xref: /XiangShan/src/main/scala/xiangshan/mem/pipeline/StoreUnit.scala (revision b03c55a5df5dc8793cb44b42dd60141566e57e78)
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.mem
18
19import org.chipsalliance.cde.config.Parameters
20import chisel3._
21import chisel3.util._
22import utils._
23import utility._
24import xiangshan.ExceptionNO._
25import xiangshan._
26import xiangshan.backend.Bundles.{MemExuInput, MemExuOutput}
27import xiangshan.backend.fu.PMPRespBundle
28import xiangshan.backend.fu.FuConfig._
29import xiangshan.backend.fu.FuType._
30import xiangshan.backend.ctrlblock.DebugLsInfoBundle
31import xiangshan.backend.fu.NewCSR._
32import xiangshan.cache.mmu.{TlbCmd, TlbReq, TlbRequestIO, TlbResp}
33import xiangshan.cache.{DcacheStoreRequestIO, DCacheStoreIO, MemoryOpConstants, HasDCacheParameters, StorePrefetchReq}
34
35class StoreUnit(implicit p: Parameters) extends XSModule
36  with HasDCacheParameters
37  with HasVLSUParameters
38  {
39  val io = IO(new Bundle() {
40    val redirect        = Flipped(ValidIO(new Redirect))
41    val stin            = Flipped(Decoupled(new MemExuInput))
42    val issue           = Valid(new MemExuInput)
43    val tlb             = new TlbRequestIO()
44    val dcache          = new DCacheStoreIO
45    val pmp             = Flipped(new PMPRespBundle())
46    val lsq             = ValidIO(new LsPipelineBundle)
47    val lsq_replenish   = Output(new LsPipelineBundle())
48    val feedback_slow   = ValidIO(new RSFeedback)
49    val prefetch_req    = Flipped(DecoupledIO(new StorePrefetchReq))
50    // provide prefetch info to sms
51    val prefetch_train  = ValidIO(new StPrefetchTrainBundle())
52    // speculative for gated control
53    val s1_prefetch_spec = Output(Bool())
54    val s2_prefetch_spec = Output(Bool())
55    val stld_nuke_query = Valid(new StoreNukeQueryIO)
56    val stout           = DecoupledIO(new MemExuOutput) // writeback store
57    val vecstout        = DecoupledIO(new VecPipelineFeedbackIO(isVStore = true))
58    // store mask, send to sq in store_s0
59    val st_mask_out     = Valid(new StoreMaskBundle)
60    val debug_ls        = Output(new DebugLsInfoBundle)
61    // vector
62    val vecstin           = Flipped(Decoupled(new VecPipeBundle(isVStore = true)))
63    val vec_isFirstIssue  = Input(Bool())
64    // trigger
65    val fromCsrTrigger = Input(new CsrTriggerBundle)
66  })
67
68  val s1_ready, s2_ready, s3_ready = WireInit(false.B)
69
70  // Pipeline
71  // --------------------------------------------------------------------------------
72  // stage 0
73  // --------------------------------------------------------------------------------
74  // generate addr, use addr to query DCache and DTLB
75  val s0_iss_valid    = io.stin.valid
76  val s0_prf_valid    = io.prefetch_req.valid && io.dcache.req.ready
77  val s0_vec_valid    = io.vecstin.valid
78  val s0_valid        = s0_iss_valid || s0_prf_valid || s0_vec_valid
79  val s0_use_flow_vec = s0_vec_valid
80  val s0_use_flow_rs  = s0_iss_valid && !s0_vec_valid
81  val s0_use_flow_prf = !s0_iss_valid && !s0_vec_valid && s0_prf_valid
82  val s0_stin         = Mux(s0_use_flow_rs, io.stin.bits, 0.U.asTypeOf(io.stin.bits))
83  val s0_vecstin      = Mux(s0_use_flow_vec, io.vecstin.bits, 0.U.asTypeOf(io.vecstin.bits))
84  val s0_uop          = Mux(s0_use_flow_rs, s0_stin.uop, s0_vecstin.uop)
85  val s0_isFirstIssue = s0_use_flow_rs && io.stin.bits.isFirstIssue || s0_use_flow_vec && io.vec_isFirstIssue
86  val s0_size         = Mux(s0_use_flow_rs || s0_use_flow_vec, s0_uop.fuOpType(2,0), 0.U)// may broken if use it in feature
87  val s0_mem_idx      = Mux(s0_use_flow_rs || s0_use_flow_vec, s0_uop.sqIdx.value, 0.U)
88  val s0_rob_idx      = Mux(s0_use_flow_rs || s0_use_flow_vec, s0_uop.robIdx, 0.U.asTypeOf(s0_uop.robIdx))
89  val s0_pc           = Mux(s0_use_flow_rs || s0_use_flow_vec, s0_uop.pc, 0.U)
90  val s0_instr_type   = Mux(s0_use_flow_rs || s0_use_flow_vec, STORE_SOURCE.U, DCACHE_PREFETCH_SOURCE.U)
91  val s0_wlineflag    = Mux(s0_use_flow_rs, s0_uop.fuOpType === LSUOpType.cbo_zero, false.B)
92  val s0_out          = Wire(new LsPipelineBundle)
93  val s0_kill         = s0_uop.robIdx.needFlush(io.redirect)
94  val s0_can_go       = s1_ready
95  val s0_fire         = s0_valid && !s0_kill && s0_can_go
96  val s0_is128bit     = is128Bit(s0_vecstin.alignedType)
97  // vector
98  val s0_vecActive    = !s0_use_flow_vec || s0_vecstin.vecActive
99  // val s0_flowPtr      = s0_vecstin.flowPtr
100  // val s0_isLastElem   = s0_vecstin.isLastElem
101  val s0_secondInv    = s0_vecstin.usSecondInv
102  val s0_elemIdx      = s0_vecstin.elemIdx
103  val s0_alignedType  = s0_vecstin.alignedType
104  val s0_mBIndex      = s0_vecstin.mBIndex
105
106  // generate addr
107  // val saddr = s0_in.bits.src(0) + SignExt(s0_in.bits.uop.imm(11,0), VAddrBits)
108  val imm12 = WireInit(s0_uop.imm(11,0))
109  val saddr_lo = s0_stin.src(0)(11,0) + Cat(0.U(1.W), imm12)
110  val saddr_hi = Mux(saddr_lo(12),
111    Mux(imm12(11), s0_stin.src(0)(VAddrBits-1, 12), s0_stin.src(0)(VAddrBits-1, 12)+1.U),
112    Mux(imm12(11), s0_stin.src(0)(VAddrBits-1, 12)+SignExt(1.U, VAddrBits-12), s0_stin.src(0)(VAddrBits-1, 12)),
113  )
114  val s0_saddr = Cat(saddr_hi, saddr_lo(11,0))
115  val s0_vaddr = Mux(
116    s0_use_flow_rs,
117    s0_saddr,
118    Mux(
119      s0_use_flow_vec,
120      s0_vecstin.vaddr,
121      io.prefetch_req.bits.vaddr
122    )
123  )
124  val s0_mask  = Mux(
125    s0_use_flow_rs,
126    genVWmask128(s0_saddr, s0_uop.fuOpType(2,0)),
127    Mux(
128      s0_use_flow_vec,
129      s0_vecstin.mask,
130      // -1.asSInt.asUInt
131      Fill(VLEN/8, 1.U(1.W))
132    )
133  )
134
135  io.tlb.req.valid                   := s0_valid
136  io.tlb.req.bits.vaddr              := s0_vaddr
137  io.tlb.req.bits.cmd                := TlbCmd.write
138  io.tlb.req.bits.size               := s0_size
139  io.tlb.req.bits.kill               := false.B
140  io.tlb.req.bits.memidx.is_ld       := false.B
141  io.tlb.req.bits.memidx.is_st       := true.B
142  io.tlb.req.bits.memidx.idx         := s0_mem_idx
143  io.tlb.req.bits.debug.robIdx       := s0_rob_idx
144  io.tlb.req.bits.no_translate       := false.B
145  io.tlb.req.bits.debug.pc           := s0_pc
146  io.tlb.req.bits.debug.isFirstIssue := s0_isFirstIssue
147  io.tlb.req_kill                    := false.B
148  io.tlb.req.bits.hyperinst          := LSUOpType.isHsv(s0_uop.fuOpType)
149  io.tlb.req.bits.hlvx               := false.B
150
151  // Dcache access here: not **real** dcache write
152  // just read meta and tag in dcache, to find out the store will hit or miss
153
154  // NOTE: The store request does not wait for the dcache to be ready.
155  //       If the dcache is not ready at this time, the dcache is not queried.
156  //       But, store prefetch request will always wait for dcache to be ready to make progress.
157  io.dcache.req.valid              := s0_fire
158  io.dcache.req.bits.cmd           := MemoryOpConstants.M_PFW
159  io.dcache.req.bits.vaddr         := s0_vaddr
160  io.dcache.req.bits.instrtype     := s0_instr_type
161
162  s0_out              := DontCare
163  s0_out.vaddr        := s0_vaddr
164  // Now data use its own io
165  // s1_out.data := genWdata(s1_in.src(1), s1_in.uop.fuOpType(1,0))
166  s0_out.data         := s0_stin.src(1)
167  s0_out.uop          := s0_uop
168  s0_out.miss         := false.B
169  s0_out.mask         := s0_mask
170  s0_out.isFirstIssue := s0_isFirstIssue
171  s0_out.isHWPrefetch := s0_use_flow_prf
172  s0_out.wlineflag    := s0_wlineflag
173  s0_out.isvec        := s0_use_flow_vec
174  s0_out.is128bit     := s0_is128bit
175  s0_out.vecActive    := s0_vecActive
176  s0_out.usSecondInv  := s0_secondInv
177  s0_out.elemIdx      := s0_elemIdx
178  s0_out.alignedType  := s0_alignedType
179  s0_out.mbIndex      := s0_mBIndex
180  when(s0_valid && s0_isFirstIssue) {
181    s0_out.uop.debugInfo.tlbFirstReqTime := GTimer()
182  }
183
184  // exception check
185  val s0_addr_aligned = LookupTree(Mux(s0_use_flow_vec, s0_vecstin.alignedType(1,0), s0_uop.fuOpType(1, 0)), List(
186    "b00".U   -> true.B,              //b
187    "b01".U   -> (s0_out.vaddr(0) === 0.U),   //h
188    "b10".U   -> (s0_out.vaddr(1,0) === 0.U), //w
189    "b11".U   -> (s0_out.vaddr(2,0) === 0.U)  //d
190  ))
191  // if vector store sends 128-bit requests, its address must be 128-aligned
192  XSError(s0_use_flow_vec && s0_out.vaddr(3, 0) =/= 0.U && s0_vecstin.alignedType(2), "unit stride 128 bit element is not aligned!")
193  s0_out.uop.exceptionVec(storeAddrMisaligned) := Mux(s0_use_flow_rs || s0_use_flow_vec, !s0_addr_aligned, false.B)
194
195  io.st_mask_out.valid       := s0_use_flow_rs || s0_use_flow_vec
196  io.st_mask_out.bits.mask   := s0_out.mask
197  io.st_mask_out.bits.sqIdx  := s0_out.uop.sqIdx
198
199  io.stin.ready := s1_ready && s0_use_flow_rs
200  io.vecstin.ready := s1_ready && s0_use_flow_vec
201  io.prefetch_req.ready := s1_ready && io.dcache.req.ready && !s0_iss_valid && !s0_vec_valid
202
203  // Pipeline
204  // --------------------------------------------------------------------------------
205  // stage 1
206  // --------------------------------------------------------------------------------
207  // TLB resp (send paddr to dcache)
208  val s1_valid  = RegInit(false.B)
209  val s1_in     = RegEnable(s0_out, s0_fire)
210  val s1_out    = Wire(new LsPipelineBundle)
211  val s1_kill   = Wire(Bool())
212  val s1_can_go = s2_ready
213  val s1_fire   = s1_valid && !s1_kill && s1_can_go
214  val s1_vecActive    = RegEnable(s0_out.vecActive, true.B, s0_fire)
215
216  // mmio cbo decoder
217  val s1_mmio_cbo  = s1_in.uop.fuOpType === LSUOpType.cbo_clean ||
218                     s1_in.uop.fuOpType === LSUOpType.cbo_flush ||
219                     s1_in.uop.fuOpType === LSUOpType.cbo_inval
220  val s1_paddr     = io.tlb.resp.bits.paddr(0)
221  val s1_gpaddr    = io.tlb.resp.bits.gpaddr(0)
222  val s1_tlb_miss  = io.tlb.resp.bits.miss
223  val s1_mmio      = s1_mmio_cbo
224  val s1_exception = ExceptionNO.selectByFu(s1_out.uop.exceptionVec, StaCfg).asUInt.orR
225  val s1_isvec     = RegEnable(s0_out.isvec, false.B, s0_fire)
226  // val s1_isLastElem = RegEnable(s0_isLastElem, false.B, s0_fire)
227  s1_kill := s1_in.uop.robIdx.needFlush(io.redirect) || (s1_tlb_miss && !s1_isvec)
228
229  s1_ready := !s1_valid || s1_kill || s2_ready
230  io.tlb.resp.ready := true.B // TODO: why dtlbResp needs a ready?
231  when (s0_fire) { s1_valid := true.B }
232  .elsewhen (s1_fire) { s1_valid := false.B }
233  .elsewhen (s1_kill) { s1_valid := false.B }
234
235  // st-ld violation dectect request.
236  io.stld_nuke_query.valid       := s1_valid && !s1_tlb_miss && !s1_in.isHWPrefetch
237  io.stld_nuke_query.bits.robIdx := s1_in.uop.robIdx
238  io.stld_nuke_query.bits.paddr  := s1_paddr
239  io.stld_nuke_query.bits.mask   := s1_in.mask
240  io.stld_nuke_query.bits.matchLine := s1_in.isvec && s1_in.is128bit
241
242  // issue
243  io.issue.valid := s1_valid && !s1_tlb_miss && !s1_in.isHWPrefetch && !s1_isvec
244  io.issue.bits  := RegEnable(s0_stin, s0_valid)
245
246
247  // Send TLB feedback to store issue queue
248  // Store feedback is generated in store_s1, sent to RS in store_s2
249  val s1_feedback = Wire(Valid(new RSFeedback))
250  s1_feedback.valid                 := s1_valid & !s1_in.isHWPrefetch
251  s1_feedback.bits.hit              := !s1_tlb_miss
252  s1_feedback.bits.flushState       := io.tlb.resp.bits.ptwBack
253  s1_feedback.bits.robIdx           := s1_out.uop.robIdx
254  s1_feedback.bits.sourceType       := RSFeedbackType.tlbMiss
255  s1_feedback.bits.dataInvalidSqIdx := DontCare
256  s1_feedback.bits.sqIdx            := s1_out.uop.sqIdx
257  s1_feedback.bits.lqIdx            := s1_out.uop.lqIdx
258
259  XSDebug(s1_feedback.valid,
260    "S1 Store: tlbHit: %d robIdx: %d\n",
261    s1_feedback.bits.hit,
262    s1_feedback.bits.robIdx.value
263  )
264
265  // io.feedback_slow := s1_feedback
266
267  // get paddr from dtlb, check if rollback is needed
268  // writeback store inst to lsq
269  s1_out         := s1_in
270  s1_out.paddr   := s1_paddr
271  s1_out.gpaddr  := s1_gpaddr
272  s1_out.miss    := false.B
273  s1_out.mmio    := s1_mmio
274  s1_out.tlbMiss := s1_tlb_miss
275  s1_out.atomic  := s1_mmio
276  s1_out.uop.exceptionVec(storePageFault)      := io.tlb.resp.bits.excp(0).pf.st && s1_vecActive
277  s1_out.uop.exceptionVec(storeAccessFault)    := io.tlb.resp.bits.excp(0).af.st && s1_vecActive
278  s1_out.uop.exceptionVec(storeGuestPageFault) := io.tlb.resp.bits.excp(0).gpf.st && s1_vecActive
279
280  // trigger
281  val storeTrigger = Module(new StoreTrigger)
282  storeTrigger.io.fromCsrTrigger.tdataVec             := io.fromCsrTrigger.tdataVec
283  storeTrigger.io.fromCsrTrigger.tEnableVec           := io.fromCsrTrigger.tEnableVec
284  storeTrigger.io.fromCsrTrigger.triggerCanRaiseBpExp := io.fromCsrTrigger.triggerCanRaiseBpExp
285  storeTrigger.io.fromStore.vaddr                     := s1_in.vaddr
286
287  s1_out.uop.trigger.backendHit       := storeTrigger.io.toStore.triggerHitVec
288  s1_out.uop.trigger.backendCanFire   := storeTrigger.io.toStore.triggerCanFireVec
289  s1_out.uop.exceptionVec(breakPoint) := storeTrigger.io.toStore.breakPointExp
290
291  // scalar store and scalar load nuke check, and also other purposes
292  io.lsq.valid     := s1_valid && !s1_in.isHWPrefetch
293  io.lsq.bits      := s1_out
294  io.lsq.bits.miss := s1_tlb_miss
295
296  // kill dcache write intent request when tlb miss or exception
297  io.dcache.s1_kill  := (s1_tlb_miss || s1_exception || s1_mmio || s1_in.uop.robIdx.needFlush(io.redirect))
298  io.dcache.s1_paddr := s1_paddr
299
300  // write below io.out.bits assign sentence to prevent overwriting values
301  val s1_tlb_memidx = io.tlb.resp.bits.memidx
302  when(s1_tlb_memidx.is_st && io.tlb.resp.valid && !s1_tlb_miss && s1_tlb_memidx.idx === s1_out.uop.sqIdx.value) {
303    // printf("Store idx = %d\n", s1_tlb_memidx.idx)
304    s1_out.uop.debugInfo.tlbRespTime := GTimer()
305  }
306
307  // Pipeline
308  // --------------------------------------------------------------------------------
309  // stage 2
310  // --------------------------------------------------------------------------------
311  // mmio check
312  val s2_valid  = RegInit(false.B)
313  val s2_in     = RegEnable(s1_out, s1_fire)
314  val s2_out    = Wire(new LsPipelineBundle)
315  val s2_kill   = Wire(Bool())
316  val s2_can_go = s3_ready
317  val s2_fire   = s2_valid && !s2_kill && s2_can_go
318  val s2_vecActive    = RegEnable(s1_out.vecActive, true.B, s1_fire)
319
320  s2_ready := !s2_valid || s2_kill || s3_ready
321  when (s1_fire) { s2_valid := true.B }
322  .elsewhen (s2_fire) { s2_valid := false.B }
323  .elsewhen (s2_kill) { s2_valid := false.B }
324
325  val s2_pmp = WireInit(io.pmp)
326
327  val s2_exception = (ExceptionNO.selectByFu(s2_out.uop.exceptionVec, StaCfg).asUInt.orR) && RegNext(s1_feedback.bits.hit)
328  val s2_mmio = (s2_in.mmio || s2_pmp.mmio) && RegNext(s1_feedback.bits.hit)
329  s2_kill := ((s2_mmio && !s2_exception) && !s2_in.isvec) || s2_in.uop.robIdx.needFlush(io.redirect)
330
331  s2_out        := s2_in
332  s2_out.af     := s2_pmp.st && !s2_in.isvec
333  s2_out.mmio   := s2_mmio && !s2_exception
334  s2_out.atomic := s2_in.atomic || s2_pmp.atomic
335  s2_out.uop.exceptionVec(storeAccessFault) := (s2_in.uop.exceptionVec(storeAccessFault) ||
336                                                s2_pmp.st ||
337                                                (s2_in.isvec && s2_pmp.mmio && RegNext(s1_feedback.bits.hit))
338                                                ) && s2_vecActive
339
340  // kill dcache write intent request when mmio or exception
341  io.dcache.s2_kill := (s2_mmio || s2_exception || s2_in.uop.robIdx.needFlush(io.redirect))
342  io.dcache.s2_pc   := s2_out.uop.pc
343  // TODO: dcache resp
344  io.dcache.resp.ready := true.B
345
346  // feedback tlb miss to RS in store_s2
347  val feedback_slow_valid = WireInit(false.B)
348  feedback_slow_valid := s1_feedback.valid && !s1_out.uop.robIdx.needFlush(io.redirect) && !s1_out.isvec
349  io.feedback_slow.valid := GatedValidRegNext(feedback_slow_valid)
350  io.feedback_slow.bits  := RegEnable(s1_feedback.bits, feedback_slow_valid)
351
352  val s2_vecFeedback = RegNext(!s1_out.uop.robIdx.needFlush(io.redirect) && s1_feedback.bits.hit) && s2_in.isvec
353
354  // mmio and exception
355  io.lsq_replenish := s2_out
356  io.lsq_replenish.af := s2_out.af && !s2_kill
357
358  // prefetch related
359  io.lsq_replenish.miss := io.dcache.resp.fire && io.dcache.resp.bits.miss // miss info
360
361  // RegNext prefetch train for better timing
362  // ** Now, prefetch train is valid at store s3 **
363  val s2_prefetch_train_valid = WireInit(false.B)
364  s2_prefetch_train_valid := s2_valid && io.dcache.resp.fire && !s2_out.mmio && !s2_in.tlbMiss && !s2_in.isHWPrefetch
365  if(EnableStorePrefetchSMS) {
366    io.s1_prefetch_spec := s1_fire
367    io.s2_prefetch_spec := s2_prefetch_train_valid
368    io.prefetch_train.valid := RegNext(s2_prefetch_train_valid)
369    io.prefetch_train.bits.fromLsPipelineBundle(s2_in, latch = true, enable = s2_prefetch_train_valid)
370  }else {
371    io.s1_prefetch_spec := false.B
372    io.s2_prefetch_spec := false.B
373    io.prefetch_train.valid := false.B
374    io.prefetch_train.bits.fromLsPipelineBundle(s2_in, latch = true, enable = false.B)
375  }
376  // override miss bit
377  io.prefetch_train.bits.miss := RegEnable(io.dcache.resp.bits.miss, s2_prefetch_train_valid)
378  // TODO: add prefetch and access bit
379  io.prefetch_train.bits.meta_prefetch := false.B
380  io.prefetch_train.bits.meta_access := false.B
381
382  // Pipeline
383  // --------------------------------------------------------------------------------
384  // stage 3
385  // --------------------------------------------------------------------------------
386  // store write back
387  val s3_valid  = RegInit(false.B)
388  val s3_in     = RegEnable(s2_out, s2_fire)
389  val s3_out    = Wire(new MemExuOutput(isVector = true))
390  val s3_kill   = s3_in.uop.robIdx.needFlush(io.redirect)
391  val s3_can_go = s3_ready
392  val s3_fire   = s3_valid && !s3_kill && s3_can_go
393  val s3_vecFeedback = RegEnable(s2_vecFeedback, s2_fire)
394
395  when (s2_fire) { s3_valid := (!s2_mmio || s2_exception) && !s2_out.isHWPrefetch  }
396  .elsewhen (s3_fire) { s3_valid := false.B }
397  .elsewhen (s3_kill) { s3_valid := false.B }
398
399  // wb: writeback
400  val SelectGroupSize   = RollbackGroupSize
401  val lgSelectGroupSize = log2Ceil(SelectGroupSize)
402  val TotalSelectCycles = scala.math.ceil(log2Ceil(LoadQueueRAWSize).toFloat / lgSelectGroupSize).toInt + 1
403
404  s3_out                 := DontCare
405  s3_out.uop             := s3_in.uop
406  s3_out.data            := DontCare
407  s3_out.debug.isMMIO    := s3_in.mmio
408  s3_out.debug.paddr     := s3_in.paddr
409  s3_out.debug.vaddr     := s3_in.vaddr
410  s3_out.debug.isPerfCnt := false.B
411
412  // Pipeline
413  // --------------------------------------------------------------------------------
414  // stage x
415  // --------------------------------------------------------------------------------
416  // delay TotalSelectCycles - 2 cycle(s)
417  val TotalDelayCycles = TotalSelectCycles - 2
418  val sx_valid = Wire(Vec(TotalDelayCycles + 1, Bool()))
419  val sx_ready = Wire(Vec(TotalDelayCycles + 1, Bool()))
420  val sx_in    = Wire(Vec(TotalDelayCycles + 1, new VecMemExuOutput(isVector = true)))
421
422  // backward ready signal
423  s3_ready := sx_ready.head
424  for (i <- 0 until TotalDelayCycles + 1) {
425    if (i == 0) {
426      sx_valid(i)          := s3_valid
427      sx_in(i).output      := s3_out
428      sx_in(i).vecFeedback := s3_vecFeedback
429      sx_in(i).mmio        := s3_in.mmio
430      sx_in(i).usSecondInv := s3_in.usSecondInv
431      sx_in(i).elemIdx     := s3_in.elemIdx
432      sx_in(i).alignedType := s3_in.alignedType
433      sx_in(i).mbIndex     := s3_in.mbIndex
434      sx_in(i).mask        := s3_in.mask
435      sx_in(i).vaddr       := s3_in.vaddr
436      sx_ready(i) := !s3_valid(i) || sx_in(i).output.uop.robIdx.needFlush(io.redirect) || (if (TotalDelayCycles == 0) io.stout.ready else sx_ready(i+1))
437    } else {
438      val cur_kill   = sx_in(i).output.uop.robIdx.needFlush(io.redirect)
439      val cur_can_go = (if (i == TotalDelayCycles) io.stout.ready else sx_ready(i+1))
440      val cur_fire   = sx_valid(i) && !cur_kill && cur_can_go
441      val prev_fire  = sx_valid(i-1) && !sx_in(i-1).output.uop.robIdx.needFlush(io.redirect) && sx_ready(i)
442
443      sx_ready(i) := !sx_valid(i) || cur_kill || (if (i == TotalDelayCycles) io.stout.ready else sx_ready(i+1))
444      val sx_valid_can_go = prev_fire || cur_fire || cur_kill
445      sx_valid(i) := RegEnable(Mux(prev_fire, true.B, false.B), false.B, sx_valid_can_go)
446      sx_in(i) := RegEnable(sx_in(i-1), prev_fire)
447    }
448  }
449  val sx_last_valid = sx_valid.takeRight(1).head
450  val sx_last_ready = sx_ready.takeRight(1).head
451  val sx_last_in    = sx_in.takeRight(1).head
452  sx_last_ready := !sx_last_valid || sx_last_in.output.uop.robIdx.needFlush(io.redirect) || io.stout.ready
453
454  io.stout.valid := sx_last_valid && !sx_last_in.output.uop.robIdx.needFlush(io.redirect) && isStore(sx_last_in.output.uop.fuType)
455  io.stout.bits := sx_last_in.output
456  io.stout.bits.uop.exceptionVec := ExceptionNO.selectByFu(sx_last_in.output.uop.exceptionVec, StaCfg)
457
458  io.vecstout.valid := sx_last_valid && !sx_last_in.output.uop.robIdx.needFlush(io.redirect) && isVStore(sx_last_in.output.uop.fuType)
459  // TODO: implement it!
460  io.vecstout.bits.mBIndex := sx_last_in.mbIndex
461  io.vecstout.bits.hit := sx_last_in.vecFeedback
462  io.vecstout.bits.isvec := true.B
463  io.vecstout.bits.sourceType := RSFeedbackType.tlbMiss
464  io.vecstout.bits.flushState := DontCare
465  io.vecstout.bits.mmio := sx_last_in.mmio
466  io.vecstout.bits.exceptionVec := ExceptionNO.selectByFu(sx_last_in.output.uop.exceptionVec, VstuCfg)
467  io.vecstout.bits.usSecondInv := sx_last_in.usSecondInv
468  io.vecstout.bits.vecFeedback := sx_last_in.vecFeedback
469  io.vecstout.bits.elemIdx     := sx_last_in.elemIdx
470  io.vecstout.bits.alignedType := sx_last_in.alignedType
471  io.vecstout.bits.mask        := sx_last_in.mask
472  io.vecstout.bits.vaddr       := sx_last_in.vaddr
473  // io.vecstout.bits.reg_offset.map(_ := DontCare)
474  // io.vecstout.bits.elemIdx.map(_ := sx_last_in.elemIdx)
475  // io.vecstout.bits.elemIdxInsideVd.map(_ := DontCare)
476  // io.vecstout.bits.vecdata.map(_ := DontCare)
477  // io.vecstout.bits.mask.map(_ := DontCare)
478  // io.vecstout.bits.alignedType.map(_ := sx_last_in.alignedType)
479
480  io.debug_ls := DontCare
481  io.debug_ls.s1_robIdx := s1_in.uop.robIdx.value
482  io.debug_ls.s1_isTlbFirstMiss := io.tlb.resp.valid && io.tlb.resp.bits.miss && io.tlb.resp.bits.debug.isFirstIssue && !s1_in.isHWPrefetch
483
484  private def printPipeLine(pipeline: LsPipelineBundle, cond: Bool, name: String): Unit = {
485    XSDebug(cond,
486      p"$name" + p" pc ${Hexadecimal(pipeline.uop.pc)} " +
487        p"addr ${Hexadecimal(pipeline.vaddr)} -> ${Hexadecimal(pipeline.paddr)} " +
488        p"op ${Binary(pipeline.uop.fuOpType)} " +
489        p"data ${Hexadecimal(pipeline.data)} " +
490        p"mask ${Hexadecimal(pipeline.mask)}\n"
491    )
492  }
493
494  printPipeLine(s0_out, s0_valid, "S0")
495  printPipeLine(s1_out, s1_valid, "S1")
496
497  // perf cnt
498  XSPerfAccumulate("s0_in_valid",                s0_valid)
499  XSPerfAccumulate("s0_in_fire",                 s0_fire)
500  XSPerfAccumulate("s0_vecin_fire",              s0_fire && s0_use_flow_vec)
501  XSPerfAccumulate("s0_in_fire_first_issue",     s0_fire && s0_isFirstIssue)
502  XSPerfAccumulate("s0_addr_spec_success",       s0_fire && !s0_use_flow_vec && s0_saddr(VAddrBits-1, 12) === s0_stin.src(0)(VAddrBits-1, 12))
503  XSPerfAccumulate("s0_addr_spec_failed",        s0_fire && !s0_use_flow_vec && s0_saddr(VAddrBits-1, 12) =/= s0_stin.src(0)(VAddrBits-1, 12))
504  XSPerfAccumulate("s0_addr_spec_success_once",  s0_fire && !s0_use_flow_vec && s0_saddr(VAddrBits-1, 12) === s0_stin.src(0)(VAddrBits-1, 12) && s0_isFirstIssue)
505  XSPerfAccumulate("s0_addr_spec_failed_once",   s0_fire && !s0_use_flow_vec && s0_saddr(VAddrBits-1, 12) =/= s0_stin.src(0)(VAddrBits-1, 12) && s0_isFirstIssue)
506
507  XSPerfAccumulate("s1_in_valid",                s1_valid)
508  XSPerfAccumulate("s1_in_fire",                 s1_fire)
509  XSPerfAccumulate("s1_in_fire_first_issue",     s1_fire && s1_in.isFirstIssue)
510  XSPerfAccumulate("s1_tlb_miss",                s1_fire && s1_tlb_miss)
511  XSPerfAccumulate("s1_tlb_miss_first_issue",    s1_fire && s1_tlb_miss && s1_in.isFirstIssue)
512  // end
513}