xref: /XiangShan/src/main/scala/xiangshan/backend/rename/Rename.scala (revision 015fbae33410bd33d4801fd420ae082ec58e15a0)
1package xiangshan.backend.rename
2
3import chisel3._
4import chisel3.util._
5import xiangshan._
6import xiangshan.utils.{ParallelOR, 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(NRWritePorts, Flipped(ValidIO(new ExuOutput)))
13    val wbFpResults = Vec(NRWritePorts, Flipped(ValidIO(new ExuOutput)))
14    val intRfReadAddr = Vec(NRReadPorts, Input(UInt(PhyRegIdxWidth.W)))
15    val fpRfReadAddr = Vec(NRReadPorts, Input(UInt(PhyRegIdxWidth.W)))
16    val intPregRdy = Vec(NRReadPorts, Output(Bool()))
17    val fpPregRdy = Vec(NRReadPorts, Output(Bool()))
18    // from decode buffer
19    val in = Vec(RenameWidth, Flipped(DecoupledIO(new CfCtrl)))
20    // to dispatch1
21    val out = Vec(RenameWidth, DecoupledIO(new MicroOp))
22  })
23
24  val isWalk = ParallelOR(io.roqCommits.map(x => x.valid && x.bits.isWalk)).asBool()
25
26  val debug_exception = io.redirect.valid && io.redirect.bits.isException
27  val debug_walk = isWalk
28  val debug_norm = !(debug_exception || debug_walk)
29
30  def printRenameInfo(in: DecoupledIO[CfCtrl], out: DecoupledIO[MicroOp]) = {
31    XSInfo(
32      debug_norm,
33      p"pc:${Hexadecimal(in.bits.cf.pc)} v:${in.valid} rdy:${in.ready} " +
34        p"lsrc1:${in.bits.ctrl.lsrc1} -> psrc1:${out.bits.psrc1} " +
35        p"lsrc2:${in.bits.ctrl.lsrc2} -> psrc2:${out.bits.psrc2} " +
36        p"lsrc3:${in.bits.ctrl.lsrc3} -> psrc3:${out.bits.psrc3} " +
37        p"ldest:${in.bits.ctrl.ldest} -> pdest:${out.bits.pdest} " +
38        p"old_pdest:${out.bits.old_pdest}\n"
39    )
40  }
41
42  for((x,y) <- io.in.zip(io.out)){
43    printRenameInfo(x, y)
44  }
45
46  val fpFreeList, intFreeList = Module(new FreeList).io
47  val fpRat = Module(new RenameTable(float = true)).io
48  val intRat = Module(new RenameTable(float = false)).io
49  val fpBusyTable, intBusyTable = Module(new BusyTable).io
50
51  fpFreeList.redirect := io.redirect
52  intFreeList.redirect := io.redirect
53
54  val flush = io.redirect.valid && io.redirect.bits.isException
55  fpRat.flush := flush
56  intRat.flush := flush
57  fpBusyTable.flush := flush
58  intBusyTable.flush := flush
59
60  def needDestReg[T <: CfCtrl](fp: Boolean, x: T): Bool = {
61    {if(fp) x.ctrl.fpWen else x.ctrl.rfWen && (x.ctrl.ldest =/= 0.U)}
62  }
63
64  val uops = Wire(Vec(RenameWidth, new MicroOp))
65
66  uops.foreach( uop => {
67//    uop.brMask := DontCare
68//    uop.brTag := DontCare
69    uop.src1State := DontCare
70    uop.src2State := DontCare
71    uop.src3State := DontCare
72    uop.roqIdx := DontCare
73  })
74
75  var last_can_alloc = WireInit(true.B)
76  for(i <- 0 until RenameWidth) {
77    uops(i).cf := io.in(i).bits.cf
78    uops(i).ctrl := io.in(i).bits.ctrl
79    uops(i).brMask := io.in(i).bits.brMask
80    uops(i).brTag := io.in(i).bits.brTag
81
82    val inValid = io.in(i).valid && !isWalk
83
84    // alloc a new phy reg
85    val needFpDest = inValid && needDestReg(fp = true, io.in(i).bits)
86    val needIntDest = inValid && needDestReg(fp = false, io.in(i).bits)
87    fpFreeList.allocReqs(i) := needFpDest && last_can_alloc && io.out(i).ready
88    intFreeList.allocReqs(i) := needIntDest && last_can_alloc && io.out(i).ready
89    val fpCanAlloc = fpFreeList.canAlloc(i)
90    val intCanAlloc = intFreeList.canAlloc(i)
91    val this_can_alloc = Mux(needIntDest, intCanAlloc, fpCanAlloc)
92    io.in(i).ready := this_can_alloc && !isWalk
93    last_can_alloc = last_can_alloc && this_can_alloc
94    uops(i).pdest := Mux(needIntDest, intFreeList.pdests(i), Mux(uops(i).ctrl.ldest===0.U && uops(i).ctrl.rfWen, 0.U, fpFreeList.pdests(i)))
95    uops(i).freelistAllocPtr := Mux(needIntDest, intFreeList.allocPtrs(i), fpFreeList.allocPtrs(i))
96
97    io.out(i).valid := io.in(i).fire()
98    io.out(i).bits := uops(i)
99
100    // write rename table
101    def writeRat(fp: Boolean) = {
102      val rat = if(fp) fpRat else intRat
103      val freeList = if(fp) fpFreeList else intFreeList
104      val busyTable = if(fp) fpBusyTable else intBusyTable
105      // speculative inst write
106      val specWen = freeList.allocReqs(i) && freeList.canAlloc(i)
107      // walk back write
108      val commitDestValid = io.roqCommits(i).valid && needDestReg(fp, io.roqCommits(i).bits.uop)
109      val walkWen = commitDestValid && io.roqCommits(i).bits.isWalk
110
111      rat.specWritePorts(i).wen := specWen || walkWen
112      rat.specWritePorts(i).addr := Mux(specWen, uops(i).ctrl.ldest, io.roqCommits(i).bits.uop.ctrl.ldest)
113      rat.specWritePorts(i).wdata := Mux(specWen, freeList.pdests(i), io.roqCommits(i).bits.uop.old_pdest)
114
115      busyTable.wbPregs(NRWritePorts + i).valid := walkWen
116      busyTable.wbPregs(NRWritePorts + i).bits := io.roqCommits(i).bits.uop.pdest
117
118      XSInfo(walkWen,
119        {if(fp) p"fp" else p"int "} + p"walk: pc:${Hexadecimal(io.roqCommits(i).bits.uop.cf.pc)}" +
120          p" ldst:${rat.specWritePorts(i).addr} old_pdest:${rat.specWritePorts(i).wdata}\n"
121      )
122
123      rat.archWritePorts(i).wen := commitDestValid && !io.roqCommits(i).bits.isWalk
124      rat.archWritePorts(i).addr := io.roqCommits(i).bits.uop.ctrl.ldest
125      rat.archWritePorts(i).wdata := io.roqCommits(i).bits.uop.pdest
126
127      XSInfo(rat.archWritePorts(i).wen,
128        {if(fp) p"fp" else p"int "} + p" rat arch: ldest:${rat.archWritePorts(i).addr}" +
129          p" pdest:${rat.archWritePorts(i).wdata}\n"
130      )
131
132      freeList.deallocReqs(i) := rat.archWritePorts(i).wen
133      freeList.deallocPregs(i) := io.roqCommits(i).bits.uop.old_pdest
134
135      // set phy reg status to busy
136      busyTable.allocPregs(i).valid := specWen
137      busyTable.allocPregs(i).bits := freeList.pdests(i)
138    }
139
140    writeRat(fp = false)
141    writeRat(fp = true)
142
143    // read rename table
144    def readRat(lsrcList: List[UInt], ldest: UInt, fp: Boolean) = {
145      val rat = if(fp) fpRat else intRat
146      val srcCnt = lsrcList.size
147      val psrcVec = Wire(Vec(srcCnt, UInt(PhyRegIdxWidth.W)))
148      val old_pdest = Wire(UInt(PhyRegIdxWidth.W))
149      for(k <- 0 until srcCnt+1){
150        val rportIdx = i * (srcCnt+1) + k
151        if(k != srcCnt){
152          rat.readPorts(rportIdx).addr := lsrcList(k)
153          psrcVec(k) := rat.readPorts(rportIdx).rdata
154        } else {
155          rat.readPorts(rportIdx).addr := ldest
156          old_pdest := rat.readPorts(rportIdx).rdata
157        }
158      }
159      (psrcVec, old_pdest)
160    }
161    val lsrcList = List(uops(i).ctrl.lsrc1, uops(i).ctrl.lsrc2, uops(i).ctrl.lsrc3)
162    val ldest = uops(i).ctrl.ldest
163    val (intPhySrcVec, intOldPdest) = readRat(lsrcList.take(2), ldest, fp = false)
164    val (fpPhySrcVec, fpOldPdest) = readRat(lsrcList, ldest, fp = true)
165    uops(i).psrc1 := Mux(uops(i).ctrl.src1Type === SrcType.reg, intPhySrcVec(0), fpPhySrcVec(0))
166    uops(i).psrc2 := Mux(uops(i).ctrl.src1Type === SrcType.reg, intPhySrcVec(1), fpPhySrcVec(1))
167    uops(i).psrc3 := fpPhySrcVec(2)
168    uops(i).old_pdest := Mux(uops(i).ctrl.rfWen, intOldPdest, fpOldPdest)
169  }
170
171
172  def updateBusyTable(fp: Boolean) = {
173    val wbResults = if(fp) io.wbFpResults else io.wbIntResults
174    val busyTable = if(fp) fpBusyTable else intBusyTable
175    for((wb, setPhyRegRdy) <- wbResults.zip(busyTable.wbPregs.take(NRWritePorts))){
176      setPhyRegRdy.valid := wb.valid && needDestReg(fp, wb.bits.uop)
177      setPhyRegRdy.bits := wb.bits.uop.pdest
178    }
179  }
180
181  updateBusyTable(false)
182  updateBusyTable(true)
183
184  intBusyTable.rfReadAddr <> io.intRfReadAddr
185  intBusyTable.pregRdy <> io.intPregRdy
186  fpBusyTable.rfReadAddr <> io.fpRfReadAddr
187  fpBusyTable.pregRdy <> io.fpPregRdy
188}
189