BPU: Initiate refactoring

src/main/scala/xiangshan/Bundle.scala

@@ -60,7 +60,7 @@ class BranchInfo extends XSBundle {
     this.histPtr := histPtr
     this.tageMeta := tageMeta
     this.rasSp := rasSp
-    this.rasTopCtr
+    this.rasTopCtr := rasTopCtr
     this.asUInt
   }
   def size = 0.U.asTypeOf(this).getWidth
@@ -142,7 +142,6 @@ class Redirect extends XSBundle with HasRoqIdx {
   val pc = UInt(VAddrBits.W)
   val target = UInt(VAddrBits.W)
   val brTag = new BrqPtr
-  val histPtr = UInt(log2Up(ExtHistoryLength).W)
 }
 
 class Dp1ToDp2IO extends XSBundle {

src/main/scala/xiangshan/frontend/IFU.scala

@@ -24,28 +24,6 @@ class IFUIO extends XSBundle
   val icacheResp = Flipped(DecoupledIO(new FakeIcacheResp))
 }
 
-class BaseBPU extends XSModule {
-  val io = IO(new Bundle() {
-    val redirect = Flipped(ValidIO(new Redirect))
-    val outOfOrderBrInfo = Flipped(ValidIO(new BranchUpdateInfo))
-    val inOrderBrInfo = Flipped(ValidIO(new BranchUpdateInfo))
-    val in = new Bundle { val pc = Flipped(Valid(UInt(VAddrBits.W))) }
-    val btbOut = ValidIO(new BranchPrediction)
-    val tageOut = Decoupled(new BranchPrediction)
-    val predecode = Flipped(ValidIO(new Predecode))
-  })
-}
-
-class FakeBPU extends BaseBPU {
-
-  io.btbOut.valid := false.B
-  io.btbOut.bits <> DontCare
-  io.btbOut.bits.redirect := false.B
-  io.btbOut.bits.target := DontCare
-  io.tageOut.valid := false.B
-  io.tageOut.bits <> DontCare
-}
-
 
 class IFU extends XSModule with HasIFUConst
 {

src/main/scala/xiangshan/frontend/jbtac.scala

-//package xiangshan.frontend
-//
-//import chisel3._
-//import chisel3.util._
-//import xiangshan._
-//import utils._
-//import xiangshan.backend.ALUOpType
-//
-//
-//class JBTACUpdateBundle extends XSBundle {
-//  val fetchPC = UInt(VAddrBits.W)
-//  val fetchIdx = UInt(log2Up(PredictWidth).W)
-//  val hist = UInt(HistoryLength.W)
-//  val target = UInt(VAddrBits.W)
-//  val btbType = UInt(2.W)
-//  val misPred = Bool()
-//  val isRVC = Bool()
-//}
-//
-//class JBTACPred extends XSBundle {
-//  val hit = Bool()
-//  val target = UInt(VAddrBits.W)
-//  val hitIdx = UInt(log2Up(PredictWidth).W)
-//  val isRVILateJump = Bool()
-//  val isRVC = Bool()
-//}
-//
-//class JBTAC extends XSModule {
-//  val io = IO(new Bundle {
-//    val in = new Bundle {
-//      val pc = Flipped(Decoupled(UInt(VAddrBits.W)))
-//      val pcLatch = Input(UInt(VAddrBits.W))
-//      val mask = Input(UInt(PredictWidth.W))
-//      val hist = Input(UInt(HistoryLength.W))
-//    }
-//    val redirectValid = Input(Bool())
-//    val flush = Input(Bool())
-//    val update = Input(new JBTACUpdateBundle)
-//
-//    val out = Output(new JBTACPred)
-//  })
-//
-//  io.in.pc.ready := true.B
-//
-//  val fireLatch = RegNext(io.in.pc.fire())
-//
-//  // JBTAC, divided into 8 banks, makes prediction for indirect jump except ret.
-//  val jbtacAddr = new TableAddr(log2Up(JbtacSize), JbtacBanks)
-//  def jbtacEntry() = new Bundle {
-//    val valid = Bool()
-//    // TODO: don't need full length of tag and target
-//    val tag = UInt(jbtacAddr.tagBits.W + jbtacAddr.idxBits.W)
-//    val target = UInt(VAddrBits.W)
-//    val offset = UInt(log2Up(PredictWidth).W)
-//    val isRVC = Bool()
-//  }
-//
-//  val jbtac = List.fill(JbtacBanks)(Module(new SRAMTemplate(jbtacEntry(), set = JbtacSize / JbtacBanks, shouldReset = true, holdRead = true, singlePort = false)))
-//
-//  val readEntries = Wire(Vec(JbtacBanks, jbtacEntry()))
-//
-//  val readFire = Reg(Vec(JbtacBanks, Bool()))
-//  // Only read one bank
-//  val histXORAddr = io.in.pc.bits ^ Cat(io.in.hist, 0.U(1.W))(VAddrBits - 1, 0)
-//  val histXORAddrLatch = RegEnable(histXORAddr, io.in.pc.valid)
-//
-//  val readBank = jbtacAddr.getBank(histXORAddr)
-//  val readRow = jbtacAddr.getBankIdx(histXORAddr)
-//  readFire := 0.U.asTypeOf(Vec(JbtacBanks, Bool()))
-//  (0 until JbtacBanks).map(
-//    b => {
-//      jbtac(b).reset := reset.asBool
-//      jbtac(b).io.r.req.valid := io.in.pc.fire() && b.U === readBank
-//      jbtac(b).io.r.req.bits.setIdx := readRow
-//      readFire(b) := jbtac(b).io.r.req.fire()
-//      readEntries(b) := jbtac(b).io.r.resp.data(0)
-//    }
-//  )
-//
-//  val readBankLatch = jbtacAddr.getBank(histXORAddrLatch)
-//  val readRowLatch = jbtacAddr.getBankIdx(histXORAddrLatch)
-//  val readMaskLatch = RegEnable(io.in.mask, io.in.pc.fire())
-//
-//  val outHit = readEntries(readBankLatch).valid &&
-//    readEntries(readBankLatch).tag === Cat(jbtacAddr.getTag(io.in.pcLatch), jbtacAddr.getIdx(io.in.pcLatch)) &&
-//    !io.flush && RegNext(readFire(readBankLatch)) && readMaskLatch(readEntries(readBankLatch).offset).asBool
-//
-//  io.out.hit := outHit
-//  io.out.hitIdx := readEntries(readBankLatch).offset
-//  io.out.target := readEntries(readBankLatch).target
-//  io.out.isRVILateJump := io.out.hit && io.out.hitIdx === OHToUInt(HighestBit(readMaskLatch, PredictWidth)) && !readEntries(readBankLatch).isRVC
-//  io.out.isRVC := readEntries(readBankLatch).isRVC
-//
-//  // update jbtac
-//  val writeEntry = Wire(jbtacEntry())
-//  // val updateHistXORAddr = updatefetchPC ^ Cat(r.hist, 0.U(2.W))(VAddrBits - 1, 0)
-//  val updateHistXORAddr = io.update.fetchPC ^ Cat(io.update.hist, 0.U(1.W))(VAddrBits - 1, 0)
-//  writeEntry.valid := true.B
-//  // writeEntry.tag := jbtacAddr.getTag(updatefetchPC)
-//  writeEntry.tag := Cat(jbtacAddr.getTag(io.update.fetchPC), jbtacAddr.getIdx(io.update.fetchPC))
-//  writeEntry.target := io.update.target
-//  // writeEntry.offset := updateFetchIdx
-//  writeEntry.offset := io.update.fetchIdx
-//  writeEntry.isRVC := io.update.isRVC
-//
-//  val writeBank = jbtacAddr.getBank(updateHistXORAddr)
-//  val writeRow = jbtacAddr.getBankIdx(updateHistXORAddr)
-//  val writeValid = io.redirectValid && io.update.misPred && io.update.btbType === BTBtype.I
-//  for (b <- 0 until JbtacBanks) {
-//    when (b.U === writeBank) {
-//      jbtac(b).io.w.req.valid := writeValid
-//      jbtac(b).io.w.req.bits.setIdx := writeRow
-//      jbtac(b).io.w.req.bits.data := writeEntry
-//    }.otherwise {
-//      jbtac(b).io.w.req.valid := false.B
-//      jbtac(b).io.w.req.bits.setIdx := DontCare
-//      jbtac(b).io.w.req.bits.data := DontCare
-//    }
-//  }
-//
-//  // read-after-write bypass
-//  val rawBypassHit = Wire(Vec(JbtacBanks, Bool()))
-//  for (b <- 0 until JbtacBanks) {
-//    when (readBank === writeBank && readRow === writeRow && b.U === readBank) {
-//      when (io.in.pc.fire() && writeValid) {
-//        rawBypassHit(b) := true.B
-//        jbtac(b).io.r.req.valid := false.B
-//        // readEntries(b) := RegNext(writeEntry)
-//        readFire(b) := true.B
-//
-//        XSDebug("raw bypass hits: bank=%d, row=%d, tag=%x, tgt=%x, offet=%d, isRVC=%d\n",
-//          b.U, readRow, writeEntry.tag, writeEntry.target, writeEntry.offset, writeEntry.isRVC)
-//      }.otherwise {
-//        rawBypassHit(b) := false.B
-//      }
-//    }.otherwise {
-//      rawBypassHit(b) := false.B
-//    }
-//
-//    when (RegNext(rawBypassHit(b))) { readEntries(b) := RegNext(writeEntry) }
-//  }
-//
-//  XSDebug(io.in.pc.fire(), "read: pc=0x%x, histXORAddr=0x%x, bank=%d, row=%d, hist=%b\n",
-//    io.in.pc.bits, histXORAddr, readBank, readRow, io.in.hist)
-//  XSDebug("out: hit=%d tgt=%x hitIdx=%d iRVILateJump=%d isRVC=%d\n",
-//    io.out.hit, io.out.target, io.out.hitIdx, io.out.isRVILateJump, io.out.isRVC)
-//  XSDebug(fireLatch, "read_resp: pc=0x%x, bank=%d, row=%d, target=0x%x, offset=%d, hit=%d\n",
-//    io.in.pcLatch, readBankLatch, readRowLatch, readEntries(readBankLatch).target, readEntries(readBankLatch).offset, outHit)
-//  XSDebug(io.redirectValid, "update_req: fetchPC=0x%x, writeValid=%d, hist=%b, bank=%d, row=%d, target=0x%x, offset=%d, type=0x%d\n",
-//    io.update.fetchPC, writeValid, io.update.hist, writeBank, writeRow, io.update.target, io.update.fetchIdx, io.update.btbType)
-//}
+package xiangshan.frontend
+
+import chisel3._
+import chisel3.util._
+import xiangshan._
+import utils._
+import xiangshan.backend.ALUOpType
+
+
+class JBTACUpdateBundle extends XSBundle {
+ val fetchPC = UInt(VAddrBits.W)
+ val fetchIdx = UInt(log2Up(PredictWidth).W)
+ val hist = UInt(HistoryLength.W)
+ val target = UInt(VAddrBits.W)
+ val btbType = UInt(2.W)
+ val misPred = Bool()
+ val isRVC = Bool()
+}
+
+class JBTACPred extends XSBundle {
+ val hit = Bool()
+ val target = UInt(VAddrBits.W)
+ val hitIdx = UInt(log2Up(PredictWidth).W)
+ val isRVILateJump = Bool()
+ val isRVC = Bool()
+}
+
+class JBTAC extends XSModule {
+ val io = IO(new Bundle {
+   val in = new Bundle {
+     val pc = Flipped(Decoupled(UInt(VAddrBits.W)))
+     val pcLatch = Input(UInt(VAddrBits.W))
+     val mask = Input(UInt(PredictWidth.W))
+     val hist = Input(UInt(HistoryLength.W))
+   }
+   val redirectValid = Input(Bool())
+   val flush = Input(Bool())
+   val update = Input(new JBTACUpdateBundle)
+
+   val out = Output(new JBTACPred)
+ })
+
+ io.in.pc.ready := true.B
+
+ val fireLatch = RegNext(io.in.pc.fire())
+
+ // JBTAC, divided into 8 banks, makes prediction for indirect jump except ret.
+ val jbtacAddr = new TableAddr(log2Up(JbtacSize), JbtacBanks)
+ def jbtacEntry() = new Bundle {
+   val valid = Bool()
+   // TODO: don't need full length of tag and target
+   val tag = UInt(jbtacAddr.tagBits.W + jbtacAddr.idxBits.W)
+   val target = UInt(VAddrBits.W)
+   val offset = UInt(log2Up(PredictWidth).W)
+   val isRVC = Bool()
+ }
+
+ val jbtac = List.fill(JbtacBanks)(Module(new SRAMTemplate(jbtacEntry(), set = JbtacSize / JbtacBanks, shouldReset = true, holdRead = true, singlePort = false)))
+
+ val readEntries = Wire(Vec(JbtacBanks, jbtacEntry()))
+
+ val readFire = Reg(Vec(JbtacBanks, Bool()))
+ // Only read one bank
+ val histXORAddr = io.in.pc.bits ^ Cat(io.in.hist, 0.U(1.W))(VAddrBits - 1, 0)
+ val histXORAddrLatch = RegEnable(histXORAddr, io.in.pc.valid)
+
+ val readBank = jbtacAddr.getBank(histXORAddr)
+ val readRow = jbtacAddr.getBankIdx(histXORAddr)
+ readFire := 0.U.asTypeOf(Vec(JbtacBanks, Bool()))
+ (0 until JbtacBanks).map(
+   b => {
+     jbtac(b).reset := reset.asBool
+     jbtac(b).io.r.req.valid := io.in.pc.fire() && b.U === readBank
+     jbtac(b).io.r.req.bits.setIdx := readRow
+     readFire(b) := jbtac(b).io.r.req.fire()
+     readEntries(b) := jbtac(b).io.r.resp.data(0)
+   }
+ )
+
+ val readBankLatch = jbtacAddr.getBank(histXORAddrLatch)
+ val readRowLatch = jbtacAddr.getBankIdx(histXORAddrLatch)
+ val readMaskLatch = RegEnable(io.in.mask, io.in.pc.fire())
+
+ val outHit = readEntries(readBankLatch).valid &&
+   readEntries(readBankLatch).tag === Cat(jbtacAddr.getTag(io.in.pcLatch), jbtacAddr.getIdx(io.in.pcLatch)) &&
+   !io.flush && RegNext(readFire(readBankLatch)) && readMaskLatch(readEntries(readBankLatch).offset).asBool
+
+ io.out.hit := outHit
+ io.out.hitIdx := readEntries(readBankLatch).offset
+ io.out.target := readEntries(readBankLatch).target
+ io.out.isRVILateJump := io.out.hit && io.out.hitIdx === OHToUInt(HighestBit(readMaskLatch, PredictWidth)) && !readEntries(readBankLatch).isRVC
+ io.out.isRVC := readEntries(readBankLatch).isRVC
+
+ // update jbtac
+ val writeEntry = Wire(jbtacEntry())
+ // val updateHistXORAddr = updatefetchPC ^ Cat(r.hist, 0.U(2.W))(VAddrBits - 1, 0)
+ val updateHistXORAddr = io.update.fetchPC ^ Cat(io.update.hist, 0.U(1.W))(VAddrBits - 1, 0)
+ writeEntry.valid := true.B
+ // writeEntry.tag := jbtacAddr.getTag(updatefetchPC)
+ writeEntry.tag := Cat(jbtacAddr.getTag(io.update.fetchPC), jbtacAddr.getIdx(io.update.fetchPC))
+ writeEntry.target := io.update.target
+ // writeEntry.offset := updateFetchIdx
+ writeEntry.offset := io.update.fetchIdx
+ writeEntry.isRVC := io.update.isRVC
+
+ val writeBank = jbtacAddr.getBank(updateHistXORAddr)
+ val writeRow = jbtacAddr.getBankIdx(updateHistXORAddr)
+ val writeValid = io.redirectValid && io.update.misPred && io.update.btbType === BTBtype.I
+ for (b <- 0 until JbtacBanks) {
+   when (b.U === writeBank) {
+     jbtac(b).io.w.req.valid := writeValid
+     jbtac(b).io.w.req.bits.setIdx := writeRow
+     jbtac(b).io.w.req.bits.data := writeEntry
+   }.otherwise {
+     jbtac(b).io.w.req.valid := false.B
+     jbtac(b).io.w.req.bits.setIdx := DontCare
+     jbtac(b).io.w.req.bits.data := DontCare
+   }
+ }
+
+ // read-after-write bypass
+ val rawBypassHit = Wire(Vec(JbtacBanks, Bool()))
+ for (b <- 0 until JbtacBanks) {
+   when (readBank === writeBank && readRow === writeRow && b.U === readBank) {
+     when (io.in.pc.fire() && writeValid) {
+       rawBypassHit(b) := true.B
+       jbtac(b).io.r.req.valid := false.B
+       // readEntries(b) := RegNext(writeEntry)
+       readFire(b) := true.B
+
+       XSDebug("raw bypass hits: bank=%d, row=%d, tag=%x, tgt=%x, offet=%d, isRVC=%d\n",
+         b.U, readRow, writeEntry.tag, writeEntry.target, writeEntry.offset, writeEntry.isRVC)
+     }.otherwise {
+       rawBypassHit(b) := false.B
+     }
+   }.otherwise {
+     rawBypassHit(b) := false.B
+   }
+
+   when (RegNext(rawBypassHit(b))) { readEntries(b) := RegNext(writeEntry) }
+ }
+
+ XSDebug(io.in.pc.fire(), "read: pc=0x%x, histXORAddr=0x%x, bank=%d, row=%d, hist=%b\n",
+   io.in.pc.bits, histXORAddr, readBank, readRow, io.in.hist)
+ XSDebug("out: hit=%d tgt=%x hitIdx=%d iRVILateJump=%d isRVC=%d\n",
+   io.out.hit, io.out.target, io.out.hitIdx, io.out.isRVILateJump, io.out.isRVC)
+ XSDebug(fireLatch, "read_resp: pc=0x%x, bank=%d, row=%d, target=0x%x, offset=%d, hit=%d\n",
+   io.in.pcLatch, readBankLatch, readRowLatch, readEntries(readBankLatch).target, readEntries(readBankLatch).offset, outHit)
+ XSDebug(io.redirectValid, "update_req: fetchPC=0x%x, writeValid=%d, hist=%b, bank=%d, row=%d, target=0x%x, offset=%d, type=0x%d\n",
+   io.update.fetchPC, writeValid, io.update.hist, writeBank, writeRow, io.update.target, io.update.fetchIdx, io.update.btbType)
+}
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