xref: /XiangShan/src/main/scala/xiangshan/backend/rob/Rob.scala (revision e4f69d78f24895ac36a5a6c704cec53e4af72485)
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.rob
18
19import chipsalliance.rocketchip.config.Parameters
20import chisel3._
21import chisel3.util._
22import difftest._
23import freechips.rocketchip.diplomacy.{LazyModule, LazyModuleImp}
24import utils._
25import utility._
26import xiangshan._
27import xiangshan.backend.exu.ExuConfig
28import xiangshan.frontend.FtqPtr
29
30class DebugMdpInfo(implicit p: Parameters) extends XSBundle{
31  val ssid = UInt(SSIDWidth.W)
32  val waitAllStore = Bool()
33}
34
35class DebugLsInfo(implicit p: Parameters) extends XSBundle{
36  val s1 = new Bundle{
37    val isTlbFirstMiss = Bool() // in s1
38    val isBankConflict = Bool() // in s1
39    val isLoadToLoadForward = Bool()
40    val isReplayFast = Bool()
41  }
42  val s2 = new Bundle{
43    val isDcacheFirstMiss = Bool() // in s2 (predicted result is in s1 when using WPU, real result is in s2)
44    val isForwardFail = Bool() // in s2
45    val isReplaySlow = Bool()
46    val isLoadReplayTLBMiss = Bool()
47    val isLoadReplayCacheMiss = Bool()
48  }
49  val replayCnt = UInt(XLEN.W)
50
51  def s1SignalEnable(ena: DebugLsInfo) = {
52    when(ena.s1.isTlbFirstMiss) { s1.isTlbFirstMiss := true.B }
53    when(ena.s1.isBankConflict) { s1.isBankConflict := true.B }
54    when(ena.s1.isLoadToLoadForward) { s1.isLoadToLoadForward := true.B }
55    when(ena.s1.isReplayFast) {
56      s1.isReplayFast := true.B
57      replayCnt := replayCnt + 1.U
58    }
59  }
60
61  def s2SignalEnable(ena: DebugLsInfo) = {
62    when(ena.s2.isDcacheFirstMiss) { s2.isDcacheFirstMiss := true.B }
63    when(ena.s2.isForwardFail) { s2.isForwardFail := true.B }
64    when(ena.s2.isLoadReplayTLBMiss) { s2.isLoadReplayTLBMiss := true.B }
65    when(ena.s2.isLoadReplayCacheMiss) { s2.isLoadReplayCacheMiss := true.B }
66    when(ena.s2.isReplaySlow) {
67      s2.isReplaySlow := true.B
68      replayCnt := replayCnt + 1.U
69    }
70  }
71
72}
73object DebugLsInfo{
74  def init(implicit p: Parameters): DebugLsInfo = {
75    val lsInfo = Wire(new DebugLsInfo)
76    lsInfo.s1.isTlbFirstMiss := false.B
77    lsInfo.s1.isBankConflict := false.B
78    lsInfo.s1.isLoadToLoadForward := false.B
79    lsInfo.s1.isReplayFast := false.B
80    lsInfo.s2.isDcacheFirstMiss := false.B
81    lsInfo.s2.isForwardFail := false.B
82    lsInfo.s2.isReplaySlow := false.B
83    lsInfo.s2.isLoadReplayTLBMiss := false.B
84    lsInfo.s2.isLoadReplayCacheMiss := false.B
85    lsInfo.replayCnt := 0.U
86    lsInfo
87  }
88
89}
90class DebugLsInfoBundle(implicit p: Parameters) extends DebugLsInfo {
91  // unified processing at the end stage of load/store  ==> s2  ==> bug that will write error robIdx data
92  val s1_robIdx = UInt(log2Ceil(RobSize).W)
93  val s2_robIdx = UInt(log2Ceil(RobSize).W)
94}
95class DebugLSIO(implicit p: Parameters) extends XSBundle {
96  val debugLsInfo = Vec(exuParameters.LduCnt + exuParameters.StuCnt, Output(new DebugLsInfoBundle))
97}
98
99class RobPtr(implicit p: Parameters) extends CircularQueuePtr[RobPtr](
100  p => p(XSCoreParamsKey).RobSize
101) with HasCircularQueuePtrHelper {
102
103  def needFlush(redirect: Valid[Redirect]): Bool = {
104    val flushItself = redirect.bits.flushItself() && this === redirect.bits.robIdx
105    redirect.valid && (flushItself || isAfter(this, redirect.bits.robIdx))
106  }
107
108  def needFlush(redirect: Seq[Valid[Redirect]]): Bool = VecInit(redirect.map(needFlush)).asUInt.orR
109}
110
111object RobPtr {
112  def apply(f: Bool, v: UInt)(implicit p: Parameters): RobPtr = {
113    val ptr = Wire(new RobPtr)
114    ptr.flag := f
115    ptr.value := v
116    ptr
117  }
118}
119
120class RobCSRIO(implicit p: Parameters) extends XSBundle {
121  val intrBitSet = Input(Bool())
122  val trapTarget = Input(UInt(VAddrBits.W))
123  val isXRet     = Input(Bool())
124  val wfiEvent   = Input(Bool())
125
126  val fflags     = Output(Valid(UInt(5.W)))
127  val dirty_fs   = Output(Bool())
128  val perfinfo   = new Bundle {
129    val retiredInstr = Output(UInt(3.W))
130  }
131}
132
133class RobLsqIO(implicit p: Parameters) extends XSBundle {
134  val lcommit = Output(UInt(log2Up(CommitWidth + 1).W))
135  val scommit = Output(UInt(log2Up(CommitWidth + 1).W))
136  val pendingld = Output(Bool())
137  val pendingst = Output(Bool())
138  val commit = Output(Bool())
139  val pendingPtr = Output(new RobPtr)
140
141  val mmio = Input(Vec(LoadPipelineWidth, Bool()))
142  val uop = Input(Vec(LoadPipelineWidth, new MicroOp))
143}
144
145class RobEnqIO(implicit p: Parameters) extends XSBundle {
146  val canAccept = Output(Bool())
147  val isEmpty = Output(Bool())
148  // valid vector, for robIdx gen and walk
149  val needAlloc = Vec(RenameWidth, Input(Bool()))
150  val req = Vec(RenameWidth, Flipped(ValidIO(new MicroOp)))
151  val resp = Vec(RenameWidth, Output(new RobPtr))
152}
153
154class RobDispatchData(implicit p: Parameters) extends RobCommitInfo
155
156class RobDeqPtrWrapper(implicit p: Parameters) extends XSModule with HasCircularQueuePtrHelper {
157  val io = IO(new Bundle {
158    // for commits/flush
159    val state = Input(UInt(2.W))
160    val deq_v = Vec(CommitWidth, Input(Bool()))
161    val deq_w = Vec(CommitWidth, Input(Bool()))
162    val exception_state = Flipped(ValidIO(new RobExceptionInfo))
163    // for flush: when exception occurs, reset deqPtrs to range(0, CommitWidth)
164    val intrBitSetReg = Input(Bool())
165    val hasNoSpecExec = Input(Bool())
166    val interrupt_safe = Input(Bool())
167    val blockCommit = Input(Bool())
168    // output: the CommitWidth deqPtr
169    val out = Vec(CommitWidth, Output(new RobPtr))
170    val next_out = Vec(CommitWidth, Output(new RobPtr))
171  })
172
173  val deqPtrVec = RegInit(VecInit((0 until CommitWidth).map(_.U.asTypeOf(new RobPtr))))
174
175  // for exceptions (flushPipe included) and interrupts:
176  // only consider the first instruction
177  val intrEnable = io.intrBitSetReg && !io.hasNoSpecExec && io.interrupt_safe
178  val exceptionEnable = io.deq_w(0) && io.exception_state.valid && io.exception_state.bits.not_commit && io.exception_state.bits.robIdx === deqPtrVec(0)
179  val redirectOutValid = io.state === 0.U && io.deq_v(0) && (intrEnable || exceptionEnable)
180
181  // for normal commits: only to consider when there're no exceptions
182  // we don't need to consider whether the first instruction has exceptions since it wil trigger exceptions.
183  val commit_exception = io.exception_state.valid && !isAfter(io.exception_state.bits.robIdx, deqPtrVec.last)
184  val canCommit = VecInit((0 until CommitWidth).map(i => io.deq_v(i) && io.deq_w(i)))
185  val normalCommitCnt = PriorityEncoder(canCommit.map(c => !c) :+ true.B)
186  // when io.intrBitSetReg or there're possible exceptions in these instructions,
187  // only one instruction is allowed to commit
188  val allowOnlyOne = commit_exception || io.intrBitSetReg
189  val commitCnt = Mux(allowOnlyOne, canCommit(0), normalCommitCnt)
190
191  val commitDeqPtrVec = VecInit(deqPtrVec.map(_ + commitCnt))
192  val deqPtrVec_next = Mux(io.state === 0.U && !redirectOutValid && !io.blockCommit, commitDeqPtrVec, deqPtrVec)
193
194  deqPtrVec := deqPtrVec_next
195
196  io.next_out := deqPtrVec_next
197  io.out      := deqPtrVec
198
199  when (io.state === 0.U) {
200    XSInfo(io.state === 0.U && commitCnt > 0.U, "retired %d insts\n", commitCnt)
201  }
202
203}
204
205class RobEnqPtrWrapper(implicit p: Parameters) extends XSModule with HasCircularQueuePtrHelper {
206  val io = IO(new Bundle {
207    // for input redirect
208    val redirect = Input(Valid(new Redirect))
209    // for enqueue
210    val allowEnqueue = Input(Bool())
211    val hasBlockBackward = Input(Bool())
212    val enq = Vec(RenameWidth, Input(Bool()))
213    val out = Output(Vec(RenameWidth, new RobPtr))
214  })
215
216  val enqPtrVec = RegInit(VecInit.tabulate(RenameWidth)(_.U.asTypeOf(new RobPtr)))
217
218  // enqueue
219  val canAccept = io.allowEnqueue && !io.hasBlockBackward
220  val dispatchNum = Mux(canAccept, PopCount(io.enq), 0.U)
221
222  for ((ptr, i) <- enqPtrVec.zipWithIndex) {
223    when(io.redirect.valid) {
224      ptr := Mux(io.redirect.bits.flushItself(), io.redirect.bits.robIdx + i.U, io.redirect.bits.robIdx + (i + 1).U)
225    }.otherwise {
226      ptr := ptr + dispatchNum
227    }
228  }
229
230  io.out := enqPtrVec
231
232}
233
234class RobExceptionInfo(implicit p: Parameters) extends XSBundle {
235  // val valid = Bool()
236  val robIdx = new RobPtr
237  val exceptionVec = ExceptionVec()
238  val flushPipe = Bool()
239  val replayInst = Bool() // redirect to that inst itself
240  val singleStep = Bool() // TODO add frontend hit beneath
241  val crossPageIPFFix = Bool()
242  val trigger = new TriggerCf
243
244//  def trigger_before = !trigger.getTimingBackend && trigger.getHitBackend
245//  def trigger_after = trigger.getTimingBackend && trigger.getHitBackend
246  def has_exception = exceptionVec.asUInt.orR || flushPipe || singleStep || replayInst || trigger.hit
247  def not_commit = exceptionVec.asUInt.orR || singleStep || replayInst || trigger.hit
248  // only exceptions are allowed to writeback when enqueue
249  def can_writeback = exceptionVec.asUInt.orR || singleStep || trigger.hit
250}
251
252class ExceptionGen(implicit p: Parameters) extends XSModule with HasCircularQueuePtrHelper {
253  val io = IO(new Bundle {
254    val redirect = Input(Valid(new Redirect))
255    val flush = Input(Bool())
256    val enq = Vec(RenameWidth, Flipped(ValidIO(new RobExceptionInfo)))
257    val wb = Vec(1 + LoadPipelineWidth + StorePipelineWidth, Flipped(ValidIO(new RobExceptionInfo)))
258    val out = ValidIO(new RobExceptionInfo)
259    val state = ValidIO(new RobExceptionInfo)
260  })
261
262  def getOldest(valid: Seq[Bool], bits: Seq[RobExceptionInfo]): (Seq[Bool], Seq[RobExceptionInfo]) = {
263    assert(valid.length == bits.length)
264    assert(isPow2(valid.length))
265    if (valid.length == 1) {
266      (valid, bits)
267    } else if (valid.length == 2) {
268      val res = Seq.fill(2)(Wire(ValidIO(chiselTypeOf(bits(0)))))
269      for (i <- res.indices) {
270        res(i).valid := valid(i)
271        res(i).bits := bits(i)
272      }
273      val oldest = Mux(!valid(1) || valid(0) && isAfter(bits(1).robIdx, bits(0).robIdx), res(0), res(1))
274      (Seq(oldest.valid), Seq(oldest.bits))
275    } else {
276      val left = getOldest(valid.take(valid.length / 2), bits.take(valid.length / 2))
277      val right = getOldest(valid.takeRight(valid.length / 2), bits.takeRight(valid.length / 2))
278      getOldest(left._1 ++ right._1, left._2 ++ right._2)
279    }
280  }
281
282  val currentValid = RegInit(false.B)
283  val current = Reg(new RobExceptionInfo)
284
285  // orR the exceptionVec
286  val lastCycleFlush = RegNext(io.flush)
287  val in_enq_valid = VecInit(io.enq.map(e => e.valid && e.bits.has_exception && !lastCycleFlush))
288  val in_wb_valid = io.wb.map(w => w.valid && w.bits.has_exception && !lastCycleFlush)
289
290  // s0: compare wb(1)~wb(LoadPipelineWidth) and wb(1 + LoadPipelineWidth)~wb(LoadPipelineWidth + StorePipelineWidth)
291  val wb_valid = in_wb_valid.zip(io.wb.map(_.bits)).map{ case (v, bits) => v && !(bits.robIdx.needFlush(io.redirect) || io.flush) }
292  val csr_wb_bits = io.wb(0).bits
293  val load_wb_bits = getOldest(in_wb_valid.slice(1, 1 + LoadPipelineWidth), io.wb.map(_.bits).slice(1, 1 + LoadPipelineWidth))._2(0)
294  val store_wb_bits = getOldest(in_wb_valid.slice(1 + LoadPipelineWidth, 1 + LoadPipelineWidth + StorePipelineWidth), io.wb.map(_.bits).slice(1 + LoadPipelineWidth, 1 + LoadPipelineWidth + StorePipelineWidth))._2(0)
295  val s0_out_valid = RegNext(VecInit(Seq(wb_valid(0), wb_valid.slice(1, 1 + LoadPipelineWidth).reduce(_ || _), wb_valid.slice(1 + LoadPipelineWidth, 1 + LoadPipelineWidth + StorePipelineWidth).reduce(_ || _))))
296  val s0_out_bits = RegNext(VecInit(Seq(csr_wb_bits, load_wb_bits, store_wb_bits)))
297
298  // s1: compare last four and current flush
299  val s1_valid = VecInit(s0_out_valid.zip(s0_out_bits).map{ case (v, b) => v && !(b.robIdx.needFlush(io.redirect) || io.flush) })
300  val compare_01_valid = s0_out_valid(0) || s0_out_valid(1)
301  val compare_01_bits = Mux(!s0_out_valid(0) || s0_out_valid(1) && isAfter(s0_out_bits(0).robIdx, s0_out_bits(1).robIdx), s0_out_bits(1), s0_out_bits(0))
302  val compare_bits = Mux(!s0_out_valid(2) || compare_01_valid && isAfter(s0_out_bits(2).robIdx, compare_01_bits.robIdx), compare_01_bits, s0_out_bits(2))
303  val s1_out_bits = RegNext(compare_bits)
304  val s1_out_valid = RegNext(s1_valid.asUInt.orR)
305
306  val enq_valid = RegNext(in_enq_valid.asUInt.orR && !io.redirect.valid && !io.flush)
307  val enq_bits = RegNext(ParallelPriorityMux(in_enq_valid, io.enq.map(_.bits)))
308
309  // s2: compare the input exception with the current one
310  // priorities:
311  // (1) system reset
312  // (2) current is valid: flush, remain, merge, update
313  // (3) current is not valid: s1 or enq
314  val current_flush = current.robIdx.needFlush(io.redirect) || io.flush
315  val s1_flush = s1_out_bits.robIdx.needFlush(io.redirect) || io.flush
316  when (currentValid) {
317    when (current_flush) {
318      currentValid := Mux(s1_flush, false.B, s1_out_valid)
319    }
320    when (s1_out_valid && !s1_flush) {
321      when (isAfter(current.robIdx, s1_out_bits.robIdx)) {
322        current := s1_out_bits
323      }.elsewhen (current.robIdx === s1_out_bits.robIdx) {
324        current.exceptionVec := (s1_out_bits.exceptionVec.asUInt | current.exceptionVec.asUInt).asTypeOf(ExceptionVec())
325        current.flushPipe := s1_out_bits.flushPipe || current.flushPipe
326        current.replayInst := s1_out_bits.replayInst || current.replayInst
327        current.singleStep := s1_out_bits.singleStep || current.singleStep
328        current.trigger := (s1_out_bits.trigger.asUInt | current.trigger.asUInt).asTypeOf(new TriggerCf)
329      }
330    }
331  }.elsewhen (s1_out_valid && !s1_flush) {
332    currentValid := true.B
333    current := s1_out_bits
334  }.elsewhen (enq_valid && !(io.redirect.valid || io.flush)) {
335    currentValid := true.B
336    current := enq_bits
337  }
338
339  io.out.valid   := s1_out_valid || enq_valid && enq_bits.can_writeback
340  io.out.bits    := Mux(s1_out_valid, s1_out_bits, enq_bits)
341  io.state.valid := currentValid
342  io.state.bits  := current
343
344}
345
346class RobFlushInfo(implicit p: Parameters) extends XSBundle {
347  val ftqIdx = new FtqPtr
348  val robIdx = new RobPtr
349  val ftqOffset = UInt(log2Up(PredictWidth).W)
350  val replayInst = Bool()
351}
352
353class Rob(implicit p: Parameters) extends LazyModule with HasWritebackSink with HasXSParameter {
354
355  lazy val module = new RobImp(this)
356
357  override def generateWritebackIO(
358    thisMod: Option[HasWritebackSource] = None,
359    thisModImp: Option[HasWritebackSourceImp] = None
360  ): Unit = {
361    val sources = writebackSinksImp(thisMod, thisModImp)
362    module.io.writeback.zip(sources).foreach(x => x._1 := x._2)
363  }
364}
365
366class RobImp(outer: Rob)(implicit p: Parameters) extends LazyModuleImp(outer)
367  with HasXSParameter with HasCircularQueuePtrHelper with HasPerfEvents {
368  val wbExuConfigs = outer.writebackSinksParams.map(_.exuConfigs)
369  val numWbPorts = wbExuConfigs.map(_.length)
370
371  val io = IO(new Bundle() {
372    val hartId = Input(UInt(8.W))
373    val redirect = Input(Valid(new Redirect))
374    val enq = new RobEnqIO
375    val flushOut = ValidIO(new Redirect)
376    val exception = ValidIO(new ExceptionInfo)
377    // exu + brq
378    val writeback = MixedVec(numWbPorts.map(num => Vec(num, Flipped(ValidIO(new ExuOutput)))))
379    val commits = Output(new RobCommitIO)
380    val lsq = new RobLsqIO
381    val robDeqPtr = Output(new RobPtr)
382    val csr = new RobCSRIO
383    val robFull = Output(Bool())
384    val cpu_halt = Output(Bool())
385    val wfi_enable = Input(Bool())
386    val debug_ls = Flipped(new DebugLSIO)
387  })
388
389  def selectWb(index: Int, func: Seq[ExuConfig] => Boolean): Seq[(Seq[ExuConfig], ValidIO[ExuOutput])] = {
390    wbExuConfigs(index).zip(io.writeback(index)).filter(x => func(x._1))
391  }
392  val exeWbSel = outer.selWritebackSinks(_.exuConfigs.length)
393  val fflagsWbSel = outer.selWritebackSinks(_.exuConfigs.count(_.exists(_.writeFflags)))
394  val fflagsPorts = selectWb(fflagsWbSel, _.exists(_.writeFflags))
395  val exceptionWbSel = outer.selWritebackSinks(_.exuConfigs.count(_.exists(_.needExceptionGen)))
396  val exceptionPorts = selectWb(fflagsWbSel, _.exists(_.needExceptionGen))
397  val exuWbPorts = selectWb(exeWbSel, _.forall(_ != StdExeUnitCfg))
398  val stdWbPorts = selectWb(exeWbSel, _.contains(StdExeUnitCfg))
399  println(s"Rob: size $RobSize, numWbPorts: $numWbPorts, commitwidth: $CommitWidth")
400  println(s"exuPorts: ${exuWbPorts.map(_._1.map(_.name))}")
401  println(s"stdPorts: ${stdWbPorts.map(_._1.map(_.name))}")
402  println(s"fflags: ${fflagsPorts.map(_._1.map(_.name))}")
403
404
405  val exuWriteback = exuWbPorts.map(_._2)
406  val stdWriteback = stdWbPorts.map(_._2)
407
408  // instvalid field
409  val valid = RegInit(VecInit(Seq.fill(RobSize)(false.B)))
410  // writeback status
411  val writebacked = Mem(RobSize, Bool())
412  val store_data_writebacked = Mem(RobSize, Bool())
413  val mmio = RegInit(VecInit(Seq.fill(RobSize)(false.B)))
414  // data for redirect, exception, etc.
415  val flagBkup = Mem(RobSize, Bool())
416  // some instructions are not allowed to trigger interrupts
417  // They have side effects on the states of the processor before they write back
418  val interrupt_safe = Mem(RobSize, Bool())
419
420  // data for debug
421  // Warn: debug_* prefix should not exist in generated verilog.
422  val debug_microOp = Mem(RobSize, new MicroOp)
423  val debug_exuData = Reg(Vec(RobSize, UInt(XLEN.W)))//for debug
424  val debug_exuDebug = Reg(Vec(RobSize, new DebugBundle))//for debug
425  val debug_lsInfo = RegInit(VecInit(Seq.fill(RobSize)(DebugLsInfo.init)))
426
427  // pointers
428  // For enqueue ptr, we don't duplicate it since only enqueue needs it.
429  val enqPtrVec = Wire(Vec(RenameWidth, new RobPtr))
430  val deqPtrVec = Wire(Vec(CommitWidth, new RobPtr))
431
432  val walkPtrVec = Reg(Vec(CommitWidth, new RobPtr))
433  val allowEnqueue = RegInit(true.B)
434
435  val enqPtr = enqPtrVec.head
436  val deqPtr = deqPtrVec(0)
437  val walkPtr = walkPtrVec(0)
438
439  val isEmpty = enqPtr === deqPtr
440  val isReplaying = io.redirect.valid && RedirectLevel.flushItself(io.redirect.bits.level)
441
442  /**
443    * states of Rob
444    */
445  val s_idle :: s_walk :: Nil = Enum(2)
446  val state = RegInit(s_idle)
447
448  /**
449    * Data Modules
450    *
451    * CommitDataModule: data from dispatch
452    * (1) read: commits/walk/exception
453    * (2) write: enqueue
454    *
455    * WritebackData: data from writeback
456    * (1) read: commits/walk/exception
457    * (2) write: write back from exe units
458    */
459  val dispatchData = Module(new SyncDataModuleTemplate(new RobDispatchData, RobSize, CommitWidth, RenameWidth))
460  val dispatchDataRead = dispatchData.io.rdata
461
462  val exceptionGen = Module(new ExceptionGen)
463  val exceptionDataRead = exceptionGen.io.state
464  val fflagsDataRead = Wire(Vec(CommitWidth, UInt(5.W)))
465
466  io.robDeqPtr := deqPtr
467
468  /**
469    * Enqueue (from dispatch)
470    */
471  // special cases
472  val hasBlockBackward = RegInit(false.B)
473  val hasNoSpecExec = RegInit(false.B)
474  val doingSvinval = RegInit(false.B)
475  // When blockBackward instruction leaves Rob (commit or walk), hasBlockBackward should be set to false.B
476  // To reduce registers usage, for hasBlockBackward cases, we allow enqueue after ROB is empty.
477  when (isEmpty) { hasBlockBackward:= false.B }
478  // When any instruction commits, hasNoSpecExec should be set to false.B
479  when (io.commits.hasWalkInstr || io.commits.hasCommitInstr) { hasNoSpecExec:= false.B }
480
481  // The wait-for-interrupt (WFI) instruction waits in the ROB until an interrupt might need servicing.
482  // io.csr.wfiEvent will be asserted if the WFI can resume execution, and we change the state to s_wfi_idle.
483  // It does not affect how interrupts are serviced. Note that WFI is noSpecExec and it does not trigger interrupts.
484  val hasWFI = RegInit(false.B)
485  io.cpu_halt := hasWFI
486  // WFI Timeout: 2^20 = 1M cycles
487  val wfi_cycles = RegInit(0.U(20.W))
488  when (hasWFI) {
489    wfi_cycles := wfi_cycles + 1.U
490  }.elsewhen (!hasWFI && RegNext(hasWFI)) {
491    wfi_cycles := 0.U
492  }
493  val wfi_timeout = wfi_cycles.andR
494  when (RegNext(RegNext(io.csr.wfiEvent)) || io.flushOut.valid || wfi_timeout) {
495    hasWFI := false.B
496  }
497
498  val allocatePtrVec = VecInit((0 until RenameWidth).map(i => enqPtrVec(PopCount(io.enq.needAlloc.take(i)))))
499  io.enq.canAccept := allowEnqueue && !hasBlockBackward
500  io.enq.resp      := allocatePtrVec
501  val canEnqueue = VecInit(io.enq.req.map(_.valid && io.enq.canAccept))
502  val timer = GTimer()
503  for (i <- 0 until RenameWidth) {
504    // we don't check whether io.redirect is valid here since redirect has higher priority
505    when (canEnqueue(i)) {
506      val enqUop = io.enq.req(i).bits
507      val enqIndex = allocatePtrVec(i).value
508      // store uop in data module and debug_microOp Vec
509      debug_microOp(enqIndex) := enqUop
510      debug_microOp(enqIndex).debugInfo.dispatchTime := timer
511      debug_microOp(enqIndex).debugInfo.enqRsTime := timer
512      debug_microOp(enqIndex).debugInfo.selectTime := timer
513      debug_microOp(enqIndex).debugInfo.issueTime := timer
514      debug_microOp(enqIndex).debugInfo.writebackTime := timer
515      debug_microOp(enqIndex).debugInfo.tlbFirstReqTime := timer
516      debug_microOp(enqIndex).debugInfo.tlbRespTime := timer
517      debug_lsInfo(enqIndex) := DebugLsInfo.init
518      when (enqUop.ctrl.blockBackward) {
519        hasBlockBackward := true.B
520      }
521      when (enqUop.ctrl.noSpecExec) {
522        hasNoSpecExec := true.B
523      }
524      val enqHasTriggerHit = io.enq.req(i).bits.cf.trigger.getHitFrontend
525      val enqHasException = ExceptionNO.selectFrontend(enqUop.cf.exceptionVec).asUInt.orR
526      // the begin instruction of Svinval enqs so mark doingSvinval as true to indicate this process
527      when(!enqHasTriggerHit && !enqHasException && FuType.isSvinvalBegin(enqUop.ctrl.fuType, enqUop.ctrl.fuOpType, enqUop.ctrl.flushPipe))
528      {
529        doingSvinval := true.B
530      }
531      // the end instruction of Svinval enqs so clear doingSvinval
532      when(!enqHasTriggerHit && !enqHasException && FuType.isSvinvalEnd(enqUop.ctrl.fuType, enqUop.ctrl.fuOpType, enqUop.ctrl.flushPipe))
533      {
534        doingSvinval := false.B
535      }
536      // when we are in the process of Svinval software code area , only Svinval.vma and end instruction of Svinval can appear
537      assert(!doingSvinval || (FuType.isSvinval(enqUop.ctrl.fuType, enqUop.ctrl.fuOpType, enqUop.ctrl.flushPipe) ||
538        FuType.isSvinvalEnd(enqUop.ctrl.fuType, enqUop.ctrl.fuOpType, enqUop.ctrl.flushPipe)))
539      when (enqUop.ctrl.isWFI && !enqHasException && !enqHasTriggerHit) {
540        hasWFI := true.B
541      }
542
543      mmio(enqIndex) := false.B
544    }
545  }
546  val dispatchNum = Mux(io.enq.canAccept, PopCount(io.enq.req.map(_.valid)), 0.U)
547  io.enq.isEmpty   := RegNext(isEmpty && !VecInit(io.enq.req.map(_.valid)).asUInt.orR)
548
549  when (!io.wfi_enable) {
550    hasWFI := false.B
551  }
552
553  /**
554    * Writeback (from execution units)
555    */
556  for (wb <- exuWriteback) {
557    when (wb.valid) {
558      val wbIdx = wb.bits.uop.robIdx.value
559      debug_exuData(wbIdx) := wb.bits.data
560      debug_exuDebug(wbIdx) := wb.bits.debug
561      debug_microOp(wbIdx).debugInfo.enqRsTime := wb.bits.uop.debugInfo.enqRsTime
562      debug_microOp(wbIdx).debugInfo.selectTime := wb.bits.uop.debugInfo.selectTime
563      debug_microOp(wbIdx).debugInfo.issueTime := wb.bits.uop.debugInfo.issueTime
564      debug_microOp(wbIdx).debugInfo.writebackTime := wb.bits.uop.debugInfo.writebackTime
565      debug_microOp(wbIdx).debugInfo.tlbFirstReqTime := wb.bits.uop.debugInfo.tlbFirstReqTime
566      debug_microOp(wbIdx).debugInfo.tlbRespTime := wb.bits.uop.debugInfo.tlbRespTime
567
568      // debug for lqidx and sqidx
569      debug_microOp(wbIdx).lqIdx := wb.bits.uop.lqIdx
570      debug_microOp(wbIdx).sqIdx := wb.bits.uop.sqIdx
571
572      val debug_Uop = debug_microOp(wbIdx)
573      XSInfo(true.B,
574        p"writebacked pc 0x${Hexadecimal(debug_Uop.cf.pc)} wen ${debug_Uop.ctrl.rfWen} " +
575        p"data 0x${Hexadecimal(wb.bits.data)} ldst ${debug_Uop.ctrl.ldest} pdst ${debug_Uop.pdest} " +
576        p"skip ${wb.bits.debug.isMMIO} robIdx: ${wb.bits.uop.robIdx}\n"
577      )
578    }
579  }
580  val writebackNum = PopCount(exuWriteback.map(_.valid))
581  XSInfo(writebackNum =/= 0.U, "writebacked %d insts\n", writebackNum)
582
583  for (i <- 0 until LoadPipelineWidth) {
584    when (RegNext(io.lsq.mmio(i))) {
585      mmio(RegNext(io.lsq.uop(i).robIdx).value) := true.B
586    }
587  }
588
589  /**
590    * RedirectOut: Interrupt and Exceptions
591    */
592  val deqDispatchData = dispatchDataRead(0)
593  val debug_deqUop = debug_microOp(deqPtr.value)
594
595  val intrBitSetReg = RegNext(io.csr.intrBitSet)
596  val intrEnable = intrBitSetReg && !hasNoSpecExec && interrupt_safe(deqPtr.value)
597  val deqHasExceptionOrFlush = exceptionDataRead.valid && exceptionDataRead.bits.robIdx === deqPtr
598  val deqHasException = deqHasExceptionOrFlush && (exceptionDataRead.bits.exceptionVec.asUInt.orR ||
599    exceptionDataRead.bits.singleStep || exceptionDataRead.bits.trigger.hit)
600  val deqHasFlushPipe = deqHasExceptionOrFlush && exceptionDataRead.bits.flushPipe
601  val deqHasReplayInst = deqHasExceptionOrFlush && exceptionDataRead.bits.replayInst
602  val exceptionEnable = writebacked(deqPtr.value) && deqHasException
603
604  XSDebug(deqHasException && exceptionDataRead.bits.singleStep, "Debug Mode: Deq has singlestep exception\n")
605  XSDebug(deqHasException && exceptionDataRead.bits.trigger.getHitFrontend, "Debug Mode: Deq has frontend trigger exception\n")
606  XSDebug(deqHasException && exceptionDataRead.bits.trigger.getHitBackend, "Debug Mode: Deq has backend trigger exception\n")
607
608  val isFlushPipe = writebacked(deqPtr.value) && (deqHasFlushPipe || deqHasReplayInst)
609
610  // io.flushOut will trigger redirect at the next cycle.
611  // Block any redirect or commit at the next cycle.
612  val lastCycleFlush = RegNext(io.flushOut.valid)
613
614  io.flushOut.valid := (state === s_idle) && valid(deqPtr.value) && (intrEnable || exceptionEnable || isFlushPipe) && !lastCycleFlush
615  io.flushOut.bits := DontCare
616  io.flushOut.bits.robIdx := deqPtr
617  io.flushOut.bits.ftqIdx := deqDispatchData.ftqIdx
618  io.flushOut.bits.ftqOffset := deqDispatchData.ftqOffset
619  io.flushOut.bits.level := Mux(deqHasReplayInst || intrEnable || exceptionEnable, RedirectLevel.flush, RedirectLevel.flushAfter) // TODO use this to implement "exception next"
620  io.flushOut.bits.interrupt := true.B
621  XSPerfAccumulate("interrupt_num", io.flushOut.valid && intrEnable)
622  XSPerfAccumulate("exception_num", io.flushOut.valid && exceptionEnable)
623  XSPerfAccumulate("flush_pipe_num", io.flushOut.valid && isFlushPipe)
624  XSPerfAccumulate("replay_inst_num", io.flushOut.valid && isFlushPipe && deqHasReplayInst)
625
626  val exceptionHappen = (state === s_idle) && valid(deqPtr.value) && (intrEnable || exceptionEnable) && !lastCycleFlush
627  io.exception.valid := RegNext(exceptionHappen)
628  io.exception.bits.uop := RegEnable(debug_deqUop, exceptionHappen)
629  io.exception.bits.uop.ctrl.commitType := RegEnable(deqDispatchData.commitType, exceptionHappen)
630  io.exception.bits.uop.cf.exceptionVec := RegEnable(exceptionDataRead.bits.exceptionVec, exceptionHappen)
631  io.exception.bits.uop.ctrl.singleStep := RegEnable(exceptionDataRead.bits.singleStep, exceptionHappen)
632  io.exception.bits.uop.cf.crossPageIPFFix := RegEnable(exceptionDataRead.bits.crossPageIPFFix, exceptionHappen)
633  io.exception.bits.isInterrupt := RegEnable(intrEnable, exceptionHappen)
634  io.exception.bits.uop.cf.trigger := RegEnable(exceptionDataRead.bits.trigger, exceptionHappen)
635
636  XSDebug(io.flushOut.valid,
637    p"generate redirect: pc 0x${Hexadecimal(io.exception.bits.uop.cf.pc)} intr $intrEnable " +
638    p"excp $exceptionEnable flushPipe $isFlushPipe " +
639    p"Trap_target 0x${Hexadecimal(io.csr.trapTarget)} exceptionVec ${Binary(exceptionDataRead.bits.exceptionVec.asUInt)}\n")
640
641
642  /**
643    * Commits (and walk)
644    * They share the same width.
645    */
646  val walkCounter = Reg(UInt(log2Up(RobSize + 1).W))
647  val shouldWalkVec = VecInit((0 until CommitWidth).map(_.U < walkCounter))
648  val walkFinished = walkCounter <= CommitWidth.U
649
650  require(RenameWidth <= CommitWidth)
651
652  // wiring to csr
653  val (wflags, fpWen) = (0 until CommitWidth).map(i => {
654    val v = io.commits.commitValid(i)
655    val info = io.commits.info(i)
656    (v & info.wflags, v & info.fpWen)
657  }).unzip
658  val fflags = Wire(Valid(UInt(5.W)))
659  fflags.valid := io.commits.isCommit && VecInit(wflags).asUInt.orR
660  fflags.bits := wflags.zip(fflagsDataRead).map({
661    case (w, f) => Mux(w, f, 0.U)
662  }).reduce(_|_)
663  val dirty_fs = io.commits.isCommit && VecInit(fpWen).asUInt.orR
664
665  // when mispredict branches writeback, stop commit in the next 2 cycles
666  // TODO: don't check all exu write back
667  val misPredWb = Cat(VecInit(exuWriteback.map(wb =>
668    wb.bits.redirect.cfiUpdate.isMisPred && wb.bits.redirectValid
669  ))).orR
670  val misPredBlockCounter = Reg(UInt(3.W))
671  misPredBlockCounter := Mux(misPredWb,
672    "b111".U,
673    misPredBlockCounter >> 1.U
674  )
675  val misPredBlock = misPredBlockCounter(0)
676  val blockCommit = misPredBlock || isReplaying || lastCycleFlush || hasWFI
677
678  io.commits.isWalk := state === s_walk
679  io.commits.isCommit := state === s_idle && !blockCommit
680  val walk_v = VecInit(walkPtrVec.map(ptr => valid(ptr.value)))
681  val commit_v = VecInit(deqPtrVec.map(ptr => valid(ptr.value)))
682  // store will be commited iff both sta & std have been writebacked
683  val commit_w = VecInit(deqPtrVec.map(ptr => writebacked(ptr.value) && store_data_writebacked(ptr.value)))
684  val commit_exception = exceptionDataRead.valid && !isAfter(exceptionDataRead.bits.robIdx, deqPtrVec.last)
685  val commit_block = VecInit((0 until CommitWidth).map(i => !commit_w(i)))
686  val allowOnlyOneCommit = commit_exception || intrBitSetReg
687  // for instructions that may block others, we don't allow them to commit
688  for (i <- 0 until CommitWidth) {
689    // defaults: state === s_idle and instructions commit
690    // when intrBitSetReg, allow only one instruction to commit at each clock cycle
691    val isBlocked = if (i != 0) Cat(commit_block.take(i)).orR || allowOnlyOneCommit else intrEnable || deqHasException || deqHasReplayInst
692    io.commits.commitValid(i) := commit_v(i) && commit_w(i) && !isBlocked
693    io.commits.info(i)  := dispatchDataRead(i)
694
695    when (state === s_walk) {
696      io.commits.walkValid(i) := shouldWalkVec(i)
697      when (io.commits.isWalk && state === s_walk && shouldWalkVec(i)) {
698        XSError(!walk_v(i), s"why not $i???\n")
699      }
700    }
701
702    XSInfo(io.commits.isCommit && io.commits.commitValid(i),
703      "retired pc %x wen %d ldest %d pdest %x old_pdest %x data %x fflags: %b\n",
704      debug_microOp(deqPtrVec(i).value).cf.pc,
705      io.commits.info(i).rfWen,
706      io.commits.info(i).ldest,
707      io.commits.info(i).pdest,
708      io.commits.info(i).old_pdest,
709      debug_exuData(deqPtrVec(i).value),
710      fflagsDataRead(i)
711    )
712    XSInfo(state === s_walk && io.commits.walkValid(i), "walked pc %x wen %d ldst %d data %x\n",
713      debug_microOp(walkPtrVec(i).value).cf.pc,
714      io.commits.info(i).rfWen,
715      io.commits.info(i).ldest,
716      debug_exuData(walkPtrVec(i).value)
717    )
718  }
719  if (env.EnableDifftest) {
720    io.commits.info.map(info => dontTouch(info.pc))
721  }
722
723  // sync fflags/dirty_fs to csr
724  io.csr.fflags := RegNext(fflags)
725  io.csr.dirty_fs := RegNext(dirty_fs)
726
727  // commit load/store to lsq
728  val ldCommitVec = VecInit((0 until CommitWidth).map(i => io.commits.commitValid(i) && io.commits.info(i).commitType === CommitType.LOAD))
729  val stCommitVec = VecInit((0 until CommitWidth).map(i => io.commits.commitValid(i) && io.commits.info(i).commitType === CommitType.STORE))
730  io.lsq.lcommit := RegNext(Mux(io.commits.isCommit, PopCount(ldCommitVec), 0.U))
731  io.lsq.scommit := RegNext(Mux(io.commits.isCommit, PopCount(stCommitVec), 0.U))
732  // indicate a pending load or store
733  io.lsq.pendingld := RegNext(io.commits.isCommit && io.commits.info(0).commitType === CommitType.LOAD && valid(deqPtr.value) && mmio(deqPtr.value))
734  io.lsq.pendingst := RegNext(io.commits.isCommit && io.commits.info(0).commitType === CommitType.STORE && valid(deqPtr.value))
735  io.lsq.commit := RegNext(io.commits.isCommit && io.commits.commitValid(0))
736  io.lsq.pendingPtr := RegNext(deqPtr)
737
738  /**
739    * state changes
740    * (1) redirect: switch to s_walk
741    * (2) walk: when walking comes to the end, switch to s_idle
742    */
743  val state_next = Mux(io.redirect.valid, s_walk, Mux(state === s_walk && walkFinished, s_idle, state))
744  XSPerfAccumulate("s_idle_to_idle",            state === s_idle && state_next === s_idle)
745  XSPerfAccumulate("s_idle_to_walk",            state === s_idle && state_next === s_walk)
746  XSPerfAccumulate("s_walk_to_idle",            state === s_walk && state_next === s_idle)
747  XSPerfAccumulate("s_walk_to_walk",            state === s_walk && state_next === s_walk)
748  state := state_next
749
750  /**
751    * pointers and counters
752    */
753  val deqPtrGenModule = Module(new RobDeqPtrWrapper)
754  deqPtrGenModule.io.state := state
755  deqPtrGenModule.io.deq_v := commit_v
756  deqPtrGenModule.io.deq_w := commit_w
757  deqPtrGenModule.io.exception_state := exceptionDataRead
758  deqPtrGenModule.io.intrBitSetReg := intrBitSetReg
759  deqPtrGenModule.io.hasNoSpecExec := hasNoSpecExec
760  deqPtrGenModule.io.interrupt_safe := interrupt_safe(deqPtr.value)
761  deqPtrGenModule.io.blockCommit := blockCommit
762  deqPtrVec := deqPtrGenModule.io.out
763  val deqPtrVec_next = deqPtrGenModule.io.next_out
764
765  val enqPtrGenModule = Module(new RobEnqPtrWrapper)
766  enqPtrGenModule.io.redirect := io.redirect
767  enqPtrGenModule.io.allowEnqueue := allowEnqueue
768  enqPtrGenModule.io.hasBlockBackward := hasBlockBackward
769  enqPtrGenModule.io.enq := VecInit(io.enq.req.map(_.valid))
770  enqPtrVec := enqPtrGenModule.io.out
771
772  val thisCycleWalkCount = Mux(walkFinished, walkCounter, CommitWidth.U)
773  // next walkPtrVec:
774  // (1) redirect occurs: update according to state
775  // (2) walk: move forwards
776  val walkPtrVec_next = Mux(io.redirect.valid,
777    deqPtrVec_next,
778    Mux(state === s_walk, VecInit(walkPtrVec.map(_ + CommitWidth.U)), walkPtrVec)
779  )
780  walkPtrVec := walkPtrVec_next
781
782  val numValidEntries = distanceBetween(enqPtr, deqPtr)
783  val commitCnt = PopCount(io.commits.commitValid)
784
785  allowEnqueue := numValidEntries + dispatchNum <= (RobSize - RenameWidth).U
786
787  val currentWalkPtr = Mux(state === s_walk, walkPtr, deqPtrVec_next(0))
788  val redirectWalkDistance = distanceBetween(io.redirect.bits.robIdx, deqPtrVec_next(0))
789  when (io.redirect.valid) {
790    // full condition:
791    // +& is used here because:
792    // When rob is full and the tail instruction causes a misprediction,
793    // the redirect robIdx is the deqPtr - 1. In this case, redirectWalkDistance
794    // is RobSize - 1.
795    // Since misprediction does not flush the instruction itself, flushItSelf is false.B.
796    // Previously we use `+` to count the walk distance and it causes overflows
797    // when RobSize is power of 2. We change it to `+&` to allow walkCounter to be RobSize.
798    // The width of walkCounter also needs to be changed.
799    // empty condition:
800    // When the last instruction in ROB commits and causes a flush, a redirect
801    // will be raised later. In such circumstances, the redirect robIdx is before
802    // the deqPtrVec_next(0) and will cause underflow.
803    walkCounter := Mux(isBefore(io.redirect.bits.robIdx, deqPtrVec_next(0)), 0.U,
804                       redirectWalkDistance +& !io.redirect.bits.flushItself())
805  }.elsewhen (state === s_walk) {
806    walkCounter := walkCounter - thisCycleWalkCount
807    XSInfo(p"rolling back: $enqPtr $deqPtr walk $walkPtr walkcnt $walkCounter\n")
808  }
809
810
811  /**
812    * States
813    * We put all the stage bits changes here.
814
815    * All events: (1) enqueue (dispatch); (2) writeback; (3) cancel; (4) dequeue (commit);
816    * All states: (1) valid; (2) writebacked; (3) flagBkup
817    */
818  val commitReadAddr = Mux(state === s_idle, VecInit(deqPtrVec.map(_.value)), VecInit(walkPtrVec.map(_.value)))
819
820  // redirect logic writes 6 valid
821  val redirectHeadVec = Reg(Vec(RenameWidth, new RobPtr))
822  val redirectTail = Reg(new RobPtr)
823  val redirectIdle :: redirectBusy :: Nil = Enum(2)
824  val redirectState = RegInit(redirectIdle)
825  val invMask = redirectHeadVec.map(redirectHead => isBefore(redirectHead, redirectTail))
826  when(redirectState === redirectBusy) {
827    redirectHeadVec.foreach(redirectHead => redirectHead := redirectHead + RenameWidth.U)
828    redirectHeadVec zip invMask foreach {
829      case (redirectHead, inv) => when(inv) {
830        valid(redirectHead.value) := false.B
831      }
832    }
833    when(!invMask.last) {
834      redirectState := redirectIdle
835    }
836  }
837  when(io.redirect.valid) {
838    redirectState := redirectBusy
839    when(redirectState === redirectIdle) {
840      redirectTail := enqPtr
841    }
842    redirectHeadVec.zipWithIndex.foreach { case (redirectHead, i) =>
843      redirectHead := Mux(io.redirect.bits.flushItself(), io.redirect.bits.robIdx + i.U, io.redirect.bits.robIdx + (i + 1).U)
844    }
845  }
846  // enqueue logic writes 6 valid
847  for (i <- 0 until RenameWidth) {
848    when (canEnqueue(i) && !io.redirect.valid) {
849      valid(allocatePtrVec(i).value) := true.B
850    }
851  }
852  // dequeue logic writes 6 valid
853  for (i <- 0 until CommitWidth) {
854    val commitValid = io.commits.isCommit && io.commits.commitValid(i)
855    when (commitValid) {
856      valid(commitReadAddr(i)) := false.B
857    }
858  }
859
860  // debug_inst update
861  for(i <- 0 until (exuParameters.LduCnt + exuParameters.StuCnt)) {
862    debug_lsInfo(io.debug_ls.debugLsInfo(i).s1_robIdx).s1SignalEnable(io.debug_ls.debugLsInfo(i))
863    debug_lsInfo(io.debug_ls.debugLsInfo(i).s2_robIdx).s2SignalEnable(io.debug_ls.debugLsInfo(i))
864  }
865
866  // status field: writebacked
867  // enqueue logic set 6 writebacked to false
868  for (i <- 0 until RenameWidth) {
869    when (canEnqueue(i)) {
870      val enqHasException = ExceptionNO.selectFrontend(io.enq.req(i).bits.cf.exceptionVec).asUInt.orR
871      val enqHasTriggerHit = io.enq.req(i).bits.cf.trigger.getHitFrontend
872      val enqIsWritebacked = io.enq.req(i).bits.eliminatedMove
873      writebacked(allocatePtrVec(i).value) := enqIsWritebacked && !enqHasException && !enqHasTriggerHit
874      val isStu = io.enq.req(i).bits.ctrl.fuType === FuType.stu
875      store_data_writebacked(allocatePtrVec(i).value) := !isStu
876    }
877  }
878  when (exceptionGen.io.out.valid) {
879    val wbIdx = exceptionGen.io.out.bits.robIdx.value
880    writebacked(wbIdx) := true.B
881    store_data_writebacked(wbIdx) := true.B
882  }
883  // writeback logic set numWbPorts writebacked to true
884  for ((wb, cfgs) <- exuWriteback.zip(wbExuConfigs(exeWbSel))) {
885    when (wb.valid) {
886      val wbIdx = wb.bits.uop.robIdx.value
887      val wbHasException = ExceptionNO.selectByExu(wb.bits.uop.cf.exceptionVec, cfgs).asUInt.orR
888      val wbHasTriggerHit = wb.bits.uop.cf.trigger.getHitBackend
889      val wbHasFlushPipe = cfgs.exists(_.flushPipe).B && wb.bits.uop.ctrl.flushPipe
890      val wbHasReplayInst = cfgs.exists(_.replayInst).B && wb.bits.uop.ctrl.replayInst
891      val block_wb = wbHasException || wbHasFlushPipe || wbHasReplayInst || wbHasTriggerHit
892      writebacked(wbIdx) := !block_wb
893    }
894  }
895  // store data writeback logic mark store as data_writebacked
896  for (wb <- stdWriteback) {
897    when(RegNext(wb.valid)) {
898      store_data_writebacked(RegNext(wb.bits.uop.robIdx.value)) := true.B
899    }
900  }
901
902  // flagBkup
903  // enqueue logic set 6 flagBkup at most
904  for (i <- 0 until RenameWidth) {
905    when (canEnqueue(i)) {
906      flagBkup(allocatePtrVec(i).value) := allocatePtrVec(i).flag
907    }
908  }
909
910  // interrupt_safe
911  for (i <- 0 until RenameWidth) {
912    // We RegNext the updates for better timing.
913    // Note that instructions won't change the system's states in this cycle.
914    when (RegNext(canEnqueue(i))) {
915      // For now, we allow non-load-store instructions to trigger interrupts
916      // For MMIO instructions, they should not trigger interrupts since they may
917      // be sent to lower level before it writes back.
918      // However, we cannot determine whether a load/store instruction is MMIO.
919      // Thus, we don't allow load/store instructions to trigger an interrupt.
920      // TODO: support non-MMIO load-store instructions to trigger interrupts
921      val allow_interrupts = !CommitType.isLoadStore(io.enq.req(i).bits.ctrl.commitType)
922      interrupt_safe(RegNext(allocatePtrVec(i).value)) := RegNext(allow_interrupts)
923    }
924  }
925
926  /**
927    * read and write of data modules
928    */
929  val commitReadAddr_next = Mux(state_next === s_idle,
930    VecInit(deqPtrVec_next.map(_.value)),
931    VecInit(walkPtrVec_next.map(_.value))
932  )
933  // NOTE: dispatch info will record the uop of inst
934  dispatchData.io.wen := canEnqueue
935  dispatchData.io.waddr := allocatePtrVec.map(_.value)
936  dispatchData.io.wdata.zip(io.enq.req.map(_.bits)).foreach{ case (wdata, req) =>
937    wdata.ldest := req.ctrl.ldest
938    wdata.rfWen := req.ctrl.rfWen
939    wdata.fpWen := req.ctrl.fpWen
940    wdata.wflags := req.ctrl.fpu.wflags
941    wdata.commitType := req.ctrl.commitType
942    wdata.pdest := req.pdest
943    wdata.old_pdest := req.old_pdest
944    wdata.ftqIdx := req.cf.ftqPtr
945    wdata.ftqOffset := req.cf.ftqOffset
946    wdata.isMove := req.eliminatedMove
947    wdata.pc := req.cf.pc
948  }
949  dispatchData.io.raddr := commitReadAddr_next
950
951  exceptionGen.io.redirect <> io.redirect
952  exceptionGen.io.flush := io.flushOut.valid
953  for (i <- 0 until RenameWidth) {
954    exceptionGen.io.enq(i).valid := canEnqueue(i)
955    exceptionGen.io.enq(i).bits.robIdx := io.enq.req(i).bits.robIdx
956    exceptionGen.io.enq(i).bits.exceptionVec := ExceptionNO.selectFrontend(io.enq.req(i).bits.cf.exceptionVec)
957    exceptionGen.io.enq(i).bits.flushPipe := io.enq.req(i).bits.ctrl.flushPipe
958    exceptionGen.io.enq(i).bits.replayInst := false.B
959    XSError(canEnqueue(i) && io.enq.req(i).bits.ctrl.replayInst, "enq should not set replayInst")
960    exceptionGen.io.enq(i).bits.singleStep := io.enq.req(i).bits.ctrl.singleStep
961    exceptionGen.io.enq(i).bits.crossPageIPFFix := io.enq.req(i).bits.cf.crossPageIPFFix
962    exceptionGen.io.enq(i).bits.trigger.clear()
963    exceptionGen.io.enq(i).bits.trigger.frontendHit := io.enq.req(i).bits.cf.trigger.frontendHit
964  }
965
966  println(s"ExceptionGen:")
967  val exceptionCases = exceptionPorts.map(_._1.flatMap(_.exceptionOut).distinct.sorted)
968  require(exceptionCases.length == exceptionGen.io.wb.length)
969  for ((((configs, wb), exc_wb), i) <- exceptionPorts.zip(exceptionGen.io.wb).zipWithIndex) {
970    exc_wb.valid                := wb.valid
971    exc_wb.bits.robIdx          := wb.bits.uop.robIdx
972    exc_wb.bits.exceptionVec    := ExceptionNO.selectByExu(wb.bits.uop.cf.exceptionVec, configs)
973    exc_wb.bits.flushPipe       := configs.exists(_.flushPipe).B && wb.bits.uop.ctrl.flushPipe
974    exc_wb.bits.replayInst      := configs.exists(_.replayInst).B && wb.bits.uop.ctrl.replayInst
975    exc_wb.bits.singleStep      := false.B
976    exc_wb.bits.crossPageIPFFix := false.B
977    // TODO: make trigger configurable
978    exc_wb.bits.trigger.clear()
979    exc_wb.bits.trigger.backendHit := wb.bits.uop.cf.trigger.backendHit
980    println(s"  [$i] ${configs.map(_.name)}: exception ${exceptionCases(i)}, " +
981      s"flushPipe ${configs.exists(_.flushPipe)}, " +
982      s"replayInst ${configs.exists(_.replayInst)}")
983  }
984
985  val fflags_wb = fflagsPorts.map(_._2)
986  val fflagsDataModule = Module(new SyncDataModuleTemplate(
987    UInt(5.W), RobSize, CommitWidth, fflags_wb.size)
988  )
989  for(i <- fflags_wb.indices){
990    fflagsDataModule.io.wen  (i) := fflags_wb(i).valid
991    fflagsDataModule.io.waddr(i) := fflags_wb(i).bits.uop.robIdx.value
992    fflagsDataModule.io.wdata(i) := fflags_wb(i).bits.fflags
993  }
994  fflagsDataModule.io.raddr := VecInit(deqPtrVec_next.map(_.value))
995  fflagsDataRead := fflagsDataModule.io.rdata
996
997  val instrCntReg = RegInit(0.U(64.W))
998  val fuseCommitCnt = PopCount(io.commits.commitValid.zip(io.commits.info).map{ case (v, i) => RegNext(v && CommitType.isFused(i.commitType)) })
999  val trueCommitCnt = RegNext(commitCnt) +& fuseCommitCnt
1000  val retireCounter = Mux(RegNext(io.commits.isCommit), trueCommitCnt, 0.U)
1001  val instrCnt = instrCntReg + retireCounter
1002  instrCntReg := instrCnt
1003  io.csr.perfinfo.retiredInstr := retireCounter
1004  io.robFull := !allowEnqueue
1005
1006  /**
1007    * debug info
1008    */
1009  XSDebug(p"enqPtr ${enqPtr} deqPtr ${deqPtr}\n")
1010  XSDebug("")
1011  for(i <- 0 until RobSize){
1012    XSDebug(false, !valid(i), "-")
1013    XSDebug(false, valid(i) && writebacked(i), "w")
1014    XSDebug(false, valid(i) && !writebacked(i), "v")
1015  }
1016  XSDebug(false, true.B, "\n")
1017
1018  for(i <- 0 until RobSize) {
1019    if(i % 4 == 0) XSDebug("")
1020    XSDebug(false, true.B, "%x ", debug_microOp(i).cf.pc)
1021    XSDebug(false, !valid(i), "- ")
1022    XSDebug(false, valid(i) && writebacked(i), "w ")
1023    XSDebug(false, valid(i) && !writebacked(i), "v ")
1024    if(i % 4 == 3) XSDebug(false, true.B, "\n")
1025  }
1026
1027  def ifCommit(counter: UInt): UInt = Mux(io.commits.isCommit, counter, 0.U)
1028  def ifCommitReg(counter: UInt): UInt = Mux(RegNext(io.commits.isCommit), counter, 0.U)
1029
1030  val commitDebugExu = deqPtrVec.map(_.value).map(debug_exuDebug(_))
1031  val commitDebugUop = deqPtrVec.map(_.value).map(debug_microOp(_))
1032  val commitDebugLsInfo = deqPtrVec.map(_.value).map(debug_lsInfo(_))
1033  XSPerfAccumulate("clock_cycle", 1.U)
1034  QueuePerf(RobSize, PopCount((0 until RobSize).map(valid(_))), !allowEnqueue)
1035  XSPerfAccumulate("commitUop", ifCommit(commitCnt))
1036  XSPerfAccumulate("commitInstr", ifCommitReg(trueCommitCnt))
1037  val commitIsMove = commitDebugUop.map(_.ctrl.isMove)
1038  XSPerfAccumulate("commitInstrMove", ifCommit(PopCount(io.commits.commitValid.zip(commitIsMove).map{ case (v, m) => v && m })))
1039  val commitMoveElim = commitDebugUop.map(_.debugInfo.eliminatedMove)
1040  XSPerfAccumulate("commitInstrMoveElim", ifCommit(PopCount(io.commits.commitValid zip commitMoveElim map { case (v, e) => v && e })))
1041  XSPerfAccumulate("commitInstrFused", ifCommitReg(fuseCommitCnt))
1042  val commitIsLoad = io.commits.info.map(_.commitType).map(_ === CommitType.LOAD)
1043  val commitLoadValid = io.commits.commitValid.zip(commitIsLoad).map{ case (v, t) => v && t }
1044  XSPerfAccumulate("commitInstrLoad", ifCommit(PopCount(commitLoadValid)))
1045  val commitIsBranch = io.commits.info.map(_.commitType).map(_ === CommitType.BRANCH)
1046  val commitBranchValid = io.commits.commitValid.zip(commitIsBranch).map{ case (v, t) => v && t }
1047  XSPerfAccumulate("commitInstrBranch", ifCommit(PopCount(commitBranchValid)))
1048  val commitLoadWaitBit = commitDebugUop.map(_.cf.loadWaitBit)
1049  XSPerfAccumulate("commitInstrLoadWait", ifCommit(PopCount(commitLoadValid.zip(commitLoadWaitBit).map{ case (v, w) => v && w })))
1050  val commitIsStore = io.commits.info.map(_.commitType).map(_ === CommitType.STORE)
1051  XSPerfAccumulate("commitInstrStore", ifCommit(PopCount(io.commits.commitValid.zip(commitIsStore).map{ case (v, t) => v && t })))
1052  XSPerfAccumulate("writeback", PopCount((0 until RobSize).map(i => valid(i) && writebacked(i))))
1053  // XSPerfAccumulate("enqInstr", PopCount(io.dp1Req.map(_.fire)))
1054  // XSPerfAccumulate("d2rVnR", PopCount(io.dp1Req.map(p => p.valid && !p.ready)))
1055  XSPerfAccumulate("walkInstr", Mux(io.commits.isWalk, PopCount(io.commits.walkValid), 0.U))
1056  XSPerfAccumulate("walkCycle", state === s_walk)
1057  val deqNotWritebacked = valid(deqPtr.value) && !writebacked(deqPtr.value)
1058  val deqUopCommitType = io.commits.info(0).commitType
1059  XSPerfAccumulate("waitNormalCycle", deqNotWritebacked && deqUopCommitType === CommitType.NORMAL)
1060  XSPerfAccumulate("waitBranchCycle", deqNotWritebacked && deqUopCommitType === CommitType.BRANCH)
1061  XSPerfAccumulate("waitLoadCycle", deqNotWritebacked && deqUopCommitType === CommitType.LOAD)
1062  XSPerfAccumulate("waitStoreCycle", deqNotWritebacked && deqUopCommitType === CommitType.STORE)
1063  XSPerfAccumulate("robHeadPC", io.commits.info(0).pc)
1064  val dispatchLatency = commitDebugUop.map(uop => uop.debugInfo.dispatchTime - uop.debugInfo.renameTime)
1065  val enqRsLatency = commitDebugUop.map(uop => uop.debugInfo.enqRsTime - uop.debugInfo.dispatchTime)
1066  val selectLatency = commitDebugUop.map(uop => uop.debugInfo.selectTime - uop.debugInfo.enqRsTime)
1067  val issueLatency = commitDebugUop.map(uop => uop.debugInfo.issueTime - uop.debugInfo.selectTime)
1068  val executeLatency = commitDebugUop.map(uop => uop.debugInfo.writebackTime - uop.debugInfo.issueTime)
1069  val rsFuLatency = commitDebugUop.map(uop => uop.debugInfo.writebackTime - uop.debugInfo.enqRsTime)
1070  val commitLatency = commitDebugUop.map(uop => timer - uop.debugInfo.writebackTime)
1071  val accessLatency = commitDebugUop.map(uop => uop.debugInfo.writebackTime - uop.debugInfo.issueTime)
1072  val tlbLatency = commitDebugUop.map(uop => uop.debugInfo.tlbRespTime - uop.debugInfo.tlbFirstReqTime)
1073  def latencySum(cond: Seq[Bool], latency: Seq[UInt]): UInt = {
1074    cond.zip(latency).map(x => Mux(x._1, x._2, 0.U)).reduce(_ +& _)
1075  }
1076  for (fuType <- FuType.functionNameMap.keys) {
1077    val fuName = FuType.functionNameMap(fuType)
1078    val commitIsFuType = io.commits.commitValid.zip(commitDebugUop).map(x => x._1 && x._2.ctrl.fuType === fuType.U )
1079    XSPerfAccumulate(s"${fuName}_instr_cnt", ifCommit(PopCount(commitIsFuType)))
1080    XSPerfAccumulate(s"${fuName}_latency_dispatch", ifCommit(latencySum(commitIsFuType, dispatchLatency)))
1081    XSPerfAccumulate(s"${fuName}_latency_enq_rs", ifCommit(latencySum(commitIsFuType, enqRsLatency)))
1082    XSPerfAccumulate(s"${fuName}_latency_select", ifCommit(latencySum(commitIsFuType, selectLatency)))
1083    XSPerfAccumulate(s"${fuName}_latency_issue", ifCommit(latencySum(commitIsFuType, issueLatency)))
1084    XSPerfAccumulate(s"${fuName}_latency_execute", ifCommit(latencySum(commitIsFuType, executeLatency)))
1085    XSPerfAccumulate(s"${fuName}_latency_enq_rs_execute", ifCommit(latencySum(commitIsFuType, rsFuLatency)))
1086    XSPerfAccumulate(s"${fuName}_latency_commit", ifCommit(latencySum(commitIsFuType, commitLatency)))
1087    if (fuType == FuType.fmac.litValue) {
1088      val commitIsFma = commitIsFuType.zip(commitDebugUop).map(x => x._1 && x._2.ctrl.fpu.ren3 )
1089      XSPerfAccumulate(s"${fuName}_instr_cnt_fma", ifCommit(PopCount(commitIsFma)))
1090      XSPerfAccumulate(s"${fuName}_latency_enq_rs_execute_fma", ifCommit(latencySum(commitIsFma, rsFuLatency)))
1091      XSPerfAccumulate(s"${fuName}_latency_execute_fma", ifCommit(latencySum(commitIsFma, executeLatency)))
1092    }
1093  }
1094
1095  if (env.EnableTopDown) {
1096    ExcitingUtils.addSource(commit_v(0) && !commit_w(0) && state =/= s_walk && io.commits.info(0).commitType === CommitType.LOAD,
1097                            "rob_first_load", ExcitingUtils.Perf)
1098    ExcitingUtils.addSource(commit_v(0) && !commit_w(0) && state =/= s_walk && io.commits.info(0).commitType === CommitType.STORE,
1099                            "rob_first_store", ExcitingUtils.Perf)
1100  }
1101
1102  /**
1103    * DataBase info:
1104    * log trigger is at writeback valid
1105    * */
1106  if(!env.FPGAPlatform){
1107    val isWriteInstInfoTable = WireInit(Constantin.createRecord("isWriteInstInfoTable" + p(XSCoreParamsKey).HartId.toString))
1108    val instTableName = "InstTable" + p(XSCoreParamsKey).HartId.toString
1109    val instSiteName = "Rob" + p(XSCoreParamsKey).HartId.toString
1110    val debug_instTable = ChiselDB.createTable(instTableName, new InstInfoEntry)
1111    // FIXME lyq: only get inst (alu, bj, ls) in exuWriteback
1112    for (wb <- exuWriteback) {
1113      when(wb.valid) {
1114        val debug_instData = Wire(new InstInfoEntry)
1115        val idx = wb.bits.uop.robIdx.value
1116        debug_instData.globalID := wb.bits.uop.ctrl.debug_globalID
1117        debug_instData.robIdx := idx
1118        debug_instData.instType := wb.bits.uop.ctrl.fuType
1119        debug_instData.ivaddr := wb.bits.uop.cf.pc
1120        debug_instData.dvaddr := wb.bits.debug.vaddr
1121        debug_instData.dpaddr := wb.bits.debug.paddr
1122        debug_instData.tlbLatency := wb.bits.uop.debugInfo.tlbRespTime - wb.bits.uop.debugInfo.tlbFirstReqTime
1123        debug_instData.accessLatency := wb.bits.uop.debugInfo.writebackTime - wb.bits.uop.debugInfo.issueTime
1124        debug_instData.executeLatency := wb.bits.uop.debugInfo.writebackTime - wb.bits.uop.debugInfo.issueTime
1125        debug_instData.issueLatency := wb.bits.uop.debugInfo.issueTime - wb.bits.uop.debugInfo.selectTime
1126        debug_instData.exceptType := Cat(wb.bits.uop.cf.exceptionVec)
1127        debug_instData.lsInfo := debug_lsInfo(idx)
1128        debug_instData.mdpInfo.ssid := wb.bits.uop.cf.ssid
1129        debug_instData.mdpInfo.waitAllStore := wb.bits.uop.cf.loadWaitStrict && wb.bits.uop.cf.loadWaitBit
1130        debug_instData.issueTime := wb.bits.uop.debugInfo.issueTime
1131        debug_instData.writebackTime := wb.bits.uop.debugInfo.writebackTime
1132        debug_instTable.log(
1133          data = debug_instData,
1134          en = wb.valid,
1135          site = instSiteName,
1136          clock = clock,
1137          reset = reset
1138        )
1139      }
1140    }
1141  }
1142
1143
1144  //difftest signals
1145  val firstValidCommit = (deqPtr + PriorityMux(io.commits.commitValid, VecInit(List.tabulate(CommitWidth)(_.U(log2Up(CommitWidth).W))))).value
1146
1147  val wdata = Wire(Vec(CommitWidth, UInt(XLEN.W)))
1148  val wpc = Wire(Vec(CommitWidth, UInt(XLEN.W)))
1149
1150  for(i <- 0 until CommitWidth) {
1151    val idx = deqPtrVec(i).value
1152    wdata(i) := debug_exuData(idx)
1153    wpc(i) := SignExt(commitDebugUop(i).cf.pc, XLEN)
1154  }
1155
1156  if (env.EnableDifftest) {
1157    for (i <- 0 until CommitWidth) {
1158      val difftest = Module(new DifftestInstrCommit)
1159      // assgin default value
1160      difftest.io := DontCare
1161
1162      difftest.io.clock    := clock
1163      difftest.io.coreid   := io.hartId
1164      difftest.io.index    := i.U
1165
1166      val ptr = deqPtrVec(i).value
1167      val uop = commitDebugUop(i)
1168      val exuOut = debug_exuDebug(ptr)
1169      val exuData = debug_exuData(ptr)
1170      difftest.io.valid    := RegNext(RegNext(RegNext(io.commits.commitValid(i) && io.commits.isCommit)))
1171      difftest.io.pc       := RegNext(RegNext(RegNext(SignExt(uop.cf.pc, XLEN))))
1172      difftest.io.instr    := RegNext(RegNext(RegNext(uop.cf.instr)))
1173      difftest.io.robIdx   := RegNext(RegNext(RegNext(ZeroExt(ptr, 10))))
1174      difftest.io.lqIdx    := RegNext(RegNext(RegNext(ZeroExt(uop.lqIdx.value, 7))))
1175      difftest.io.sqIdx    := RegNext(RegNext(RegNext(ZeroExt(uop.sqIdx.value, 7))))
1176      difftest.io.isLoad   := RegNext(RegNext(RegNext(io.commits.info(i).commitType === CommitType.LOAD)))
1177      difftest.io.isStore  := RegNext(RegNext(RegNext(io.commits.info(i).commitType === CommitType.STORE)))
1178      difftest.io.special  := RegNext(RegNext(RegNext(CommitType.isFused(io.commits.info(i).commitType))))
1179      // when committing an eliminated move instruction,
1180      // we must make sure that skip is properly set to false (output from EXU is random value)
1181      difftest.io.skip     := RegNext(RegNext(RegNext(Mux(uop.eliminatedMove, false.B, exuOut.isMMIO || exuOut.isPerfCnt))))
1182      difftest.io.isRVC    := RegNext(RegNext(RegNext(uop.cf.pd.isRVC)))
1183      difftest.io.rfwen    := RegNext(RegNext(RegNext(io.commits.commitValid(i) && io.commits.info(i).rfWen && io.commits.info(i).ldest =/= 0.U)))
1184      difftest.io.fpwen    := RegNext(RegNext(RegNext(io.commits.commitValid(i) && io.commits.info(i).fpWen)))
1185      difftest.io.wpdest   := RegNext(RegNext(RegNext(io.commits.info(i).pdest)))
1186      difftest.io.wdest    := RegNext(RegNext(RegNext(io.commits.info(i).ldest)))
1187
1188      // // runahead commit hint
1189      // val runahead_commit = Module(new DifftestRunaheadCommitEvent)
1190      // runahead_commit.io.clock := clock
1191      // runahead_commit.io.coreid := io.hartId
1192      // runahead_commit.io.index := i.U
1193      // runahead_commit.io.valid := difftest.io.valid &&
1194      //   (commitBranchValid(i) || commitIsStore(i))
1195      // // TODO: is branch or store
1196      // runahead_commit.io.pc    := difftest.io.pc
1197    }
1198  }
1199  else if (env.AlwaysBasicDiff) {
1200    // These are the structures used by difftest only and should be optimized after synthesis.
1201    val dt_eliminatedMove = Mem(RobSize, Bool())
1202    val dt_isRVC = Mem(RobSize, Bool())
1203    val dt_exuDebug = Reg(Vec(RobSize, new DebugBundle))
1204    for (i <- 0 until RenameWidth) {
1205      when (canEnqueue(i)) {
1206        dt_eliminatedMove(allocatePtrVec(i).value) := io.enq.req(i).bits.eliminatedMove
1207        dt_isRVC(allocatePtrVec(i).value) := io.enq.req(i).bits.cf.pd.isRVC
1208      }
1209    }
1210    for (wb <- exuWriteback) {
1211      when (wb.valid) {
1212        val wbIdx = wb.bits.uop.robIdx.value
1213        dt_exuDebug(wbIdx) := wb.bits.debug
1214      }
1215    }
1216    // Always instantiate basic difftest modules.
1217    for (i <- 0 until CommitWidth) {
1218      val commitInfo = io.commits.info(i)
1219      val ptr = deqPtrVec(i).value
1220      val exuOut = dt_exuDebug(ptr)
1221      val eliminatedMove = dt_eliminatedMove(ptr)
1222      val isRVC = dt_isRVC(ptr)
1223
1224      val difftest = Module(new DifftestBasicInstrCommit)
1225      difftest.io.clock   := clock
1226      difftest.io.coreid  := io.hartId
1227      difftest.io.index   := i.U
1228      difftest.io.valid   := RegNext(RegNext(RegNext(io.commits.commitValid(i) && io.commits.isCommit)))
1229      difftest.io.special := RegNext(RegNext(RegNext(CommitType.isFused(commitInfo.commitType))))
1230      difftest.io.skip    := RegNext(RegNext(RegNext(Mux(eliminatedMove, false.B, exuOut.isMMIO || exuOut.isPerfCnt))))
1231      difftest.io.isRVC   := RegNext(RegNext(RegNext(isRVC)))
1232      difftest.io.rfwen   := RegNext(RegNext(RegNext(io.commits.commitValid(i) && commitInfo.rfWen && commitInfo.ldest =/= 0.U)))
1233      difftest.io.fpwen   := RegNext(RegNext(RegNext(io.commits.commitValid(i) && commitInfo.fpWen)))
1234      difftest.io.wpdest  := RegNext(RegNext(RegNext(commitInfo.pdest)))
1235      difftest.io.wdest   := RegNext(RegNext(RegNext(commitInfo.ldest)))
1236    }
1237  }
1238
1239  if (env.EnableDifftest) {
1240    for (i <- 0 until CommitWidth) {
1241      val difftest = Module(new DifftestLoadEvent)
1242      difftest.io.clock  := clock
1243      difftest.io.coreid := io.hartId
1244      difftest.io.index  := i.U
1245
1246      val ptr = deqPtrVec(i).value
1247      val uop = commitDebugUop(i)
1248      val exuOut = debug_exuDebug(ptr)
1249      difftest.io.valid  := RegNext(RegNext(RegNext(io.commits.commitValid(i) && io.commits.isCommit)))
1250      difftest.io.paddr  := RegNext(RegNext(RegNext(exuOut.paddr)))
1251      difftest.io.opType := RegNext(RegNext(RegNext(uop.ctrl.fuOpType)))
1252      difftest.io.fuType := RegNext(RegNext(RegNext(uop.ctrl.fuType)))
1253    }
1254  }
1255
1256  // Always instantiate basic difftest modules.
1257  if (env.EnableDifftest) {
1258    val dt_isXSTrap = Mem(RobSize, Bool())
1259    for (i <- 0 until RenameWidth) {
1260      when (canEnqueue(i)) {
1261        dt_isXSTrap(allocatePtrVec(i).value) := io.enq.req(i).bits.ctrl.isXSTrap
1262      }
1263    }
1264    val trapVec = io.commits.commitValid.zip(deqPtrVec).map{ case (v, d) => io.commits.isCommit && v && dt_isXSTrap(d.value) }
1265    val hitTrap = trapVec.reduce(_||_)
1266    val trapCode = PriorityMux(wdata.zip(trapVec).map(x => x._2 -> x._1))
1267    val trapPC = SignExt(PriorityMux(wpc.zip(trapVec).map(x => x._2 ->x._1)), XLEN)
1268    val difftest = Module(new DifftestTrapEvent)
1269    difftest.io.clock    := clock
1270    difftest.io.coreid   := io.hartId
1271    difftest.io.valid    := hitTrap
1272    difftest.io.code     := trapCode
1273    difftest.io.pc       := trapPC
1274    difftest.io.cycleCnt := timer
1275    difftest.io.instrCnt := instrCnt
1276    difftest.io.hasWFI   := hasWFI
1277  }
1278  else if (env.AlwaysBasicDiff) {
1279    val dt_isXSTrap = Mem(RobSize, Bool())
1280    for (i <- 0 until RenameWidth) {
1281      when (canEnqueue(i)) {
1282        dt_isXSTrap(allocatePtrVec(i).value) := io.enq.req(i).bits.ctrl.isXSTrap
1283      }
1284    }
1285    val trapVec = io.commits.commitValid.zip(deqPtrVec).map{ case (v, d) => io.commits.isCommit && v && dt_isXSTrap(d.value) }
1286    val hitTrap = trapVec.reduce(_||_)
1287    val difftest = Module(new DifftestBasicTrapEvent)
1288    difftest.io.clock    := clock
1289    difftest.io.coreid   := io.hartId
1290    difftest.io.valid    := hitTrap
1291    difftest.io.cycleCnt := timer
1292    difftest.io.instrCnt := instrCnt
1293  }
1294
1295  val validEntriesBanks = (0 until (RobSize + 63) / 64).map(i => RegNext(PopCount(valid.drop(i * 64).take(64))))
1296  val validEntries = RegNext(ParallelOperation(validEntriesBanks, (a: UInt, b: UInt) => a +& b))
1297  val commitMoveVec = VecInit(io.commits.commitValid.zip(commitIsMove).map{ case (v, m) => v && m })
1298  val commitLoadVec = VecInit(commitLoadValid)
1299  val commitBranchVec = VecInit(commitBranchValid)
1300  val commitLoadWaitVec = VecInit(commitLoadValid.zip(commitLoadWaitBit).map{ case (v, w) => v && w })
1301  val commitStoreVec = VecInit(io.commits.commitValid.zip(commitIsStore).map{ case (v, t) => v && t })
1302  val perfEvents = Seq(
1303    ("rob_interrupt_num      ", io.flushOut.valid && intrEnable                                       ),
1304    ("rob_exception_num      ", io.flushOut.valid && exceptionEnable                                  ),
1305    ("rob_flush_pipe_num     ", io.flushOut.valid && isFlushPipe                                      ),
1306    ("rob_replay_inst_num    ", io.flushOut.valid && isFlushPipe && deqHasReplayInst                  ),
1307    ("rob_commitUop          ", ifCommit(commitCnt)                                                   ),
1308    ("rob_commitInstr        ", ifCommitReg(trueCommitCnt)                                            ),
1309    ("rob_commitInstrMove    ", ifCommitReg(PopCount(RegNext(commitMoveVec)))                         ),
1310    ("rob_commitInstrFused   ", ifCommitReg(fuseCommitCnt)                                            ),
1311    ("rob_commitInstrLoad    ", ifCommitReg(PopCount(RegNext(commitLoadVec)))                         ),
1312    ("rob_commitInstrBranch  ", ifCommitReg(PopCount(RegNext(commitBranchVec)))                       ),
1313    ("rob_commitInstrLoadWait", ifCommitReg(PopCount(RegNext(commitLoadWaitVec)))                     ),
1314    ("rob_commitInstrStore   ", ifCommitReg(PopCount(RegNext(commitStoreVec)))                        ),
1315    ("rob_walkInstr          ", Mux(io.commits.isWalk, PopCount(io.commits.walkValid), 0.U)           ),
1316    ("rob_walkCycle          ", (state === s_walk)                                                    ),
1317    ("rob_1_4_valid          ", validEntries <= (RobSize / 4).U                                       ),
1318    ("rob_2_4_valid          ", validEntries >  (RobSize / 4).U && validEntries <= (RobSize / 2).U    ),
1319    ("rob_3_4_valid          ", validEntries >  (RobSize / 2).U && validEntries <= (RobSize * 3 / 4).U),
1320    ("rob_4_4_valid          ", validEntries >  (RobSize * 3 / 4).U                                   ),
1321  )
1322  generatePerfEvent()
1323}
1324