xref: /XiangShan/src/main/scala/xiangshan/backend/rename/RenameTable.scala (revision aeadbae06049cd419f67aac119ffd3d9af058d6e)
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 => numVecRatPorts // +1 ldest
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(_ := arch_table.take(rdataNums))
169  io.debug_v0.foreach(_ := arch_table(0))
170  io.debug_vl.foreach(_ := arch_table(0))
171  if (env.EnableDifftest || env.AlwaysBasicDiff) {
172    val difftest_table = RegInit(rename_table_init)
173    val difftest_table_next = WireDefault(difftest_table)
174
175    for (w <- io.diffWritePorts.get) {
176      when(w.wen) {
177        difftest_table_next(w.addr) := w.data
178      }
179    }
180    difftest_table := difftest_table_next
181
182    io.diff_rdata.foreach(_ := difftest_table.take(rdataNums))
183    io.diff_v0.foreach(_ := difftest_table(0))
184    io.diff_vl.foreach(_ := difftest_table(0))
185  }
186  else {
187    io.diff_rdata.foreach(_ := 0.U.asTypeOf(io.debug_rdata.get))
188    io.diff_v0.foreach(_ := 0.U)
189    io.diff_vl.foreach(_ := 0.U)
190  }
191}
192
193class RenameTableWrapper(implicit p: Parameters) extends XSModule {
194
195  // params alias
196  private val numVecRegSrc = backendParams.numVecRegSrc
197  private val numVecRatPorts = numVecRegSrc
198
199  val io = IO(new Bundle() {
200    val redirect = Input(Bool())
201    val rabCommits = Input(new RabCommitIO)
202    val diffCommits = if (backendParams.debugEn) Some(Input(new DiffCommitIO)) else None
203    val intReadPorts = Vec(RenameWidth, Vec(2, new RatReadPort))
204    val intRenamePorts = Vec(RenameWidth, Input(new RatWritePort))
205    val fpReadPorts = Vec(RenameWidth, Vec(3, new RatReadPort))
206    val fpRenamePorts = Vec(RenameWidth, Input(new RatWritePort))
207    val vecReadPorts = Vec(RenameWidth, Vec(numVecRatPorts, new RatReadPort))
208    val vecRenamePorts = Vec(RenameWidth, Input(new RatWritePort))
209    val v0ReadPorts = Vec(RenameWidth, new RatReadPort)
210    val v0RenamePorts = Vec(RenameWidth, Input(new RatWritePort))
211    val vlReadPorts = Vec(RenameWidth, new RatReadPort)
212    val vlRenamePorts = Vec(RenameWidth, Input(new RatWritePort))
213
214    val int_old_pdest = Vec(RabCommitWidth, Output(UInt(PhyRegIdxWidth.W)))
215    val fp_old_pdest = Vec(RabCommitWidth, Output(UInt(PhyRegIdxWidth.W)))
216    val vec_old_pdest = Vec(RabCommitWidth, Output(UInt(PhyRegIdxWidth.W)))
217    val v0_old_pdest = Vec(RabCommitWidth, Output(UInt(PhyRegIdxWidth.W)))
218    val vl_old_pdest = Vec(RabCommitWidth, Output(UInt(PhyRegIdxWidth.W)))
219    val int_need_free = Vec(RabCommitWidth, Output(Bool()))
220    val snpt = Input(new SnapshotPort)
221
222    // for debug printing
223    val debug_int_rat     = if (backendParams.debugEn) Some(Vec(32, Output(UInt(PhyRegIdxWidth.W)))) else None
224    val debug_fp_rat      = if (backendParams.debugEn) Some(Vec(32, Output(UInt(PhyRegIdxWidth.W)))) else None
225    val debug_vec_rat     = if (backendParams.debugEn) Some(Vec(31, Output(UInt(PhyRegIdxWidth.W)))) else None
226    val debug_v0_rat      = if (backendParams.debugEn) Some(Output(UInt(PhyRegIdxWidth.W))) else None
227    val debug_vl_rat      = if (backendParams.debugEn) Some(Output(UInt(PhyRegIdxWidth.W))) else None
228
229    val diff_int_rat     = if (backendParams.debugEn) Some(Vec(32, Output(UInt(PhyRegIdxWidth.W)))) else None
230    val diff_fp_rat      = if (backendParams.debugEn) Some(Vec(32, Output(UInt(PhyRegIdxWidth.W)))) else None
231    val diff_vec_rat     = if (backendParams.debugEn) Some(Vec(31, Output(UInt(PhyRegIdxWidth.W)))) else None
232    val diff_v0_rat      = if (backendParams.debugEn) Some(Output(UInt(PhyRegIdxWidth.W))) else None
233    val diff_vl_rat      = if (backendParams.debugEn) Some(Output(UInt(PhyRegIdxWidth.W))) else None
234  })
235
236  val intRat = Module(new RenameTable(Reg_I))
237  val fpRat  = Module(new RenameTable(Reg_F))
238  val vecRat = Module(new RenameTable(Reg_V))
239  val v0Rat  = Module(new RenameTable(Reg_V0))
240  val vlRat  = Module(new RenameTable(Reg_Vl))
241
242  io.debug_int_rat .foreach(_ := intRat.io.debug_rdata.get)
243  io.diff_int_rat  .foreach(_ := intRat.io.diff_rdata.get)
244  intRat.io.readPorts <> io.intReadPorts.flatten
245  intRat.io.redirect := io.redirect
246  intRat.io.snpt := io.snpt
247  io.int_old_pdest := intRat.io.old_pdest
248  io.int_need_free := intRat.io.need_free
249  val intDestValid = io.rabCommits.info.map(_.rfWen)
250  for ((arch, i) <- intRat.io.archWritePorts.zipWithIndex) {
251    arch.wen  := io.rabCommits.isCommit && io.rabCommits.commitValid(i) && intDestValid(i)
252    arch.addr := io.rabCommits.info(i).ldest
253    arch.data := io.rabCommits.info(i).pdest
254    XSError(arch.wen && arch.addr === 0.U && arch.data =/= 0.U, "pdest for $0 should be 0\n")
255  }
256  for ((spec, i) <- intRat.io.specWritePorts.zipWithIndex) {
257    spec.wen  := io.rabCommits.isWalk && io.rabCommits.walkValid(i) && intDestValid(i)
258    spec.addr := io.rabCommits.info(i).ldest
259    spec.data := io.rabCommits.info(i).pdest
260    XSError(spec.wen && spec.addr === 0.U && spec.data =/= 0.U, "pdest for $0 should be 0\n")
261  }
262  for ((spec, rename) <- intRat.io.specWritePorts.zip(io.intRenamePorts)) {
263    when (rename.wen) {
264      spec.wen  := true.B
265      spec.addr := rename.addr
266      spec.data := rename.data
267    }
268  }
269  if (backendParams.debugEn) {
270    for ((diff, i) <- intRat.io.diffWritePorts.get.zipWithIndex) {
271      diff.wen := io.diffCommits.get.isCommit && io.diffCommits.get.commitValid(i) && io.diffCommits.get.info(i).rfWen
272      diff.addr := io.diffCommits.get.info(i).ldest
273      diff.data := io.diffCommits.get.info(i).pdest
274    }
275  }
276
277  // debug read ports for difftest
278  io.debug_fp_rat.foreach(_ := fpRat.io.debug_rdata.get)
279  io.diff_fp_rat .foreach(_ := fpRat.io.diff_rdata.get)
280  fpRat.io.readPorts <> io.fpReadPorts.flatten
281  fpRat.io.redirect := io.redirect
282  fpRat.io.snpt := io.snpt
283  io.fp_old_pdest := fpRat.io.old_pdest
284
285  for ((arch, i) <- fpRat.io.archWritePorts.zipWithIndex) {
286    arch.wen  := io.rabCommits.isCommit && io.rabCommits.commitValid(i) && io.rabCommits.info(i).fpWen
287    arch.addr := io.rabCommits.info(i).ldest
288    arch.data := io.rabCommits.info(i).pdest
289  }
290  for ((spec, i) <- fpRat.io.specWritePorts.zipWithIndex) {
291    spec.wen  := io.rabCommits.isWalk && io.rabCommits.walkValid(i) && io.rabCommits.info(i).fpWen
292    spec.addr := io.rabCommits.info(i).ldest
293    spec.data := io.rabCommits.info(i).pdest
294  }
295  for ((spec, rename) <- fpRat.io.specWritePorts.zip(io.fpRenamePorts)) {
296    when (rename.wen) {
297      spec.wen  := true.B
298      spec.addr := rename.addr
299      spec.data := rename.data
300    }
301  }
302  if (backendParams.debugEn) {
303    for ((diff, i) <- fpRat.io.diffWritePorts.get.zipWithIndex) {
304      diff.wen := io.diffCommits.get.isCommit && io.diffCommits.get.commitValid(i) && io.diffCommits.get.info(i).fpWen
305      diff.addr := io.diffCommits.get.info(i).ldest
306      diff.data := io.diffCommits.get.info(i).pdest
307    }
308  }
309
310  // debug read ports for difftest
311  io.debug_vec_rat    .foreach(_ := vecRat.io.debug_rdata.get)
312  io.diff_vec_rat     .foreach(_ := vecRat.io.diff_rdata.get)
313  vecRat.io.readPorts <> io.vecReadPorts.flatten
314  vecRat.io.redirect := io.redirect
315  vecRat.io.snpt := io.snpt
316  io.vec_old_pdest := vecRat.io.old_pdest
317
318  //TODO: RM the donTouch
319  if(backendParams.debugEn) {
320    dontTouch(vecRat.io)
321  }
322  for ((arch, i) <- vecRat.io.archWritePorts.zipWithIndex) {
323    arch.wen  := io.rabCommits.isCommit && io.rabCommits.commitValid(i) && io.rabCommits.info(i).vecWen
324    arch.addr := io.rabCommits.info(i).ldest
325    arch.data := io.rabCommits.info(i).pdest
326  }
327  for ((spec, i) <- vecRat.io.specWritePorts.zipWithIndex) {
328    spec.wen  := io.rabCommits.isWalk && io.rabCommits.walkValid(i) && io.rabCommits.info(i).vecWen
329    spec.addr := io.rabCommits.info(i).ldest
330    spec.data := io.rabCommits.info(i).pdest
331  }
332  for ((spec, rename) <- vecRat.io.specWritePorts.zip(io.vecRenamePorts)) {
333    when (rename.wen) {
334      spec.wen  := true.B
335      spec.addr := rename.addr
336      spec.data := rename.data
337    }
338  }
339  if (backendParams.debugEn) {
340    for ((diff, i) <- vecRat.io.diffWritePorts.get.zipWithIndex) {
341      diff.wen := io.diffCommits.get.isCommit && io.diffCommits.get.commitValid(i) && io.diffCommits.get.info(i).vecWen
342      diff.addr := io.diffCommits.get.info(i).ldest
343      diff.data := io.diffCommits.get.info(i).pdest
344    }
345  }
346
347  // debug read ports for difftest
348  io.debug_v0_rat.foreach(_ := v0Rat.io.debug_rdata.get)
349  io.diff_v0_rat.foreach(_ := v0Rat.io.diff_rdata.get)
350  v0Rat.io.readPorts <> io.v0ReadPorts
351  v0Rat.io.redirect := io.redirect
352  v0Rat.io.snpt := io.snpt
353  io.v0_old_pdest := v0Rat.io.old_pdest
354
355  if (backendParams.debugEn) {
356    dontTouch(v0Rat.io)
357  }
358  for ((arch, i) <- v0Rat.io.archWritePorts.zipWithIndex) {
359    arch.wen := io.rabCommits.isCommit && io.rabCommits.commitValid(i) && io.rabCommits.info(i).v0Wen
360    arch.addr := io.rabCommits.info(i).ldest
361    arch.data := io.rabCommits.info(i).pdest
362  }
363  for ((spec, i) <- v0Rat.io.specWritePorts.zipWithIndex) {
364    spec.wen := io.rabCommits.isWalk && io.rabCommits.walkValid(i) && io.rabCommits.info(i).v0Wen
365    spec.addr := io.rabCommits.info(i).ldest
366    spec.data := io.rabCommits.info(i).pdest
367  }
368  for ((spec, rename) <- v0Rat.io.specWritePorts.zip(io.v0RenamePorts)) {
369    when(rename.wen) {
370      spec.wen := true.B
371      spec.addr := rename.addr
372      spec.data := rename.data
373    }
374  }
375  if (backendParams.debugEn) {
376    for ((diff, i) <- v0Rat.io.diffWritePorts.get.zipWithIndex) {
377      diff.wen := io.diffCommits.get.isCommit && io.diffCommits.get.commitValid(i) && io.diffCommits.get.info(i).v0Wen
378      diff.addr := io.diffCommits.get.info(i).ldest
379      diff.data := io.diffCommits.get.info(i).pdest
380    }
381  }
382
383  // debug read ports for difftest
384  io.debug_vl_rat.foreach(_ := vlRat.io.debug_rdata.get)
385  io.diff_vl_rat.foreach(_ := vlRat.io.diff_rdata.get)
386  vlRat.io.readPorts <> io.vlReadPorts
387  vlRat.io.redirect := io.redirect
388  vlRat.io.snpt := io.snpt
389  io.vl_old_pdest := vlRat.io.old_pdest
390
391  if (backendParams.debugEn) {
392    dontTouch(vlRat.io)
393  }
394  for ((arch, i) <- vlRat.io.archWritePorts.zipWithIndex) {
395    arch.wen := io.rabCommits.isCommit && io.rabCommits.commitValid(i) && io.rabCommits.info(i).vlWen
396    arch.addr := io.rabCommits.info(i).ldest
397    arch.data := io.rabCommits.info(i).pdest
398  }
399  for ((spec, i) <- vlRat.io.specWritePorts.zipWithIndex) {
400    spec.wen := io.rabCommits.isWalk && io.rabCommits.walkValid(i) && io.rabCommits.info(i).vlWen
401    spec.addr := io.rabCommits.info(i).ldest
402    spec.data := io.rabCommits.info(i).pdest
403  }
404  for ((spec, rename) <- vlRat.io.specWritePorts.zip(io.vlRenamePorts)) {
405    when(rename.wen) {
406      spec.wen := true.B
407      spec.addr := rename.addr
408      spec.data := rename.data
409    }
410  }
411  if (backendParams.debugEn) {
412    for ((diff, i) <- vlRat.io.diffWritePorts.get.zipWithIndex) {
413      diff.wen := io.diffCommits.get.isCommit && io.diffCommits.get.commitValid(i) && io.diffCommits.get.info(i).vlWen
414      diff.addr := io.diffCommits.get.info(i).ldest
415      diff.data := io.diffCommits.get.info(i).pdest
416    }
417  }
418}
419