xref: /XiangShan/src/main/scala/xiangshan/backend/fu/Jump.scala (revision 708ceed4afe43fb0ea3a52407e46b2794c573634)
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 xiangshan._
23import utils._
24import xiangshan.backend._
25import xiangshan.backend.decode.ImmUnion
26import xiangshan.backend.decode.isa._
27
28trait HasRedirectOut { this: XSModule =>
29  val redirectOutValid = IO(Output(Bool()))
30  val redirectOut = IO(Output(new Redirect))
31}
32
33class JumpDataModule(implicit p: Parameters) extends XSModule {
34  val io = IO(new Bundle() {
35    val src = Input(UInt(XLEN.W))
36    val pc = Input(UInt(XLEN.W)) // sign-ext to XLEN
37    val immMin = Input(UInt(ImmUnion.maxLen.W))
38    val func = Input(FuOpType())
39    val isRVC = Input(Bool())
40    val result, target = Output(UInt(XLEN.W))
41    val isAuipc = Output(Bool())
42  })
43  val (src1, pc, immMin, func, isRVC) = (io.src, io.pc, io.immMin, io.func, io.isRVC)
44
45  val isJalr = JumpOpType.jumpOpisJalr(func)
46  val isAuipc = JumpOpType.jumpOpisAuipc(func)
47  val offset = SignExt(ParallelMux(Seq(
48    isJalr -> ImmUnion.I.toImm32(immMin),
49    isAuipc -> ImmUnion.U.toImm32(immMin),
50    !(isJalr || isAuipc) -> ImmUnion.J.toImm32(immMin)
51  )), XLEN)
52
53  val snpc = Mux(isRVC, pc + 2.U, pc + 4.U)
54  val target = src1 + offset // NOTE: src1 is (pc/rf(rs1)), src2 is (offset)
55
56  io.target := target
57  io.result := Mux(JumpOpType.jumpOpisAuipc(func), target, snpc)
58  io.isAuipc := isAuipc
59}
60
61class Jump(implicit p: Parameters) extends FUWithRedirect {
62
63  val (src1, jalr_target, pc, immMin, func, uop) = (
64    io.in.bits.src(0),
65    io.in.bits.src(1)(VAddrBits - 1, 0),
66    SignExt(io.in.bits.uop.cf.pc, XLEN),
67    io.in.bits.uop.ctrl.imm,
68    io.in.bits.uop.ctrl.fuOpType,
69    io.in.bits.uop
70  )
71
72  val redirectHit = uop.roqIdx.needFlush(io.redirectIn, io.flushIn)
73  val valid = io.in.valid
74  val isRVC = uop.cf.pd.isRVC
75
76  val jumpDataModule = Module(new JumpDataModule)
77  jumpDataModule.io.src := src1
78  jumpDataModule.io.pc := pc
79  jumpDataModule.io.immMin := immMin
80  jumpDataModule.io.func := func
81  jumpDataModule.io.isRVC := isRVC
82
83  redirectOutValid := valid && !jumpDataModule.io.isAuipc
84  redirectOut := DontCare
85  redirectOut.level := RedirectLevel.flushAfter
86  redirectOut.roqIdx := uop.roqIdx
87  redirectOut.ftqIdx := uop.cf.ftqPtr
88  redirectOut.ftqOffset := uop.cf.ftqOffset
89  redirectOut.cfiUpdate.predTaken := true.B
90  redirectOut.cfiUpdate.taken := true.B
91  redirectOut.cfiUpdate.target := jumpDataModule.io.target
92  redirectOut.cfiUpdate.isMisPred := jumpDataModule.io.target(VAddrBits - 1, 0) =/= jalr_target || !uop.cf.pred_taken
93
94  io.in.ready := io.out.ready
95  io.out.valid := valid
96  io.out.bits.uop <> io.in.bits.uop
97  io.out.bits.data := jumpDataModule.io.result
98
99  // NOTE: the debug info is for one-cycle exec, if FMV needs multi-cycle, may needs change it
100  XSDebug(io.in.valid, "In(%d %d) Out(%d %d) Redirect:(%d %d %d)\n",
101    io.in.valid,
102    io.in.ready,
103    io.out.valid,
104    io.out.ready,
105    io.redirectIn.valid,
106    io.redirectIn.bits.level,
107    redirectHit
108  )
109}
110