xref: /XiangShan/src/main/scala/xiangshan/backend/fu/Jump.scala (revision 3449c7696d5b7112508c0a75f7f4a995c42ce632)
1package xiangshan.backend.fu
2
3import chisel3._
4import chisel3.util._
5import xiangshan._
6import utils._
7import xiangshan.backend._
8import xiangshan.backend.fu.FunctionUnit._
9
10class Jump extends FunctionUnit(jmpCfg){
11  val io = IO(new ExuIO)
12
13  val (iovalid, src1, offset, func, pc, uop) = (io.in.valid, io.in.bits.src1, io.in.bits.uop.ctrl.imm, io.in.bits.uop.ctrl.fuOpType, SignExt(io.in.bits.uop.cf.pc, AddrBits), io.in.bits.uop)
14
15  val redirectHit = uop.brTag.needFlush(io.redirect)
16  val valid = iovalid && !redirectHit
17
18  val isRVC = uop.cf.isRVC
19  val pcDelaySlot = Mux(isRVC, pc + 2.U, pc + 4.U)
20  val target = src1 + offset // NOTE: src1 is (pc/rf(rs1)), src2 is (offset)
21
22  io.out.bits.redirectValid := valid
23  io.out.bits.redirect.target := target
24  io.out.bits.redirect.brTag := uop.brTag
25  io.out.bits.redirect.isException := false.B
26  io.out.bits.redirect.roqIdx := uop.roqIdx
27
28  // Output
29  val res = pcDelaySlot
30
31  io.in.ready := io.out.ready
32  io.out.valid := valid // TODO: CSR/MOU/FMV may need change it
33  io.out.bits.uop <> io.in.bits.uop
34  io.out.bits.data := res
35
36  io.dmem <> DontCare
37  io.out.bits.debug <> DontCare
38
39  // NOTE: the debug info is for one-cycle exec, if FMV needs multi-cycle, may needs change it
40  XSDebug(io.in.valid, "In(%d %d) Out(%d %d) Redirect:(%d %d %d) brTag:%x\n",
41    io.in.valid,
42    io.in.ready,
43    io.out.valid,
44    io.out.ready,
45    io.redirect.valid,
46    io.redirect.bits.isException,
47    redirectHit,
48    io.redirect.bits.brTag.value
49  )
50  XSDebug(io.in.valid, "src1:%x offset:%x func:%b type:JUMP pc:%x res:%x\n", src1, offset, func, pc, res)
51}
52