xref: /XiangShan/src/main/scala/xiangshan/backend/rename/RenameTable.scala (revision d197680e9f3f42d3466646f91d1570ce6afccefe)
1/***************************************************************************************
2* Copyright (c) 2020-2021 Institute of Computing Technology, Chinese Academy of Sciences
3* Copyright (c) 2020-2021 Peng Cheng Laboratory
4*
5* XiangShan is licensed under Mulan PSL v2.
6* You can use this software according to the terms and conditions of the Mulan PSL v2.
7* You may obtain a copy of Mulan PSL v2 at:
8*          http://license.coscl.org.cn/MulanPSL2
9*
10* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
11* EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
12* MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
13*
14* See the Mulan PSL v2 for more details.
15***************************************************************************************/
16
17package xiangshan.backend.rename
18
19import org.chipsalliance.cde.config.Parameters
20import chisel3._
21import chisel3.util._
22import utility.HasCircularQueuePtrHelper
23import utility.ParallelPriorityMux
24import utility.GatedValidRegNext
25import utils.XSError
26import xiangshan._
27
28abstract class RegType
29case object Reg_I extends RegType
30case object Reg_F extends RegType
31case object Reg_V extends RegType
32case object Reg_V0 extends RegType
33case object Reg_Vl extends RegType
34
35class RatReadPort(implicit p: Parameters) extends XSBundle {
36  val hold = Input(Bool())
37  val addr = Input(UInt(6.W))
38  val data = Output(UInt(PhyRegIdxWidth.W))
39}
40
41class RatWritePort(implicit p: Parameters) extends XSBundle {
42  val wen = Bool()
43  val addr = UInt(6.W)
44  val data = UInt(PhyRegIdxWidth.W)
45}
46
47class RenameTable(reg_t: RegType)(implicit p: Parameters) extends XSModule with HasCircularQueuePtrHelper {
48
49  // params alias
50  private val numVecRegSrc = backendParams.numVecRegSrc
51  private val numVecRatPorts = numVecRegSrc
52
53  val readPortsNum = reg_t match {
54    case Reg_I => 2
55    case Reg_F => 3
56    case Reg_V => 3
57    case Reg_V0 => 1
58    case Reg_Vl => 1
59  }
60  val rdataNums = reg_t match {
61    case Reg_I => 32
62    case Reg_F => 32
63    case Reg_V => 31 // no v0
64    case Reg_V0 => 1 // v0
65    case Reg_Vl => 1 // vl
66  }
67  val io = IO(new Bundle {
68    val redirect = Input(Bool())
69    val readPorts = Vec(readPortsNum * RenameWidth, new RatReadPort)
70    val specWritePorts = Vec(RabCommitWidth, Input(new RatWritePort))
71    val archWritePorts = Vec(RabCommitWidth, Input(new RatWritePort))
72    val old_pdest = Vec(RabCommitWidth, Output(UInt(PhyRegIdxWidth.W)))
73    val need_free = Vec(RabCommitWidth, Output(Bool()))
74    val snpt = Input(new SnapshotPort)
75    val diffWritePorts = if (backendParams.debugEn) Some(Vec(RabCommitWidth * MaxUopSize, Input(new RatWritePort))) else None
76    val debug_rdata = if (backendParams.debugEn) Some(Vec(rdataNums, Output(UInt(PhyRegIdxWidth.W)))) else None
77    val diff_rdata = if (backendParams.debugEn) Some(Vec(rdataNums, Output(UInt(PhyRegIdxWidth.W)))) else None
78    val debug_v0 = if (backendParams.debugEn) reg_t match {
79      case Reg_V0 => Some(Output(UInt(PhyRegIdxWidth.W)))
80      case _ => None
81    } else None
82    val diff_v0 = if (backendParams.debugEn) reg_t match {
83      case Reg_V0 => Some(Output(UInt(PhyRegIdxWidth.W)))
84      case _ => None
85    } else None
86    val debug_vl = if (backendParams.debugEn) reg_t match {
87      case Reg_Vl => Some(Output(UInt(PhyRegIdxWidth.W)))
88      case _ => None
89    } else None
90    val diff_vl = if (backendParams.debugEn) reg_t match {
91      case Reg_Vl => Some(Output(UInt(PhyRegIdxWidth.W)))
92      case _ => None
93    } else None
94  })
95
96  // speculative rename table
97  val rename_table_init = reg_t match {
98    case Reg_I => VecInit.fill    (IntLogicRegs)(0.U(PhyRegIdxWidth.W))
99    case Reg_F => VecInit.tabulate(FpLogicRegs)(_.U(PhyRegIdxWidth.W))
100    case Reg_V => VecInit.tabulate(VecLogicRegs)(_.U(PhyRegIdxWidth.W))
101    case Reg_V0 => VecInit.tabulate(V0LogicRegs)(_.U(PhyRegIdxWidth.W))
102    case Reg_Vl => VecInit.tabulate(VlLogicRegs)(_.U(PhyRegIdxWidth.W))
103  }
104  val spec_table = RegInit(rename_table_init)
105  val spec_table_next = WireInit(spec_table)
106  // arch state rename table
107  val arch_table = RegInit(rename_table_init)
108  val arch_table_next = WireDefault(arch_table)
109  // old_pdest
110  val old_pdest = RegInit(VecInit.fill(RabCommitWidth)(0.U(PhyRegIdxWidth.W)))
111  val need_free = RegInit(VecInit.fill(RabCommitWidth)(false.B))
112
113  // For better timing, we optimize reading and writing to RenameTable as follows:
114  // (1) Writing at T0 will be actually processed at T1.
115  // (2) Reading is synchronous now.
116  // (3) RAddr at T0 will be used to access the table and get data at T0.
117  // (4) WData at T0 is bypassed to RData at T1.
118  val t1_redirect = GatedValidRegNext(io.redirect, false.B)
119  val t1_raddr = io.readPorts.map(p => RegEnable(p.addr, !p.hold))
120  val t1_rdata_use_t1_raddr = VecInit(t1_raddr.map(spec_table(_)))
121  val t1_wSpec = RegNext(Mux(io.redirect, 0.U.asTypeOf(io.specWritePorts), io.specWritePorts))
122
123  val t1_snpt = RegNext(io.snpt, 0.U.asTypeOf(io.snpt))
124
125  val snapshots = SnapshotGenerator(spec_table, t1_snpt.snptEnq, t1_snpt.snptDeq, t1_redirect, t1_snpt.flushVec)
126
127  // WRITE: when instruction commits or walking
128  val t1_wSpec_addr = t1_wSpec.map(w => Mux(w.wen, UIntToOH(w.addr), 0.U))
129  for ((next, i) <- spec_table_next.zipWithIndex) {
130    val matchVec = t1_wSpec_addr.map(w => w(i))
131    val wMatch = ParallelPriorityMux(matchVec.reverse, t1_wSpec.map(_.data).reverse)
132    // When there's a flush, we use arch_table to update spec_table.
133    next := Mux(
134      t1_redirect,
135      Mux(t1_snpt.useSnpt, snapshots(t1_snpt.snptSelect)(i), arch_table(i)),
136      Mux(VecInit(matchVec).asUInt.orR, wMatch, spec_table(i))
137    )
138  }
139  spec_table := spec_table_next
140
141  // READ: decode-rename stage
142  for ((r, i) <- io.readPorts.zipWithIndex) {
143    val t0_bypass = io.specWritePorts.map(w => w.wen && Mux(r.hold, w.addr === t1_raddr(i), w.addr === r.addr))
144    val t1_bypass = RegNext(Mux(io.redirect, 0.U.asTypeOf(VecInit(t0_bypass)), VecInit(t0_bypass)))
145    val bypass_data = ParallelPriorityMux(t1_bypass.reverse, t1_wSpec.map(_.data).reverse)
146    r.data := Mux(t1_bypass.asUInt.orR, bypass_data, t1_rdata_use_t1_raddr(i))
147  }
148
149  for ((w, i) <- io.archWritePorts.zipWithIndex) {
150    when (w.wen) {
151      arch_table_next(w.addr) := w.data
152    }
153    val arch_mask = VecInit.fill(PhyRegIdxWidth)(w.wen).asUInt
154    old_pdest(i) :=
155      MuxCase(arch_table(w.addr) & arch_mask,
156              io.archWritePorts.take(i).reverse.map(x => (x.wen && x.addr === w.addr, x.data & arch_mask)))
157  }
158  arch_table := arch_table_next
159
160  for (((old, free), i) <- (old_pdest zip need_free).zipWithIndex) {
161    val hasDuplicate = old_pdest.take(i).map(_ === old)
162    val blockedByDup = if (i == 0) false.B else VecInit(hasDuplicate).asUInt.orR
163    free := VecInit(arch_table.map(_ =/= old)).asUInt.andR && !blockedByDup
164  }
165
166  io.old_pdest := old_pdest
167  io.need_free := need_free
168  io.debug_rdata.foreach{ x => reg_t match {
169      case Reg_V => x := arch_table.drop(1).take(rdataNums)
170      case _ => x := arch_table.take(rdataNums)
171    }
172  }
173  io.debug_v0.foreach(_ := arch_table(0))
174  io.debug_vl.foreach(_ := arch_table(0))
175  if (env.EnableDifftest || env.AlwaysBasicDiff) {
176    val difftest_table = RegInit(rename_table_init)
177    val difftest_table_next = WireDefault(difftest_table)
178
179    for (w <- io.diffWritePorts.get) {
180      when(w.wen) {
181        difftest_table_next(w.addr) := w.data
182      }
183    }
184    difftest_table := difftest_table_next
185
186    io.diff_rdata.foreach{ x => reg_t match {
187        case Reg_V => x := difftest_table.drop(1).take(rdataNums)
188        case _ => x := difftest_table.take(rdataNums)
189      }
190    }
191    io.diff_v0.foreach(_ := difftest_table(0))
192    io.diff_vl.foreach(_ := difftest_table(0))
193  }
194  else {
195    io.diff_rdata.foreach(_ := 0.U.asTypeOf(io.debug_rdata.get))
196    io.diff_v0.foreach(_ := 0.U)
197    io.diff_vl.foreach(_ := 0.U)
198  }
199}
200
201class RenameTableWrapper(implicit p: Parameters) extends XSModule {
202
203  // params alias
204  private val numVecRegSrc = backendParams.numVecRegSrc
205  private val numVecRatPorts = numVecRegSrc
206
207  val io = IO(new Bundle() {
208    val redirect = Input(Bool())
209    val rabCommits = Input(new RabCommitIO)
210    val diffCommits = if (backendParams.debugEn) Some(Input(new DiffCommitIO)) else None
211    val intReadPorts = Vec(RenameWidth, Vec(2, new RatReadPort))
212    val intRenamePorts = Vec(RenameWidth, Input(new RatWritePort))
213    val fpReadPorts = Vec(RenameWidth, Vec(3, new RatReadPort))
214    val fpRenamePorts = Vec(RenameWidth, Input(new RatWritePort))
215    val vecReadPorts = Vec(RenameWidth, Vec(numVecRatPorts, new RatReadPort))
216    val vecRenamePorts = Vec(RenameWidth, Input(new RatWritePort))
217    val v0ReadPorts = Vec(RenameWidth, new RatReadPort)
218    val v0RenamePorts = Vec(RenameWidth, Input(new RatWritePort))
219    val vlReadPorts = Vec(RenameWidth, new RatReadPort)
220    val vlRenamePorts = Vec(RenameWidth, Input(new RatWritePort))
221
222    val int_old_pdest = Vec(RabCommitWidth, Output(UInt(PhyRegIdxWidth.W)))
223    val fp_old_pdest = Vec(RabCommitWidth, Output(UInt(PhyRegIdxWidth.W)))
224    val vec_old_pdest = Vec(RabCommitWidth, Output(UInt(PhyRegIdxWidth.W)))
225    val v0_old_pdest = Vec(RabCommitWidth, Output(UInt(PhyRegIdxWidth.W)))
226    val vl_old_pdest = Vec(RabCommitWidth, Output(UInt(PhyRegIdxWidth.W)))
227    val int_need_free = Vec(RabCommitWidth, Output(Bool()))
228    val snpt = Input(new SnapshotPort)
229
230    // for debug printing
231    val debug_int_rat     = if (backendParams.debugEn) Some(Vec(32, Output(UInt(PhyRegIdxWidth.W)))) else None
232    val debug_fp_rat      = if (backendParams.debugEn) Some(Vec(32, Output(UInt(PhyRegIdxWidth.W)))) else None
233    val debug_vec_rat     = if (backendParams.debugEn) Some(Vec(31, Output(UInt(PhyRegIdxWidth.W)))) else None
234    val debug_v0_rat      = if (backendParams.debugEn) Some(Vec(1,Output(UInt(PhyRegIdxWidth.W)))) else None
235    val debug_vl_rat      = if (backendParams.debugEn) Some(Vec(1,Output(UInt(PhyRegIdxWidth.W)))) else None
236
237    val diff_int_rat     = if (backendParams.debugEn) Some(Vec(32, Output(UInt(PhyRegIdxWidth.W)))) else None
238    val diff_fp_rat      = if (backendParams.debugEn) Some(Vec(32, Output(UInt(PhyRegIdxWidth.W)))) else None
239    val diff_vec_rat     = if (backendParams.debugEn) Some(Vec(31, Output(UInt(PhyRegIdxWidth.W)))) else None
240    val diff_v0_rat      = if (backendParams.debugEn) Some(Vec(1,Output(UInt(PhyRegIdxWidth.W)))) else None
241    val diff_vl_rat      = if (backendParams.debugEn) Some(Vec(1,Output(UInt(PhyRegIdxWidth.W)))) else None
242  })
243
244  val intRat = Module(new RenameTable(Reg_I))
245  val fpRat  = Module(new RenameTable(Reg_F))
246  val vecRat = Module(new RenameTable(Reg_V))
247  val v0Rat  = Module(new RenameTable(Reg_V0))
248  val vlRat  = Module(new RenameTable(Reg_Vl))
249
250  io.debug_int_rat .foreach(_ := intRat.io.debug_rdata.get)
251  io.diff_int_rat  .foreach(_ := intRat.io.diff_rdata.get)
252  intRat.io.readPorts <> io.intReadPorts.flatten
253  intRat.io.redirect := io.redirect
254  intRat.io.snpt := io.snpt
255  io.int_old_pdest := intRat.io.old_pdest
256  io.int_need_free := intRat.io.need_free
257  val intDestValid = io.rabCommits.info.map(_.rfWen)
258  for ((arch, i) <- intRat.io.archWritePorts.zipWithIndex) {
259    arch.wen  := io.rabCommits.isCommit && io.rabCommits.commitValid(i) && intDestValid(i)
260    arch.addr := io.rabCommits.info(i).ldest
261    arch.data := io.rabCommits.info(i).pdest
262    XSError(arch.wen && arch.addr === 0.U && arch.data =/= 0.U, "pdest for $0 should be 0\n")
263  }
264  for ((spec, i) <- intRat.io.specWritePorts.zipWithIndex) {
265    spec.wen  := io.rabCommits.isWalk && io.rabCommits.walkValid(i) && intDestValid(i)
266    spec.addr := io.rabCommits.info(i).ldest
267    spec.data := io.rabCommits.info(i).pdest
268    XSError(spec.wen && spec.addr === 0.U && spec.data =/= 0.U, "pdest for $0 should be 0\n")
269  }
270  for ((spec, rename) <- intRat.io.specWritePorts.zip(io.intRenamePorts)) {
271    when (rename.wen) {
272      spec.wen  := true.B
273      spec.addr := rename.addr
274      spec.data := rename.data
275    }
276  }
277  if (backendParams.debugEn) {
278    for ((diff, i) <- intRat.io.diffWritePorts.get.zipWithIndex) {
279      diff.wen := io.diffCommits.get.isCommit && io.diffCommits.get.commitValid(i) && io.diffCommits.get.info(i).rfWen
280      diff.addr := io.diffCommits.get.info(i).ldest
281      diff.data := io.diffCommits.get.info(i).pdest
282    }
283  }
284
285  // debug read ports for difftest
286  io.debug_fp_rat.foreach(_ := fpRat.io.debug_rdata.get)
287  io.diff_fp_rat .foreach(_ := fpRat.io.diff_rdata.get)
288  fpRat.io.readPorts <> io.fpReadPorts.flatten
289  fpRat.io.redirect := io.redirect
290  fpRat.io.snpt := io.snpt
291  io.fp_old_pdest := fpRat.io.old_pdest
292
293  for ((arch, i) <- fpRat.io.archWritePorts.zipWithIndex) {
294    arch.wen  := io.rabCommits.isCommit && io.rabCommits.commitValid(i) && io.rabCommits.info(i).fpWen
295    arch.addr := io.rabCommits.info(i).ldest
296    arch.data := io.rabCommits.info(i).pdest
297  }
298  for ((spec, i) <- fpRat.io.specWritePorts.zipWithIndex) {
299    spec.wen  := io.rabCommits.isWalk && io.rabCommits.walkValid(i) && io.rabCommits.info(i).fpWen
300    spec.addr := io.rabCommits.info(i).ldest
301    spec.data := io.rabCommits.info(i).pdest
302  }
303  for ((spec, rename) <- fpRat.io.specWritePorts.zip(io.fpRenamePorts)) {
304    when (rename.wen) {
305      spec.wen  := true.B
306      spec.addr := rename.addr
307      spec.data := rename.data
308    }
309  }
310  if (backendParams.debugEn) {
311    for ((diff, i) <- fpRat.io.diffWritePorts.get.zipWithIndex) {
312      diff.wen := io.diffCommits.get.isCommit && io.diffCommits.get.commitValid(i) && io.diffCommits.get.info(i).fpWen
313      diff.addr := io.diffCommits.get.info(i).ldest
314      diff.data := io.diffCommits.get.info(i).pdest
315    }
316  }
317
318  // debug read ports for difftest
319  io.debug_vec_rat    .foreach(_ := vecRat.io.debug_rdata.get)
320  io.diff_vec_rat     .foreach(_ := vecRat.io.diff_rdata.get)
321  vecRat.io.readPorts <> io.vecReadPorts.flatten
322  vecRat.io.redirect := io.redirect
323  vecRat.io.snpt := io.snpt
324  io.vec_old_pdest := vecRat.io.old_pdest
325
326  //TODO: RM the donTouch
327  if(backendParams.debugEn) {
328    dontTouch(vecRat.io)
329  }
330  for ((arch, i) <- vecRat.io.archWritePorts.zipWithIndex) {
331    arch.wen  := io.rabCommits.isCommit && io.rabCommits.commitValid(i) && io.rabCommits.info(i).vecWen
332    arch.addr := io.rabCommits.info(i).ldest
333    arch.data := io.rabCommits.info(i).pdest
334  }
335  for ((spec, i) <- vecRat.io.specWritePorts.zipWithIndex) {
336    spec.wen  := io.rabCommits.isWalk && io.rabCommits.walkValid(i) && io.rabCommits.info(i).vecWen
337    spec.addr := io.rabCommits.info(i).ldest
338    spec.data := io.rabCommits.info(i).pdest
339  }
340  for ((spec, rename) <- vecRat.io.specWritePorts.zip(io.vecRenamePorts)) {
341    when (rename.wen) {
342      spec.wen  := true.B
343      spec.addr := rename.addr
344      spec.data := rename.data
345    }
346  }
347  if (backendParams.debugEn) {
348    for ((diff, i) <- vecRat.io.diffWritePorts.get.zipWithIndex) {
349      diff.wen := io.diffCommits.get.isCommit && io.diffCommits.get.commitValid(i) && io.diffCommits.get.info(i).vecWen
350      diff.addr := io.diffCommits.get.info(i).ldest
351      diff.data := io.diffCommits.get.info(i).pdest
352    }
353  }
354
355  // debug read ports for difftest
356  io.debug_v0_rat.foreach(_ := v0Rat.io.debug_rdata.get)
357  io.diff_v0_rat.foreach(_ := v0Rat.io.diff_rdata.get)
358  v0Rat.io.readPorts <> io.v0ReadPorts
359  v0Rat.io.redirect := io.redirect
360  v0Rat.io.snpt := io.snpt
361  io.v0_old_pdest := v0Rat.io.old_pdest
362
363  if (backendParams.debugEn) {
364    dontTouch(v0Rat.io)
365  }
366  for ((arch, i) <- v0Rat.io.archWritePorts.zipWithIndex) {
367    arch.wen := io.rabCommits.isCommit && io.rabCommits.commitValid(i) && io.rabCommits.info(i).v0Wen
368    arch.addr := io.rabCommits.info(i).ldest
369    arch.data := io.rabCommits.info(i).pdest
370  }
371  for ((spec, i) <- v0Rat.io.specWritePorts.zipWithIndex) {
372    spec.wen := io.rabCommits.isWalk && io.rabCommits.walkValid(i) && io.rabCommits.info(i).v0Wen
373    spec.addr := io.rabCommits.info(i).ldest
374    spec.data := io.rabCommits.info(i).pdest
375  }
376  for ((spec, rename) <- v0Rat.io.specWritePorts.zip(io.v0RenamePorts)) {
377    when(rename.wen) {
378      spec.wen := true.B
379      spec.addr := rename.addr
380      spec.data := rename.data
381    }
382  }
383  if (backendParams.debugEn) {
384    for ((diff, i) <- v0Rat.io.diffWritePorts.get.zipWithIndex) {
385      diff.wen := io.diffCommits.get.isCommit && io.diffCommits.get.commitValid(i) && io.diffCommits.get.info(i).v0Wen
386      diff.addr := io.diffCommits.get.info(i).ldest
387      diff.data := io.diffCommits.get.info(i).pdest
388    }
389  }
390
391  // debug read ports for difftest
392  io.debug_vl_rat.foreach(_ := vlRat.io.debug_rdata.get)
393  io.diff_vl_rat.foreach(_ := vlRat.io.diff_rdata.get)
394  vlRat.io.readPorts <> io.vlReadPorts
395  vlRat.io.redirect := io.redirect
396  vlRat.io.snpt := io.snpt
397  io.vl_old_pdest := vlRat.io.old_pdest
398
399  if (backendParams.debugEn) {
400    dontTouch(vlRat.io)
401  }
402  for ((arch, i) <- vlRat.io.archWritePorts.zipWithIndex) {
403    arch.wen := io.rabCommits.isCommit && io.rabCommits.commitValid(i) && io.rabCommits.info(i).vlWen
404    arch.addr := io.rabCommits.info(i).ldest
405    arch.data := io.rabCommits.info(i).pdest
406  }
407  for ((spec, i) <- vlRat.io.specWritePorts.zipWithIndex) {
408    spec.wen := io.rabCommits.isWalk && io.rabCommits.walkValid(i) && io.rabCommits.info(i).vlWen
409    spec.addr := io.rabCommits.info(i).ldest
410    spec.data := io.rabCommits.info(i).pdest
411  }
412  for ((spec, rename) <- vlRat.io.specWritePorts.zip(io.vlRenamePorts)) {
413    when(rename.wen) {
414      spec.wen := true.B
415      spec.addr := rename.addr
416      spec.data := rename.data
417    }
418  }
419  if (backendParams.debugEn) {
420    for ((diff, i) <- vlRat.io.diffWritePorts.get.zipWithIndex) {
421      diff.wen := io.diffCommits.get.isCommit && io.diffCommits.get.commitValid(i) && io.diffCommits.get.info(i).vlWen
422      diff.addr := io.diffCommits.get.info(i).ldest
423      diff.data := io.diffCommits.get.info(i).pdest
424    }
425  }
426}
427