xref: /XiangShan/src/main/scala/xiangshan/backend/rename/Rename.scala (revision dc597826530cb6803c2396d6ab0e5eb176b732e0)
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.roq.RoqPtr
25import xiangshan.backend.dispatch.PreDispatchInfo
26
27class RenameBypassInfo(implicit p: Parameters) extends XSBundle {
28  val lsrc1_bypass = MixedVec(List.tabulate(RenameWidth-1)(i => UInt((i+1).W)))
29  val lsrc2_bypass = MixedVec(List.tabulate(RenameWidth-1)(i => UInt((i+1).W)))
30  val lsrc3_bypass = MixedVec(List.tabulate(RenameWidth-1)(i => UInt((i+1).W)))
31  val ldest_bypass = MixedVec(List.tabulate(RenameWidth-1)(i => UInt((i+1).W)))
32}
33
34class Rename(implicit p: Parameters) extends XSModule with HasCircularQueuePtrHelper {
35  val io = IO(new Bundle() {
36    val redirect = Flipped(ValidIO(new Redirect))
37    val flush = Input(Bool())
38    val roqCommits = Flipped(new RoqCommitIO)
39    // from decode buffer
40    val in = Vec(RenameWidth, Flipped(DecoupledIO(new CfCtrl)))
41    // to dispatch1
42    val out = Vec(RenameWidth, DecoupledIO(new MicroOp))
43    val renameBypass = Output(new RenameBypassInfo)
44    val dispatchInfo = Output(new PreDispatchInfo)
45    // for debug printing
46    val debug_int_rat = Vec(32, Output(UInt(PhyRegIdxWidth.W)))
47    val debug_fp_rat = Vec(32, Output(UInt(PhyRegIdxWidth.W)))
48  })
49
50  // create free list and rat
51  val intFreeList = Module(new AlternativeFreeList)
52  val fpFreeList = Module(new FreeList)
53
54  val intRat = Module(new RenameTable(float = false))
55  val fpRat = Module(new RenameTable(float = true))
56
57  // connect flush and redirect ports for rat
58  Seq(intRat, fpRat) foreach { case rat =>
59    rat.io.redirect := io.redirect.valid
60    rat.io.flush := io.flush
61    rat.io.walkWen := io.roqCommits.isWalk
62  }
63
64  // connect flush and redirect ports for __float point__ free list
65  fpFreeList.io.flush := io.flush
66  fpFreeList.io.redirect := io.redirect.valid
67  fpFreeList.io.walk.valid := io.roqCommits.isWalk
68
69  // connect flush and redirect ports for __integer__ free list *(walk) is handled by dec
70  intFreeList.io.flush := io.flush
71  intFreeList.io.redirect := io.redirect.valid
72  intFreeList.io.walk := io.roqCommits.isWalk
73
74  //           dispatch1 ready ++ float point free list ready ++ int free list ready      ++ not walk
75  val canOut = io.out(0).ready && fpFreeList.io.req.canAlloc && intFreeList.io.inc.canInc && !io.roqCommits.isWalk
76
77  // decide if given instruction needs allocating a new physical register (CfCtrl: from decode; RoqCommitInfo: from roq)
78  def needDestReg[T <: CfCtrl](fp: Boolean, x: T): Bool = {
79    {if(fp) x.ctrl.fpWen else x.ctrl.rfWen && (x.ctrl.ldest =/= 0.U)}
80  }
81  def needDestRegCommit[T <: RoqCommitInfo](fp: Boolean, x: T): Bool = {
82    {if(fp) x.fpWen else x.rfWen && (x.ldest =/= 0.U)}
83  }
84
85  // when roqCommits.isWalk, use walk.bits to restore head pointer of free list
86  fpFreeList.io.walk.bits := PopCount(io.roqCommits.valid.zip(io.roqCommits.info).map{case (v, i) => v && needDestRegCommit(true, i)})
87
88
89  // walk has higher priority than allocation and thus we don't use isWalk here
90  // only when both fp and int free list and dispatch1 has enough space can we do allocation
91  fpFreeList.io.req.doAlloc := intFreeList.io.inc.canInc && io.out(0).ready
92  intFreeList.io.inc.doInc := fpFreeList.io.req.canAlloc && io.out(0).ready
93
94
95
96  // speculatively assign the instruction with an roqIdx
97  val validCount = PopCount(io.in.map(_.valid)) // number of instructions waiting to enter roq (from decode)
98  val roqIdxHead = RegInit(0.U.asTypeOf(new RoqPtr))
99  val lastCycleMisprediction = RegNext(io.redirect.valid && !io.redirect.bits.flushItself())
100  val roqIdxHeadNext = Mux(io.flush, 0.U.asTypeOf(new RoqPtr), // flush: clear roq
101              Mux(io.redirect.valid, io.redirect.bits.roqIdx, // redirect: move ptr to given roq index (flush itself)
102         Mux(lastCycleMisprediction, roqIdxHead + 1.U, // mis-predict: not flush roqIdx itself
103                         Mux(canOut, roqIdxHead + validCount, // instructions successfully entered next stage: increase roqIdx
104                      /* default */  roqIdxHead)))) // no instructions passed by this cycle: stick to old value
105  roqIdxHead := roqIdxHeadNext
106
107
108  /**
109    * Rename: allocate free physical register and update rename table
110    */
111  val uops = Wire(Vec(RenameWidth, new MicroOp))
112  uops.foreach( uop => {
113    uop.srcState(0) := DontCare
114    uop.srcState(1) := DontCare
115    uop.srcState(2) := DontCare
116    uop.roqIdx := DontCare
117    uop.diffTestDebugLrScValid := DontCare
118    uop.debugInfo := DontCare
119    uop.lqIdx := DontCare
120    uop.sqIdx := DontCare
121  })
122
123  val needFpDest = Wire(Vec(RenameWidth, Bool()))
124  val needIntDest = Wire(Vec(RenameWidth, Bool()))
125  val hasValid = Cat(io.in.map(_.valid)).orR
126
127  val isMove = io.in.map(_.bits.ctrl.isMove)
128  val isMax = intFreeList.io.maxVec
129  val meEnable = WireInit(VecInit(Seq.fill(RenameWidth)(false.B)))
130  val psrc_cmp = Wire(MixedVec(List.tabulate(RenameWidth-1)(i => UInt((i+1).W))))
131
132  val intSpecWen = Wire(Vec(RenameWidth, Bool()))
133  val fpSpecWen = Wire(Vec(RenameWidth, Bool()))
134
135  // uop calculation
136  for (i <- 0 until RenameWidth) {
137    uops(i).cf := io.in(i).bits.cf
138    uops(i).ctrl := io.in(i).bits.ctrl
139
140    val inValid = io.in(i).valid
141
142    // alloc a new phy reg
143    needFpDest(i) := inValid && needDestReg(fp = true, io.in(i).bits)
144    needIntDest(i) := inValid && needDestReg(fp = false, io.in(i).bits)
145    fpFreeList.io.req.allocReqs(i) := needFpDest(i)
146    intFreeList.io.inc.req(i) := needIntDest(i)
147
148    // no valid instruction from decode stage || all resources (dispatch1 + both free lists) ready
149    io.in(i).ready := !hasValid || canOut
150
151    // do checkpoints when a branch inst come
152    // for(fl <- Seq(fpFreeList, intFreeList)){
153    //   fl.cpReqs(i).valid := inValid
154    //   fl.cpReqs(i).bits := io.in(i).bits.brTag
155    // }
156
157
158    uops(i).roqIdx := roqIdxHead + i.U
159
160    io.out(i).valid := io.in(i).valid && intFreeList.io.inc.canInc && fpFreeList.io.req.canAlloc && !io.roqCommits.isWalk
161    io.out(i).bits := uops(i)
162
163
164    // read rename table
165    def readRat(lsrcList: List[UInt], ldest: UInt, fp: Boolean) = {
166      val rat = if(fp) fpRat else intRat
167      val srcCnt = lsrcList.size
168      val psrcVec = Wire(Vec(srcCnt, UInt(PhyRegIdxWidth.W)))
169      val old_pdest = Wire(UInt(PhyRegIdxWidth.W))
170      for(k <- 0 until srcCnt+1){
171        val rportIdx = i * (srcCnt+1) + k
172        if(k != srcCnt){
173          rat.io.readPorts(rportIdx).addr := lsrcList(k)
174          psrcVec(k) := rat.io.readPorts(rportIdx).rdata
175        } else {
176          rat.io.readPorts(rportIdx).addr := ldest
177          old_pdest := rat.io.readPorts(rportIdx).rdata
178        }
179      }
180      (psrcVec, old_pdest)
181    }
182    val lsrcList = List(uops(i).ctrl.lsrc(0), uops(i).ctrl.lsrc(1), uops(i).ctrl.lsrc(2))
183    val ldest = uops(i).ctrl.ldest
184    val (intPhySrcVec, intOldPdest) = readRat(lsrcList.take(2), ldest, fp = false)
185    val (fpPhySrcVec, fpOldPdest) = readRat(lsrcList, ldest, fp = true)
186    uops(i).psrc(0) := Mux(uops(i).ctrl.srcType(0) === SrcType.reg, intPhySrcVec(0), fpPhySrcVec(0))
187    uops(i).psrc(1) := Mux(uops(i).ctrl.srcType(1) === SrcType.reg, intPhySrcVec(1), fpPhySrcVec(1))
188    uops(i).psrc(2) := fpPhySrcVec(2)
189    uops(i).old_pdest := Mux(uops(i).ctrl.rfWen, intOldPdest, fpOldPdest)
190
191    if (i == 0) {
192      // calculate meEnable
193      meEnable(i) := isMove(i) && !isMax(uops(i).psrc(0))
194    } else {
195      // compare psrc0
196      psrc_cmp(i-1) := Cat((0 until i).map(j => {
197        uops(i).psrc(0) === uops(j).psrc(0) && io.in(i).bits.ctrl.isMove && io.in(j).bits.ctrl.isMove
198      }) /* reverse is not necessary here */)
199
200      // calculate meEnable
201      meEnable(i) := isMove(i) && !(io.renameBypass.lsrc1_bypass(i-1).orR | psrc_cmp(i-1).orR | isMax(uops(i).psrc(0)))
202    }
203    uops(i).eliminatedMove := meEnable(i)
204
205    // send psrc of eliminated move instructions to free list and label them as eliminated
206    when (meEnable(i)) {
207      intFreeList.io.inc.psrcOfMove(i).valid := true.B
208      intFreeList.io.inc.psrcOfMove(i).bits := uops(i).psrc(0)
209      XSInfo(io.in(i).valid && io.out(i).valid, p"Move instruction ${Hexadecimal(io.in(i).bits.cf.pc)} eliminated successfully! psrc:${uops(i).psrc(0)}\n")
210    } .otherwise {
211      intFreeList.io.inc.psrcOfMove(i).valid := false.B
212      intFreeList.io.inc.psrcOfMove(i).bits := DontCare
213      XSInfo(io.in(i).valid && io.out(i).valid && isMove(i), p"Move instruction ${Hexadecimal(io.in(i).bits.cf.pc)} failed to be eliminated! psrc:${uops(i).psrc(0)}\n")
214    }
215
216    // update pdest
217    uops(i).pdest := Mux(meEnable(i), uops(i).psrc(0), // move eliminated
218                     Mux(needIntDest(i), intFreeList.io.inc.pdests(i), // normal int inst
219                     Mux(uops(i).ctrl.ldest===0.U && uops(i).ctrl.rfWen, 0.U // int inst with dst=r0
220                     /* default */, fpFreeList.io.req.pdests(i)))) // normal fp inst
221
222    // write speculative rename table
223    intSpecWen(i) := intFreeList.io.inc.req(i) && intFreeList.io.inc.canInc && intFreeList.io.inc.doInc && !io.roqCommits.isWalk
224    // intRat.io.specWritePorts(i).wen := intSpecWen
225    // intRat.io.specWritePorts(i).addr := uops(i).ctrl.ldest
226    // intRat.io.specWritePorts(i).wdata := Mux(meEnable(i), uops(i).psrc(0), intFreeList.io.inc.pdests(i))
227
228    fpSpecWen(i) := fpFreeList.io.req.allocReqs(i) && fpFreeList.io.req.canAlloc && fpFreeList.io.req.doAlloc && !io.roqCommits.isWalk
229    // fpRat.io.specWritePorts(i).wen := fpSpecWen
230    // fpRat.io.specWritePorts(i).addr := uops(i).ctrl.ldest
231    // fpRat.io.specWritePorts(i).wdata := fpFreeList.io.req.pdests(i)
232  }
233
234  // We don't bypass the old_pdest from valid instructions with the same ldest currently in rename stage.
235  // Instead, we determine whether there're some dependencies between the valid instructions.
236  for (i <- 1 until RenameWidth) {
237    io.renameBypass.lsrc1_bypass(i-1) := Cat((0 until i).map(j => {
238      val fpMatch  = needFpDest(j) && io.in(i).bits.ctrl.srcType(0) === SrcType.fp
239      val intMatch = needIntDest(j) && io.in(i).bits.ctrl.srcType(0) === SrcType.reg
240      (fpMatch || intMatch) && io.in(j).bits.ctrl.ldest === io.in(i).bits.ctrl.lsrc(0)
241    }).reverse)
242    io.renameBypass.lsrc2_bypass(i-1) := Cat((0 until i).map(j => {
243      val fpMatch  = needFpDest(j) && io.in(i).bits.ctrl.srcType(1) === SrcType.fp
244      val intMatch = needIntDest(j) && io.in(i).bits.ctrl.srcType(1) === SrcType.reg
245      (fpMatch || intMatch) && io.in(j).bits.ctrl.ldest === io.in(i).bits.ctrl.lsrc(1)
246    }).reverse)
247    io.renameBypass.lsrc3_bypass(i-1) := Cat((0 until i).map(j => {
248      val fpMatch  = needFpDest(j) && io.in(i).bits.ctrl.srcType(2) === SrcType.fp
249      val intMatch = needIntDest(j) && io.in(i).bits.ctrl.srcType(2) === SrcType.reg
250      (fpMatch || intMatch) && io.in(j).bits.ctrl.ldest === io.in(i).bits.ctrl.lsrc(2)
251    }).reverse)
252    io.renameBypass.ldest_bypass(i-1) := Cat((0 until i).map(j => {
253      val fpMatch  = needFpDest(j) && needFpDest(i)
254      val intMatch = needIntDest(j) && needIntDest(i)
255      (fpMatch || intMatch) && io.in(j).bits.ctrl.ldest === io.in(i).bits.ctrl.ldest
256    }).reverse)
257  }
258
259  // calculate lsq space requirement
260  val isLs    = VecInit(uops.map(uop => FuType.isLoadStore(uop.ctrl.fuType)))
261  val isStore = VecInit(uops.map(uop => FuType.isStoreExu(uop.ctrl.fuType)))
262  val isAMO   = VecInit(uops.map(uop => FuType.isAMO(uop.ctrl.fuType)))
263  io.dispatchInfo.lsqNeedAlloc := VecInit((0 until RenameWidth).map(i =>
264    Mux(isLs(i), Mux(isStore(i) && !isAMO(i), 2.U, 1.U), 0.U)))
265
266  /**
267    * Instructions commit: update freelist and rename table
268    */
269  for (i <- 0 until CommitWidth) {
270    // when RenameWidth <= CommitWidth, there will be more write ports than read ports, which must be initialized
271    // normally, they are initialized in 'normal write' section
272    if (i >= RenameWidth) {
273      Seq(intRat, fpRat) foreach { case rat =>
274        rat.io.specWritePorts(i).wen   := false.B
275        rat.io.specWritePorts(i).addr  := DontCare
276        rat.io.specWritePorts(i).wdata := DontCare
277      }
278    }
279
280    Seq((intRat, false), (fpRat, true)) foreach { case (rat, fp) =>
281      // is valid commit req and given instruction has destination register
282      val commitDestValid = io.roqCommits.valid(i) && needDestRegCommit(fp, io.roqCommits.info(i))
283      XSDebug(p"isFp[${fp}]index[$i]-commitDestValid:$commitDestValid,isWalk:${io.roqCommits.isWalk}\n")
284
285      /*
286      I. RAT Update
287       */
288
289      // walk back write - restore spec state : ldest => old_pdest
290      if (fp && i < RenameWidth) {
291        rat.io.specWritePorts(i).wen := (commitDestValid && io.roqCommits.isWalk) || fpSpecWen(i)
292        rat.io.specWritePorts(i).addr := Mux(fpSpecWen(i), uops(i).ctrl.ldest, io.roqCommits.info(i).ldest)
293        rat.io.specWritePorts(i).wdata := Mux(fpSpecWen(i), fpFreeList.io.req.pdests(i), io.roqCommits.info(i).old_pdest)
294      } else if (!fp && i < RenameWidth) {
295        rat.io.specWritePorts(i).wen := (commitDestValid && io.roqCommits.isWalk) || intSpecWen(i)
296        rat.io.specWritePorts(i).addr := Mux(intSpecWen(i), uops(i).ctrl.ldest, io.roqCommits.info(i).ldest)
297        rat.io.specWritePorts(i).wdata := Mux(intSpecWen(i), Mux(meEnable(i), uops(i).psrc(0), intFreeList.io.inc.pdests(i)), io.roqCommits.info(i).old_pdest)
298      } else if (fp && i >= RenameWidth) {
299        rat.io.specWritePorts(i).wen := commitDestValid && io.roqCommits.isWalk
300        rat.io.specWritePorts(i).addr := io.roqCommits.info(i).ldest
301        rat.io.specWritePorts(i).wdata := io.roqCommits.info(i).old_pdest
302      } else if (!fp && i >= RenameWidth) {
303        rat.io.specWritePorts(i).wen := commitDestValid && io.roqCommits.isWalk
304        rat.io.specWritePorts(i).addr := io.roqCommits.info(i).ldest
305        rat.io.specWritePorts(i).wdata := io.roqCommits.info(i).old_pdest
306      }
307
308      when (commitDestValid && io.roqCommits.isWalk) {
309        XSInfo({if(fp) p"[fp" else p"[int"} + p" walk] " +
310          p"ldest:${rat.io.specWritePorts(i).addr} -> old_pdest:${rat.io.specWritePorts(i).wdata}\n")
311      }
312
313      // normal write - update arch state (serve as initialization)
314      rat.io.archWritePorts(i).wen := commitDestValid && !io.roqCommits.isWalk
315      rat.io.archWritePorts(i).addr := io.roqCommits.info(i).ldest
316      rat.io.archWritePorts(i).wdata := io.roqCommits.info(i).pdest
317
318      XSInfo(rat.io.archWritePorts(i).wen,
319        {if(fp) p"[fp" else p"[int"} + p" arch rat update] ldest:${rat.io.archWritePorts(i).addr} ->" +
320        p" pdest:${rat.io.archWritePorts(i).wdata}\n"
321      )
322
323
324      /*
325      II. Free List Update
326       */
327
328      if (fp) { // Float Point free list
329        fpFreeList.io.deallocReqs(i)  := commitDestValid && !io.roqCommits.isWalk
330        fpFreeList.io.deallocPregs(i) := io.roqCommits.info(i).old_pdest
331      } else { // Integer free list
332
333        // during walk process:
334        // 1. for normal inst, free pdest + revert rat from ldest->pdest to ldest->old_pdest
335        // 2. for ME inst, free pdest(commit counter++) + revert rat
336
337        // conclusion:
338        // a. rat recovery has nothing to do with ME or not
339        // b. treat walk as normal commit except replace old_pdests with pdests and set io.walk to true
340        // c. ignore pdests port when walking
341
342        intFreeList.io.dec.req(i) := commitDestValid // walk or not walk
343        intFreeList.io.dec.old_pdests(i)  := Mux(io.roqCommits.isWalk, io.roqCommits.info(i).pdest, io.roqCommits.info(i).old_pdest)
344        intFreeList.io.dec.eliminatedMove(i) := io.roqCommits.info(i).eliminatedMove
345        intFreeList.io.dec.pdests(i) := io.roqCommits.info(i).pdest
346      }
347    }
348  }
349
350
351  /*
352  Debug and performance counter
353   */
354
355  def printRenameInfo(in: DecoupledIO[CfCtrl], out: DecoupledIO[MicroOp]) = {
356    XSInfo(
357      in.valid && in.ready,
358      p"pc:${Hexadecimal(in.bits.cf.pc)} in v:${in.valid} in rdy:${in.ready} " +
359        p"lsrc(0):${in.bits.ctrl.lsrc(0)} -> psrc(0):${out.bits.psrc(0)} " +
360        p"lsrc(1):${in.bits.ctrl.lsrc(1)} -> psrc(1):${out.bits.psrc(1)} " +
361        p"lsrc(2):${in.bits.ctrl.lsrc(2)} -> psrc(2):${out.bits.psrc(2)} " +
362        p"ldest:${in.bits.ctrl.ldest} -> pdest:${out.bits.pdest} " +
363        p"old_pdest:${out.bits.old_pdest} " +
364        p"out v:${out.valid} r:${out.ready}\n"
365    )
366  }
367
368  for((x,y) <- io.in.zip(io.out)){
369    printRenameInfo(x, y)
370  }
371
372  XSDebug(io.roqCommits.isWalk, p"Walk Recovery Enabled\n")
373  XSDebug(io.roqCommits.isWalk, p"validVec:${Binary(io.roqCommits.valid.asUInt)}\n")
374  for (i <- 0 until CommitWidth) {
375    val info = io.roqCommits.info(i)
376    XSDebug(io.roqCommits.isWalk && io.roqCommits.valid(i), p"[#$i walk info] pc:${Hexadecimal(info.pc)} " +
377      p"ldest:${info.ldest} rfWen:${info.rfWen} fpWen:${info.fpWen} eliminatedMove:${info.eliminatedMove} " +
378      p"pdest:${info.pdest} old_pdest:${info.old_pdest}\n")
379  }
380
381  XSDebug(p"inValidVec: ${Binary(Cat(io.in.map(_.valid)))}\n")
382  XSInfo(!canOut, p"stall at rename, hasValid:${hasValid}, fpCanAlloc:${fpFreeList.io.req.canAlloc}, intCanAlloc:${intFreeList.io.inc.canInc} dispatch1ready:${io.out(0).ready}, isWalk:${io.roqCommits.isWalk}\n")
383  XSInfo(meEnable.asUInt().orR(), p"meEnableVec:${Binary(meEnable.asUInt)}\n")
384
385  intRat.io.debug_rdata <> io.debug_int_rat
386  fpRat.io.debug_rdata <> io.debug_fp_rat
387
388  XSDebug(p"Arch Int RAT:" + io.debug_int_rat.zipWithIndex.map{ case (r, i) => p"#$i:$r " }.reduceLeft(_ + _) + p"\n")
389
390  XSPerfAccumulate("in", Mux(RegNext(io.in(0).ready), PopCount(io.in.map(_.valid)), 0.U))
391  XSPerfAccumulate("utilization", PopCount(io.in.map(_.valid)))
392  XSPerfAccumulate("waitInstr", PopCount((0 until RenameWidth).map(i => io.in(i).valid && !io.in(i).ready)))
393  XSPerfAccumulate("stall_cycle_dispatch", hasValid && !io.out(0).ready && fpFreeList.io.req.canAlloc && intFreeList.io.inc.canInc && !io.roqCommits.isWalk)
394  XSPerfAccumulate("stall_cycle_fp", hasValid && io.out(0).ready && !fpFreeList.io.req.canAlloc && intFreeList.io.inc.canInc && !io.roqCommits.isWalk)
395  XSPerfAccumulate("stall_cycle_int", hasValid && io.out(0).ready && fpFreeList.io.req.canAlloc && !intFreeList.io.inc.canInc && !io.roqCommits.isWalk)
396  XSPerfAccumulate("stall_cycle_walk", hasValid && io.out(0).ready && fpFreeList.io.req.canAlloc && intFreeList.io.inc.canInc && io.roqCommits.isWalk)
397  if (!env.FPGAPlatform) {
398    ExcitingUtils.addSource(io.roqCommits.isWalk, "TMA_backendiswalk")
399  }
400  XSPerfAccumulate("move_instr_count", PopCount(Seq.tabulate(RenameWidth)(i => io.out(i).fire() && io.in(i).bits.ctrl.isMove)))
401  XSPerfAccumulate("move_elim_enabled", PopCount(Seq.tabulate(RenameWidth)(i => io.out(i).fire() && meEnable(i))))
402  XSPerfAccumulate("move_elim_cancelled", PopCount(Seq.tabulate(RenameWidth)(i => io.out(i).fire() && io.in(i).bits.ctrl.isMove && !meEnable(i))))
403  XSPerfAccumulate("move_elim_cancelled_psrc_bypass", PopCount(Seq.tabulate(RenameWidth)(i => io.out(i).fire() && io.in(i).bits.ctrl.isMove && !meEnable(i) && { if (i == 0) false.B else io.renameBypass.lsrc1_bypass(i-1).orR })))
404  XSPerfAccumulate("move_elim_cancelled_cnt_limit", PopCount(Seq.tabulate(RenameWidth)(i => io.out(i).fire() && io.in(i).bits.ctrl.isMove && !meEnable(i) && isMax(io.out(i).bits.psrc(0)))))
405  XSPerfAccumulate("move_elim_cancelled_inc_more_than_one", PopCount(Seq.tabulate(RenameWidth)(i => io.out(i).fire() && io.in(i).bits.ctrl.isMove && !meEnable(i) && { if (i == 0) false.B else psrc_cmp(i-1).orR })))
406
407  // to make sure meEnable functions as expected
408  for (i <- 0 until RenameWidth) {
409    XSDebug(io.out(i).fire() && io.in(i).bits.ctrl.isMove && !meEnable(i) && isMax(io.out(i).bits.psrc(0)),
410      p"ME_CANCELLED: ref counter hits max value (pc:0x${Hexadecimal(io.in(i).bits.cf.pc)})\n")
411    XSDebug(io.out(i).fire() && io.in(i).bits.ctrl.isMove && !meEnable(i) && { if (i == 0) false.B else io.renameBypass.lsrc1_bypass(i-1).orR },
412      p"ME_CANCELLED: RAW dependency (pc:0x${Hexadecimal(io.in(i).bits.cf.pc)})\n")
413    XSDebug(io.out(i).fire() && io.in(i).bits.ctrl.isMove && !meEnable(i) && { if (i == 0) false.B else psrc_cmp(i-1).orR },
414      p"ME_CANCELLED: psrc duplicates with former instruction (pc:0x${Hexadecimal(io.in(i).bits.cf.pc)})\n")
415  }
416  XSDebug(VecInit(Seq.tabulate(RenameWidth)(i => io.out(i).fire() && io.in(i).bits.ctrl.isMove && !meEnable(i))).asUInt().orR,
417    p"ME_CANCELLED: pc group [ " + (0 until RenameWidth).map(i => p"fire:${io.out(i).fire()},pc:0x${Hexadecimal(io.in(i).bits.cf.pc)} ").reduceLeft(_ + _) + p"]\n")
418}
419