xref: /XiangShan/src/main/scala/xiangshan/backend/fu/wrapper/VCVT.scala (revision 5f8b6c9e67f55ac00fba78753bbe60377a9c8448)
1package xiangshan.backend.fu.wrapper
2
3import org.chipsalliance.cde.config.Parameters
4import chisel3._
5import chisel3.util._
6import chisel3.util.experimental.decode._
7import utils.XSError
8import xiangshan.backend.fu.FuConfig
9import xiangshan.backend.fu.vector.{Mgu, VecPipedFuncUnit}
10import xiangshan.ExceptionNO
11import yunsuan.VfpuType
12import yunsuan.vector.VectorConvert.VectorCvt
13import yunsuan.util._
14
15
16class VCVT(cfg: FuConfig)(implicit p: Parameters) extends VecPipedFuncUnit(cfg) {
17  XSError(io.in.valid && io.in.bits.ctrl.fuOpType === VfpuType.dummy, "Vfcvt OpType not supported")
18
19  // params alias
20  private val dataWidth = cfg.dataBits
21  private val dataWidthOfDataModule = 64
22  private val numVecModule = dataWidth / dataWidthOfDataModule
23
24  // io alias
25  private val opcode = fuOpType(7, 0)
26  private val sew = vsew
27
28  private val isRtz = opcode(2) & opcode(1)
29  private val isRod = opcode(2) & !opcode(1) & opcode(0)
30  private val isFrm = !isRtz && !isRod
31  private val rm = Mux1H(
32    Seq(isRtz, isRod, isFrm),
33    Seq(1.U, 6.U, frm)
34  )
35
36  private val lmul = vlmul // -3->3 => 1/8 ->8
37
38  val widen = opcode(4, 3) // 0->single 1->widen 2->norrow => width of result
39  val isSingleCvt = !widen(1) & !widen(0)
40  val isWidenCvt = !widen(1) & widen(0)
41  val isNarrowCvt = widen(1) & !widen(0)
42  val fire = io.in.valid
43  val fireReg = GatedValidRegNext(fire)
44
45  // output width 8, 16, 32, 64
46  val output1H = Wire(UInt(4.W))
47  output1H := chisel3.util.experimental.decode.decoder(
48    widen ## sew,
49    TruthTable(
50      Seq(
51        BitPat("b00_01") -> BitPat("b0010"), // 16
52        BitPat("b00_10") -> BitPat("b0100"), // 32
53        BitPat("b00_11") -> BitPat("b1000"), // 64
54
55        BitPat("b01_00") -> BitPat("b0010"), // 16
56        BitPat("b01_01") -> BitPat("b0100"), // 32
57        BitPat("b01_10") -> BitPat("b1000"), // 64
58
59        BitPat("b10_00") -> BitPat("b0001"), // 8
60        BitPat("b10_01") -> BitPat("b0010"), // 16
61        BitPat("b10_10") -> BitPat("b0100"), // 32
62      ),
63      BitPat.N(4)
64    )
65  )
66  if(backendParams.debugEn) {
67    dontTouch(output1H)
68  }
69  val outputWidth1H = output1H
70
71  val outEew = RegEnable(RegEnable(Mux1H(output1H, Seq(0,1,2,3).map(i => i.U)), fire), fireReg)
72  private val needNoMask = outVecCtrl.fpu.isFpToVecInst
73  val maskToMgu = Mux(needNoMask, allMaskTrue, outSrcMask)
74
75  // modules
76  private val vfcvt = Module(new VectorCvtTop(dataWidth, dataWidthOfDataModule))
77  private val mgu = Module(new Mgu(dataWidth))
78
79  val vs2Vec = Wire(Vec(numVecModule, UInt(dataWidthOfDataModule.W)))
80  vs2Vec := vs2.asTypeOf(vs2Vec)
81
82  /**
83   * [[vfcvt]]'s in connection
84   */
85  vfcvt.uopIdx := vuopIdx(0)
86  vfcvt.src := vs2Vec
87  vfcvt.opType := opcode
88  vfcvt.sew := sew
89  vfcvt.rm := rm
90  vfcvt.outputWidth1H := outputWidth1H
91  vfcvt.isWiden := isWidenCvt
92  vfcvt.isNarrow := isNarrowCvt
93  vfcvt.fire := fire
94  val vfcvtResult = vfcvt.io.result
95  val vfcvtFflags = vfcvt.io.fflags
96
97  /** fflags:
98   */
99  val eNum1H = chisel3.util.experimental.decode.decoder(sew ## (isWidenCvt || isNarrowCvt),
100    TruthTable(
101      Seq(                     // 8, 4, 2, 1
102        BitPat("b001") -> BitPat("b1000"), //8
103        BitPat("b010") -> BitPat("b1000"), //8
104        BitPat("b011") -> BitPat("b0100"), //4
105        BitPat("b100") -> BitPat("b0100"), //4
106        BitPat("b101") -> BitPat("b0010"), //2
107        BitPat("b110") -> BitPat("b0010"), //2
108      ),
109      BitPat.N(4)
110    )
111  )
112  val eNumMax1H = Mux(lmul.head(1).asBool, eNum1H >> ((~lmul.tail(1)).asUInt +1.U), eNum1H << lmul.tail(1)).asUInt(6, 0)
113  val eNumMax = Mux1H(eNumMax1H, Seq(1,2,4,8,16,32,64).map(i => i.U)) //only for cvt intr, don't exist 128 in cvt
114  val eNumEffectIdx = Mux(vl > eNumMax, eNumMax, vl)
115
116  val eNum = Mux1H(eNum1H, Seq(1, 2, 4, 8).map(num =>num.U))
117  val eStart = vuopIdx * eNum
118  val maskPart = srcMask >> eStart
119  val mask =  Mux1H(eNum1H, Seq(1, 2, 4, 8).map(num => maskPart(num-1, 0)))
120  val fflagsEn = Wire(Vec(4 * numVecModule, Bool()))
121
122  fflagsEn := mask.asBools.zipWithIndex.map{case(mask, i) => mask & (eNumEffectIdx > eStart + i.U) }
123
124  val fflagsEnCycle2 = RegEnable(RegEnable(fflagsEn, fire), fireReg)
125  val fflagsAll = Wire(Vec(8, UInt(5.W)))
126  fflagsAll := vfcvtFflags.asTypeOf(fflagsAll)
127  val fflags = fflagsEnCycle2.zip(fflagsAll).map{case(en, fflag) => Mux(en, fflag, 0.U(5.W))}.reduce(_ | _)
128  io.out.bits.res.fflags.get := fflags
129
130
131  /**
132   * [[mgu]]'s in connection
133   */
134  val resultDataUInt = Wire(UInt(dataWidth.W))
135  resultDataUInt := vfcvtResult
136
137  private val narrow = RegEnable(RegEnable(isNarrowCvt, fire), fireReg)
138  private val narrowNeedCat = outVecCtrl.vuopIdx(0).asBool && narrow
139  private val outNarrowVd = Mux(narrowNeedCat, Cat(resultDataUInt(dataWidth / 2 - 1, 0), outOldVd(dataWidth / 2 - 1, 0)), resultDataUInt)
140
141  mgu.io.in.vd := resultDataUInt
142  mgu.io.in.vd := Mux(narrow, outNarrowVd, resultDataUInt)
143  mgu.io.in.oldVd := outOldVd
144  mgu.io.in.mask := maskToMgu
145  mgu.io.in.info.ta := outVecCtrl.vta
146  mgu.io.in.info.ma := outVecCtrl.vma
147  mgu.io.in.info.vl := Mux(outVecCtrl.fpu.isFpToVecInst, 1.U, outVl)
148  mgu.io.in.info.vlmul := outVecCtrl.vlmul
149  mgu.io.in.info.valid := io.out.valid
150  mgu.io.in.info.vstart := Mux(outVecCtrl.fpu.isFpToVecInst, 0.U, outVecCtrl.vstart)
151  mgu.io.in.info.eew := outEew
152  mgu.io.in.info.vsew := outVecCtrl.vsew
153  mgu.io.in.info.vdIdx := outVecCtrl.vuopIdx
154  mgu.io.in.info.narrow := narrow
155  mgu.io.in.info.dstMask := outVecCtrl.isDstMask
156  mgu.io.in.isIndexedVls := false.B
157
158  io.out.bits.res.data := mgu.io.out.vd
159  io.out.bits.ctrl.exceptionVec.get(ExceptionNO.illegalInstr) := mgu.io.out.illegal
160}
161
162class VectorCvtTopIO(vlen: Int, xlen: Int) extends Bundle{
163  val fire = Input(Bool())
164  val uopIdx = Input(Bool())
165  val src = Input(Vec(vlen / xlen, UInt(xlen.W)))
166  val opType = Input(UInt(8.W))
167  val sew = Input(UInt(2.W))
168  val rm = Input(UInt(3.W))
169  val outputWidth1H = Input(UInt(4.W))
170  val isWiden = Input(Bool())
171  val isNarrow = Input(Bool())
172
173  val result = Output(UInt(vlen.W))
174  val fflags = Output(UInt((vlen/16*5).W))
175}
176
177
178
179//according to uopindex, 1: high64 0:low64
180class VectorCvtTop(vlen: Int, xlen: Int) extends Module{
181  val io = IO(new VectorCvtTopIO(vlen, xlen))
182
183  val (fire, uopIdx, src, opType, sew, rm, outputWidth1H, isWiden, isNarrow) = (
184    io.fire, io.uopIdx, io.src, io.opType, io.sew, io.rm, io.outputWidth1H, io.isWiden, io.isNarrow
185  )
186  val fireReg = GatedValidRegNext(fire)
187
188  val in0 = Mux(isWiden,
189    Mux(uopIdx, src(1).tail(32), src(0).tail(32)),
190    src(0)
191  )
192
193  val in1 = Mux(isWiden,
194    Mux(uopIdx, src(1).head(32), src(0).head(32)),
195    src(1)
196  )
197
198  val vectorCvt0 = Module(new VectorCvt(xlen))
199  vectorCvt0.fire := fire
200  vectorCvt0.src := in0
201  vectorCvt0.opType := opType
202  vectorCvt0.sew := sew
203  vectorCvt0.rm := rm
204
205  val vectorCvt1 = Module(new VectorCvt(xlen))
206  vectorCvt1.fire := fire
207  vectorCvt1.src := in1
208  vectorCvt1.opType := opType
209  vectorCvt1.sew := sew
210  vectorCvt1.rm := rm
211
212  val isNarrowCycle2 = RegEnable(RegEnable(isNarrow, fire), fireReg)
213  val outputWidth1HCycle2 = RegEnable(RegEnable(outputWidth1H, fire), fireReg)
214
215  //cycle2
216  io.result := Mux(isNarrowCycle2,
217    vectorCvt1.io.result.tail(32) ## vectorCvt0.io.result.tail(32),
218    vectorCvt1.io.result ## vectorCvt0.io.result)
219
220  io.fflags := Mux1H(outputWidth1HCycle2, Seq(
221    vectorCvt1.io.fflags ## vectorCvt0.io.fflags,
222    Mux(isNarrowCycle2, vectorCvt1.io.fflags.tail(10) ## vectorCvt0.io.fflags.tail(10), vectorCvt1.io.fflags ## vectorCvt0.io.fflags),
223    Mux(isNarrowCycle2, vectorCvt1.io.fflags(4,0) ## vectorCvt0.io.fflags(4,0), vectorCvt1.io.fflags.tail(10) ## vectorCvt0.io.fflags.tail(10)),
224    vectorCvt1.io.fflags(4,0) ## vectorCvt0.io.fflags(4,0)
225  ))
226}
227
228
229