xref: /XiangShan/src/main/scala/xiangshan/frontend/BPU.scala (revision a72b131f07300a509f1c6a7ef8f2926105bb8443)
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.frontend
18
19import org.chipsalliance.cde.config.Parameters
20import chisel3._
21import chisel3.util._
22import xiangshan._
23import utils._
24import utility._
25
26import scala.math.min
27import xiangshan.backend.decode.ImmUnion
28
29trait HasBPUConst extends HasXSParameter {
30  val MaxMetaBaseLength =  if (!env.FPGAPlatform) 512 else 247 // TODO: Reduce meta length
31  val MaxMetaLength = if (HasHExtension) MaxMetaBaseLength + 4 else MaxMetaBaseLength
32  val MaxBasicBlockSize = 32
33  val LHistoryLength = 32
34  // val numBr = 2
35  val useBPD = true
36  val useLHist = true
37  val numBrSlot = numBr-1
38  val totalSlot = numBrSlot + 1
39
40  val numDup = 4
41
42  def BP_STAGES = (0 until 3).map(_.U(2.W))
43  def BP_S1 = BP_STAGES(0)
44  def BP_S2 = BP_STAGES(1)
45  def BP_S3 = BP_STAGES(2)
46
47  def dup_seq[T](src: T, num: Int = numDup) = Seq.tabulate(num)(n => src)
48  def dup[T <: Data](src: T, num: Int = numDup) = VecInit(Seq.tabulate(num)(n => src))
49  def dup_wire[T <: Data](src: T, num: Int = numDup) = Wire(Vec(num, src.cloneType))
50  def dup_idx = Seq.tabulate(numDup)(n => n.toString())
51  val numBpStages = BP_STAGES.length
52
53  val debug = true
54  // TODO: Replace log2Up by log2Ceil
55}
56
57trait HasBPUParameter extends HasXSParameter with HasBPUConst {
58  val BPUDebug = true && !env.FPGAPlatform && env.EnablePerfDebug
59  val EnableCFICommitLog = true
60  val EnbaleCFIPredLog = true
61  val EnableBPUTimeRecord = (EnableCFICommitLog || EnbaleCFIPredLog) && !env.FPGAPlatform
62  val EnableCommit = false
63}
64
65class BPUCtrl(implicit p: Parameters) extends XSBundle {
66  val ubtb_enable = Bool()
67  val btb_enable  = Bool()
68  val bim_enable  = Bool()
69  val tage_enable = Bool()
70  val sc_enable   = Bool()
71  val ras_enable  = Bool()
72  val loop_enable = Bool()
73}
74
75trait BPUUtils extends HasXSParameter {
76  // circular shifting
77  def circularShiftLeft(source: UInt, len: Int, shamt: UInt): UInt = {
78    val res = Wire(UInt(len.W))
79    val higher = source << shamt
80    val lower = source >> (len.U - shamt)
81    res := higher | lower
82    res
83  }
84
85  def circularShiftRight(source: UInt, len: Int, shamt: UInt): UInt = {
86    val res = Wire(UInt(len.W))
87    val higher = source << (len.U - shamt)
88    val lower = source >> shamt
89    res := higher | lower
90    res
91  }
92
93  // To be verified
94  def satUpdate(old: UInt, len: Int, taken: Bool): UInt = {
95    val oldSatTaken = old === ((1 << len)-1).U
96    val oldSatNotTaken = old === 0.U
97    Mux(oldSatTaken && taken, ((1 << len)-1).U,
98      Mux(oldSatNotTaken && !taken, 0.U,
99        Mux(taken, old + 1.U, old - 1.U)))
100  }
101
102  def signedSatUpdate(old: SInt, len: Int, taken: Bool): SInt = {
103    val oldSatTaken = old === ((1 << (len-1))-1).S
104    val oldSatNotTaken = old === (-(1 << (len-1))).S
105    Mux(oldSatTaken && taken, ((1 << (len-1))-1).S,
106      Mux(oldSatNotTaken && !taken, (-(1 << (len-1))).S,
107        Mux(taken, old + 1.S, old - 1.S)))
108  }
109
110  def getFallThroughAddr(start: UInt, carry: Bool, pft: UInt) = {
111    val higher = start.head(VAddrBits-log2Ceil(PredictWidth)-instOffsetBits)
112    Cat(Mux(carry, higher+1.U, higher), pft, 0.U(instOffsetBits.W))
113  }
114
115  def foldTag(tag: UInt, l: Int): UInt = {
116    val nChunks = (tag.getWidth + l - 1) / l
117    val chunks = (0 until nChunks).map { i =>
118      tag(min((i+1)*l, tag.getWidth)-1, i*l)
119    }
120    ParallelXOR(chunks)
121  }
122}
123
124class BasePredictorInput (implicit p: Parameters) extends XSBundle with HasBPUConst {
125  def nInputs = 1
126
127  val s0_pc = Vec(numDup, UInt(VAddrBits.W))
128
129  val folded_hist = Vec(numDup, new AllFoldedHistories(foldedGHistInfos))
130  val ghist = UInt(HistoryLength.W)
131
132  val resp_in = Vec(nInputs, new BranchPredictionResp)
133
134  // val final_preds = Vec(numBpStages, new)
135  // val toFtq_fire = Bool()
136
137  // val s0_all_ready = Bool()
138}
139
140class BasePredictorOutput (implicit p: Parameters) extends BranchPredictionResp {}
141
142class BasePredictorIO (implicit p: Parameters) extends XSBundle with HasBPUConst {
143  val reset_vector = Input(UInt(PAddrBits.W))
144  val in  = Flipped(DecoupledIO(new BasePredictorInput)) // TODO: Remove DecoupledIO
145  // val out = DecoupledIO(new BasePredictorOutput)
146  val out = Output(new BasePredictorOutput)
147  // val flush_out = Valid(UInt(VAddrBits.W))
148
149  val ctrl = Input(new BPUCtrl)
150
151  val s0_fire = Input(Vec(numDup, Bool()))
152  val s1_fire = Input(Vec(numDup, Bool()))
153  val s2_fire = Input(Vec(numDup, Bool()))
154  val s3_fire = Input(Vec(numDup, Bool()))
155
156  val s2_redirect = Input(Vec(numDup, Bool()))
157  val s3_redirect = Input(Vec(numDup, Bool()))
158
159  val s1_ready = Output(Bool())
160  val s2_ready = Output(Bool())
161  val s3_ready = Output(Bool())
162
163  val update = Flipped(Valid(new BranchPredictionUpdate))
164  val redirect = Flipped(Valid(new BranchPredictionRedirect))
165}
166
167abstract class BasePredictor(implicit p: Parameters) extends XSModule
168  with HasBPUConst with BPUUtils with HasPerfEvents {
169  val meta_size = 0
170  val spec_meta_size = 0
171  val is_fast_pred = false
172  val io = IO(new BasePredictorIO())
173
174  io.out := io.in.bits.resp_in(0)
175
176  io.out.last_stage_meta := 0.U
177
178  io.in.ready := !io.redirect.valid
179
180  io.s1_ready := true.B
181  io.s2_ready := true.B
182  io.s3_ready := true.B
183
184  val reset_vector = DelayN(io.reset_vector, 5)
185
186  val s0_pc_dup   = WireInit(io.in.bits.s0_pc) // fetchIdx(io.f0_pc)
187  val s1_pc_dup   = s0_pc_dup.zip(io.s0_fire).map {case (s0_pc, s0_fire) => RegEnable(s0_pc, s0_fire)}
188  val s2_pc_dup   = s1_pc_dup.zip(io.s1_fire).map {case (s1_pc, s1_fire) => RegEnable(s1_pc, s1_fire)}
189  val s3_pc_dup   = s2_pc_dup.zip(io.s2_fire).map {case (s2_pc, s2_fire) => RegEnable(s2_pc, s2_fire)}
190
191  when (RegNext(RegNext(reset.asBool) && !reset.asBool)) {
192    s1_pc_dup.map{case s1_pc => s1_pc := reset_vector}
193  }
194
195  io.out.s1.pc := s1_pc_dup
196  io.out.s2.pc := s2_pc_dup
197  io.out.s3.pc := s3_pc_dup
198
199  val perfEvents: Seq[(String, UInt)] = Seq()
200
201
202  def getFoldedHistoryInfo: Option[Set[FoldedHistoryInfo]] = None
203}
204
205class FakePredictor(implicit p: Parameters) extends BasePredictor {
206  io.in.ready                 := true.B
207  io.out.last_stage_meta      := 0.U
208  io.out := io.in.bits.resp_in(0)
209}
210
211class BpuToFtqIO(implicit p: Parameters) extends XSBundle {
212  val resp = DecoupledIO(new BpuToFtqBundle())
213}
214
215class PredictorIO(implicit p: Parameters) extends XSBundle {
216  val bpu_to_ftq = new BpuToFtqIO()
217  val ftq_to_bpu = Flipped(new FtqToBpuIO)
218  val ctrl = Input(new BPUCtrl)
219  val reset_vector = Input(UInt(PAddrBits.W))
220}
221
222class Predictor(implicit p: Parameters) extends XSModule with HasBPUConst with HasPerfEvents with HasCircularQueuePtrHelper {
223  val io = IO(new PredictorIO)
224
225  val ctrl = DelayN(io.ctrl, 1)
226  val predictors = Module(if (useBPD) new Composer else new FakePredictor)
227
228  def numOfStage = 3
229  require(numOfStage > 1, "BPU numOfStage must be greater than 1")
230  val topdown_stages = RegInit(VecInit(Seq.fill(numOfStage)(0.U.asTypeOf(new FrontendTopDownBundle))))
231
232  // following can only happen on s1
233  val controlRedirectBubble = Wire(Bool())
234  val ControlBTBMissBubble = Wire(Bool())
235  val TAGEMissBubble = Wire(Bool())
236  val SCMissBubble = Wire(Bool())
237  val ITTAGEMissBubble = Wire(Bool())
238  val RASMissBubble = Wire(Bool())
239
240  val memVioRedirectBubble = Wire(Bool())
241  val otherRedirectBubble = Wire(Bool())
242  val btbMissBubble = Wire(Bool())
243  otherRedirectBubble := false.B
244  memVioRedirectBubble := false.B
245
246  // override can happen between s1-s2 and s2-s3
247  val overrideBubble = Wire(Vec(numOfStage - 1, Bool()))
248  def overrideStage = 1
249  // ftq update block can happen on s1, s2 and s3
250  val ftqUpdateBubble = Wire(Vec(numOfStage, Bool()))
251  def ftqUpdateStage = 0
252  // ftq full stall only happens on s3 (last stage)
253  val ftqFullStall = Wire(Bool())
254
255  // by default, no bubble event
256  topdown_stages(0) := 0.U.asTypeOf(new FrontendTopDownBundle)
257  // event movement driven by clock only
258  for (i <- 0 until numOfStage - 1) {
259    topdown_stages(i + 1) := topdown_stages(i)
260  }
261
262
263
264  // ctrl signal
265  predictors.io.ctrl := ctrl
266  predictors.io.reset_vector := io.reset_vector
267
268
269  val reset_vector = DelayN(io.reset_vector, 5)
270
271  val s0_fire_dup, s1_fire_dup, s2_fire_dup, s3_fire_dup = dup_wire(Bool())
272  val s1_valid_dup, s2_valid_dup, s3_valid_dup = dup_seq(RegInit(false.B))
273  val s1_ready_dup, s2_ready_dup, s3_ready_dup = dup_wire(Bool())
274  val s1_components_ready_dup, s2_components_ready_dup, s3_components_ready_dup = dup_wire(Bool())
275
276  val s0_pc_dup = dup(WireInit(0.U.asTypeOf(UInt(VAddrBits.W))))
277  val s0_pc_reg_dup = s0_pc_dup.map(x => RegNext(x))
278  when (RegNext(RegNext(reset.asBool) && !reset.asBool)) {
279    s0_pc_reg_dup.map{case s0_pc => s0_pc := reset_vector}
280  }
281  val s1_pc = RegEnable(s0_pc_dup(0), s0_fire_dup(0))
282  val s2_pc = RegEnable(s1_pc, s1_fire_dup(0))
283  val s3_pc = RegEnable(s2_pc, s2_fire_dup(0))
284
285  val s0_folded_gh_dup = dup_wire(new AllFoldedHistories(foldedGHistInfos))
286  val s0_folded_gh_reg_dup = s0_folded_gh_dup.map(x => RegNext(x, init=0.U.asTypeOf(s0_folded_gh_dup(0))))
287  val s1_folded_gh_dup = RegEnable(s0_folded_gh_dup, 0.U.asTypeOf(s0_folded_gh_dup), s0_fire_dup(1))
288  val s2_folded_gh_dup = RegEnable(s1_folded_gh_dup, 0.U.asTypeOf(s0_folded_gh_dup), s1_fire_dup(1))
289  val s3_folded_gh_dup = RegEnable(s2_folded_gh_dup, 0.U.asTypeOf(s0_folded_gh_dup), s2_fire_dup(1))
290
291  val s0_last_br_num_oh_dup = dup_wire(UInt((numBr+1).W))
292  val s0_last_br_num_oh_reg_dup = s0_last_br_num_oh_dup.map(x => RegNext(x, init=0.U))
293  val s1_last_br_num_oh_dup = RegEnable(s0_last_br_num_oh_dup, 0.U.asTypeOf(s0_last_br_num_oh_dup), s0_fire_dup(1))
294  val s2_last_br_num_oh_dup = RegEnable(s1_last_br_num_oh_dup, 0.U.asTypeOf(s0_last_br_num_oh_dup), s1_fire_dup(1))
295  val s3_last_br_num_oh_dup = RegEnable(s2_last_br_num_oh_dup, 0.U.asTypeOf(s0_last_br_num_oh_dup), s2_fire_dup(1))
296
297  val s0_ahead_fh_oldest_bits_dup = dup_wire(new AllAheadFoldedHistoryOldestBits(foldedGHistInfos))
298  val s0_ahead_fh_oldest_bits_reg_dup = s0_ahead_fh_oldest_bits_dup.map(x => RegNext(x, init=0.U.asTypeOf(s0_ahead_fh_oldest_bits_dup(0))))
299  val s1_ahead_fh_oldest_bits_dup = RegEnable(s0_ahead_fh_oldest_bits_dup, 0.U.asTypeOf(s0_ahead_fh_oldest_bits_dup), s0_fire_dup(1))
300  val s2_ahead_fh_oldest_bits_dup = RegEnable(s1_ahead_fh_oldest_bits_dup, 0.U.asTypeOf(s0_ahead_fh_oldest_bits_dup), s1_fire_dup(1))
301  val s3_ahead_fh_oldest_bits_dup = RegEnable(s2_ahead_fh_oldest_bits_dup, 0.U.asTypeOf(s0_ahead_fh_oldest_bits_dup), s2_fire_dup(1))
302
303  val npcGen_dup         = Seq.tabulate(numDup)(n => new PhyPriorityMuxGenerator[UInt])
304  val foldedGhGen_dup    = Seq.tabulate(numDup)(n => new PhyPriorityMuxGenerator[AllFoldedHistories])
305  val ghistPtrGen_dup    = Seq.tabulate(numDup)(n => new PhyPriorityMuxGenerator[CGHPtr])
306  val lastBrNumOHGen_dup = Seq.tabulate(numDup)(n => new PhyPriorityMuxGenerator[UInt])
307  val aheadFhObGen_dup   = Seq.tabulate(numDup)(n => new PhyPriorityMuxGenerator[AllAheadFoldedHistoryOldestBits])
308
309  val ghvBitWriteGens = Seq.tabulate(HistoryLength)(n => new PhyPriorityMuxGenerator[Bool])
310  // val ghistGen = new PhyPriorityMuxGenerator[UInt]
311
312  val ghv = RegInit(0.U.asTypeOf(Vec(HistoryLength, Bool())))
313  val ghv_wire = WireInit(ghv)
314
315  val s0_ghist = WireInit(0.U.asTypeOf(UInt(HistoryLength.W)))
316
317
318  println(f"history buffer length ${HistoryLength}")
319  val ghv_write_datas = Wire(Vec(HistoryLength, Bool()))
320  val ghv_wens = Wire(Vec(HistoryLength, Bool()))
321
322  val s0_ghist_ptr_dup = dup_wire(new CGHPtr)
323  val s0_ghist_ptr_reg_dup = s0_ghist_ptr_dup.map(x => RegNext(x, init=0.U.asTypeOf(new CGHPtr)))
324  val s1_ghist_ptr_dup = RegEnable(s0_ghist_ptr_dup, 0.U.asTypeOf(s0_ghist_ptr_dup), s0_fire_dup(1))
325  val s2_ghist_ptr_dup = RegEnable(s1_ghist_ptr_dup, 0.U.asTypeOf(s0_ghist_ptr_dup), s1_fire_dup(1))
326  val s3_ghist_ptr_dup = RegEnable(s2_ghist_ptr_dup, 0.U.asTypeOf(s0_ghist_ptr_dup), s2_fire_dup(1))
327
328  def getHist(ptr: CGHPtr): UInt = (Cat(ghv_wire.asUInt, ghv_wire.asUInt) >> (ptr.value+1.U))(HistoryLength-1, 0)
329  s0_ghist := getHist(s0_ghist_ptr_dup(0))
330
331  val resp = predictors.io.out
332
333
334  val toFtq_fire = io.bpu_to_ftq.resp.valid && io.bpu_to_ftq.resp.ready
335
336  val s1_flush_dup, s2_flush_dup, s3_flush_dup = dup_wire(Bool())
337  val s2_redirect_dup, s3_redirect_dup = dup_wire(Bool())
338
339  // predictors.io := DontCare
340  predictors.io.in.valid := s0_fire_dup(0)
341  predictors.io.in.bits.s0_pc := s0_pc_dup
342  predictors.io.in.bits.ghist := s0_ghist
343  predictors.io.in.bits.folded_hist := s0_folded_gh_dup
344  predictors.io.in.bits.resp_in(0) := (0.U).asTypeOf(new BranchPredictionResp)
345  // predictors.io.in.bits.resp_in(0).s1.pc := s0_pc
346  // predictors.io.in.bits.toFtq_fire := toFtq_fire
347
348  // predictors.io.out.ready := io.bpu_to_ftq.resp.ready
349
350  val redirect_req = io.ftq_to_bpu.redirect
351  val do_redirect_dup = dup_seq(RegNextWithEnable(redirect_req))
352
353  // Pipeline logic
354  s2_redirect_dup.map(_ := false.B)
355  s3_redirect_dup.map(_ := false.B)
356
357  s3_flush_dup.map(_ := redirect_req.valid) // flush when redirect comes
358  for (((s2_flush, s3_flush), s3_redirect) <- s2_flush_dup zip s3_flush_dup zip s3_redirect_dup)
359    s2_flush := s3_flush || s3_redirect
360  for (((s1_flush, s2_flush), s2_redirect) <- s1_flush_dup zip s2_flush_dup zip s2_redirect_dup)
361    s1_flush := s2_flush || s2_redirect
362
363
364  s1_components_ready_dup.map(_ := predictors.io.s1_ready)
365  for (((s1_ready, s1_fire), s1_valid) <- s1_ready_dup zip s1_fire_dup zip s1_valid_dup)
366    s1_ready := s1_fire || !s1_valid
367  for (((s0_fire, s1_components_ready), s1_ready) <- s0_fire_dup zip s1_components_ready_dup zip s1_ready_dup)
368    s0_fire := s1_components_ready && s1_ready
369  predictors.io.s0_fire := s0_fire_dup
370
371  s2_components_ready_dup.map(_ := predictors.io.s2_ready)
372  for (((s2_ready, s2_fire), s2_valid) <- s2_ready_dup zip s2_fire_dup zip s2_valid_dup)
373    s2_ready := s2_fire || !s2_valid
374  for ((((s1_fire, s2_components_ready), s2_ready), s1_valid) <- s1_fire_dup zip s2_components_ready_dup zip s2_ready_dup zip s1_valid_dup)
375    s1_fire := s1_valid && s2_components_ready && s2_ready && io.bpu_to_ftq.resp.ready
376
377  s3_components_ready_dup.map(_ := predictors.io.s3_ready)
378  for (((s3_ready, s3_fire), s3_valid) <- s3_ready_dup zip s3_fire_dup zip s3_valid_dup)
379    s3_ready := s3_fire || !s3_valid
380  for ((((s2_fire, s3_components_ready), s3_ready), s2_valid) <- s2_fire_dup zip s3_components_ready_dup zip s3_ready_dup zip s2_valid_dup)
381    s2_fire := s2_valid && s3_components_ready && s3_ready
382
383  for ((((s0_fire, s1_flush), s1_fire), s1_valid) <- s0_fire_dup zip s1_flush_dup zip s1_fire_dup zip s1_valid_dup) {
384    when (redirect_req.valid) { s1_valid := false.B }
385      .elsewhen(s0_fire)      { s1_valid := true.B  }
386      .elsewhen(s1_flush)     { s1_valid := false.B }
387      .elsewhen(s1_fire)      { s1_valid := false.B }
388  }
389  predictors.io.s1_fire := s1_fire_dup
390
391  s2_fire_dup := s2_valid_dup
392
393  for (((((s1_fire, s2_flush), s2_fire), s2_valid), s1_flush) <-
394    s1_fire_dup zip s2_flush_dup zip s2_fire_dup zip s2_valid_dup zip s1_flush_dup) {
395
396    when (s2_flush)      { s2_valid := false.B   }
397      .elsewhen(s1_fire) { s2_valid := !s1_flush }
398      .elsewhen(s2_fire) { s2_valid := false.B   }
399  }
400
401  predictors.io.s2_fire := s2_fire_dup
402  predictors.io.s2_redirect := s2_redirect_dup
403
404  s3_fire_dup := s3_valid_dup
405
406  for (((((s2_fire, s3_flush), s3_fire), s3_valid), s2_flush) <-
407    s2_fire_dup zip s3_flush_dup zip s3_fire_dup zip s3_valid_dup zip s2_flush_dup) {
408
409    when (s3_flush)      { s3_valid := false.B   }
410      .elsewhen(s2_fire) { s3_valid := !s2_flush }
411      .elsewhen(s3_fire) { s3_valid := false.B   }
412  }
413
414  predictors.io.s3_fire := s3_fire_dup
415  predictors.io.s3_redirect := s3_redirect_dup
416
417
418  io.bpu_to_ftq.resp.valid :=
419    s1_valid_dup(2) && s2_components_ready_dup(2) && s2_ready_dup(2) ||
420    s2_fire_dup(2) && s2_redirect_dup(2) ||
421    s3_fire_dup(2) && s3_redirect_dup(2)
422  io.bpu_to_ftq.resp.bits  := predictors.io.out
423  io.bpu_to_ftq.resp.bits.last_stage_spec_info.histPtr     := s3_ghist_ptr_dup(2)
424
425  val full_pred_diff = WireInit(false.B)
426  val full_pred_diff_stage = WireInit(0.U)
427  val full_pred_diff_offset = WireInit(0.U)
428  for (i <- 0 until numDup - 1) {
429    when (io.bpu_to_ftq.resp.valid &&
430      ((io.bpu_to_ftq.resp.bits.s1.full_pred(i).asTypeOf(UInt()) =/= io.bpu_to_ftq.resp.bits.s1.full_pred(i+1).asTypeOf(UInt()) && io.bpu_to_ftq.resp.bits.s1.full_pred(i).hit) ||
431          (io.bpu_to_ftq.resp.bits.s2.full_pred(i).asTypeOf(UInt()) =/= io.bpu_to_ftq.resp.bits.s2.full_pred(i+1).asTypeOf(UInt()) && io.bpu_to_ftq.resp.bits.s2.full_pred(i).hit) ||
432          (io.bpu_to_ftq.resp.bits.s3.full_pred(i).asTypeOf(UInt()) =/= io.bpu_to_ftq.resp.bits.s3.full_pred(i+1).asTypeOf(UInt()) && io.bpu_to_ftq.resp.bits.s3.full_pred(i).hit))) {
433      full_pred_diff := true.B
434      full_pred_diff_offset := i.U
435      when (io.bpu_to_ftq.resp.bits.s1.full_pred(i).asTypeOf(UInt()) =/= io.bpu_to_ftq.resp.bits.s1.full_pred(i+1).asTypeOf(UInt())) {
436        full_pred_diff_stage := 1.U
437      } .elsewhen (io.bpu_to_ftq.resp.bits.s2.full_pred(i).asTypeOf(UInt()) =/= io.bpu_to_ftq.resp.bits.s2.full_pred(i+1).asTypeOf(UInt())) {
438        full_pred_diff_stage := 2.U
439      } .otherwise {
440        full_pred_diff_stage := 3.U
441      }
442    }
443  }
444  XSError(full_pred_diff, "Full prediction difference detected!")
445
446  npcGen_dup.zip(s0_pc_reg_dup).map{ case (gen, reg) =>
447    gen.register(true.B, reg, Some("stallPC"), 0)}
448  foldedGhGen_dup.zip(s0_folded_gh_reg_dup).map{ case (gen, reg) =>
449    gen.register(true.B, reg, Some("stallFGH"), 0)}
450  ghistPtrGen_dup.zip(s0_ghist_ptr_reg_dup).map{ case (gen, reg) =>
451    gen.register(true.B, reg, Some("stallGHPtr"), 0)}
452  lastBrNumOHGen_dup.zip(s0_last_br_num_oh_reg_dup).map{ case (gen, reg) =>
453    gen.register(true.B, reg, Some("stallBrNumOH"), 0)}
454  aheadFhObGen_dup.zip(s0_ahead_fh_oldest_bits_reg_dup).map{ case (gen, reg) =>
455    gen.register(true.B, reg, Some("stallAFHOB"), 0)}
456
457  // assign pred cycle for profiling
458  io.bpu_to_ftq.resp.bits.s1.full_pred.map(_.predCycle.map(_ := GTimer()))
459  io.bpu_to_ftq.resp.bits.s2.full_pred.map(_.predCycle.map(_ := GTimer()))
460  io.bpu_to_ftq.resp.bits.s3.full_pred.map(_.predCycle.map(_ := GTimer()))
461
462
463
464  // History manage
465  // s1
466  val s1_possible_predicted_ghist_ptrs_dup = s1_ghist_ptr_dup.map(ptr => (0 to numBr).map(ptr - _.U))
467  val s1_predicted_ghist_ptr_dup = s1_possible_predicted_ghist_ptrs_dup.zip(resp.s1.lastBrPosOH).map{ case (ptr, oh) => Mux1H(oh, ptr)}
468  val s1_possible_predicted_fhs_dup =
469    for (((((fgh, afh), br_num_oh), t), br_pos_oh) <-
470      s1_folded_gh_dup zip s1_ahead_fh_oldest_bits_dup zip s1_last_br_num_oh_dup zip resp.s1.brTaken zip resp.s1.lastBrPosOH)
471      yield (0 to numBr).map(i =>
472        fgh.update(afh, br_num_oh, i, t & br_pos_oh(i))
473      )
474  val s1_predicted_fh_dup = resp.s1.lastBrPosOH.zip(s1_possible_predicted_fhs_dup).map{ case (oh, fh) => Mux1H(oh, fh)}
475
476  val s1_ahead_fh_ob_src_dup = dup_wire(new AllAheadFoldedHistoryOldestBits(foldedGHistInfos))
477  s1_ahead_fh_ob_src_dup.zip(s1_ghist_ptr_dup).map{ case (src, ptr) => src.read(ghv, ptr)}
478
479  if (EnableGHistDiff) {
480    val s1_predicted_ghist = WireInit(getHist(s1_predicted_ghist_ptr_dup(0)).asTypeOf(Vec(HistoryLength, Bool())))
481    for (i <- 0 until numBr) {
482      when (resp.s1.shouldShiftVec(0)(i)) {
483        s1_predicted_ghist(i) := resp.s1.brTaken(0) && (i==0).B
484      }
485    }
486    when (s1_valid_dup(0)) {
487      s0_ghist := s1_predicted_ghist.asUInt
488    }
489  }
490
491  val s1_ghv_wens = (0 until HistoryLength).map(n =>
492    (0 until numBr).map(b => (s1_ghist_ptr_dup(0)).value === (CGHPtr(false.B, n.U) + b.U).value && resp.s1.shouldShiftVec(0)(b) && s1_valid_dup(0)))
493  val s1_ghv_wdatas = (0 until HistoryLength).map(n =>
494    Mux1H(
495      (0 until numBr).map(b => (
496        (s1_ghist_ptr_dup(0)).value === (CGHPtr(false.B, n.U) + b.U).value && resp.s1.shouldShiftVec(0)(b),
497        resp.s1.brTaken(0) && resp.s1.lastBrPosOH(0)(b+1)
498      ))
499    )
500  )
501
502
503  for (((npcGen, s1_valid), s1_target) <- npcGen_dup zip s1_valid_dup zip resp.s1.getTarget)
504    npcGen.register(s1_valid, s1_target, Some("s1_target"), 4)
505  for (((foldedGhGen, s1_valid), s1_predicted_fh) <- foldedGhGen_dup zip s1_valid_dup zip s1_predicted_fh_dup)
506    foldedGhGen.register(s1_valid, s1_predicted_fh, Some("s1_FGH"), 4)
507  for (((ghistPtrGen, s1_valid), s1_predicted_ghist_ptr) <- ghistPtrGen_dup zip s1_valid_dup zip s1_predicted_ghist_ptr_dup)
508    ghistPtrGen.register(s1_valid, s1_predicted_ghist_ptr, Some("s1_GHPtr"), 4)
509  for (((lastBrNumOHGen, s1_valid), s1_brPosOH) <- lastBrNumOHGen_dup zip s1_valid_dup zip resp.s1.lastBrPosOH.map(_.asUInt))
510    lastBrNumOHGen.register(s1_valid, s1_brPosOH, Some("s1_BrNumOH"), 4)
511  for (((aheadFhObGen, s1_valid), s1_ahead_fh_ob_src) <- aheadFhObGen_dup zip s1_valid_dup zip s1_ahead_fh_ob_src_dup)
512    aheadFhObGen.register(s1_valid, s1_ahead_fh_ob_src, Some("s1_AFHOB"), 4)
513  ghvBitWriteGens.zip(s1_ghv_wens).zipWithIndex.map{case ((b, w), i) =>
514    b.register(w.reduce(_||_), s1_ghv_wdatas(i), Some(s"s1_new_bit_$i"), 4)
515  }
516
517  class PreviousPredInfo extends Bundle {
518    val hit = Vec(numDup, Bool())
519    val target = Vec(numDup, UInt(VAddrBits.W))
520    val lastBrPosOH = Vec(numDup, Vec(numBr+1, Bool()))
521    val taken = Vec(numDup, Bool())
522    val takenMask = Vec(numDup, Vec(numBr, Bool()))
523    val cfiIndex = Vec(numDup, UInt(log2Ceil(PredictWidth).W))
524  }
525
526  def preds_needs_redirect_vec_dup(x: PreviousPredInfo, y: BranchPredictionBundle) = {
527    // Timing optimization
528    // We first compare all target with previous stage target,
529    // then select the difference by taken & hit
530    // Usually target is generated quicker than taken, so do target compare before select can help timing
531    val targetDiffVec: IndexedSeq[Vec[Bool]] =
532      x.target.zip(y.getAllTargets).map {
533        case (xTarget, yAllTarget) => VecInit(yAllTarget.map(_ =/= xTarget))
534      } // [numDup][all Target comparison]
535    val targetDiff   : IndexedSeq[Bool]      =
536      targetDiffVec.zip(x.hit).zip(x.takenMask).map {
537        case ((diff, hit), takenMask) => selectByTaken(takenMask, hit, diff)
538      } // [numDup]
539
540    val lastBrPosOHDiff: IndexedSeq[Bool]      = x.lastBrPosOH.zip(y.lastBrPosOH).map { case (oh1, oh2) => oh1.asUInt =/= oh2.asUInt }
541    val takenDiff      : IndexedSeq[Bool]      = x.taken.zip(y.taken).map { case (t1, t2) => t1 =/= t2 }
542    val takenOffsetDiff: IndexedSeq[Bool]      = x.cfiIndex.zip(y.cfiIndex).zip(x.taken).zip(y.taken).map { case (((i1, i2), xt), yt) => xt && yt && i1 =/= i2.bits }
543    VecInit(
544      for ((((tgtd, lbpohd), tkd), tod) <-
545             targetDiff zip lastBrPosOHDiff zip takenDiff zip takenOffsetDiff)
546      yield VecInit(tgtd, lbpohd, tkd, tod)
547      // x.shouldShiftVec.asUInt =/= y.shouldShiftVec.asUInt,
548      // x.brTaken =/= y.brTaken
549    )
550  }
551
552  // s2
553  val s2_possible_predicted_ghist_ptrs_dup = s2_ghist_ptr_dup.map(ptr => (0 to numBr).map(ptr - _.U))
554  val s2_predicted_ghist_ptr_dup = s2_possible_predicted_ghist_ptrs_dup.zip(resp.s2.lastBrPosOH).map{ case (ptr, oh) => Mux1H(oh, ptr)}
555
556  val s2_possible_predicted_fhs_dup =
557    for ((((fgh, afh), br_num_oh), full_pred) <-
558      s2_folded_gh_dup zip s2_ahead_fh_oldest_bits_dup zip s2_last_br_num_oh_dup zip resp.s2.full_pred)
559      yield (0 to numBr).map(i =>
560        fgh.update(afh, br_num_oh, i, if (i > 0) full_pred.br_taken_mask(i-1) else false.B)
561      )
562  val s2_predicted_fh_dup = resp.s2.lastBrPosOH.zip(s2_possible_predicted_fhs_dup).map{ case (oh, fh) => Mux1H(oh, fh)}
563
564  val s2_ahead_fh_ob_src_dup = dup_wire(new AllAheadFoldedHistoryOldestBits(foldedGHistInfos))
565  s2_ahead_fh_ob_src_dup.zip(s2_ghist_ptr_dup).map{ case (src, ptr) => src.read(ghv, ptr)}
566
567  if (EnableGHistDiff) {
568    val s2_predicted_ghist = WireInit(getHist(s2_predicted_ghist_ptr_dup(0)).asTypeOf(Vec(HistoryLength, Bool())))
569    for (i <- 0 until numBr) {
570      when (resp.s2.shouldShiftVec(0)(i)) {
571        s2_predicted_ghist(i) := resp.s2.brTaken(0) && (i==0).B
572      }
573    }
574    when(s2_redirect_dup(0)) {
575      s0_ghist := s2_predicted_ghist.asUInt
576    }
577  }
578
579  val s2_ghv_wens = (0 until HistoryLength).map(n =>
580    (0 until numBr).map(b => (s2_ghist_ptr_dup(0)).value === (CGHPtr(false.B, n.U) + b.U).value && resp.s2.shouldShiftVec(0)(b) && s2_redirect_dup(0)))
581  val s2_ghv_wdatas = (0 until HistoryLength).map(n =>
582    Mux1H(
583      (0 until numBr).map(b => (
584        (s2_ghist_ptr_dup(0)).value === (CGHPtr(false.B, n.U) + b.U).value && resp.s2.shouldShiftVec(0)(b),
585        resp.s2.full_pred(0).real_br_taken_mask()(b)
586      ))
587    )
588  )
589
590  val s1_pred_info = Wire(new PreviousPredInfo)
591  s1_pred_info.hit := resp.s1.full_pred.map(_.hit)
592  s1_pred_info.target := resp.s1.getTarget
593  s1_pred_info.lastBrPosOH := resp.s1.lastBrPosOH
594  s1_pred_info.taken := resp.s1.taken
595  s1_pred_info.takenMask := resp.s1.full_pred.map(_.taken_mask_on_slot)
596  s1_pred_info.cfiIndex := resp.s1.cfiIndex.map { case x => x.bits }
597
598  val previous_s1_pred_info = RegEnable(s1_pred_info, 0.U.asTypeOf(new PreviousPredInfo), s1_fire_dup(0))
599
600  val s2_redirect_s1_last_pred_vec_dup = preds_needs_redirect_vec_dup(previous_s1_pred_info, resp.s2)
601
602  for (((s2_redirect, s2_fire), s2_redirect_s1_last_pred_vec) <- s2_redirect_dup zip s2_fire_dup zip s2_redirect_s1_last_pred_vec_dup)
603    s2_redirect := s2_fire && s2_redirect_s1_last_pred_vec.reduce(_||_)
604
605
606  for (((npcGen, s2_redirect), s2_target) <- npcGen_dup zip s2_redirect_dup zip resp.s2.getTarget)
607    npcGen.register(s2_redirect, s2_target, Some("s2_target"), 5)
608  for (((foldedGhGen, s2_redirect), s2_predicted_fh) <- foldedGhGen_dup zip s2_redirect_dup zip s2_predicted_fh_dup)
609    foldedGhGen.register(s2_redirect, s2_predicted_fh, Some("s2_FGH"), 5)
610  for (((ghistPtrGen, s2_redirect), s2_predicted_ghist_ptr) <- ghistPtrGen_dup zip s2_redirect_dup zip s2_predicted_ghist_ptr_dup)
611    ghistPtrGen.register(s2_redirect, s2_predicted_ghist_ptr, Some("s2_GHPtr"), 5)
612  for (((lastBrNumOHGen, s2_redirect), s2_brPosOH) <- lastBrNumOHGen_dup zip s2_redirect_dup zip resp.s2.lastBrPosOH.map(_.asUInt))
613    lastBrNumOHGen.register(s2_redirect, s2_brPosOH, Some("s2_BrNumOH"), 5)
614  for (((aheadFhObGen, s2_redirect), s2_ahead_fh_ob_src) <- aheadFhObGen_dup zip s2_redirect_dup zip s2_ahead_fh_ob_src_dup)
615    aheadFhObGen.register(s2_redirect, s2_ahead_fh_ob_src, Some("s2_AFHOB"), 5)
616  ghvBitWriteGens.zip(s2_ghv_wens).zipWithIndex.map{case ((b, w), i) =>
617    b.register(w.reduce(_||_), s2_ghv_wdatas(i), Some(s"s2_new_bit_$i"), 5)
618  }
619
620  XSPerfAccumulate("s2_redirect_because_target_diff", s2_fire_dup(0) && s2_redirect_s1_last_pred_vec_dup(0)(0))
621  XSPerfAccumulate("s2_redirect_because_branch_num_diff", s2_fire_dup(0) && s2_redirect_s1_last_pred_vec_dup(0)(1))
622  XSPerfAccumulate("s2_redirect_because_direction_diff", s2_fire_dup(0) && s2_redirect_s1_last_pred_vec_dup(0)(2))
623  XSPerfAccumulate("s2_redirect_because_cfi_idx_diff", s2_fire_dup(0) && s2_redirect_s1_last_pred_vec_dup(0)(3))
624  // XSPerfAccumulate("s2_redirect_because_shouldShiftVec_diff", s2_fire && s2_redirect_s1_last_pred_vec(4))
625  // XSPerfAccumulate("s2_redirect_because_brTaken_diff", s2_fire && s2_redirect_s1_last_pred_vec(5))
626  XSPerfAccumulate("s2_redirect_because_fallThroughError", s2_fire_dup(0) && resp.s2.fallThruError(0))
627
628  XSPerfAccumulate("s2_redirect_when_taken", s2_redirect_dup(0) && resp.s2.taken(0) && resp.s2.full_pred(0).hit)
629  XSPerfAccumulate("s2_redirect_when_not_taken", s2_redirect_dup(0) && !resp.s2.taken(0) && resp.s2.full_pred(0).hit)
630  XSPerfAccumulate("s2_redirect_when_not_hit", s2_redirect_dup(0) && !resp.s2.full_pred(0).hit)
631
632
633  // s3
634  val s3_possible_predicted_ghist_ptrs_dup = s3_ghist_ptr_dup.map(ptr => (0 to numBr).map(ptr - _.U))
635  val s3_predicted_ghist_ptr_dup = s3_possible_predicted_ghist_ptrs_dup.zip(resp.s3.lastBrPosOH).map{ case (ptr, oh) => Mux1H(oh, ptr)}
636
637  val s3_possible_predicted_fhs_dup =
638    for ((((fgh, afh), br_num_oh), full_pred) <-
639      s3_folded_gh_dup zip s3_ahead_fh_oldest_bits_dup zip s3_last_br_num_oh_dup zip resp.s3.full_pred)
640      yield (0 to numBr).map(i =>
641        fgh.update(afh, br_num_oh, i, if (i > 0) full_pred.br_taken_mask(i-1) else false.B)
642      )
643  val s3_predicted_fh_dup = resp.s3.lastBrPosOH.zip(s3_possible_predicted_fhs_dup).map{ case (oh, fh) => Mux1H(oh, fh)}
644
645  val s3_ahead_fh_ob_src_dup = dup_wire(new AllAheadFoldedHistoryOldestBits(foldedGHistInfos))
646  s3_ahead_fh_ob_src_dup.zip(s3_ghist_ptr_dup).map{ case (src, ptr) => src.read(ghv, ptr)}
647
648  if (EnableGHistDiff) {
649    val s3_predicted_ghist = WireInit(getHist(s3_predicted_ghist_ptr_dup(0)).asTypeOf(Vec(HistoryLength, Bool())))
650    for (i <- 0 until numBr) {
651      when (resp.s3.shouldShiftVec(0)(i)) {
652        s3_predicted_ghist(i) := resp.s3.brTaken(0) && (i==0).B
653      }
654    }
655    when(s3_redirect_dup(0)) {
656      s0_ghist := s3_predicted_ghist.asUInt
657    }
658  }
659
660  val s3_ghv_wens = (0 until HistoryLength).map(n =>
661    (0 until numBr).map(b => (s3_ghist_ptr_dup(0)).value === (CGHPtr(false.B, n.U) + b.U).value && resp.s3.shouldShiftVec(0)(b) && s3_redirect_dup(0)))
662  val s3_ghv_wdatas = (0 until HistoryLength).map(n =>
663    Mux1H(
664      (0 until numBr).map(b => (
665        (s3_ghist_ptr_dup(0)).value === (CGHPtr(false.B, n.U) + b.U).value && resp.s3.shouldShiftVec(0)(b),
666        resp.s3.full_pred(0).real_br_taken_mask()(b)
667      ))
668    )
669  )
670
671  val previous_s2_pred = RegEnable(resp.s2, 0.U.asTypeOf(resp.s2), s2_fire_dup(0))
672
673  val s3_redirect_on_br_taken_dup = resp.s3.full_pred.zip(previous_s2_pred.full_pred).map {case (fp1, fp2) => fp1.real_br_taken_mask().asUInt =/= fp2.real_br_taken_mask().asUInt}
674  val s3_both_first_taken_dup = resp.s3.full_pred.zip(previous_s2_pred.full_pred).map {case (fp1, fp2) => fp1.real_br_taken_mask()(0) && fp2.real_br_taken_mask()(0)}
675  val s3_redirect_on_target_dup = resp.s3.getTarget.zip(previous_s2_pred.getTarget).map {case (t1, t2) => t1 =/= t2}
676  val s3_redirect_on_jalr_target_dup = resp.s3.full_pred.zip(previous_s2_pred.full_pred).map {case (fp1, fp2) => fp1.hit_taken_on_jalr && fp1.jalr_target =/= fp2.jalr_target}
677  val s3_redirect_on_fall_thru_error_dup = resp.s3.fallThruError
678
679  for ((((((s3_redirect, s3_fire), s3_redirect_on_br_taken), s3_redirect_on_target), s3_redirect_on_fall_thru_error), s3_both_first_taken) <-
680    s3_redirect_dup zip s3_fire_dup zip s3_redirect_on_br_taken_dup zip s3_redirect_on_target_dup zip s3_redirect_on_fall_thru_error_dup zip s3_both_first_taken_dup) {
681
682    s3_redirect := s3_fire && (
683      (s3_redirect_on_br_taken && !s3_both_first_taken) || s3_redirect_on_target || s3_redirect_on_fall_thru_error
684    )
685  }
686
687  XSPerfAccumulate(f"s3_redirect_on_br_taken", s3_fire_dup(0) && s3_redirect_on_br_taken_dup(0))
688  XSPerfAccumulate(f"s3_redirect_on_jalr_target", s3_fire_dup(0) && s3_redirect_on_jalr_target_dup(0))
689  XSPerfAccumulate(f"s3_redirect_on_others", s3_redirect_dup(0) && !(s3_redirect_on_br_taken_dup(0) || s3_redirect_on_jalr_target_dup(0)))
690
691  for (((npcGen, s3_redirect), s3_target) <- npcGen_dup zip s3_redirect_dup zip resp.s3.getTarget)
692    npcGen.register(s3_redirect, s3_target, Some("s3_target"), 3)
693  for (((foldedGhGen, s3_redirect), s3_predicted_fh) <- foldedGhGen_dup zip s3_redirect_dup zip s3_predicted_fh_dup)
694    foldedGhGen.register(s3_redirect, s3_predicted_fh, Some("s3_FGH"), 3)
695  for (((ghistPtrGen, s3_redirect), s3_predicted_ghist_ptr) <- ghistPtrGen_dup zip s3_redirect_dup zip s3_predicted_ghist_ptr_dup)
696    ghistPtrGen.register(s3_redirect, s3_predicted_ghist_ptr, Some("s3_GHPtr"), 3)
697  for (((lastBrNumOHGen, s3_redirect), s3_brPosOH) <- lastBrNumOHGen_dup zip s3_redirect_dup zip resp.s3.lastBrPosOH.map(_.asUInt))
698    lastBrNumOHGen.register(s3_redirect, s3_brPosOH, Some("s3_BrNumOH"), 3)
699  for (((aheadFhObGen, s3_redirect), s3_ahead_fh_ob_src) <- aheadFhObGen_dup zip s3_redirect_dup zip s3_ahead_fh_ob_src_dup)
700    aheadFhObGen.register(s3_redirect, s3_ahead_fh_ob_src, Some("s3_AFHOB"), 3)
701  ghvBitWriteGens.zip(s3_ghv_wens).zipWithIndex.map{case ((b, w), i) =>
702    b.register(w.reduce(_||_), s3_ghv_wdatas(i), Some(s"s3_new_bit_$i"), 3)
703  }
704
705  // Send signal tell Ftq override
706  val s2_ftq_idx = RegEnable(io.ftq_to_bpu.enq_ptr, s1_fire_dup(0))
707  val s3_ftq_idx = RegEnable(s2_ftq_idx, s2_fire_dup(0))
708
709  for (((to_ftq_s1_valid, s1_fire), s1_flush) <- io.bpu_to_ftq.resp.bits.s1.valid zip s1_fire_dup zip s1_flush_dup) {
710    to_ftq_s1_valid := s1_fire && !s1_flush
711  }
712  io.bpu_to_ftq.resp.bits.s1.hasRedirect.map(_ := false.B)
713  io.bpu_to_ftq.resp.bits.s1.ftq_idx := DontCare
714  for (((to_ftq_s2_valid, s2_fire), s2_flush) <- io.bpu_to_ftq.resp.bits.s2.valid zip s2_fire_dup zip s2_flush_dup) {
715    to_ftq_s2_valid := s2_fire && !s2_flush
716  }
717  io.bpu_to_ftq.resp.bits.s2.hasRedirect.zip(s2_redirect_dup).map {case (hr, r) => hr := r}
718  io.bpu_to_ftq.resp.bits.s2.ftq_idx := s2_ftq_idx
719  for (((to_ftq_s3_valid, s3_fire), s3_flush) <- io.bpu_to_ftq.resp.bits.s3.valid zip s3_fire_dup zip s3_flush_dup) {
720    to_ftq_s3_valid := s3_fire && !s3_flush
721  }
722  io.bpu_to_ftq.resp.bits.s3.hasRedirect.zip(s3_redirect_dup).map {case (hr, r) => hr := r}
723  io.bpu_to_ftq.resp.bits.s3.ftq_idx := s3_ftq_idx
724
725  predictors.io.update.valid := RegNext(io.ftq_to_bpu.update.valid, init = false.B)
726  predictors.io.update.bits := RegEnable(io.ftq_to_bpu.update.bits, io.ftq_to_bpu.update.valid)
727  predictors.io.update.bits.ghist := RegEnable(
728    getHist(io.ftq_to_bpu.update.bits.spec_info.histPtr), io.ftq_to_bpu.update.valid)
729
730  val redirect_dup = do_redirect_dup.map(_.bits)
731  predictors.io.redirect := do_redirect_dup(0)
732
733  // Redirect logic
734  val shift_dup = redirect_dup.map(_.cfiUpdate.shift)
735  val addIntoHist_dup = redirect_dup.map(_.cfiUpdate.addIntoHist)
736  // TODO: remove these below
737  val shouldShiftVec_dup = shift_dup.map(shift => Mux(shift === 0.U, VecInit(0.U((1 << (log2Ceil(numBr) + 1)).W).asBools), VecInit((LowerMask(1.U << (shift-1.U))).asBools)))
738  // TODO end
739  val afhob_dup = redirect_dup.map(_.cfiUpdate.afhob)
740  val lastBrNumOH_dup = redirect_dup.map(_.cfiUpdate.lastBrNumOH)
741
742
743  val isBr_dup = redirect_dup.map(_.cfiUpdate.pd.isBr)
744  val taken_dup = redirect_dup.map(_.cfiUpdate.taken)
745  val real_br_taken_mask_dup =
746    for (((shift, taken), addIntoHist) <- shift_dup zip taken_dup zip addIntoHist_dup)
747      yield (0 until numBr).map(i => shift === (i+1).U && taken && addIntoHist )
748
749  val oldPtr_dup = redirect_dup.map(_.cfiUpdate.histPtr)
750  val updated_ptr_dup = oldPtr_dup.zip(shift_dup).map {case (oldPtr, shift) => oldPtr - shift}
751  def computeFoldedHist(hist: UInt, compLen: Int)(histLen: Int): UInt = {
752    if (histLen > 0) {
753      val nChunks     = (histLen + compLen - 1) / compLen
754      val hist_chunks = (0 until nChunks) map { i =>
755        hist(min((i + 1) * compLen, histLen) - 1, i * compLen)
756      }
757      ParallelXOR(hist_chunks)
758    }
759    else 0.U
760  }
761
762  val oldFh_dup = dup_seq(WireInit(0.U.asTypeOf(new AllFoldedHistories(foldedGHistInfos))))
763  oldFh_dup.zip(oldPtr_dup).map { case (oldFh, oldPtr) =>
764      foldedGHistInfos.foreach { case (histLen, compLen) =>
765        oldFh.getHistWithInfo((histLen, compLen)).folded_hist := computeFoldedHist(getHist(oldPtr), compLen)(histLen)
766      }
767  }
768
769  val updated_fh_dup =
770    for (((((oldFh, oldPtr), taken), addIntoHist), shift) <-
771      oldFh_dup zip oldPtr_dup zip taken_dup zip addIntoHist_dup zip shift_dup)
772    yield VecInit((0 to numBr).map(i => oldFh.update(ghv, oldPtr, i, taken && addIntoHist)))(shift)
773  val thisBrNumOH_dup = shift_dup.map(shift => UIntToOH(shift, numBr+1))
774  val thisAheadFhOb_dup = dup_wire(new AllAheadFoldedHistoryOldestBits(foldedGHistInfos))
775  thisAheadFhOb_dup.zip(oldPtr_dup).map {case (afhob, oldPtr) => afhob.read(ghv, oldPtr)}
776  val redirect_ghv_wens = (0 until HistoryLength).map(n =>
777    (0 until numBr).map(b => oldPtr_dup(0).value === (CGHPtr(false.B, n.U) + b.U).value && shouldShiftVec_dup(0)(b) && do_redirect_dup(0).valid))
778  val redirect_ghv_wdatas = (0 until HistoryLength).map(n =>
779    Mux1H(
780      (0 until numBr).map(b => oldPtr_dup(0).value === (CGHPtr(false.B, n.U) + b.U).value && shouldShiftVec_dup(0)(b)),
781      real_br_taken_mask_dup(0)
782    )
783  )
784
785  if (EnableGHistDiff) {
786    val updated_ghist = WireInit(getHist(updated_ptr_dup(0)).asTypeOf(Vec(HistoryLength, Bool())))
787    for (i <- 0 until numBr) {
788      when (shift_dup(0) >= (i+1).U) {
789        updated_ghist(i) := taken_dup(0) && addIntoHist_dup(0) && (i==0).B
790      }
791    }
792    when(do_redirect_dup(0).valid) {
793      s0_ghist := updated_ghist.asUInt
794    }
795  }
796
797  // Commit time history checker
798  if (EnableCommitGHistDiff) {
799    val commitGHist = RegInit(0.U.asTypeOf(Vec(HistoryLength, Bool())))
800    val commitGHistPtr = RegInit(0.U.asTypeOf(new CGHPtr))
801    def getCommitHist(ptr: CGHPtr): UInt =
802      (Cat(commitGHist.asUInt, commitGHist.asUInt) >> (ptr.value+1.U))(HistoryLength-1, 0)
803
804    val updateValid        : Bool      = io.ftq_to_bpu.update.valid
805    val branchValidMask    : UInt      = io.ftq_to_bpu.update.bits.ftb_entry.brValids.asUInt
806    val branchCommittedMask: Vec[Bool] = io.ftq_to_bpu.update.bits.br_committed
807    val misPredictMask     : UInt      = io.ftq_to_bpu.update.bits.mispred_mask.asUInt
808    val takenMask          : UInt      =
809      io.ftq_to_bpu.update.bits.br_taken_mask.asUInt |
810        io.ftq_to_bpu.update.bits.ftb_entry.always_taken.asUInt // Always taken branch is recorded in history
811    val takenIdx       : UInt = (PriorityEncoder(takenMask) + 1.U((log2Ceil(numBr)+1).W)).asUInt
812    val misPredictIdx  : UInt = (PriorityEncoder(misPredictMask) + 1.U((log2Ceil(numBr)+1).W)).asUInt
813    val shouldShiftMask: UInt = Mux(takenMask.orR,
814        LowerMask(takenIdx).asUInt,
815        ((1 << numBr) - 1).asUInt) &
816      Mux(misPredictMask.orR,
817        LowerMask(misPredictIdx).asUInt,
818        ((1 << numBr) - 1).asUInt) &
819      branchCommittedMask.asUInt
820    val updateShift    : UInt   =
821      Mux(updateValid && branchValidMask.orR, PopCount(branchValidMask & shouldShiftMask), 0.U)
822
823    // Maintain the commitGHist
824    for (i <- 0 until numBr) {
825      when(updateShift >= (i + 1).U) {
826        val ptr: CGHPtr = commitGHistPtr - i.asUInt
827        commitGHist(ptr.value) := takenMask(i)
828      }
829    }
830    when(updateValid) {
831      commitGHistPtr := commitGHistPtr - updateShift
832    }
833
834    // Calculate true history using Parallel XOR
835    // Do differential
836    TageTableInfos.map {
837      case (nRows, histLen, _) => {
838        val nRowsPerBr = nRows / numBr
839        val predictGHistPtr = io.ftq_to_bpu.update.bits.spec_info.histPtr
840        val commitTrueHist: UInt = computeFoldedHist(getCommitHist(commitGHistPtr), log2Ceil(nRowsPerBr))(histLen)
841        val predictFHist  : UInt = computeFoldedHist(getHist(predictGHistPtr), log2Ceil(nRowsPerBr))(histLen)
842        XSWarn(updateValid && predictFHist =/= commitTrueHist,
843          p"predict time ghist: ${predictFHist} is different from commit time: ${commitTrueHist}\n")
844      }
845    }
846  }
847
848
849  // val updatedGh = oldGh.update(shift, taken && addIntoHist)
850  for ((npcGen, do_redirect) <- npcGen_dup zip do_redirect_dup)
851    npcGen.register(do_redirect.valid, do_redirect.bits.cfiUpdate.target, Some("redirect_target"), 2)
852  for (((foldedGhGen, do_redirect), updated_fh) <- foldedGhGen_dup zip do_redirect_dup zip updated_fh_dup)
853    foldedGhGen.register(do_redirect.valid, updated_fh, Some("redirect_FGHT"), 2)
854  for (((ghistPtrGen, do_redirect), updated_ptr) <- ghistPtrGen_dup zip do_redirect_dup zip updated_ptr_dup)
855    ghistPtrGen.register(do_redirect.valid, updated_ptr, Some("redirect_GHPtr"), 2)
856  for (((lastBrNumOHGen, do_redirect), thisBrNumOH) <- lastBrNumOHGen_dup zip do_redirect_dup zip thisBrNumOH_dup)
857    lastBrNumOHGen.register(do_redirect.valid, thisBrNumOH, Some("redirect_BrNumOH"), 2)
858  for (((aheadFhObGen, do_redirect), thisAheadFhOb) <- aheadFhObGen_dup zip do_redirect_dup zip thisAheadFhOb_dup)
859    aheadFhObGen.register(do_redirect.valid, thisAheadFhOb, Some("redirect_AFHOB"), 2)
860  ghvBitWriteGens.zip(redirect_ghv_wens).zipWithIndex.map{case ((b, w), i) =>
861    b.register(w.reduce(_||_), redirect_ghv_wdatas(i), Some(s"redirect_new_bit_$i"), 2)
862  }
863  // no need to assign s0_last_pred
864
865  // val need_reset = RegNext(reset.asBool) && !reset.asBool
866
867  // Reset
868  // npcGen.register(need_reset, resetVector.U, Some("reset_pc"), 1)
869  // foldedGhGen.register(need_reset, 0.U.asTypeOf(s0_folded_gh), Some("reset_FGH"), 1)
870  // ghistPtrGen.register(need_reset, 0.U.asTypeOf(new CGHPtr), Some("reset_GHPtr"), 1)
871
872  s0_pc_dup.zip(npcGen_dup).map {case (s0_pc, npcGen) => s0_pc := npcGen()}
873  s0_folded_gh_dup.zip(foldedGhGen_dup).map {case (s0_folded_gh, foldedGhGen) => s0_folded_gh := foldedGhGen()}
874  s0_ghist_ptr_dup.zip(ghistPtrGen_dup).map {case (s0_ghist_ptr, ghistPtrGen) => s0_ghist_ptr := ghistPtrGen()}
875  s0_ahead_fh_oldest_bits_dup.zip(aheadFhObGen_dup).map {case (s0_ahead_fh_oldest_bits, aheadFhObGen) =>
876    s0_ahead_fh_oldest_bits := aheadFhObGen()}
877  s0_last_br_num_oh_dup.zip(lastBrNumOHGen_dup).map {case (s0_last_br_num_oh, lastBrNumOHGen) =>
878    s0_last_br_num_oh := lastBrNumOHGen()}
879  (ghv_write_datas zip ghvBitWriteGens).map{case (wd, d) => wd := d()}
880  for (i <- 0 until HistoryLength) {
881    ghv_wens(i) := Seq(s1_ghv_wens, s2_ghv_wens, s3_ghv_wens, redirect_ghv_wens).map(_(i).reduce(_||_)).reduce(_||_)
882    when (ghv_wens(i)) {
883      ghv(i) := ghv_write_datas(i)
884    }
885  }
886
887  // TODO: signals for memVio and other Redirects
888  controlRedirectBubble := do_redirect_dup(0).valid && do_redirect_dup(0).bits.ControlRedirectBubble
889  ControlBTBMissBubble := do_redirect_dup(0).bits.ControlBTBMissBubble
890  TAGEMissBubble := do_redirect_dup(0).bits.TAGEMissBubble
891  SCMissBubble := do_redirect_dup(0).bits.SCMissBubble
892  ITTAGEMissBubble := do_redirect_dup(0).bits.ITTAGEMissBubble
893  RASMissBubble := do_redirect_dup(0).bits.RASMissBubble
894
895  memVioRedirectBubble := do_redirect_dup(0).valid && do_redirect_dup(0).bits.MemVioRedirectBubble
896  otherRedirectBubble := do_redirect_dup(0).valid && do_redirect_dup(0).bits.OtherRedirectBubble
897  btbMissBubble := do_redirect_dup(0).valid && do_redirect_dup(0).bits.BTBMissBubble
898  overrideBubble(0) := s2_redirect_dup(0)
899  overrideBubble(1) := s3_redirect_dup(0)
900  ftqUpdateBubble(0) := !s1_components_ready_dup(0)
901  ftqUpdateBubble(1) := !s2_components_ready_dup(0)
902  ftqUpdateBubble(2) := !s3_components_ready_dup(0)
903  ftqFullStall := !io.bpu_to_ftq.resp.ready
904  io.bpu_to_ftq.resp.bits.topdown_info := topdown_stages(numOfStage - 1)
905
906  // topdown handling logic here
907  when (controlRedirectBubble) {
908    /*
909    for (i <- 0 until numOfStage)
910      topdown_stages(i).reasons(TopDownCounters.ControlRedirectBubble.id) := true.B
911    io.bpu_to_ftq.resp.bits.topdown_info.reasons(TopDownCounters.ControlRedirectBubble.id) := true.B
912    */
913    when (ControlBTBMissBubble) {
914      for (i <- 0 until numOfStage)
915        topdown_stages(i).reasons(TopDownCounters.BTBMissBubble.id) := true.B
916      io.bpu_to_ftq.resp.bits.topdown_info.reasons(TopDownCounters.BTBMissBubble.id) := true.B
917    } .elsewhen (TAGEMissBubble) {
918      for (i <- 0 until numOfStage)
919        topdown_stages(i).reasons(TopDownCounters.TAGEMissBubble.id) := true.B
920      io.bpu_to_ftq.resp.bits.topdown_info.reasons(TopDownCounters.TAGEMissBubble.id) := true.B
921    } .elsewhen (SCMissBubble) {
922      for (i <- 0 until numOfStage)
923        topdown_stages(i).reasons(TopDownCounters.SCMissBubble.id) := true.B
924      io.bpu_to_ftq.resp.bits.topdown_info.reasons(TopDownCounters.SCMissBubble.id) := true.B
925    } .elsewhen (ITTAGEMissBubble) {
926      for (i <- 0 until numOfStage)
927        topdown_stages(i).reasons(TopDownCounters.ITTAGEMissBubble.id) := true.B
928      io.bpu_to_ftq.resp.bits.topdown_info.reasons(TopDownCounters.ITTAGEMissBubble.id) := true.B
929    } .elsewhen (RASMissBubble) {
930      for (i <- 0 until numOfStage)
931        topdown_stages(i).reasons(TopDownCounters.RASMissBubble.id) := true.B
932      io.bpu_to_ftq.resp.bits.topdown_info.reasons(TopDownCounters.RASMissBubble.id) := true.B
933    }
934  }
935  when (memVioRedirectBubble) {
936    for (i <- 0 until numOfStage)
937      topdown_stages(i).reasons(TopDownCounters.MemVioRedirectBubble.id) := true.B
938    io.bpu_to_ftq.resp.bits.topdown_info.reasons(TopDownCounters.MemVioRedirectBubble.id) := true.B
939  }
940  when (otherRedirectBubble) {
941    for (i <- 0 until numOfStage)
942      topdown_stages(i).reasons(TopDownCounters.OtherRedirectBubble.id) := true.B
943    io.bpu_to_ftq.resp.bits.topdown_info.reasons(TopDownCounters.OtherRedirectBubble.id) := true.B
944  }
945  when (btbMissBubble) {
946    for (i <- 0 until numOfStage)
947      topdown_stages(i).reasons(TopDownCounters.BTBMissBubble.id) := true.B
948    io.bpu_to_ftq.resp.bits.topdown_info.reasons(TopDownCounters.BTBMissBubble.id) := true.B
949  }
950
951  for (i <- 0 until numOfStage) {
952    if (i < numOfStage - overrideStage) {
953      when (overrideBubble(i)) {
954        for (j <- 0 to i)
955          topdown_stages(j).reasons(TopDownCounters.OverrideBubble.id) := true.B
956      }
957    }
958    if (i < numOfStage - ftqUpdateStage) {
959      when (ftqUpdateBubble(i)) {
960        topdown_stages(i).reasons(TopDownCounters.FtqUpdateBubble.id) := true.B
961      }
962    }
963  }
964  when (ftqFullStall) {
965    topdown_stages(0).reasons(TopDownCounters.FtqFullStall.id) := true.B
966  }
967
968  XSError(isBefore(redirect_dup(0).cfiUpdate.histPtr, s3_ghist_ptr_dup(0)) && do_redirect_dup(0).valid,
969    p"s3_ghist_ptr ${s3_ghist_ptr_dup(0)} exceeds redirect histPtr ${redirect_dup(0).cfiUpdate.histPtr}\n")
970  XSError(isBefore(redirect_dup(0).cfiUpdate.histPtr, s2_ghist_ptr_dup(0)) && do_redirect_dup(0).valid,
971    p"s2_ghist_ptr ${s2_ghist_ptr_dup(0)} exceeds redirect histPtr ${redirect_dup(0).cfiUpdate.histPtr}\n")
972  XSError(isBefore(redirect_dup(0).cfiUpdate.histPtr, s1_ghist_ptr_dup(0)) && do_redirect_dup(0).valid,
973    p"s1_ghist_ptr ${s1_ghist_ptr_dup(0)} exceeds redirect histPtr ${redirect_dup(0).cfiUpdate.histPtr}\n")
974
975  XSDebug(RegNext(reset.asBool) && !reset.asBool, "Reseting...\n")
976  XSDebug(io.ftq_to_bpu.update.valid, p"Update from ftq\n")
977  XSDebug(io.ftq_to_bpu.redirect.valid, p"Redirect from ftq\n")
978
979  XSDebug("[BP0]                 fire=%d                      pc=%x\n", s0_fire_dup(0), s0_pc_dup(0))
980  XSDebug("[BP1] v=%d r=%d cr=%d fire=%d             flush=%d pc=%x\n",
981    s1_valid_dup(0), s1_ready_dup(0), s1_components_ready_dup(0), s1_fire_dup(0), s1_flush_dup(0), s1_pc)
982  XSDebug("[BP2] v=%d r=%d cr=%d fire=%d redirect=%d flush=%d pc=%x\n",
983    s2_valid_dup(0), s2_ready_dup(0), s2_components_ready_dup(0), s2_fire_dup(0), s2_redirect_dup(0), s2_flush_dup(0), s2_pc)
984  XSDebug("[BP3] v=%d r=%d cr=%d fire=%d redirect=%d flush=%d pc=%x\n",
985    s3_valid_dup(0), s3_ready_dup(0), s3_components_ready_dup(0), s3_fire_dup(0), s3_redirect_dup(0), s3_flush_dup(0), s3_pc)
986  XSDebug("[FTQ] ready=%d\n", io.bpu_to_ftq.resp.ready)
987  XSDebug("resp.s1.target=%x\n", resp.s1.getTarget(0))
988  XSDebug("resp.s2.target=%x\n", resp.s2.getTarget(0))
989  // XSDebug("s0_ghist: %b\n", s0_ghist.predHist)
990  // XSDebug("s1_ghist: %b\n", s1_ghist.predHist)
991  // XSDebug("s2_ghist: %b\n", s2_ghist.predHist)
992  // XSDebug("s2_predicted_ghist: %b\n", s2_predicted_ghist.predHist)
993  XSDebug(p"s0_ghist_ptr: ${s0_ghist_ptr_dup(0)}\n")
994  XSDebug(p"s1_ghist_ptr: ${s1_ghist_ptr_dup(0)}\n")
995  XSDebug(p"s2_ghist_ptr: ${s2_ghist_ptr_dup(0)}\n")
996  XSDebug(p"s3_ghist_ptr: ${s3_ghist_ptr_dup(0)}\n")
997
998  io.ftq_to_bpu.update.bits.display(io.ftq_to_bpu.update.valid)
999  io.ftq_to_bpu.redirect.bits.display(io.ftq_to_bpu.redirect.valid)
1000
1001
1002  XSPerfAccumulate("s2_redirect", s2_redirect_dup(0))
1003  XSPerfAccumulate("s3_redirect", s3_redirect_dup(0))
1004  XSPerfAccumulate("s1_not_valid", !s1_valid_dup(0))
1005
1006  val perfEvents = predictors.asInstanceOf[Composer].getPerfEvents
1007  generatePerfEvent()
1008}
1009