xref: /XiangShan/src/main/scala/xiangshan/backend/fu/Jump.scala (revision 49272fa467f97c3293eb9ed685e99ecf79691182) 
1package xiangshan.backend.fu
2
3import chisel3._
4import chisel3.util._
5import xiangshan._
6import utils._
7import xiangshan.backend._
8import xiangshan.backend.fu.FunctionUnit._
9import xiangshan.backend.decode.isa._
10
11trait HasRedirectOut { this: RawModule =>
12  val redirectOutValid = IO(Output(Bool()))
13  val redirectOut = IO(Output(new Redirect))
14  val brUpdate = IO(Output(new CfiUpdateInfo))
15}
16
17class Jump extends FunctionUnit with HasRedirectOut {
18
19  val (src1, offset, func, pc, uop) = (
20    io.in.bits.src(0),
21    io.in.bits.uop.ctrl.imm,
22    io.in.bits.uop.ctrl.fuOpType,
23    SignExt(io.in.bits.uop.cf.pc, AddrBits),
24    io.in.bits.uop
25  )
26
27  val redirectHit = uop.roqIdx.needFlush(io.redirectIn)
28  val valid = io.in.valid && !redirectHit
29
30  val isRVC = uop.cf.brUpdate.pd.isRVC
31  val snpc = Mux(isRVC, pc + 2.U, pc + 4.U)
32  val target = src1 + offset // NOTE: src1 is (pc/rf(rs1)), src2 is (offset)
33
34  redirectOutValid := valid
35  redirectOut.pc := uop.cf.pc
36  redirectOut.target := target
37  redirectOut.brTag := uop.brTag
38  redirectOut.isException := false.B
39  redirectOut.isFlushPipe := false.B
40  redirectOut.isMisPred := DontCare // check this in brq
41  redirectOut.isReplay := false.B
42  redirectOut.roqIdx := uop.roqIdx
43
44  brUpdate := uop.cf.brUpdate
45  brUpdate.pc := uop.cf.pc
46  brUpdate.target := target
47  brUpdate.brTarget := target
48  brUpdate.taken := true.B
49
50  // Output
51  val res = snpc
52
53  io.in.ready := io.out.ready
54  io.out.valid := valid
55  io.out.bits.uop <> io.in.bits.uop
56  io.out.bits.data := res
57
58  // NOTE: the debug info is for one-cycle exec, if FMV needs multi-cycle, may needs change it
59  XSDebug(io.in.valid, "In(%d %d) Out(%d %d) Redirect:(%d %d %d %d) brTag:%x\n",
60    io.in.valid,
61    io.in.ready,
62    io.out.valid,
63    io.out.ready,
64    io.redirectIn.valid,
65    io.redirectIn.bits.isException,
66    io.redirectIn.bits.isFlushPipe,
67    redirectHit,
68    io.redirectIn.bits.brTag.value
69  )
70  XSDebug(io.in.valid, "src1:%x offset:%x func:%b type:JUMP pc:%x res:%x\n", src1, offset, func, pc, res)
71}
72