xref: /XiangShan/src/main/scala/xiangshan/backend/fu/Jump.scala (revision b0ae3ac4e5cdf55b27f5ffddd32e68a0733d3982) 
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 offset = SignExt(Mux(JumpOpType.jumpOpIsJal(func),
29    ImmUnion.J.toImm32(immMin),
30    ImmUnion.I.toImm32(immMin)
31  ), XLEN)
32
33  val redirectHit = uop.roqIdx.needFlush(io.redirectIn)
34  val valid = io.in.valid
35
36  val isRVC = uop.cf.brUpdate.pd.isRVC
37  val snpc = Mux(isRVC, pc + 2.U, pc + 4.U)
38  val target = src1 + offset // NOTE: src1 is (pc/rf(rs1)), src2 is (offset)
39
40  redirectOutValid := valid
41  redirectOut.pc := uop.cf.pc
42  redirectOut.target := target
43  redirectOut.brTag := uop.brTag
44  redirectOut.level := RedirectLevel.flushAfter
45  redirectOut.interrupt := DontCare
46  redirectOut.roqIdx := uop.roqIdx
47
48  brUpdate := uop.cf.brUpdate
49  brUpdate.pc := uop.cf.pc
50  brUpdate.target := target
51  brUpdate.brTarget := target
52  brUpdate.taken := true.B
53
54  // Output
55  val res = snpc
56
57  io.in.ready := io.out.ready
58  io.out.valid := valid
59  io.out.bits.uop <> io.in.bits.uop
60  io.out.bits.data := res
61
62  // NOTE: the debug info is for one-cycle exec, if FMV needs multi-cycle, may needs change it
63  XSDebug(io.in.valid, "In(%d %d) Out(%d %d) Redirect:(%d %d %d) brTag:%x\n",
64    io.in.valid,
65    io.in.ready,
66    io.out.valid,
67    io.out.ready,
68    io.redirectIn.valid,
69    io.redirectIn.bits.level,
70    redirectHit,
71    io.redirectIn.bits.brTag.value
72  )
73  XSDebug(io.in.valid, "src1:%x offset:%x func:%b type:JUMP pc:%x res:%x\n", src1, offset, func, pc, res)
74}
75