xref: /XiangShan/src/main/scala/xiangshan/backend/fu/Jump.scala (revision ec4b629128e8d079c26c89cba29b20f2c77748a2) 
1package xiangshan.backend.fu
2
3import chisel3._
4import chisel3.util._
5import xiangshan._
6import utils._
7import xiangshan.backend._
8import xiangshan.backend.decode.ImmUnion
9import xiangshan.backend.fu.FunctionUnit._
10import xiangshan.backend.decode.isa._
11
12trait HasRedirectOut { this: RawModule =>
13  val redirectOutValid = IO(Output(Bool()))
14  val redirectOut = IO(Output(new Redirect))
15  val brUpdate = IO(Output(new CfiUpdateInfo))
16}
17
18class Jump extends FunctionUnit with HasRedirectOut {
19
20  val (src1, immMin, func, pc, uop) = (
21    io.in.bits.src(0),
22    io.in.bits.uop.ctrl.imm,
23    io.in.bits.uop.ctrl.fuOpType,
24    SignExt(io.in.bits.uop.cf.pc, AddrBits),
25    io.in.bits.uop
26  )
27
28  val isJalr = JumpOpType.jumpOpisJalr(func)
29  val isAuipc = JumpOpType.jumpOpisAuipc(func)
30  val offset = SignExt(Mux1H(Seq(
31    isJalr -> ImmUnion.I.toImm32(immMin),
32    isAuipc -> ImmUnion.U.toImm32(immMin),
33    !(isJalr || isAuipc) -> ImmUnion.J.toImm32(immMin)
34  )), XLEN)
35
36  val redirectHit = uop.roqIdx.needFlush(io.redirectIn)
37  val valid = io.in.valid
38
39  val isRVC = uop.cf.brUpdate.pd.isRVC
40  val snpc = Mux(isRVC, pc + 2.U, pc + 4.U)
41  val target = src1 + offset // NOTE: src1 is (pc/rf(rs1)), src2 is (offset)
42
43  redirectOutValid := valid
44  redirectOut := DontCare
45//  redirectOut.pc := uop.cf.pc
46  redirectOut.target := target
47  redirectOut.brTag := uop.brTag
48  redirectOut.level := RedirectLevel.flushAfter
49//  redirectOut.interrupt := DontCare
50  redirectOut.roqIdx := uop.roqIdx
51
52  brUpdate := DontCare //uop.cf.brUpdate
53//  brUpdate.pc := uop.cf.pc
54  brUpdate.target := target
55  brUpdate.brTarget := target
56  brUpdate.taken := true.B
57
58  // Output
59  val res = Mux(JumpOpType.jumpOpisAuipc(func), target, snpc)
60
61  io.in.ready := io.out.ready
62  io.out.valid := valid
63  io.out.bits.uop <> io.in.bits.uop
64  io.out.bits.data := res
65
66  // NOTE: the debug info is for one-cycle exec, if FMV needs multi-cycle, may needs change it
67  XSDebug(io.in.valid, "In(%d %d) Out(%d %d) Redirect:(%d %d %d) brTag:%x\n",
68    io.in.valid,
69    io.in.ready,
70    io.out.valid,
71    io.out.ready,
72    io.redirectIn.valid,
73    io.redirectIn.bits.level,
74    redirectHit,
75    io.redirectIn.bits.brTag.value
76  )
77  XSDebug(io.in.valid, "src1:%x offset:%x func:%b type:JUMP pc:%x res:%x\n", src1, offset, func, pc, res)
78}
79