riscv/rocket-chip
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Use UInt instead of Vec[Bool]

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This commit is contained in:
Andrew Waterman 2015-07-31 04:59:45 -07:00
parent 57930e8a26
commit 45cf64dbd7
1 changed files with 8 additions and 9 deletions
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17
rocket/src/main/scala/btb.scala
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@ -133,7 +133,7 @@ class BTB(updates_out_of_order: Boolean = false) extends Module with BTBParamete
val invalidate = Bool(INPUT)
}
val idxValid = Reg(Vec(Bool(), entries))
val idxValid = Reg(init=UInt(0, entries))
val idxs = Mem(UInt(width=matchBits), entries)
val idxPages = Mem(UInt(width=log2Up(nPages)), entries)
val tgts = Mem(UInt(width=matchBits), entries)
@ -152,12 +152,11 @@ class BTB(updates_out_of_order: Boolean = false) extends Module with BTBParamete
val p = page(addr)
Vec(pages.map(_ === p)).toBits & pageValid
}
private def tagMatch(addr: UInt, pgMatch: UInt): Vec[Bool] = {
private def tagMatch(addr: UInt, pgMatch: UInt) = {
val idx = addr(matchBits-1,0)
val idxMatch = idxs.map(_ === idx).toBits
val idxPageMatch = idxPagesOH.map(_ & pgMatch).map(_.orR).toBits
Vec(for (i <- 0 until entries)
yield idxValid(i) && idxMatch(i) && idxPageMatch(i))
idxValid & idxMatch & idxPageMatch
}
val r_btb_update = Pipe(io.btb_update)
@ -199,14 +198,14 @@ class BTB(updates_out_of_order: Boolean = false) extends Module with BTBParamete
val nextRepl = Counter(!updateHit, entries)._1
val waddr =
if (updates_out_of_order) Mux(updateHits.reduce(_||_), OHToUInt(updateHits), nextRepl)
if (updates_out_of_order) Mux(updateHits.orR, OHToUInt(updateHits), nextRepl)
else Mux(updateHit, r_btb_update.bits.prediction.bits.entry, nextRepl)
// invalidate entries if we stomp on pages they depend upon
for (i <- 0 until idxValid.size)
when ((pageReplEn & (idxPagesOH(i) | tgtPagesOH(i))).orR) { idxValid(i) := false }
val invalidateMask = Vec.tabulate(entries)(i => (pageReplEn & (idxPagesOH(i) | tgtPagesOH(i))).orR).toBits
val validateMask = UIntToOH(waddr)
idxValid := (idxValid & ~invalidateMask) | validateMask
idxValid(waddr) := Bool(true)
idxs(waddr) := r_btb_update.bits.pc
tgts(waddr) := update_target
idxPages(waddr) := idxPageUpdate
@ -239,7 +238,7 @@ class BTB(updates_out_of_order: Boolean = false) extends Module with BTBParamete
pageValid := 0
}
io.resp.valid := hits.reduce(_||_)
io.resp.valid := hits.orR
io.resp.bits.taken := io.resp.valid
io.resp.bits.target := Cat(Mux1H(Mux1H(hits, tgtPagesOH), pages), Mux1H(hits, tgts))
io.resp.bits.entry := OHToUInt(hits)