(new StdFreeList(NRPhyRegs - 32))
56
57  intRefCounter.io.commit        <> io.robCommits
58  intRefCounter.io.redirect      := io.redirect.valid
59  intRefCounter.io.debug_int_rat <> io.debug_int_rat
60  intFreeList.io.commit    <> io.robCommits
61  intFreeList.io.debug_rat <> io.debug_int_rat
62  fpFreeList.io.commit     <> io.robCommits
63  fpFreeList.io.debug_rat  <> io.debug_fp_rat
64
65  // decide if given instruction needs allocating a new physical register (CfCtrl: from decode; RobCommitInfo: from rob)
66  def needDestReg[T <: CfCtrl](fp: Boolean, x: T): Bool = {
67    {if(fp) x.ctrl.fpWen else x.ctrl.rfWen && (x.ctrl.ldest =/= 0.U)}
68  }
69  def needDestRegCommit[T <: RobCommitInfo](fp: Boolean, x: T): Bool = {
70    if(fp) x.fpWen else x.rfWen
71  }
72  def needDestRegWalk[T <: RobCommitInfo](fp: Boolean, x: T): Bool = {
73    if(fp) x.fpWen else x.rfWen && x.ldest =/= 0.U
74  }
75
76  // connect [redirect + walk] ports for __float point__ & __integer__ free list
77  Seq((fpFreeList, true), (intFreeList, false)).foreach{ case (fl, isFp) =>
78    fl.io.redirect := io.redirect.valid
79    fl.io.walk := io.robCommits.isWalk
80  }
81  // only when both fp and int free list and dispatch1 has enough space can we do allocation
82  // when isWalk, freelist can definitely allocate
83  intFreeList.io.doAllocate := fpFreeList.io.canAllocate && io.out(0).ready || io.robCommits.isWalk
84  fpFreeList.io.doAllocate := intFreeList.io.canAllocate && io.out(0).ready || io.robCommits.isWalk
85
86  //           dispatch1 ready ++ float point free list ready ++ int free list ready      ++ not walk
87  val canOut = io.out(0).ready && fpFreeList.io.canAllocate && intFreeList.io.canAllocate && !io.robCommits.isWalk
88
89
90  // speculatively assign the instruction with an robIdx
91  val validCount = PopCount(io.in.map(_.valid)) // number of instructions waiting to enter rob (from decode)
92  val robIdxHead = RegInit(0.U.asTypeOf(new RobPtr))
93  val lastCycleMisprediction = RegNext(io.redirect.valid && !io.redirect.bits.flushItself())
94  val robIdxHeadNext = Mux(io.redirect.valid, io.redirect.bits.robIdx, // redirect: move ptr to given rob index
95         Mux(lastCycleMisprediction, robIdxHead + 1.U, // mis-predict: not flush robIdx itself
96                         Mux(canOut, robIdxHead + validCount, // instructions successfully entered next stage: increase robIdx
97                      /* default */  robIdxHead))) // no instructions passed by this cycle: stick to old value
98  robIdxHead := robIdxHeadNext
99
100  /**
101    * Rename: allocate free physical register and update rename table
102    */
103  val uops = Wire(Vec(RenameWidth, new MicroOp))
104  uops.foreach( uop => {
105    uop.srcState(0) := DontCare
106    uop.srcState(1) := DontCare
107    uop.srcState(2) := DontCare
108    uop.robIdx := DontCare
109    uop.debugInfo := DontCare
110    uop.lqIdx := DontCare
111    uop.sqIdx := DontCare
112  })
113
114  require(RenameWidth >= CommitWidth)
115
116  val needFpDest = Wire(Vec(RenameWidth, Bool()))
117  val needIntDest = Wire(Vec(RenameWidth, Bool()))
118  val hasValid = Cat(io.in.map(_.valid)).orR
119
120  val isMove = io.in.map(_.bits.ctrl.isMove)
121
122  val walkNeedFpDest = WireDefault(VecInit(Seq.fill(RenameWidth)(false.B)))
123  val walkNeedIntDest = WireDefault(VecInit(Seq.fill(RenameWidth)(false.B)))
124  val walkIsMove = WireDefault(VecInit(Seq.fill(RenameWidth)(false.B)))
125
126  val intSpecWen = Wire(Vec(RenameWidth, Bool()))
127  val fpSpecWen = Wire(Vec(RenameWidth, Bool()))
128
129  val walkIntSpecWen = WireDefault(VecInit(Seq.fill(RenameWidth)(false.B)))
130
131  val walkPdest = Wire(Vec(RenameWidth, UInt(PhyRegIdxWidth.W)))
132
133  // uop calculation
134  for (i <- 0 until RenameWidth) {
135    uops(i).cf := io.in(i).bits.cf
136    uops(i).ctrl := io.in(i).bits.ctrl
137
138    // update cf according to ssit result
139    uops(i).cf.storeSetHit := io.ssit(i).valid
140    uops(i).cf.loadWaitStrict := io.ssit(i).strict && io.ssit(i).valid
141    uops(i).cf.ssid := io.ssit(i).ssid
142
143    // update cf according to waittable result
144    uops(i).cf.loadWaitBit := io.waittable(i)
145
146    // alloc a new phy reg
147    needFpDest(i) := io.in(i).valid && needDestReg(fp = true, io.in(i).bits)
148    needIntDest(i) := io.in(i).valid && needDestReg(fp = false, io.in(i).bits)
149    if (i < CommitWidth) {
150      walkNeedFpDest(i) := io.robCommits.walkValid(i) && needDestRegWalk(fp = true, io.robCommits.info(i))
151      walkNeedIntDest(i) := io.robCommits.walkValid(i) && needDestRegWalk(fp = false, io.robCommits.info(i))
152      walkIsMove(i) := io.robCommits.info(i).isMove
153    }
154    fpFreeList.io.allocateReq(i) := Mux(io.robCommits.isWalk, walkNeedFpDest(i), needFpDest(i))
155    intFreeList.io.allocateReq(i) := Mux(io.robCommits.isWalk, walkNeedIntDest(i) && !walkIsMove(i), needIntDest(i) && !isMove(i))
156
157    // no valid instruction from decode stage || all resources (dispatch1 + both free lists) ready
158    io.in(i).ready := !hasValid || canOut
159
160    uops(i).robIdx := robIdxHead + PopCount(io.in.take(i).map(_.valid))
161
162    uops(i).psrc(0) := Mux(uops(i).ctrl.srcType(0) === SrcType.reg, io.intReadPorts(i)(0), io.fpReadPorts(i)(0))
163    uops(i).psrc(1) := Mux(uops(i).ctrl.srcType(1) === SrcType.reg, io.intReadPorts(i)(1), io.fpReadPorts(i)(1))
164    // int psrc2 should be bypassed from next instruction if it is fused
165    if (i < RenameWidth - 1) {
166      when (io.fusionInfo(i).rs2FromRs2 || io.fusionInfo(i).rs2FromRs1) {
167        uops(i).psrc(1) := Mux(io.fusionInfo(i).rs2FromRs2, io.intReadPorts(i + 1)(1), io.intReadPorts(i + 1)(0))
168      }.elsewhen(io.fusionInfo(i).rs2FromZero) {
169        uops(i).psrc(1) := 0.U
170      }
171    }
172    uops(i).psrc(2) := io.fpReadPorts(i)(2)
173    uops(i).old_pdest := Mux(uops(i).ctrl.rfWen, io.intReadPorts(i).last, io.fpReadPorts(i).last)
174    uops(i).eliminatedMove := isMove(i)
175
176    // update pdest
177    uops(i).pdest := Mux(needIntDest(i), intFreeList.io.allocatePhyReg(i), // normal int inst
178      // normal fp inst
179      Mux(needFpDest(i), fpFreeList.io.allocatePhyReg(i),
180        /* default */0.U))
181
182    // Assign performance counters
183    uops(i).debugInfo.renameTime := GTimer()
184
185    io.out(i).valid := io.in(i).valid && intFreeList.io.canAllocate && fpFreeList.io.canAllocate && !io.robCommits.isWalk
186    io.out(i).bits := uops(i)
187    // dirty code for fence. The lsrc is passed by imm.
188    when (io.out(i).bits.ctrl.fuType === FuType.fence) {
189      io.out(i).bits.ctrl.imm := Cat(io.in(i).bits.ctrl.lsrc(1), io.in(i).bits.ctrl.lsrc(0))
190    }
191    // dirty code for SoftPrefetch (prefetch.r/prefetch.w)
192    when (io.in(i).bits.ctrl.isSoftPrefetch) {
193      io.out(i).bits.ctrl.fuType := FuType.ldu
194      io.out(i).bits.ctrl.fuOpType := Mux(io.in(i).bits.ctrl.lsrc(1) === 1.U, LSUOpType.prefetch_r, LSUOpType.prefetch_w)
195      io.out(i).bits.ctrl.selImm := SelImm.IMM_S
196      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))
197    }
198
199    // write speculative rename table
200    // we update rat later inside commit code
201    intSpecWen(i) := needIntDest(i) && intFreeList.io.canAllocate && intFreeList.io.doAllocate && !io.robCommits.isWalk && !io.redirect.valid
202    fpSpecWen(i) := needFpDest(i) && fpFreeList.io.canAllocate && fpFreeList.io.doAllocate && !io.robCommits.isWalk && !io.redirect.valid
203
204    if (i < CommitWidth) {
205      walkIntSpecWen(i) := walkNeedIntDest(i) && !io.redirect.valid
206      walkPdest(i) := io.robCommits.info(i).pdest
207    } else {
208      walkPdest(i) := io.out(i).bits.pdest
209    }
210
211    intRefCounter.io.allocate(i).valid := Mux(io.robCommits.isWalk, walkIntSpecWen(i), intSpecWen(i))
212    intRefCounter.io.allocate(i).bits := Mux(io.robCommits.isWalk, walkPdest(i), io.out(i).bits.pdest)
213  }
214
215  /**
216    * How to set psrc:
217    * - bypass the pdest to psrc if previous instructions write to the same ldest as lsrc
218    * - default: psrc from RAT
219    * How to set pdest:
220    * - Mux(isMove, psrc, pdest_from_freelist).
221    *
222    * The critical path of rename lies here:
223    * When move elimination is enabled, we need to update the rat with psrc.
224    * However, psrc maybe comes from previous instructions' pdest, which comes from freelist.
225    *
226    * If we expand these logic for pdest(N):
227    * pdest(N) = Mux(isMove(N), psrc(N), freelist_out(N))
228    *          = Mux(isMove(N), Mux(bypass(N, N - 1), pdest(N - 1),
229    *                           Mux(bypass(N, N - 2), pdest(N - 2),
230    *                           ...
231    *                           Mux(bypass(N, 0),     pdest(0),
232    *                                                 rat_out(N))...)),
233    *                           freelist_out(N))
234    */
235  // a simple functional model for now
236  io.out(0).bits.pdest := Mux(isMove(0), uops(0).psrc.head, uops(0).pdest)
237  val bypassCond = Wire(Vec(4, MixedVec(List.tabulate(RenameWidth-1)(i => UInt((i+1).W)))))
238  for (i <- 1 until RenameWidth) {
239    val fpCond = io.in(i).bits.ctrl.srcType.map(_ === SrcType.fp) :+ needFpDest(i)
240    val intCond = io.in(i).bits.ctrl.srcType.map(_ === SrcType.reg) :+ needIntDest(i)
241    val target = io.in(i).bits.ctrl.lsrc :+ io.in(i).bits.ctrl.ldest
242    for ((((cond1, cond2), t), j) <- fpCond.zip(intCond).zip(target).zipWithIndex) {
243      val destToSrc = io.in.take(i).zipWithIndex.map { case (in, j) =>
244        val indexMatch = in.bits.ctrl.ldest === t
245        val writeMatch =  cond2 && needIntDest(j) || cond1 && needFpDest(j)
246        indexMatch && writeMatch
247      }
248      bypassCond(j)(i - 1) := VecInit(destToSrc).asUInt
249    }
250    io.out(i).bits.psrc(0) := io.out.take(i).map(_.bits.pdest).zip(bypassCond(0)(i-1).asBools).foldLeft(uops(i).psrc(0)) {
251      (z, next) => Mux(next._2, next._1, z)
252    }
253    io.out(i).bits.psrc(1) := io.out.take(i).map(_.bits.pdest).zip(bypassCond(1)(i-1).asBools).foldLeft(uops(i).psrc(1)) {
254      (z, next) => Mux(next._2, next._1, z)
255    }
256    io.out(i).bits.psrc(2) := io.out.take(i).map(_.bits.pdest).zip(bypassCond(2)(i-1).asBools).foldLeft(uops(i).psrc(2)) {
257      (z, next) => Mux(next._2, next._1, z)
258    }
259    io.out(i).bits.old_pdest := io.out.take(i).map(_.bits.pdest).zip(bypassCond(3)(i-1).asBools).foldLeft(uops(i).old_pdest) {
260      (z, next) => Mux(next._2, next._1, z)
261    }
262    io.out(i).bits.pdest := Mux(isMove(i), io.out(i).bits.psrc(0), uops(i).pdest)
263
264    // For fused-lui-load, load.src(0) is replaced by the imm.
265    val last_is_lui = io.in(i - 1).bits.ctrl.selImm === SelImm.IMM_U && io.in(i - 1).bits.ctrl.srcType(0) =/= SrcType.pc
266    val this_is_load = io.in(i).bits.ctrl.fuType === FuType.ldu
267    val lui_to_load = io.in(i - 1).valid && io.in(i - 1).bits.ctrl.ldest === io.in(i).bits.ctrl.lsrc(0)
268    val fused_lui_load = last_is_lui && this_is_load && lui_to_load
269    when (fused_lui_load) {
270      // The first LOAD operand (base address) is replaced by LUI-imm and stored in {psrc, imm}
271      val lui_imm = io.in(i - 1).bits.ctrl.imm
272      val ld_imm = io.in(i).bits.ctrl.imm
273      io.out(i).bits.ctrl.srcType(0) := SrcType.imm
274      io.out(i).bits.ctrl.imm := Imm_LUI_LOAD().immFromLuiLoad(lui_imm, ld_imm)
275      val psrcWidth = uops(i).psrc.head.getWidth
276      val lui_imm_in_imm = uops(i).ctrl.imm.getWidth - Imm_I().len
277      val left_lui_imm = Imm_U().len - lui_imm_in_imm
278      require(2 * psrcWidth >= left_lui_imm, "cannot fused lui and load with psrc")
279      io.out(i).bits.psrc(0) := lui_imm(lui_imm_in_imm + psrcWidth - 1, lui_imm_in_imm)
280      io.out(i).bits.psrc(1) := lui_imm(lui_imm.getWidth - 1, lui_imm_in_imm + psrcWidth)
281    }
282
283  }
284
285  /**
286    * Instructions commit: update freelist and rename table
287    */
288  for (i <- 0 until CommitWidth) {
289    val commitValid = io.robCommits.isCommit && io.robCommits.commitValid(i)
290    val walkValid = io.robCommits.isWalk && io.robCommits.walkValid(i)
291
292    Seq((io.intRenamePorts, false), (io.fpRenamePorts, true)) foreach { case (rat, fp) =>
293      /*
294      I. RAT Update
295       */
296
297      // walk back write - restore spec state : ldest => old_pdest
298      if (fp && i < RenameWidth) {
299        // When redirect happens (mis-prediction), don't update the rename table
300        rat(i).wen := fpSpecWen(i)
301        rat(i).addr := uops(i).ctrl.ldest
302        rat(i).data := fpFreeList.io.allocatePhyReg(i)
303      } else if (!fp && i < RenameWidth) {
304        rat(i).wen := intSpecWen(i)
305        rat(i).addr := uops(i).ctrl.ldest
306        rat(i).data := io.out(i).bits.pdest
307      }
308
309      /*
310      II. Free List Update
311       */
312      if (fp) { // Float Point free list
313        fpFreeList.io.freeReq(i)  := commitValid && needDestRegCommit(fp, io.robCommits.info(i))
314        fpFreeList.io.freePhyReg(i) := io.robCommits.info(i).old_pdest
315      } else { // Integer free list
316        intFreeList.io.freeReq(i) := intRefCounter.io.freeRegs(i).valid
317        intFreeList.io.freePhyReg(i) := intRefCounter.io.freeRegs(i).bits
318      }
319    }
320    intRefCounter.io.deallocate(i).valid := commitValid && needDestRegCommit(false, io.robCommits.info(i)) && !io.robCommits.isWalk
321    intRefCounter.io.deallocate(i).bits := io.robCommits.info(i).old_pdest
322  }
323
324  when(io.robCommits.isWalk) {
325    (intFreeList.io.allocateReq zip intFreeList.io.allocatePhyReg).take(CommitWidth) zip io.robCommits.info foreach {
326      case ((reqValid, allocReg), commitInfo) => when(reqValid) {
327        XSError(allocReg =/= commitInfo.pdest, "walk alloc reg =/= rob reg\n")
328      }
329    }
330    (fpFreeList.io.allocateReq zip fpFreeList.io.allocatePhyReg).take(CommitWidth) zip io.robCommits.info foreach {
331      case ((reqValid, allocReg), commitInfo) => when(reqValid) {
332        XSError(allocReg =/= commitInfo.pdest, "walk alloc reg =/= rob reg\n")
333      }
334    }
335  }
336
337  /*
338  Debug and performance counters
339   */
340  def printRenameInfo(in: DecoupledIO[CfCtrl], out: DecoupledIO[MicroOp]) = {
341    XSInfo(out.fire, p"pc:${Hexadecimal(in.bits.cf.pc)} in(${in.valid},${in.ready}) " +
342      p"lsrc(0):${in.bits.ctrl.lsrc(0)} -> psrc(0):${out.bits.psrc(0)} " +
343      p"lsrc(1):${in.bits.ctrl.lsrc(1)} -> psrc(1):${out.bits.psrc(1)} " +
344      p"lsrc(2):${in.bits.ctrl.lsrc(2)} -> psrc(2):${out.bits.psrc(2)} " +
345      p"ldest:${in.bits.ctrl.ldest} -> pdest:${out.bits.pdest} " +
346      p"old_pdest:${out.bits.old_pdest}\n"
347    )
348  }
349
350  for((x,y) <- io.in.zip(io.out)){
351    printRenameInfo(x, y)
352  }
353
354  XSDebug(io.robCommits.isWalk, p"Walk Recovery Enabled\n")
355  XSDebug(io.robCommits.isWalk, p"validVec:${Binary(io.robCommits.walkValid.asUInt)}\n")
356  for (i <- 0 until CommitWidth) {
357    val info = io.robCommits.info(i)
358    XSDebug(io.robCommits.isWalk && io.robCommits.walkValid(i), p"[#$i walk info] pc:${Hexadecimal(info.pc)} " +
359      p"ldest:${info.ldest} rfWen:${info.rfWen} fpWen:${info.fpWen} " +
360      p"pdest:${info.pdest} old_pdest:${info.old_pdest}\n")
361  }
362
363  XSDebug(p"inValidVec: ${Binary(Cat(io.in.map(_.valid)))}\n")
364
365  XSPerfAccumulate("in", Mux(RegNext(io.in(0).ready), PopCount(io.in.map(_.valid)), 0.U))
366  XSPerfAccumulate("utilization", PopCount(io.in.map(_.valid)))
367  XSPerfAccumulate("waitInstr", PopCount((0 until RenameWidth).map(i => io.in(i).valid && !io.in(i).ready)))
368  XSPerfAccumulate("stall_cycle_dispatch", hasValid && !io.out(0).ready && fpFreeList.io.canAllocate && intFreeList.io.canAllocate && !io.robCommits.isWalk)
369  XSPerfAccumulate("stall_cycle_fp", hasValid && io.out(0).ready && !fpFreeList.io.canAllocate && intFreeList.io.canAllocate && !io.robCommits.isWalk)
370  XSPerfAccumulate("stall_cycle_int", hasValid && io.out(0).ready && fpFreeList.io.canAllocate && !intFreeList.io.canAllocate && !io.robCommits.isWalk)
371  XSPerfAccumulate("stall_cycle_walk", hasValid && io.out(0).ready && fpFreeList.io.canAllocate && intFreeList.io.canAllocate && io.robCommits.isWalk)
372  XSPerfAccumulate("recovery_bubbles", PopCount(io.in.map(_.valid && io.out(0).ready && fpFreeList.io.canAllocate && intFreeList.io.canAllocate && io.robCommits.isWalk)))
373
374  XSPerfAccumulate("move_instr_count", PopCount(io.out.map(out => out.fire && out.bits.ctrl.isMove)))
375  val is_fused_lui_load = io.out.map(o => o.fire && o.bits.ctrl.fuType === FuType.ldu && o.bits.ctrl.srcType(0) === SrcType.imm)
376  XSPerfAccumulate("fused_lui_load_instr_count", PopCount(is_fused_lui_load))
377
378
379  val renamePerf = Seq(
380    ("rename_in                  ", PopCount(io.in.map(_.valid & io.in(0).ready ))                                                               ),
381    ("rename_waitinstr           ", PopCount((0 until RenameWidth).map(i => io.in(i).valid && !io.in(i).ready))                                  ),
382    ("rename_stall_cycle_dispatch", hasValid && !io.out(0).ready &&  fpFreeList.io.canAllocate &&  intFreeList.io.canAllocate && !io.robCommits.isWalk),
383    ("rename_stall_cycle_fp      ", hasValid &&  io.out(0).ready && !fpFreeList.io.canAllocate &&  intFreeList.io.canAllocate && !io.robCommits.isWalk),
384    ("rename_stall_cycle_int     ", hasValid &&  io.out(0).ready &&  fpFreeList.io.canAllocate && !intFreeList.io.canAllocate && !io.robCommits.isWalk),
385    ("rename_stall_cycle_walk    ", hasValid &&  io.out(0).ready &&  fpFreeList.io.canAllocate &&  intFreeList.io.canAllocate &&  io.robCommits.isWalk)
386  )
387  val intFlPerf = intFreeList.getPerfEvents
388  val fpFlPerf = fpFreeList.getPerfEvents
389  val perfEvents = renamePerf ++ intFlPerf ++ fpFlPerf
390  generatePerfEvent()
391}
392