xref: /XiangShan/src/main/scala/xiangshan/backend/rename/RenameTable.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.backend.rename
18
19import org.chipsalliance.cde.config.Parameters
20import chisel3._
21import chisel3.util._
22import utility.HasCircularQueuePtrHelper
23import utility.ParallelPriorityMux
24import utility.GatedValidRegNext
25import utility.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(ratAddrWidth: Int)(implicit p: Parameters) extends XSBundle {
36  val hold = Input(Bool())
37  val addr = Input(UInt(ratAddrWidth.W))
38  val data = Output(UInt(PhyRegIdxWidth.W))
39}
40
41class RatWritePort(ratAddrWidth: Int)(implicit p: Parameters) extends XSBundle {
42  val wen = Bool()
43  val addr = UInt(ratAddrWidth.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 renameTableWidth = reg_t match {
68    case Reg_I => log2Ceil(IntLogicRegs)
69    case Reg_F => log2Ceil(FpLogicRegs)
70    case Reg_V => log2Ceil(VecLogicRegs)
71    case Reg_V0 => log2Ceil(V0LogicRegs)
72    case Reg_Vl => log2Ceil(VlLogicRegs)
73  }
74
75  val io = IO(new Bundle {
76    val redirect = Input(Bool())
77    val readPorts = Vec(readPortsNum * RenameWidth, new RatReadPort(renameTableWidth))
78    val specWritePorts = Vec(RabCommitWidth, Input(new RatWritePort(renameTableWidth)))
79    val archWritePorts = Vec(RabCommitWidth, Input(new RatWritePort(renameTableWidth)))
80    val old_pdest = Vec(RabCommitWidth, Output(UInt(PhyRegIdxWidth.W)))
81    val need_free = Vec(RabCommitWidth, Output(Bool()))
82    val snpt = Input(new SnapshotPort)
83    val diffWritePorts = if (backendParams.debugEn) Some(Vec(RabCommitWidth * MaxUopSize, Input(new RatWritePort(renameTableWidth)))) else None
84    val debug_rdata = if (backendParams.debugEn) Some(Vec(rdataNums, Output(UInt(PhyRegIdxWidth.W)))) else None
85    val diff_rdata = if (backendParams.debugEn) Some(Vec(rdataNums, Output(UInt(PhyRegIdxWidth.W)))) else None
86    val debug_v0 = if (backendParams.debugEn) reg_t match {
87      case Reg_V0 => Some(Output(UInt(PhyRegIdxWidth.W)))
88      case _ => None
89    } else None
90    val diff_v0 = if (backendParams.debugEn) reg_t match {
91      case Reg_V0 => Some(Output(UInt(PhyRegIdxWidth.W)))
92      case _ => None
93    } else None
94    val debug_vl = if (backendParams.debugEn) reg_t match {
95      case Reg_Vl => Some(Output(UInt(PhyRegIdxWidth.W)))
96      case _ => None
97    } else None
98    val diff_vl = if (backendParams.debugEn) reg_t match {
99      case Reg_Vl => Some(Output(UInt(PhyRegIdxWidth.W)))
100      case _ => None
101    } else None
102  })
103
104  // speculative rename table
105  val rename_table_init = reg_t match {
106    case Reg_I => VecInit.fill    (IntLogicRegs)(0.U(PhyRegIdxWidth.W))
107    case Reg_F => VecInit.tabulate(FpLogicRegs)(_.U(PhyRegIdxWidth.W))
108    case Reg_V => VecInit.tabulate(VecLogicRegs)(_.U(PhyRegIdxWidth.W))
109    case Reg_V0 => VecInit.tabulate(V0LogicRegs)(_.U(PhyRegIdxWidth.W))
110    case Reg_Vl => VecInit.tabulate(VlLogicRegs)(_.U(PhyRegIdxWidth.W))
111  }
112  val spec_table = RegInit(rename_table_init)
113  val spec_table_next = WireInit(spec_table)
114  // arch state rename table
115  val arch_table = RegInit(rename_table_init)
116  val arch_table_next = WireDefault(arch_table)
117  // old_pdest
118  val old_pdest = RegInit(VecInit.fill(RabCommitWidth)(0.U(PhyRegIdxWidth.W)))
119  val need_free = RegInit(VecInit.fill(RabCommitWidth)(false.B))
120
121  // For better timing, we optimize reading and writing to RenameTable as follows:
122  // (1) Writing at T0 will be actually processed at T1.
123  // (2) Reading is synchronous now.
124  // (3) RAddr at T0 will be used to access the table and get data at T0.
125  // (4) WData at T0 is bypassed to RData at T1.
126  val t1_redirect = GatedValidRegNext(io.redirect, false.B)
127  val t1_raddr = io.readPorts.map(p => RegEnable(p.addr, !p.hold))
128  val t1_rdata_use_t1_raddr = VecInit(t1_raddr.map(spec_table(_)))
129  val t1_wSpec = RegNext(Mux(io.redirect, 0.U.asTypeOf(io.specWritePorts), io.specWritePorts))
130
131  val t1_snpt = RegNext(io.snpt, 0.U.asTypeOf(io.snpt))
132
133  val snapshots = SnapshotGenerator(spec_table, t1_snpt.snptEnq, t1_snpt.snptDeq, t1_redirect, t1_snpt.flushVec)
134
135  // WRITE: when instruction commits or walking
136  val t1_wSpec_addr = t1_wSpec.map(w => Mux(w.wen, UIntToOH(w.addr), 0.U))
137  for ((next, i) <- spec_table_next.zipWithIndex) {
138    val matchVec = t1_wSpec_addr.map(w => w(i))
139    val wMatch = ParallelPriorityMux(matchVec.reverse, t1_wSpec.map(_.data).reverse)
140    // When there's a flush, we use arch_table to update spec_table.
141    next := Mux(
142      t1_redirect,
143      Mux(t1_snpt.useSnpt, snapshots(t1_snpt.snptSelect)(i), arch_table(i)),
144      Mux(VecInit(matchVec).asUInt.orR, wMatch, spec_table(i))
145    )
146  }
147  spec_table := spec_table_next
148
149  // READ: decode-rename stage
150  for ((r, i) <- io.readPorts.zipWithIndex) {
151    val t0_bypass = io.specWritePorts.map(w => w.wen && Mux(r.hold, w.addr === t1_raddr(i), w.addr === r.addr))
152    val t1_bypass = RegNext(Mux(io.redirect, 0.U.asTypeOf(VecInit(t0_bypass)), VecInit(t0_bypass)))
153    val bypass_data = ParallelPriorityMux(t1_bypass.reverse, t1_wSpec.map(_.data).reverse)
154    r.data := Mux(t1_bypass.asUInt.orR, bypass_data, t1_rdata_use_t1_raddr(i))
155  }
156
157  for ((w, i) <- io.archWritePorts.zipWithIndex) {
158    when (w.wen) {
159      arch_table_next(w.addr) := w.data
160    }
161    val arch_mask = VecInit.fill(PhyRegIdxWidth)(w.wen).asUInt
162    old_pdest(i) :=
163      MuxCase(arch_table(w.addr) & arch_mask,
164              io.archWritePorts.take(i).reverse.map(x => (x.wen && x.addr === w.addr, x.data & arch_mask)))
165  }
166  arch_table := arch_table_next
167
168  for (((old, free), i) <- (old_pdest zip need_free).zipWithIndex) {
169    val hasDuplicate = old_pdest.take(i).map(_ === old)
170    val blockedByDup = if (i == 0) false.B else VecInit(hasDuplicate).asUInt.orR
171    free := VecInit(arch_table.map(_ =/= old)).asUInt.andR && !blockedByDup
172  }
173
174  io.old_pdest := old_pdest
175  io.need_free := need_free
176  io.debug_rdata.foreach{ x => reg_t match {
177      case Reg_V => x := arch_table.drop(1).take(rdataNums)
178      case _ => x := arch_table.take(rdataNums)
179    }
180  }
181  io.debug_v0.foreach(_ := arch_table(0))
182  io.debug_vl.foreach(_ := arch_table(0))
183  if (env.EnableDifftest || env.AlwaysBasicDiff) {
184    val difftest_table = RegInit(rename_table_init)
185    val difftest_table_next = WireDefault(difftest_table)
186
187    for (w <- io.diffWritePorts.get) {
188      when(w.wen) {
189        difftest_table_next(w.addr) := w.data
190      }
191    }
192    difftest_table := difftest_table_next
193
194    io.diff_rdata.foreach{ x => reg_t match {
195        case Reg_V => x := difftest_table.drop(1).take(rdataNums)
196        case _ => x := difftest_table.take(rdataNums)
197      }
198    }
199    io.diff_v0.foreach(_ := difftest_table(0))
200    io.diff_vl.foreach(_ := difftest_table(0))
201  }
202  else {
203    io.diff_rdata.foreach(_ := 0.U.asTypeOf(io.debug_rdata.get))
204    io.diff_v0.foreach(_ := 0.U)
205    io.diff_vl.foreach(_ := 0.U)
206  }
207}
208
209class RenameTableWrapper(implicit p: Parameters) extends XSModule {
210
211  // params alias
212  private val numVecRegSrc = backendParams.numVecRegSrc
213  private val numVecRatPorts = numVecRegSrc
214
215  val io = IO(new Bundle() {
216    val redirect = Input(Bool())
217    val rabCommits = Input(new RabCommitIO)
218    val diffCommits = if (backendParams.debugEn) Some(Input(new DiffCommitIO)) else None
219    val intReadPorts = Vec(RenameWidth, Vec(2, new RatReadPort(IntLogicRegs)))
220    val intRenamePorts = Vec(RenameWidth, Input(new RatWritePort(IntLogicRegs)))
221    val fpReadPorts = Vec(RenameWidth, Vec(3, new RatReadPort(FpLogicRegs)))
222    val fpRenamePorts = Vec(RenameWidth, Input(new RatWritePort(FpLogicRegs)))
223    val vecReadPorts = Vec(RenameWidth, Vec(numVecRatPorts, new RatReadPort(VecLogicRegs)))
224    val vecRenamePorts = Vec(RenameWidth, Input(new RatWritePort(VecLogicRegs)))
225    val v0ReadPorts = Vec(RenameWidth, new RatReadPort(V0LogicRegs))
226    val v0RenamePorts = Vec(RenameWidth, Input(new RatWritePort(V0LogicRegs)))
227    val vlReadPorts = Vec(RenameWidth, new RatReadPort(VlLogicRegs))
228    val vlRenamePorts = Vec(RenameWidth, Input(new RatWritePort(VlLogicRegs)))
229
230    val int_old_pdest = Vec(RabCommitWidth, Output(UInt(PhyRegIdxWidth.W)))
231    val fp_old_pdest = Vec(RabCommitWidth, Output(UInt(PhyRegIdxWidth.W)))
232    val vec_old_pdest = Vec(RabCommitWidth, Output(UInt(PhyRegIdxWidth.W)))
233    val v0_old_pdest = Vec(RabCommitWidth, Output(UInt(PhyRegIdxWidth.W)))
234    val vl_old_pdest = Vec(RabCommitWidth, Output(UInt(PhyRegIdxWidth.W)))
235    val int_need_free = Vec(RabCommitWidth, Output(Bool()))
236    val snpt = Input(new SnapshotPort)
237
238    // for debug printing
239    val debug_int_rat     = if (backendParams.debugEn) Some(Vec(32, Output(UInt(PhyRegIdxWidth.W)))) else None
240    val debug_fp_rat      = if (backendParams.debugEn) Some(Vec(32, Output(UInt(PhyRegIdxWidth.W)))) else None
241    val debug_vec_rat     = if (backendParams.debugEn) Some(Vec(31, Output(UInt(PhyRegIdxWidth.W)))) else None
242    val debug_v0_rat      = if (backendParams.debugEn) Some(Vec(1,Output(UInt(PhyRegIdxWidth.W)))) else None
243    val debug_vl_rat      = if (backendParams.debugEn) Some(Vec(1,Output(UInt(PhyRegIdxWidth.W)))) else None
244
245    val diff_int_rat     = if (backendParams.debugEn) Some(Vec(32, Output(UInt(PhyRegIdxWidth.W)))) else None
246    val diff_fp_rat      = if (backendParams.debugEn) Some(Vec(32, Output(UInt(PhyRegIdxWidth.W)))) else None
247    val diff_vec_rat     = if (backendParams.debugEn) Some(Vec(31, Output(UInt(PhyRegIdxWidth.W)))) else None
248    val diff_v0_rat      = if (backendParams.debugEn) Some(Vec(1,Output(UInt(PhyRegIdxWidth.W)))) else None
249    val diff_vl_rat      = if (backendParams.debugEn) Some(Vec(1,Output(UInt(PhyRegIdxWidth.W)))) else None
250  })
251
252  val intRat = Module(new RenameTable(Reg_I))
253  val fpRat  = Module(new RenameTable(Reg_F))
254  val vecRat = Module(new RenameTable(Reg_V))
255  val v0Rat  = Module(new RenameTable(Reg_V0))
256  val vlRat  = Module(new RenameTable(Reg_Vl))
257
258  io.debug_int_rat .foreach(_ := intRat.io.debug_rdata.get)
259  io.diff_int_rat  .foreach(_ := intRat.io.diff_rdata.get)
260  intRat.io.readPorts <> io.intReadPorts.flatten
261  intRat.io.redirect := io.redirect
262  intRat.io.snpt := io.snpt
263  io.int_old_pdest := intRat.io.old_pdest
264  io.int_need_free := intRat.io.need_free
265  val intDestValid = io.rabCommits.info.map(_.rfWen)
266  for ((arch, i) <- intRat.io.archWritePorts.zipWithIndex) {
267    arch.wen  := io.rabCommits.isCommit && io.rabCommits.commitValid(i) && intDestValid(i)
268    arch.addr := io.rabCommits.info(i).ldest
269    arch.data := io.rabCommits.info(i).pdest
270    XSError(arch.wen && arch.addr === 0.U && arch.data =/= 0.U, "pdest for $0 should be 0\n")
271  }
272  for ((spec, i) <- intRat.io.specWritePorts.zipWithIndex) {
273    spec.wen  := io.rabCommits.isWalk && io.rabCommits.walkValid(i) && intDestValid(i)
274    spec.addr := io.rabCommits.info(i).ldest
275    spec.data := io.rabCommits.info(i).pdest
276    XSError(spec.wen && spec.addr === 0.U && spec.data =/= 0.U, "pdest for $0 should be 0\n")
277  }
278  for ((spec, rename) <- intRat.io.specWritePorts.zip(io.intRenamePorts)) {
279    when (rename.wen) {
280      spec.wen  := true.B
281      spec.addr := rename.addr
282      spec.data := rename.data
283    }
284  }
285  if (backendParams.debugEn) {
286    for ((diff, i) <- intRat.io.diffWritePorts.get.zipWithIndex) {
287      diff.wen := io.diffCommits.get.isCommit && io.diffCommits.get.commitValid(i) && io.diffCommits.get.info(i).rfWen
288      diff.addr := io.diffCommits.get.info(i).ldest
289      diff.data := io.diffCommits.get.info(i).pdest
290    }
291  }
292
293  // debug read ports for difftest
294  io.debug_fp_rat.foreach(_ := fpRat.io.debug_rdata.get)
295  io.diff_fp_rat .foreach(_ := fpRat.io.diff_rdata.get)
296  fpRat.io.readPorts <> io.fpReadPorts.flatten
297  fpRat.io.redirect := io.redirect
298  fpRat.io.snpt := io.snpt
299  io.fp_old_pdest := fpRat.io.old_pdest
300
301  for ((arch, i) <- fpRat.io.archWritePorts.zipWithIndex) {
302    arch.wen  := io.rabCommits.isCommit && io.rabCommits.commitValid(i) && io.rabCommits.info(i).fpWen
303    arch.addr := io.rabCommits.info(i).ldest
304    arch.data := io.rabCommits.info(i).pdest
305  }
306  for ((spec, i) <- fpRat.io.specWritePorts.zipWithIndex) {
307    spec.wen  := io.rabCommits.isWalk && io.rabCommits.walkValid(i) && io.rabCommits.info(i).fpWen
308    spec.addr := io.rabCommits.info(i).ldest
309    spec.data := io.rabCommits.info(i).pdest
310  }
311  for ((spec, rename) <- fpRat.io.specWritePorts.zip(io.fpRenamePorts)) {
312    when (rename.wen) {
313      spec.wen  := true.B
314      spec.addr := rename.addr
315      spec.data := rename.data
316    }
317  }
318  if (backendParams.debugEn) {
319    for ((diff, i) <- fpRat.io.diffWritePorts.get.zipWithIndex) {
320      diff.wen := io.diffCommits.get.isCommit && io.diffCommits.get.commitValid(i) && io.diffCommits.get.info(i).fpWen
321      diff.addr := io.diffCommits.get.info(i).ldest
322      diff.data := io.diffCommits.get.info(i).pdest
323    }
324  }
325
326  // debug read ports for difftest
327  io.debug_vec_rat    .foreach(_ := vecRat.io.debug_rdata.get)
328  io.diff_vec_rat     .foreach(_ := vecRat.io.diff_rdata.get)
329  vecRat.io.readPorts <> io.vecReadPorts.flatten
330  vecRat.io.redirect := io.redirect
331  vecRat.io.snpt := io.snpt
332  io.vec_old_pdest := vecRat.io.old_pdest
333
334  //TODO: RM the donTouch
335  if(backendParams.debugEn) {
336    dontTouch(vecRat.io)
337  }
338  for ((arch, i) <- vecRat.io.archWritePorts.zipWithIndex) {
339    arch.wen  := io.rabCommits.isCommit && io.rabCommits.commitValid(i) && io.rabCommits.info(i).vecWen
340    arch.addr := io.rabCommits.info(i).ldest
341    arch.data := io.rabCommits.info(i).pdest
342  }
343  for ((spec, i) <- vecRat.io.specWritePorts.zipWithIndex) {
344    spec.wen  := io.rabCommits.isWalk && io.rabCommits.walkValid(i) && io.rabCommits.info(i).vecWen
345    spec.addr := io.rabCommits.info(i).ldest
346    spec.data := io.rabCommits.info(i).pdest
347  }
348  for ((spec, rename) <- vecRat.io.specWritePorts.zip(io.vecRenamePorts)) {
349    when (rename.wen) {
350      spec.wen  := true.B
351      spec.addr := rename.addr
352      spec.data := rename.data
353    }
354  }
355  if (backendParams.debugEn) {
356    for ((diff, i) <- vecRat.io.diffWritePorts.get.zipWithIndex) {
357      diff.wen := io.diffCommits.get.isCommit && io.diffCommits.get.commitValid(i) && io.diffCommits.get.info(i).vecWen
358      diff.addr := io.diffCommits.get.info(i).ldest
359      diff.data := io.diffCommits.get.info(i).pdest
360    }
361  }
362
363  // debug read ports for difftest
364  io.debug_v0_rat.foreach(_ := v0Rat.io.debug_rdata.get)
365  io.diff_v0_rat.foreach(_ := v0Rat.io.diff_rdata.get)
366  v0Rat.io.readPorts <> io.v0ReadPorts
367  v0Rat.io.redirect := io.redirect
368  v0Rat.io.snpt := io.snpt
369  io.v0_old_pdest := v0Rat.io.old_pdest
370
371  if (backendParams.debugEn) {
372    dontTouch(v0Rat.io)
373  }
374  for ((arch, i) <- v0Rat.io.archWritePorts.zipWithIndex) {
375    arch.wen := io.rabCommits.isCommit && io.rabCommits.commitValid(i) && io.rabCommits.info(i).v0Wen
376    arch.addr := io.rabCommits.info(i).ldest
377    arch.data := io.rabCommits.info(i).pdest
378  }
379  for ((spec, i) <- v0Rat.io.specWritePorts.zipWithIndex) {
380    spec.wen := io.rabCommits.isWalk && io.rabCommits.walkValid(i) && io.rabCommits.info(i).v0Wen
381    spec.addr := io.rabCommits.info(i).ldest
382    spec.data := io.rabCommits.info(i).pdest
383  }
384  for ((spec, rename) <- v0Rat.io.specWritePorts.zip(io.v0RenamePorts)) {
385    when(rename.wen) {
386      spec.wen := true.B
387      spec.addr := rename.addr
388      spec.data := rename.data
389    }
390  }
391  if (backendParams.debugEn) {
392    for ((diff, i) <- v0Rat.io.diffWritePorts.get.zipWithIndex) {
393      diff.wen := io.diffCommits.get.isCommit && io.diffCommits.get.commitValid(i) && io.diffCommits.get.info(i).v0Wen
394      diff.addr := io.diffCommits.get.info(i).ldest
395      diff.data := io.diffCommits.get.info(i).pdest
396    }
397  }
398
399  // debug read ports for difftest
400  io.debug_vl_rat.foreach(_ := vlRat.io.debug_rdata.get)
401  io.diff_vl_rat.foreach(_ := vlRat.io.diff_rdata.get)
402  vlRat.io.readPorts <> io.vlReadPorts
403  vlRat.io.redirect := io.redirect
404  vlRat.io.snpt := io.snpt
405  io.vl_old_pdest := vlRat.io.old_pdest
406
407  if (backendParams.debugEn) {
408    dontTouch(vlRat.io)
409  }
410  for ((arch, i) <- vlRat.io.archWritePorts.zipWithIndex) {
411    arch.wen := io.rabCommits.isCommit && io.rabCommits.commitValid(i) && io.rabCommits.info(i).vlWen
412    arch.addr := io.rabCommits.info(i).ldest
413    arch.data := io.rabCommits.info(i).pdest
414  }
415  for ((spec, i) <- vlRat.io.specWritePorts.zipWithIndex) {
416    spec.wen := io.rabCommits.isWalk && io.rabCommits.walkValid(i) && io.rabCommits.info(i).vlWen
417    spec.addr := io.rabCommits.info(i).ldest
418    spec.data := io.rabCommits.info(i).pdest
419  }
420  for ((spec, rename) <- vlRat.io.specWritePorts.zip(io.vlRenamePorts)) {
421    when(rename.wen) {
422      spec.wen := true.B
423      spec.addr := rename.addr
424      spec.data := rename.data
425    }
426  }
427  if (backendParams.debugEn) {
428    for ((diff, i) <- vlRat.io.diffWritePorts.get.zipWithIndex) {
429      diff.wen := io.diffCommits.get.isCommit && io.diffCommits.get.commitValid(i) && io.diffCommits.get.info(i).vlWen
430      diff.addr := io.diffCommits.get.info(i).ldest
431      diff.data := io.diffCommits.get.info(i).pdest
432    }
433  }
434}
435