xref: /XiangShan/src/main/scala/xiangshan/frontend/IFU.scala (revision f3501106acc5da5db0f9ad13e38d2f599df11b56)
1package xiangshan.frontend
2
3import chisel3._
4import chisel3.util._
5import device.RAMHelper
6import xiangshan._
7import utils._
8
9trait HasIFUConst { this: XSModule =>
10  val resetVector = 0x80000000L//TODO: set reset vec
11  val groupAlign = log2Up(FetchWidth * 4 * 2)
12  def groupPC(pc: UInt): UInt = Cat(pc(VAddrBits-1, groupAlign), 0.U(groupAlign.W))
13  // each 1 bit in mask stands for 2 Bytes
14  def mask(pc: UInt): UInt = (Fill(PredictWidth * 2, 1.U(1.W)) >> pc(groupAlign - 1, 1))(PredictWidth - 1, 0)
15  def snpc(pc: UInt): UInt = pc + (PopCount(mask(pc)) << 1)
16
17  val IFUDebug = true
18}
19
20class IFUIO extends XSBundle
21{
22  val fetchPacket = DecoupledIO(new FetchPacket)
23  val redirect = Flipped(ValidIO(new Redirect))
24  val outOfOrderBrInfo = Flipped(ValidIO(new BranchUpdateInfo))
25  val inOrderBrInfo = Flipped(ValidIO(new BranchUpdateInfo))
26  val icacheReq = DecoupledIO(new FakeIcacheReq)
27  val icacheResp = Flipped(DecoupledIO(new FakeIcacheResp))
28  val icacheFlush = Output(UInt(2.W))
29}
30
31
32class IFU extends XSModule with HasIFUConst
33{
34  val io = IO(new IFUIO)
35  val bpu = BPU(EnableBPU)
36  val pd = Module(new PreDecode)
37
38  val if2_redirect, if3_redirect, if4_redirect = WireInit(false.B)
39  val if1_flush, if2_flush, if3_flush, if4_flush = WireInit(false.B)
40
41  if4_flush := io.redirect.valid
42  if3_flush := if4_flush || if4_redirect
43  if2_flush := if3_flush || if3_redirect
44  if1_flush := if2_flush || if2_redirect
45
46  //********************** IF1 ****************************//
47  val if1_valid = !reset.asBool
48  val if1_npc = WireInit(0.U(VAddrBits.W))
49  val if2_ready = WireInit(false.B)
50  val if1_fire = if1_valid && (if2_ready || if1_flush) && io.icacheReq.ready
51
52  // val extHist = VecInit(Fill(ExtHistoryLength, RegInit(0.U(1.W))))
53  val extHist = RegInit(VecInit(Seq.fill(ExtHistoryLength)(0.U(1.W))))
54  val headPtr = RegInit(0.U(log2Up(ExtHistoryLength).W))
55  val shiftPtr = WireInit(false.B)
56  val newPtr = Wire(UInt(log2Up(ExtHistoryLength).W))
57  val ptr = Mux(shiftPtr, newPtr, headPtr)
58  when (shiftPtr) { headPtr := newPtr }
59  val hist = Wire(Vec(HistoryLength, UInt(1.W)))
60  for (i <- 0 until HistoryLength) {
61    hist(i) := extHist(ptr + i.U)
62  }
63
64  newPtr := headPtr
65  shiftPtr := false.B
66
67  //********************** IF2 ****************************//
68  val if2_valid = RegEnable(next = if1_valid, init = false.B, enable = if1_fire)
69  val if3_ready = WireInit(false.B)
70  val if2_fire = if2_valid && if3_ready && !if2_flush
71  val if2_pc = RegEnable(next = if1_npc, init = resetVector.U, enable = if1_fire)
72  val if2_snpc = snpc(if2_pc)
73  val if2_histPtr = RegEnable(ptr, if1_fire)
74  if2_ready := if2_fire || !if2_valid || if2_flush
75  when (if2_flush) { if2_valid := if1_fire }
76  .elsewhen (if1_fire) { if2_valid := if1_valid }
77  .elsewhen (if2_fire) { if2_valid := false.B }
78
79  when (RegNext(reset.asBool) && !reset.asBool) {
80    if1_npc := resetVector.U(VAddrBits.W)
81  }.elsewhen (if2_fire) {
82    if1_npc := if2_snpc
83  }.otherwise {
84    if1_npc := RegNext(if1_npc)
85  }
86
87  val if2_bp = bpu.io.out(0).bits
88  if2_redirect := if2_fire && bpu.io.out(0).valid && if2_bp.redirect// && !if2_bp.saveHalfRVI
89  when (if2_redirect) {
90    if1_npc := if2_bp.target
91  }
92
93  when (if2_fire && (if2_bp.takenOnBr || if2_bp.hasNotTakenBrs)) {
94    shiftPtr := true.B
95    newPtr := headPtr - 1.U
96    hist(0) := if2_bp.takenOnBr.asUInt
97    extHist(newPtr) := if2_bp.takenOnBr.asUInt
98  }
99
100  // repair histptr when if4 finds a not taken branch which is
101  // not recorded in uBTB or BTB
102  val if4_shiftWithoutRedirect = WireInit(false.B)
103
104  //********************** IF3 ****************************//
105  val if3_valid = RegEnable(next = if2_valid, init = false.B, enable = if2_fire)
106  val if4_ready = WireInit(false.B)
107  val if3_fire = if3_valid && if4_ready && io.icacheResp.valid && !if3_flush
108  val if3_pc = RegEnable(if2_pc, if2_fire)
109  val if3_histPtr = RegEnable(if2_histPtr - if4_shiftWithoutRedirect.asUInt, if2_fire)
110  if3_ready := if3_fire || !if3_valid || if3_flush
111  when (if3_flush) { if3_valid := false.B }
112  .elsewhen (if2_fire) { if3_valid := if2_valid }
113  .elsewhen (if3_fire) { if3_valid := false.B }
114
115  val if3_bp = bpu.io.out(1).bits
116
117  class PrevHalfInstr extends Bundle {
118    val valid = Bool()
119    val taken = Bool()
120    val fetchpc = UInt(VAddrBits.W) // only for debug
121    val idx = UInt(VAddrBits.W) // only for debug
122    val pc = UInt(VAddrBits.W)
123    val target = UInt(VAddrBits.W)
124    val instr = UInt(16.W)
125    val takenOnBr = Bool()
126  }
127
128  val if3_prevHalfInstr = RegInit(0.U.asTypeOf(new PrevHalfInstr))
129  val if4_prevHalfInstr = Wire(new PrevHalfInstr)
130  when (if4_prevHalfInstr.valid) {
131    if3_prevHalfInstr := if4_prevHalfInstr
132  }
133  val prevHalfInstr = Mux(if4_prevHalfInstr.valid, if4_prevHalfInstr, if3_prevHalfInstr)
134
135  val if3_hasPrevHalfInstr = prevHalfInstr.valid && (prevHalfInstr.pc + 2.U) === if3_pc
136  if3_redirect := if3_fire && bpu.io.out(1).valid && (if3_hasPrevHalfInstr && prevHalfInstr.taken || if3_bp.redirect/* && !if3_bp.saveHalfRVI*/ )
137  when (if3_redirect) {
138    if1_npc := Mux(if3_hasPrevHalfInstr && prevHalfInstr.taken, prevHalfInstr.target, if3_bp.target)
139  }
140
141  when (if3_fire && if3_redirect) {
142    shiftPtr := true.B
143    newPtr := Mux(if3_hasPrevHalfInstr && prevHalfInstr.takenOnBr || if3_bp.takenOnBr || if3_bp.hasNotTakenBrs, if3_histPtr - 1.U, if3_histPtr)
144    hist(0) := Mux(if3_hasPrevHalfInstr && prevHalfInstr.takenOnBr || if3_bp.takenOnBr || if3_bp.hasNotTakenBrs,
145      (if3_hasPrevHalfInstr && prevHalfInstr.takenOnBr || if3_bp.takenOnBr).asUInt,
146      extHist(if3_histPtr))
147    extHist(newPtr) := Mux(if3_hasPrevHalfInstr && prevHalfInstr.takenOnBr || if3_bp.takenOnBr || if3_bp.hasNotTakenBrs,
148      (if3_hasPrevHalfInstr && prevHalfInstr.takenOnBr || if3_bp.takenOnBr).asUInt,
149      extHist(if3_histPtr))
150  }
151
152
153
154  // val prev_half_valid = RegInit(false.B)
155  // val prev_half_redirect = RegInit(false.B)
156  // val prev_half_fetchpc = Reg(UInt(VAddrBits.W))
157  // val prev_half_idx = Reg(UInt(log2Up(PredictWidth).W))
158  // val prev_half_tgt = Reg(UInt(VAddrBits.W))
159  // val prev_half_taken = RegInit(false.B)
160  // val prev_half_instr = Reg(UInt(16.W))
161  // when (if3_flush) {
162  //   prev_half_valid := false.B
163  //   prev_half_redirect := false.B
164  // }.elsewhen (if3_fire && if3_bp.saveHalfRVI) {
165  //   prev_half_valid := true.B
166  //   prev_half_redirect := if3_bp.redirect && bpu.io.out(1).valid
167  //   prev_half_fetchpc := if3_pc
168  //   val idx = Mux(if3_bp.redirect && bpu.io.out(1).valid, if3_bp.jmpIdx, PopCount(mask(if3_pc)) - 1.U)
169  //   prev_half_idx := idx
170  //   prev_half_tgt := if3_bp.target
171  //   prev_half_taken := if3_bp.taken
172  //   prev_half_instr := pd.io.out.instrs(idx)(15, 0)
173  // }.elsewhen (if3_fire) {
174  //   prev_half_valid := false.B
175  //   prev_half_redirect := false.B
176  // }
177
178  // when (bpu.io.out(1).valid && if3_fire) {
179  //   when (prev_half_valid && prev_half_taken) {
180  //     if3_redirect := true.B
181  //     if1_npc := prev_half_tgt
182  //     shiftPtr := true.B
183  //     newPtr := if3_histPtr - 1.U
184  //     hist(0) := 1.U
185  //     extHist(newPtr) := 1.U
186  //   }.elsewhen (if3_bp.redirect && !if3_bp.saveHalfRVI) {
187  //     if3_redirect := true.B
188  //     if1_npc := if3_bp.target
189  //     shiftPtr := true.B
190  //     newPtr := Mux(if3_bp.taken || if3_bp.hasNotTakenBrs, if3_histPtr - 1.U, if3_histPtr)
191  //     hist(0) := Mux(if3_bp.taken || if3_bp.hasNotTakenBrs, if3_bp.taken.asUInt, extHist(if3_histPtr))
192  //     extHist(newPtr) := Mux(if3_bp.taken || if3_bp.hasNotTakenBrs, if3_bp.taken.asUInt, extHist(if3_histPtr))
193  //   }.elsewhen (if3_bp.saveHalfRVI) {
194  //     if3_redirect := true.B
195  //     if1_npc := snpc(if3_pc)
196  //     shiftPtr := true.B
197  //     newPtr := Mux(if3_bp.hasNotTakenBrs, if3_histPtr - 1.U, if3_histPtr)
198  //     hist(0) := Mux(if3_bp.hasNotTakenBrs, 0.U, extHist(if3_histPtr))
199  //     extHist(newPtr) := Mux(if3_bp.hasNotTakenBrs, 0.U, extHist(if3_histPtr))
200  //   }.otherwise {
201  //     if3_redirect := false.B
202  //   }
203  // }.otherwise {
204  //   if3_redirect := false.B
205  // }
206
207
208  //********************** IF4 ****************************//
209  val if4_pd = RegEnable(pd.io.out, if3_fire)
210  val if4_valid = RegInit(false.B)
211  val if4_fire = if4_valid && io.fetchPacket.ready
212  val if4_pc = RegEnable(if3_pc, if3_fire)
213  val if4_histPtr = RegEnable(if3_histPtr - if4_shiftWithoutRedirect.asUInt, if3_fire)
214  if4_ready := (if4_fire || !if4_valid || if4_flush) && GTimer() > 500.U
215  when (if4_flush)     { if4_valid := false.B }
216  .elsewhen (if3_fire) { if4_valid := if3_valid }
217  .elsewhen(if4_fire)  { if4_valid := false.B }
218
219  val if4_bp = Wire(new BranchPrediction)
220  if4_bp := bpu.io.out(2).bits
221
222  val if4_cfi_jal = if4_pd.instrs(if4_bp.jmpIdx)
223  val if4_cfi_jal_tgt = if4_pd.pc(if4_bp.jmpIdx) + Mux(if4_pd.pd(if4_bp.jmpIdx).isRVC,
224    SignExt(Cat(if4_cfi_jal(12), if4_cfi_jal(8), if4_cfi_jal(10, 9), if4_cfi_jal(6), if4_cfi_jal(7), if4_cfi_jal(2), if4_cfi_jal(11), if4_cfi_jal(5, 3), 0.U(1.W)), XLEN),
225    SignExt(Cat(if4_cfi_jal(31), if4_cfi_jal(19, 12), if4_cfi_jal(20), if4_cfi_jal(30, 21), 0.U(1.W)), XLEN))
226  if4_bp.target := Mux(if4_pd.pd(if4_bp.jmpIdx).isJal && if4_bp.taken, if4_cfi_jal_tgt, bpu.io.out(2).bits.target)
227  if4_bp.redirect := bpu.io.out(2).bits.redirect || if4_pd.pd(if4_bp.jmpIdx).isJal && if4_bp.taken && if4_cfi_jal_tgt =/= bpu.io.out(2).bits.target
228
229  if4_prevHalfInstr := 0.U.asTypeOf(new PrevHalfInstr)
230  when (bpu.io.out(2).valid && if4_fire && if4_bp.saveHalfRVI) {
231    if4_prevHalfInstr.valid := true.B
232    if4_prevHalfInstr.taken := if4_bp.taken
233    if4_prevHalfInstr.takenOnBr := if4_bp.takenOnBr
234    if4_prevHalfInstr.fetchpc := if4_pc
235    if4_prevHalfInstr.idx := PopCount(mask(if4_pc)) - 1.U
236    if4_prevHalfInstr.pc := if4_pd.pc(if4_prevHalfInstr.idx)
237    if4_prevHalfInstr.target := if4_bp.target
238    if4_prevHalfInstr.instr := if4_pd.instrs(if4_prevHalfInstr.idx)(15, 0)
239  }
240
241  when (bpu.io.out(2).valid && if4_fire && if4_bp.redirect) {
242    if4_redirect := true.B
243    shiftPtr := true.B
244    newPtr := Mux(if4_bp.takenOnBr || if4_bp.hasNotTakenBrs, if4_histPtr - 1.U, if4_histPtr)
245    hist(0) := Mux(if4_bp.takenOnBr || if4_bp.hasNotTakenBrs, if4_bp.takenOnBr.asUInt, extHist(if4_histPtr))
246    extHist(newPtr) := Mux(if4_bp.takenOnBr || if4_bp.hasNotTakenBrs, if4_bp.takenOnBr.asUInt, extHist(if4_histPtr))
247    when (if4_bp.saveHalfRVI) {
248      if1_npc := snpc(if4_pc)
249    }.otherwise {
250      if1_npc := if4_bp.target
251    }
252  }.elsewhen (bpu.io.out(2).valid && if4_fire/* && !if4_bp.redirect*/) {
253    when (if4_bp.saveHalfRVI && if4_bp.takenOnBr) {
254      if4_redirect := true.B
255      if1_npc := snpc(if4_pc)
256      shiftPtr := true.B
257      newPtr := if4_histPtr - 1.U
258      hist(0) := 1.U
259      extHist(newPtr) := 1.U
260    }.elsewhen (if4_bp.saveHalfRVI && if4_bp.taken) {
261      if4_redirect := true.B
262      if1_npc := snpc(if4_pc)
263      shiftPtr := true.B
264      newPtr := if4_histPtr
265      hist(0) := extHist(if4_histPtr)
266      extHist(newPtr) := extHist(if4_histPtr)
267    }.otherwise {
268      if4_redirect := false.B
269      when (if4_bp.takenOnBr || if4_bp.hasNotTakenBrs) {
270        shiftPtr := true.B
271        if4_shiftWithoutRedirect := true.B
272        newPtr := if4_histPtr - 1.U
273        hist(0) := if4_bp.takenOnBr.asUInt
274        extHist(newPtr) := if4_bp.takenOnBr.asUInt
275      }
276    }
277  }.otherwise {
278    if4_redirect := false.B
279  }
280
281
282
283  // when (bpu.io.out(2).valid && if4_fire && if4_bp.redirect) {
284  //   when (!if4_bp.saveHalfRVI) {
285  //     if4_redirect := true.B
286  //     // if1_npc := if4_bp.target
287  //     if1_npc := Mux(if4_bp.taken, if4_bp.target, snpc(if4_pc))
288
289  //     shiftPtr := true.B
290  //     newPtr := Mux(if4_bp.taken || if4_bp.hasNotTakenBrs, if4_histPtr - 1.U, if4_histPtr)
291  //     hist(0) := Mux(if4_bp.taken || if4_bp.hasNotTakenBrs, if4_bp.taken.asUInt, extHist(if4_histPtr))
292  //     extHist(newPtr) := Mux(if4_bp.taken || if4_bp.hasNotTakenBrs, if4_bp.taken.asUInt, extHist(if4_histPtr))
293
294  //   }.otherwise {
295  //     if4_redirect := true.B
296  //     if1_npc := snpc(if4_pc)
297
298  //     prev_half_valid := true.B
299  //     prev_half_redirect := true.B
300  //     prev_half_fetchpc := if4_pc
301  //     val idx = PopCount(mask(if4_pc)) - 1.U
302  //     prev_half_idx := idx
303  //     prev_half_tgt := if4_bp.target
304  //     prev_half_taken := if4_bp.taken
305  //     prev_half_instr := if4_pd.instrs(idx)(15, 0)
306
307  //     shiftPtr := true.B
308  //     newPtr := Mux(if4_bp.hasNotTakenBrs, if4_histPtr - 1.U, if4_histPtr)
309  //     hist(0) := Mux(if4_bp.hasNotTakenBrs, 0.U, extHist(if4_histPtr))
310  //     extHist(newPtr) := Mux(if4_bp.hasNotTakenBrs, 0.U, extHist(if4_histPtr))
311  //   }
312  // }.otherwise {
313  //   if4_redirect := false.B
314  // }
315
316  when (io.outOfOrderBrInfo.valid && io.outOfOrderBrInfo.bits.isMisPred) {
317    val b = io.outOfOrderBrInfo.bits
318    val oldPtr = b.brInfo.histPtr
319    shiftPtr := true.B
320    when (!b.pd.isBr && !b.brInfo.sawNotTakenBranch) {
321      // If mispredicted cfi is not a branch,
322      // and there wasn't any not taken branch before it,
323      // we should only recover the pointer to an unshifted state
324      newPtr := oldPtr
325    }.otherwise {
326      newPtr := oldPtr - 1.U
327      hist(0) := Mux(b.pd.isBr, b.taken, 0.U)
328      extHist(newPtr) := Mux(b.pd.isBr, b.taken, 0.U)
329    }
330  }
331
332  when (io.redirect.valid) {
333    if1_npc := io.redirect.bits.target
334  }
335
336  io.icacheReq.valid := if1_valid && if2_ready
337  io.icacheReq.bits.addr := if1_npc
338  io.icacheResp.ready := if3_ready
339  io.icacheFlush := Cat(if3_flush, if2_flush)
340
341  val inOrderBrHist = Wire(Vec(HistoryLength, UInt(1.W)))
342  (0 until HistoryLength).foreach(i => inOrderBrHist(i) := extHist(i.U + io.inOrderBrInfo.bits.brInfo.histPtr))
343  bpu.io.inOrderBrInfo.valid := io.inOrderBrInfo.valid
344  bpu.io.inOrderBrInfo.bits := BranchUpdateInfoWithHist(io.inOrderBrInfo.bits, inOrderBrHist.asUInt)
345  bpu.io.outOfOrderBrInfo.valid := io.outOfOrderBrInfo.valid
346  bpu.io.outOfOrderBrInfo.bits := BranchUpdateInfoWithHist(io.outOfOrderBrInfo.bits, inOrderBrHist.asUInt) // Dont care about hist
347
348  // bpu.io.flush := Cat(if4_flush, if3_flush, if2_flush)
349  bpu.io.flush := VecInit(if2_flush, if3_flush, if4_flush)
350  bpu.io.in.valid := if1_fire
351  bpu.io.in.bits.pc := if1_npc
352  bpu.io.in.bits.hist := hist.asUInt
353  bpu.io.in.bits.inMask := mask(if1_npc)
354  bpu.io.out(0).ready := if2_fire
355  bpu.io.out(1).ready := if3_fire
356  bpu.io.out(2).ready := if4_fire
357  bpu.io.predecode.valid := if4_valid
358  bpu.io.predecode.bits.mask := if4_pd.mask
359  bpu.io.predecode.bits.pd := if4_pd.pd
360  bpu.io.predecode.bits.isFetchpcEqualFirstpc := if4_pc === if4_pd.pc(0)
361  bpu.io.branchInfo.ready := if4_fire
362
363  pd.io.in := io.icacheResp.bits
364  pd.io.prev.valid := if3_hasPrevHalfInstr
365  pd.io.prev.bits := prevHalfInstr.instr
366
367  io.fetchPacket.valid := if4_valid && !io.redirect.valid
368  io.fetchPacket.bits.instrs := if4_pd.instrs
369  io.fetchPacket.bits.mask := if4_pd.mask & (Fill(PredictWidth, !if4_bp.taken) | (Fill(PredictWidth, 1.U(1.W)) >> (~if4_bp.jmpIdx)))
370  io.fetchPacket.bits.pc := if4_pd.pc
371  (0 until PredictWidth).foreach(i => io.fetchPacket.bits.pnpc(i) := if4_pd.pc(i) + Mux(if4_pd.pd(i).isRVC, 2.U, 4.U))
372  when (if4_bp.taken) {
373    io.fetchPacket.bits.pnpc(if4_bp.jmpIdx) := if4_bp.target
374  }
375  io.fetchPacket.bits.brInfo := bpu.io.branchInfo.bits
376  (0 until PredictWidth).foreach(i => io.fetchPacket.bits.brInfo(i).histPtr := if4_histPtr)
377  io.fetchPacket.bits.pd := if4_pd.pd
378
379  // debug info
380  if (IFUDebug) {
381    XSDebug(RegNext(reset.asBool) && !reset.asBool, "Reseting...\n")
382    XSDebug(io.icacheFlush(0).asBool, "Flush icache stage2...\n")
383    XSDebug(io.icacheFlush(1).asBool, "Flush icache stage3...\n")
384    XSDebug(io.redirect.valid, "Redirect from backend! isExcp=%d isMisPred=%d isReplay=%d pc=%x\n",
385      io.redirect.bits.isException, io.redirect.bits.isMisPred, io.redirect.bits.isReplay, io.redirect.bits.pc)
386    XSDebug(io.redirect.valid, p"Redirect from backend! target=${Hexadecimal(io.redirect.bits.target)} brTag=${io.redirect.bits.brTag}\n")
387
388    XSDebug("[IF1] v=%d     fire=%d            flush=%d pc=%x ptr=%d mask=%b\n", if1_valid, if1_fire, if1_flush, if1_npc, ptr, mask(if1_npc))
389    XSDebug("[IF2] v=%d r=%d fire=%d redirect=%d flush=%d pc=%x ptr=%d snpc=%x\n", if2_valid, if2_ready, if2_fire, if2_redirect, if2_flush, if2_pc, if2_histPtr, if2_snpc)
390    XSDebug("[IF3] v=%d r=%d fire=%d redirect=%d flush=%d pc=%x ptr=%d\n", if3_valid, if3_ready, if3_fire, if3_redirect, if3_flush, if3_pc, if3_histPtr)
391    XSDebug("[IF4] v=%d r=%d fire=%d redirect=%d flush=%d pc=%x ptr=%d\n", if4_valid, if4_ready, if4_fire, if4_redirect, if4_flush, if4_pc, if4_histPtr)
392
393    XSDebug("[IF1][icacheReq] v=%d r=%d addr=%x\n", io.icacheReq.valid, io.icacheReq.ready, io.icacheReq.bits.addr)
394    XSDebug("[IF1][ghr] headPtr=%d shiftPtr=%d newPtr=%d ptr=%d\n", headPtr, shiftPtr, newPtr, ptr)
395    XSDebug("[IF1][ghr] hist=%b\n", hist.asUInt)
396    XSDebug("[IF1][ghr] extHist=%b\n\n", extHist.asUInt)
397
398    XSDebug("[IF2][bp] redirect=%d taken=%d jmpIdx=%d hasNTBrs=%d target=%x saveHalfRVI=%d\n\n", if2_bp.redirect, if2_bp.taken, if2_bp.jmpIdx, if2_bp.hasNotTakenBrs, if2_bp.target, if2_bp.saveHalfRVI)
399
400    XSDebug("[IF3][icacheResp] v=%d r=%d pc=%x mask=%b\n", io.icacheResp.valid, io.icacheResp.ready, io.icacheResp.bits.pc, io.icacheResp.bits.mask)
401    XSDebug("[IF3][bp] redirect=%d taken=%d jmpIdx=%d hasNTBrs=%d target=%x saveHalfRVI=%d\n", if3_bp.redirect, if3_bp.taken, if3_bp.jmpIdx, if3_bp.hasNotTakenBrs, if3_bp.target, if3_bp.saveHalfRVI)
402    // XSDebug("[IF3][prevHalfInstr] v=%d redirect=%d fetchpc=%x idx=%d tgt=%x taken=%d instr=%x\n\n",
403    //   prev_half_valid, prev_half_redirect, prev_half_fetchpc, prev_half_idx, prev_half_tgt, prev_half_taken, prev_half_instr)
404    XSDebug("[IF3][    prevHalfInstr] v=%d taken=%d fetchpc=%x idx=%d pc=%x tgt=%x instr=%x\n",
405      prevHalfInstr.valid, prevHalfInstr.taken, prevHalfInstr.fetchpc, prevHalfInstr.idx, prevHalfInstr.pc, prevHalfInstr.target, prevHalfInstr.instr)
406    XSDebug("[IF3][if3_prevHalfInstr] v=%d taken=%d fetchpc=%x idx=%d pc=%x tgt=%x instr=%x\n\n",
407      if3_prevHalfInstr.valid, if3_prevHalfInstr.taken, if3_prevHalfInstr.fetchpc, if3_prevHalfInstr.idx, if3_prevHalfInstr.pc, if3_prevHalfInstr.target, if3_prevHalfInstr.instr)
408
409
410    XSDebug("[IF4][predecode] mask=%b\n", if4_pd.mask)
411    XSDebug("[IF4][bp] redirect=%d taken=%d jmpIdx=%d hasNTBrs=%d target=%x saveHalfRVI=%d\n", if4_bp.redirect, if4_bp.taken, if4_bp.jmpIdx, if4_bp.hasNotTakenBrs, if4_bp.target, if4_bp.saveHalfRVI)
412    XSDebug(if4_pd.pd(if4_bp.jmpIdx).isJal && if4_bp.taken, "[IF4] cfi is jal!  instr=%x target=%x\n", if4_cfi_jal, if4_cfi_jal_tgt)
413    XSDebug("[IF4][if4_prevHalfInstr] v=%d taken=%d fetchpc=%x idx=%d pc=%x tgt=%x instr=%x\n",
414      if4_prevHalfInstr.valid, if4_prevHalfInstr.taken, if4_prevHalfInstr.fetchpc, if4_prevHalfInstr.idx, if4_prevHalfInstr.pc, if4_prevHalfInstr.target, if4_prevHalfInstr.instr)
415    XSDebug(io.fetchPacket.fire(), "[IF4][fetchPacket] v=%d r=%d mask=%b\n", io.fetchPacket.valid, io.fetchPacket.ready, io.fetchPacket.bits.mask)
416    for (i <- 0 until PredictWidth) {
417      XSDebug(io.fetchPacket.fire(), "[IF4][fetchPacket] %b %x pc=%x pnpc=%x pd: rvc=%d brType=%b call=%d ret=%d\n",
418        io.fetchPacket.bits.mask(i),
419        io.fetchPacket.bits.instrs(i),
420        io.fetchPacket.bits.pc(i),
421        io.fetchPacket.bits.pnpc(i),
422        io.fetchPacket.bits.pd(i).isRVC,
423        io.fetchPacket.bits.pd(i).brType,
424        io.fetchPacket.bits.pd(i).isCall,
425        io.fetchPacket.bits.pd(i).isRet
426      )
427    }
428  }
429}