xref: /XiangShan/src/main/scala/xiangshan/backend/fu/FunctionUnit.scala (revision 3b739f49c5a26805be859c7231717ecc38aade30)
1/***************************************************************************************
2* Copyright (c) 2020-2021 Institute of Computing Technology, Chinese Academy of Sciences
3* Copyright (c) 2020-2021 Peng Cheng Laboratory
4*
5* XiangShan is licensed under Mulan PSL v2.
6* You can use this software according to the terms and conditions of the Mulan PSL v2.
7* You may obtain a copy of Mulan PSL v2 at:
8*          http://license.coscl.org.cn/MulanPSL2
9*
10* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
11* EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
12* MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
13*
14* See the Mulan PSL v2 for more details.
15***************************************************************************************/
16
17package xiangshan.backend.fu
18
19import chipsalliance.rocketchip.config.Parameters
20import chisel3._
21import chisel3.util._
22import utils.XSPerfAccumulate
23import xiangshan._
24import xiangshan.backend.fu.fpu._
25
26trait HasFuLatency {
27  val latencyVal: Option[Int]
28}
29
30case class CertainLatency(value: Int) extends HasFuLatency {
31  override val latencyVal: Option[Int] = Some(value)
32}
33
34case class UncertainLatency() extends HasFuLatency {
35  override val latencyVal: Option[Int] = None
36}
37
38
39//case class FuConfig
40//(
41//  name: String,
42//  fuGen: Parameters => FunctionUnit,
43//  fuSel: MicroOp => Bool,
44//  fuType: UInt,
45//  numIntSrc: Int,
46//  numFpSrc: Int,
47//  numVecSrc: Int = 0,
48//  writeIntRf: Boolean,
49//  writeFpRf: Boolean,
50//  writeVecRf: Boolean = false,
51//  writeFflags: Boolean = false,
52//  hasRedirect: Boolean = false,
53//  latency: HasFuLatency = CertainLatency(0),
54//  fastUopOut: Boolean = false,
55//  fastImplemented: Boolean = false,
56//  hasInputBuffer: (Boolean, Int, Boolean) = (false, 0, false),
57//  exceptionOut: Seq[Int] = Seq(),
58//  hasLoadError: Boolean = false,
59//  flushPipe: Boolean = false,
60//  replayInst: Boolean = false,
61//  trigger: Boolean = false
62//) {
63//  def srcCnt: Int = math.max(math.max(numIntSrc, numFpSrc), numVecSrc)
64//  def isVectorFU: Boolean = (numVecSrc > 0) && writeVecRf
65//
66//  override def toString: String = {
67//    s"${name}: SrcNum(${numIntSrc}|${numFpSrc}|${numVecSrc}) " +
68//    s"Write(" +
69//    (if(writeIntRf) "int|" else "") +
70//    (if(writeFpRf) "fp|" else "") +
71//    (if(writeVecRf) "vec|" else "") +
72//    (if(writeFflags) "fflags" else "") +
73//    (if(!writeIntRf && !writeFpRf && !writeVecRf && !writeFflags) "none" else "") + ") " +
74//    (if(hasRedirect) "hasRedirect " else "") +
75//    (if(latency.latencyVal.getOrElse(99) != 99) "latency " + latency.latencyVal.get+" " else "") +
76//    (if(fastUopOut) "hasFastUopOut " else "") +
77//    s"inputBuffer (${hasInputBuffer._1},${hasInputBuffer._2},${hasInputBuffer._3}) "
78//  }
79//}
80
81
82class FuOutput(val len: Int)(implicit p: Parameters) extends XSBundle {
83  val data = UInt(len.W)
84  val uop = new MicroOp
85}
86
87class FunctionUnitInput(val len: Int)(implicit p: Parameters) extends XSBundle {
88  val src = Vec(3, UInt(len.W))
89  val uop = new MicroOp
90}
91
92class FunctionUnitIO(val len: Int)(implicit p: Parameters) extends XSBundle {
93  val in = Flipped(DecoupledIO(new FunctionUnitInput(len)))
94
95  val out = DecoupledIO(new FuOutput(len))
96
97  val redirectIn = Flipped(ValidIO(new Redirect))
98}
99
100abstract class FunctionUnit(len: Int = 64)(implicit p: Parameters) extends XSModule {
101
102  val io = IO(new FunctionUnitIO(len))
103
104  XSPerfAccumulate("in_valid", io.in.valid)
105  XSPerfAccumulate("in_fire", io.in.fire)
106  XSPerfAccumulate("out_valid", io.out.valid)
107  XSPerfAccumulate("out_fire", io.out.fire)
108
109}
110
111//abstract class FUWithRedirect(len: Int = 64)(implicit p: Parameters) extends FunctionUnit(len: Int) with HasRedirectOut
112//
113//trait HasPipelineReg {
114//  this: FunctionUnit =>
115//
116//  def latency: Int
117//
118//  require(latency > 0)
119//
120//  val validVec = io.in.valid +: Array.fill(latency)(RegInit(false.B))
121//  val rdyVec = (Array.fill(latency - 1)(Wire(Bool())) :+ io.out.ready) :+ WireInit(true.B)
122//  val uopVec = io.in.bits.uop +: Array.fill(latency)(Reg(new MicroOp))
123//
124//
125//  // if flush(0), valid 0 will not given, so set flushVec(0) to false.B
126//  val flushVec = validVec.zip(uopVec).map(x => x._1 && x._2.robIdx.needFlush(io.redirectIn))
127//
128//  for (i <- 0 until latency - 1) {
129//    rdyVec(i) := !validVec(i + 1) || rdyVec(i + 1)
130//  }
131//
132//  for (i <- 1 to latency) {
133//    when(rdyVec(i - 1) && validVec(i - 1) && !flushVec(i - 1)){
134//      validVec(i) := validVec(i - 1)
135//      uopVec(i) := uopVec(i - 1)
136//    }.elsewhen(flushVec(i) || rdyVec(i)){
137//      validVec(i) := false.B
138//    }
139//  }
140//
141//  io.in.ready := rdyVec(0)
142//  io.out.valid := validVec.takeRight(2).head
143//  io.out.bits.uop := uopVec.takeRight(2).head
144//
145//  def regEnable(i: Int): Bool = validVec(i - 1) && rdyVec(i - 1) && !flushVec(i - 1)
146//
147//  def PipelineReg[TT <: Data](i: Int)(next: TT) = RegEnable(
148//    next,
149//    regEnable(i)
150//  )
151//
152//  def S1Reg[TT <: Data](next: TT): TT = PipelineReg[TT](1)(next)
153//
154//  def S2Reg[TT <: Data](next: TT): TT = PipelineReg[TT](2)(next)
155//
156//  def S3Reg[TT <: Data](next: TT): TT = PipelineReg[TT](3)(next)
157//
158//  def S4Reg[TT <: Data](next: TT): TT = PipelineReg[TT](4)(next)
159//
160//  def S5Reg[TT <: Data](next: TT): TT = PipelineReg[TT](5)(next)
161//}
162