xref: /XiangShan/src/main/scala/xiangshan/backend/rename/Rename.scala (revision 95bfe4c03ef37cfa7866474159f6afb8e3bcc3cc)
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.lsroqIdx := DontCare
72    uop.diffTestDebugLrScValid := DontCare
73  })
74
75  var lastReady = WireInit(io.out(0).ready)
76  // debug assert
77  val outRdy = Cat(io.out.map(_.ready))
78  assert(outRdy===0.U || outRdy.andR())
79  for(i <- 0 until RenameWidth) {
80    uops(i).cf := io.in(i).bits.cf
81    uops(i).ctrl := io.in(i).bits.ctrl
82    uops(i).brTag := io.in(i).bits.brTag
83
84    val inValid = io.in(i).valid
85
86    // alloc a new phy reg
87    val needFpDest = inValid && needDestReg(fp = true, io.in(i).bits)
88    val needIntDest = inValid && needDestReg(fp = false, io.in(i).bits)
89    fpFreeList.allocReqs(i) := needFpDest && lastReady
90    intFreeList.allocReqs(i) := needIntDest && lastReady
91    val fpCanAlloc = fpFreeList.canAlloc(i)
92    val intCanAlloc = intFreeList.canAlloc(i)
93    val this_can_alloc = Mux(
94      needIntDest,
95      intCanAlloc,
96      Mux(
97        needFpDest,
98        fpCanAlloc,
99        true.B
100      )
101    )
102    io.in(i).ready := lastReady && this_can_alloc
103
104    // do checkpoints when a branch inst come
105    for(fl <- Seq(fpFreeList, intFreeList)){
106      fl.cpReqs(i).valid := inValid
107      fl.cpReqs(i).bits := io.in(i).bits.brTag
108    }
109
110    lastReady = io.in(i).ready
111
112    uops(i).pdest := Mux(needIntDest,
113      intFreeList.pdests(i),
114      Mux(
115        uops(i).ctrl.ldest===0.U && uops(i).ctrl.rfWen,
116        0.U, fpFreeList.pdests(i)
117      )
118    )
119
120    io.out(i).valid := io.in(i).fire()
121    io.out(i).bits := uops(i)
122
123    // write rename table
124    def writeRat(fp: Boolean) = {
125      val rat = if(fp) fpRat else intRat
126      val freeList = if(fp) fpFreeList else intFreeList
127      val busyTable = if(fp) fpBusyTable else intBusyTable
128      // speculative inst write
129      val specWen = freeList.allocReqs(i) && freeList.canAlloc(i)
130      // walk back write
131      val commitDestValid = io.roqCommits(i).valid && needDestReg(fp, io.roqCommits(i).bits.uop)
132      val walkWen = commitDestValid && io.roqCommits(i).bits.isWalk
133
134      rat.specWritePorts(i).wen := specWen || walkWen
135      rat.specWritePorts(i).addr := Mux(specWen, uops(i).ctrl.ldest, io.roqCommits(i).bits.uop.ctrl.ldest)
136      rat.specWritePorts(i).wdata := Mux(specWen, freeList.pdests(i), io.roqCommits(i).bits.uop.old_pdest)
137
138      XSInfo(walkWen,
139        {if(fp) p"fp" else p"int "} + p"walk: pc:${Hexadecimal(io.roqCommits(i).bits.uop.cf.pc)}" +
140          p" ldest:${rat.specWritePorts(i).addr} old_pdest:${rat.specWritePorts(i).wdata}\n"
141      )
142
143      rat.archWritePorts(i).wen := commitDestValid && !io.roqCommits(i).bits.isWalk
144      rat.archWritePorts(i).addr := io.roqCommits(i).bits.uop.ctrl.ldest
145      rat.archWritePorts(i).wdata := io.roqCommits(i).bits.uop.pdest
146
147      XSInfo(rat.archWritePorts(i).wen,
148        {if(fp) p"fp" else p"int "} + p" rat arch: ldest:${rat.archWritePorts(i).addr}" +
149          p" pdest:${rat.archWritePorts(i).wdata}\n"
150      )
151
152      freeList.deallocReqs(i) := rat.archWritePorts(i).wen
153      freeList.deallocPregs(i) := io.roqCommits(i).bits.uop.old_pdest
154
155      // set phy reg status to busy
156      busyTable.allocPregs(i).valid := specWen
157      busyTable.allocPregs(i).bits := freeList.pdests(i)
158    }
159
160    writeRat(fp = false)
161    writeRat(fp = true)
162
163    // read rename table
164    def readRat(lsrcList: List[UInt], ldest: UInt, fp: Boolean) = {
165      val rat = if(fp) fpRat else intRat
166      val srcCnt = lsrcList.size
167      val psrcVec = Wire(Vec(srcCnt, UInt(PhyRegIdxWidth.W)))
168      val old_pdest = Wire(UInt(PhyRegIdxWidth.W))
169      for(k <- 0 until srcCnt+1){
170        val rportIdx = i * (srcCnt+1) + k
171        if(k != srcCnt){
172          rat.readPorts(rportIdx).addr := lsrcList(k)
173          psrcVec(k) := rat.readPorts(rportIdx).rdata
174        } else {
175          rat.readPorts(rportIdx).addr := ldest
176          old_pdest := rat.readPorts(rportIdx).rdata
177        }
178      }
179      (psrcVec, old_pdest)
180    }
181    val lsrcList = List(uops(i).ctrl.lsrc1, uops(i).ctrl.lsrc2, uops(i).ctrl.lsrc3)
182    val ldest = uops(i).ctrl.ldest
183    val (intPhySrcVec, intOldPdest) = readRat(lsrcList.take(2), ldest, fp = false)
184    val (fpPhySrcVec, fpOldPdest) = readRat(lsrcList, ldest, fp = true)
185    uops(i).psrc1 := Mux(uops(i).ctrl.src1Type === SrcType.reg, intPhySrcVec(0), fpPhySrcVec(0))
186    uops(i).psrc2 := Mux(uops(i).ctrl.src2Type === SrcType.reg, intPhySrcVec(1), fpPhySrcVec(1))
187    uops(i).psrc3 := fpPhySrcVec(2)
188    uops(i).old_pdest := Mux(uops(i).ctrl.rfWen, intOldPdest, fpOldPdest)
189  }
190
191
192  def updateBusyTable(fp: Boolean) = {
193    val wbResults = if(fp) io.wbFpResults else io.wbIntResults
194    val busyTable = if(fp) fpBusyTable else intBusyTable
195    for((wb, setPhyRegRdy) <- wbResults.zip(busyTable.wbPregs)){
196      setPhyRegRdy.valid := wb.valid && needDestReg(fp, wb.bits.uop)
197      setPhyRegRdy.bits := wb.bits.uop.pdest
198    }
199  }
200
201  updateBusyTable(false)
202  updateBusyTable(true)
203
204  intBusyTable.rfReadAddr <> io.intRfReadAddr
205  intBusyTable.pregRdy <> io.intPregRdy
206  for(i <- io.replayPregReq.indices){
207    intBusyTable.replayPregs(i).valid := io.replayPregReq(i).isInt
208    fpBusyTable.replayPregs(i).valid := io.replayPregReq(i).isFp
209    intBusyTable.replayPregs(i).bits := io.replayPregReq(i).preg
210    fpBusyTable.replayPregs(i).bits := io.replayPregReq(i).preg
211  }
212  fpBusyTable.rfReadAddr <> io.fpRfReadAddr
213  fpBusyTable.pregRdy <> io.fpPregRdy
214}
215