xref: /XiangShan/src/main/scala/xiangshan/backend/rename/Rename.scala (revision 4d8915fda0e6d6f5e1468fbbcaadb531c95e25c4)
1package xiangshan.backend.rename
2
3import chisel3._
4import chisel3.util._
5import xiangshan._
6import utils.XSInfo
7
8class Rename extends XSModule {
9  val io = IO(new Bundle() {
10    val redirect = Flipped(ValidIO(new Redirect))
11    val roqCommits = Vec(CommitWidth, Flipped(ValidIO(new RoqCommit)))
12    val wbIntResults = Vec(NRIntWritePorts, Flipped(ValidIO(new ExuOutput)))
13    val wbFpResults = Vec(NRFpWritePorts, Flipped(ValidIO(new ExuOutput)))
14    val intRfReadAddr = Vec(NRIntReadPorts + NRMemReadPorts, Input(UInt(PhyRegIdxWidth.W)))
15    val fpRfReadAddr = Vec(NRFpReadPorts, Input(UInt(PhyRegIdxWidth.W)))
16    val intPregRdy = Vec(NRIntReadPorts + NRMemReadPorts, Output(Bool()))
17    val fpPregRdy = Vec(NRFpReadPorts, Output(Bool()))
18    // set preg to busy when replay
19    val replayPregReq = Vec(ReplayWidth, Input(new ReplayPregReq))
20    // from decode buffer
21    val in = Vec(RenameWidth, Flipped(DecoupledIO(new CfCtrl)))
22    // to dispatch1
23    val out = Vec(RenameWidth, DecoupledIO(new MicroOp))
24  })
25
26  def printRenameInfo(in: DecoupledIO[CfCtrl], out: DecoupledIO[MicroOp]) = {
27    XSInfo(
28      in.valid && in.ready,
29      p"pc:${Hexadecimal(in.bits.cf.pc)} in v:${in.valid} in rdy:${in.ready} " +
30        p"lsrc1:${in.bits.ctrl.lsrc1} -> psrc1:${out.bits.psrc1} " +
31        p"lsrc2:${in.bits.ctrl.lsrc2} -> psrc2:${out.bits.psrc2} " +
32        p"lsrc3:${in.bits.ctrl.lsrc3} -> psrc3:${out.bits.psrc3} " +
33        p"ldest:${in.bits.ctrl.ldest} -> pdest:${out.bits.pdest} " +
34        p"old_pdest:${out.bits.old_pdest} " +
35        p"out v:${out.valid} r:${out.ready}\n"
36    )
37  }
38
39  for((x,y) <- io.in.zip(io.out)){
40    printRenameInfo(x, y)
41  }
42
43  val fpFreeList, intFreeList = Module(new FreeList).io
44  val fpRat = Module(new RenameTable(float = true)).io
45  val intRat = Module(new RenameTable(float = false)).io
46  val fpBusyTable = Module(new BusyTable(NRFpReadPorts, NRFpWritePorts)).io
47  val intBusyTable = Module(new BusyTable(NRIntReadPorts+NRMemReadPorts, NRIntWritePorts)).io
48
49  fpFreeList.redirect := io.redirect
50  intFreeList.redirect := io.redirect
51
52  val flush = io.redirect.valid && (io.redirect.bits.isException || io.redirect.bits.isFlushPipe) // TODO: need check by JiaWei
53  fpRat.flush := flush
54  intRat.flush := flush
55  fpBusyTable.flush := flush
56  intBusyTable.flush := flush
57
58  def needDestReg[T <: CfCtrl](fp: Boolean, x: T): Bool = {
59    {if(fp) x.ctrl.fpWen else x.ctrl.rfWen && (x.ctrl.ldest =/= 0.U)}
60  }
61
62  val uops = Wire(Vec(RenameWidth, new MicroOp))
63
64  uops.foreach( uop => {
65//    uop.brMask := DontCare
66//    uop.brTag := DontCare
67    uop.src1State := DontCare
68    uop.src2State := DontCare
69    uop.src3State := DontCare
70    uop.roqIdx := DontCare
71    uop.diffTestDebugLrScValid := DontCare
72
73    uop.lsroqIdx := DontCare
74    uop.lqIdx := DontCare
75    uop.sqIdx := DontCare
76  })
77
78  var lastReady = WireInit(io.out(0).ready)
79  // debug assert
80  val outRdy = Cat(io.out.map(_.ready))
81  assert(outRdy===0.U || outRdy.andR())
82  for(i <- 0 until RenameWidth) {
83    uops(i).cf := io.in(i).bits.cf
84    uops(i).ctrl := io.in(i).bits.ctrl
85    uops(i).brTag := io.in(i).bits.brTag
86
87    val inValid = io.in(i).valid
88
89    // alloc a new phy reg
90    val needFpDest = inValid && needDestReg(fp = true, io.in(i).bits)
91    val needIntDest = inValid && needDestReg(fp = false, io.in(i).bits)
92    fpFreeList.allocReqs(i) := needFpDest && lastReady
93    intFreeList.allocReqs(i) := needIntDest && lastReady
94    val fpCanAlloc = fpFreeList.canAlloc(i)
95    val intCanAlloc = intFreeList.canAlloc(i)
96    val this_can_alloc = Mux(
97      needIntDest,
98      intCanAlloc,
99      Mux(
100        needFpDest,
101        fpCanAlloc,
102        true.B
103      )
104    )
105    io.in(i).ready := lastReady && this_can_alloc
106
107    // do checkpoints when a branch inst come
108    for(fl <- Seq(fpFreeList, intFreeList)){
109      fl.cpReqs(i).valid := inValid
110      fl.cpReqs(i).bits := io.in(i).bits.brTag
111    }
112
113    lastReady = io.in(i).ready
114
115    uops(i).pdest := Mux(needIntDest,
116      intFreeList.pdests(i),
117      Mux(
118        uops(i).ctrl.ldest===0.U && uops(i).ctrl.rfWen,
119        0.U, fpFreeList.pdests(i)
120      )
121    )
122
123    io.out(i).valid := io.in(i).fire()
124    io.out(i).bits := uops(i)
125
126    // write rename table
127    def writeRat(fp: Boolean) = {
128      val rat = if(fp) fpRat else intRat
129      val freeList = if(fp) fpFreeList else intFreeList
130      val busyTable = if(fp) fpBusyTable else intBusyTable
131      // speculative inst write
132      val specWen = freeList.allocReqs(i) && freeList.canAlloc(i)
133      // walk back write
134      val commitDestValid = io.roqCommits(i).valid && needDestReg(fp, io.roqCommits(i).bits.uop)
135      val walkWen = commitDestValid && io.roqCommits(i).bits.isWalk
136
137      rat.specWritePorts(i).wen := specWen || walkWen
138      rat.specWritePorts(i).addr := Mux(specWen, uops(i).ctrl.ldest, io.roqCommits(i).bits.uop.ctrl.ldest)
139      rat.specWritePorts(i).wdata := Mux(specWen, freeList.pdests(i), io.roqCommits(i).bits.uop.old_pdest)
140
141      XSInfo(walkWen,
142        {if(fp) p"fp" else p"int "} + p"walk: pc:${Hexadecimal(io.roqCommits(i).bits.uop.cf.pc)}" +
143          p" ldest:${rat.specWritePorts(i).addr} old_pdest:${rat.specWritePorts(i).wdata}\n"
144      )
145
146      rat.archWritePorts(i).wen := commitDestValid && !io.roqCommits(i).bits.isWalk
147      rat.archWritePorts(i).addr := io.roqCommits(i).bits.uop.ctrl.ldest
148      rat.archWritePorts(i).wdata := io.roqCommits(i).bits.uop.pdest
149
150      XSInfo(rat.archWritePorts(i).wen,
151        {if(fp) p"fp" else p"int "} + p" rat arch: ldest:${rat.archWritePorts(i).addr}" +
152          p" pdest:${rat.archWritePorts(i).wdata}\n"
153      )
154
155      freeList.deallocReqs(i) := rat.archWritePorts(i).wen
156      freeList.deallocPregs(i) := io.roqCommits(i).bits.uop.old_pdest
157
158      // set phy reg status to busy
159      busyTable.allocPregs(i).valid := specWen
160      busyTable.allocPregs(i).bits := freeList.pdests(i)
161    }
162
163    writeRat(fp = false)
164    writeRat(fp = true)
165
166    // read rename table
167    def readRat(lsrcList: List[UInt], ldest: UInt, fp: Boolean) = {
168      val rat = if(fp) fpRat else intRat
169      val srcCnt = lsrcList.size
170      val psrcVec = Wire(Vec(srcCnt, UInt(PhyRegIdxWidth.W)))
171      val old_pdest = Wire(UInt(PhyRegIdxWidth.W))
172      for(k <- 0 until srcCnt+1){
173        val rportIdx = i * (srcCnt+1) + k
174        if(k != srcCnt){
175          rat.readPorts(rportIdx).addr := lsrcList(k)
176          psrcVec(k) := rat.readPorts(rportIdx).rdata
177        } else {
178          rat.readPorts(rportIdx).addr := ldest
179          old_pdest := rat.readPorts(rportIdx).rdata
180        }
181      }
182      (psrcVec, old_pdest)
183    }
184    val lsrcList = List(uops(i).ctrl.lsrc1, uops(i).ctrl.lsrc2, uops(i).ctrl.lsrc3)
185    val ldest = uops(i).ctrl.ldest
186    val (intPhySrcVec, intOldPdest) = readRat(lsrcList.take(2), ldest, fp = false)
187    val (fpPhySrcVec, fpOldPdest) = readRat(lsrcList, ldest, fp = true)
188    uops(i).psrc1 := Mux(uops(i).ctrl.src1Type === SrcType.reg, intPhySrcVec(0), fpPhySrcVec(0))
189    uops(i).psrc2 := Mux(uops(i).ctrl.src2Type === SrcType.reg, intPhySrcVec(1), fpPhySrcVec(1))
190    uops(i).psrc3 := fpPhySrcVec(2)
191    uops(i).old_pdest := Mux(uops(i).ctrl.rfWen, intOldPdest, fpOldPdest)
192  }
193
194
195  def updateBusyTable(fp: Boolean) = {
196    val wbResults = if(fp) io.wbFpResults else io.wbIntResults
197    val busyTable = if(fp) fpBusyTable else intBusyTable
198    for((wb, setPhyRegRdy) <- wbResults.zip(busyTable.wbPregs)){
199      setPhyRegRdy.valid := wb.valid && needDestReg(fp, wb.bits.uop)
200      setPhyRegRdy.bits := wb.bits.uop.pdest
201    }
202  }
203
204  updateBusyTable(false)
205  updateBusyTable(true)
206
207  intBusyTable.rfReadAddr <> io.intRfReadAddr
208  intBusyTable.pregRdy <> io.intPregRdy
209  for(i <- io.replayPregReq.indices){
210    intBusyTable.replayPregs(i).valid := io.replayPregReq(i).isInt
211    fpBusyTable.replayPregs(i).valid := io.replayPregReq(i).isFp
212    intBusyTable.replayPregs(i).bits := io.replayPregReq(i).preg
213    fpBusyTable.replayPregs(i).bits := io.replayPregReq(i).preg
214  }
215  fpBusyTable.rfReadAddr <> io.fpRfReadAddr
216  fpBusyTable.pregRdy <> io.fpPregRdy
217}
218