1/*************************************************************************************** 2* Copyright (c) 2020-2021 Institute of Computing Technology, Chinese Academy of Sciences 3* Copyright (c) 2020-2021 Peng Cheng Laboratory 4* 5* XiangShan is licensed under Mulan PSL v2. 6* You can use this software according to the terms and conditions of the Mulan PSL v2. 7* You may obtain a copy of Mulan PSL v2 at: 8* http://license.coscl.org.cn/MulanPSL2 9* 10* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND, 11* EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT, 12* MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE. 13* 14* See the Mulan PSL v2 for more details. 15***************************************************************************************/ 16 17package xiangshan.backend.rename 18 19import org.chipsalliance.cde.config.Parameters 20import chisel3._ 21import chisel3.util._ 22import utility._ 23import utils._ 24import xiangshan._ 25import xiangshan.backend.Bundles.{DecodedInst, DynInst} 26import xiangshan.backend.decode.{FusionDecodeInfo, ImmUnion, Imm_I, Imm_LUI_LOAD, Imm_U} 27import xiangshan.backend.fu.FuType 28import xiangshan.backend.rename.freelist._ 29import xiangshan.backend.rob.{RobEnqIO, RobPtr} 30import xiangshan.mem.mdp._ 31 32class Rename(implicit p: Parameters) extends XSModule with HasCircularQueuePtrHelper with HasPerfEvents { 33 34 // params alias 35 private val numRegSrc = backendParams.numRegSrc 36 private val numVecRegSrc = backendParams.numVecRegSrc 37 private val numVecRatPorts = numVecRegSrc + 1 // +1 dst 38 39 println(s"[Rename] numRegSrc: $numRegSrc") 40 41 val io = IO(new Bundle() { 42 val redirect = Flipped(ValidIO(new Redirect)) 43 val robCommits = Input(new RobCommitIO) 44 // from decode 45 val in = Vec(RenameWidth, Flipped(DecoupledIO(new DecodedInst))) 46 val fusionInfo = Vec(DecodeWidth - 1, Flipped(new FusionDecodeInfo)) 47 // ssit read result 48 val ssit = Flipped(Vec(RenameWidth, Output(new SSITEntry))) 49 // waittable read result 50 val waittable = Flipped(Vec(RenameWidth, Output(Bool()))) 51 // to rename table 52 val intReadPorts = Vec(RenameWidth, Vec(3, Input(UInt(PhyRegIdxWidth.W)))) 53 val fpReadPorts = Vec(RenameWidth, Vec(4, Input(UInt(PhyRegIdxWidth.W)))) 54 val vecReadPorts = Vec(RenameWidth, Vec(numVecRatPorts, Input(UInt(PhyRegIdxWidth.W)))) 55 val intRenamePorts = Vec(RenameWidth, Output(new RatWritePort)) 56 val fpRenamePorts = Vec(RenameWidth, Output(new RatWritePort)) 57 val vecRenamePorts = Vec(RenameWidth, Output(new RatWritePort)) 58 // from rename table 59 val int_old_pdest = Vec(CommitWidth, Input(UInt(PhyRegIdxWidth.W))) 60 val fp_old_pdest = Vec(CommitWidth, Input(UInt(PhyRegIdxWidth.W))) 61 val vec_old_pdest = Vec(CommitWidth, Input(UInt(PhyRegIdxWidth.W))) 62 val int_need_free = Vec(CommitWidth, Input(Bool())) 63 // to dispatch1 64 val out = Vec(RenameWidth, DecoupledIO(new DynInst)) 65 // for snapshots 66 val snpt = Input(new SnapshotPort) 67 val snptLastEnq = Flipped(ValidIO(new RobPtr)) 68 val robIsEmpty = Input(Bool()) 69 val toDispatchIsFp = Output(Vec(RenameWidth,Bool())) 70 val toDispatchIsInt = Output(Vec(RenameWidth,Bool())) 71 // debug arch ports 72 val debug_int_rat = if (backendParams.debugEn) Some(Vec(32, Input(UInt(PhyRegIdxWidth.W)))) else None 73 val debug_vconfig_rat = if (backendParams.debugEn) Some(Input(UInt(PhyRegIdxWidth.W))) else None 74 val debug_fp_rat = if (backendParams.debugEn) Some(Vec(32, Input(UInt(PhyRegIdxWidth.W)))) else None 75 val debug_vec_rat = if (backendParams.debugEn) Some(Vec(32, Input(UInt(PhyRegIdxWidth.W)))) else None 76 // perf only 77 val stallReason = new Bundle { 78 val in = Flipped(new StallReasonIO(RenameWidth)) 79 val out = new StallReasonIO(RenameWidth) 80 } 81 }) 82 83 val compressUnit = Module(new CompressUnit()) 84 // create free list and rat 85 val intFreeList = Module(new MEFreeList(IntPhyRegs)) 86 val fpFreeList = Module(new StdFreeList(VfPhyRegs - FpLogicRegs - VecLogicRegs)) 87 88 intFreeList.io.commit <> io.robCommits 89 intFreeList.io.debug_rat.foreach(_ <> io.debug_int_rat.get) 90 fpFreeList.io.commit <> io.robCommits 91 fpFreeList.io.debug_rat.foreach(_ <> io.debug_fp_rat.get) 92 93 // decide if given instruction needs allocating a new physical register (CfCtrl: from decode; RobCommitInfo: from rob) 94 // fp and vec share `fpFreeList` 95 def needDestReg[T <: DecodedInst](reg_t: RegType, x: T): Bool = reg_t match { 96 case Reg_I => x.rfWen && x.ldest =/= 0.U 97 case Reg_F => x.fpWen 98 case Reg_V => x.vecWen 99 } 100 def needDestRegCommit[T <: RobCommitInfo](reg_t: RegType, x: T): Bool = { 101 reg_t match { 102 case Reg_I => x.rfWen 103 case Reg_F => x.fpWen 104 case Reg_V => x.vecWen 105 } 106 } 107 def needDestRegWalk[T <: RobCommitInfo](reg_t: RegType, x: T): Bool = { 108 reg_t match { 109 case Reg_I => x.rfWen && x.ldest =/= 0.U 110 case Reg_F => x.fpWen 111 case Reg_V => x.vecWen 112 } 113 } 114 115 // connect [redirect + walk] ports for __float point__ & __integer__ free list 116 Seq(fpFreeList, intFreeList).foreach { case fl => 117 fl.io.redirect := io.redirect.valid 118 fl.io.walk := io.robCommits.isWalk 119 } 120 // only when both fp and int free list and dispatch1 has enough space can we do allocation 121 // when isWalk, freelist can definitely allocate 122 intFreeList.io.doAllocate := fpFreeList.io.canAllocate && io.out.map(_.ready).reduce(_ || _) || io.robCommits.isWalk 123 fpFreeList.io.doAllocate := intFreeList.io.canAllocate && io.out.map(_.ready).reduce(_ || _) || io.robCommits.isWalk 124 125 // dispatch1 ready ++ float point free list ready ++ int free list ready ++ not walk 126 val canOut = io.out(0).ready && fpFreeList.io.canAllocate && intFreeList.io.canAllocate && !io.robCommits.isWalk 127 128 compressUnit.io.in.zip(io.in).foreach{ case(sink, source) => 129 sink.valid := source.valid 130 sink.bits := source.bits 131 } 132 val needRobFlags = compressUnit.io.out.needRobFlags 133 val instrSizesVec = compressUnit.io.out.instrSizes 134 val compressMasksVec = compressUnit.io.out.masks 135 136 // speculatively assign the instruction with an robIdx 137 val validCount = PopCount(io.in.zip(needRobFlags).map{ case(in, needRobFlag) => in.valid && in.bits.lastUop && needRobFlag}) // number of instructions waiting to enter rob (from decode) 138 val robIdxHead = RegInit(0.U.asTypeOf(new RobPtr)) 139 val lastCycleMisprediction = RegNext(io.redirect.valid && !io.redirect.bits.flushItself()) 140 val robIdxHeadNext = Mux(io.redirect.valid, io.redirect.bits.robIdx, // redirect: move ptr to given rob index 141 Mux(lastCycleMisprediction, robIdxHead + 1.U, // mis-predict: not flush robIdx itself 142 Mux(canOut && io.in(0).fire, robIdxHead + validCount, // instructions successfully entered next stage: increase robIdx 143 /* default */ robIdxHead))) // no instructions passed by this cycle: stick to old value 144 robIdxHead := robIdxHeadNext 145 146 /** 147 * Rename: allocate free physical register and update rename table 148 */ 149 val uops = Wire(Vec(RenameWidth, new DynInst)) 150 uops.foreach( uop => { 151 uop.srcState := DontCare 152 uop.debugInfo := DontCare 153 uop.lqIdx := DontCare 154 uop.sqIdx := DontCare 155 uop.waitForRobIdx := DontCare 156 uop.singleStep := DontCare 157 uop.snapshot := DontCare 158 }) 159 160 require(RenameWidth >= CommitWidth) 161 val needVecDest = Wire(Vec(RenameWidth, Bool())) 162 val needFpDest = Wire(Vec(RenameWidth, Bool())) 163 val needIntDest = Wire(Vec(RenameWidth, Bool())) 164 val hasValid = Cat(io.in.map(_.valid)).orR 165 private val inHeadValid = io.in.head.valid 166 167 val isMove = Wire(Vec(RenameWidth, Bool())) 168 isMove zip io.in.map(_.bits) foreach { 169 case (move, in) => move := Mux(in.exceptionVec.asUInt.orR, false.B, in.isMove) 170 } 171 172 val walkNeedIntDest = WireDefault(VecInit(Seq.fill(RenameWidth)(false.B))) 173 val walkNeedFpDest = WireDefault(VecInit(Seq.fill(RenameWidth)(false.B))) 174 val walkNeedVecDest = WireDefault(VecInit(Seq.fill(RenameWidth)(false.B))) 175 val walkIsMove = WireDefault(VecInit(Seq.fill(RenameWidth)(false.B))) 176 177 val intSpecWen = Wire(Vec(RenameWidth, Bool())) 178 val fpSpecWen = Wire(Vec(RenameWidth, Bool())) 179 val vecSpecWen = Wire(Vec(RenameWidth, Bool())) 180 181 val walkIntSpecWen = WireDefault(VecInit(Seq.fill(RenameWidth)(false.B))) 182 183 val walkPdest = Wire(Vec(RenameWidth, UInt(PhyRegIdxWidth.W))) 184 185 val hasInstr = RegInit(false.B) 186 hasInstr := io.in.head.valid && !io.in.head.ready 187 val outFireNum = RegInit(0.U(RenameWidth.U.getWidth.W)) 188 val outFireNumNext = Mux(io.in.head.fire || io.redirect.valid, 0.U, outFireNum + PopCount(io.out.map(_.fire))) 189 outFireNum := outFireNumNext 190 val inValidNum = PopCount(io.in.map(_.valid)) 191 val allOut = inValidNum === outFireNum + PopCount(io.out.map(_.fire)) 192 val outValidMask = Wire(Vec(RenameWidth, Bool())) 193 outValidMask.zipWithIndex.map{ case(m,i) => 194 m := Mux(hasInstr, Mux(outFireNum > PopCount(io.in.map(_.valid).take(i)), false.B, true.B), true.B) 195 } 196 val validWaitForward = io.in.map(_.bits.waitForward).zip(outValidMask).map(x => x._1 && x._2) 197 val isWaitForward = VecInit((0 until RenameWidth).map(i => validWaitForward.take(i).fold(false.B)(_ || _))) 198 val pdestReg = Reg(Vec(RenameWidth, chiselTypeOf(uops.head.pdest))) 199 // uop calculation 200 for (i <- 0 until RenameWidth) { 201 for ((name, data) <- uops(i).elements) { 202 if (io.in(i).bits.elements.contains(name)) { 203 data := io.in(i).bits.elements(name) 204 } 205 } 206 207 // update cf according to ssit result 208 uops(i).storeSetHit := io.ssit(i).valid 209 uops(i).loadWaitStrict := io.ssit(i).strict && io.ssit(i).valid 210 uops(i).ssid := io.ssit(i).ssid 211 212 // update cf according to waittable result 213 uops(i).loadWaitBit := io.waittable(i) 214 215 uops(i).replayInst := false.B // set by IQ or MemQ 216 // alloc a new phy reg, fp and vec share the `fpFreeList` 217 needVecDest (i) := io.in(i).valid && io.out(i).fire && needDestReg(Reg_V,io.in(i).bits) && outValidMask(i) && fpFreeList.io.canAllocate && fpFreeList.io.doAllocate && !io.robCommits.isWalk && !io.redirect.valid 218 needFpDest (i) := io.in(i).valid && io.out(i).fire && needDestReg(Reg_F,io.in(i).bits) && outValidMask(i) && fpFreeList.io.canAllocate && fpFreeList.io.doAllocate && !io.robCommits.isWalk && !io.redirect.valid 219 needIntDest (i) := io.in(i).valid && io.out(i).fire && needDestReg(Reg_I,io.in(i).bits) && outValidMask(i) && intFreeList.io.canAllocate && intFreeList.io.doAllocate && !io.robCommits.isWalk && !io.redirect.valid 220 if (i < CommitWidth) { 221 walkNeedIntDest(i) := io.robCommits.walkValid(i) && needDestRegWalk(Reg_I, io.robCommits.info(i)) 222 walkNeedFpDest(i) := io.robCommits.walkValid(i) && needDestRegWalk(Reg_F, io.robCommits.info(i)) 223 walkNeedVecDest(i) := io.robCommits.walkValid(i) && needDestRegWalk(Reg_V, io.robCommits.info(i)) 224 walkIsMove(i) := io.robCommits.info(i).isMove 225 } 226 fpFreeList.io.allocateReq(i) := needFpDest(i) || needVecDest(i) 227 fpFreeList.io.walkReq(i) := walkNeedFpDest(i) || walkNeedVecDest(i) 228 intFreeList.io.allocateReq(i) := needIntDest(i) && !isMove(i) 229 intFreeList.io.walkReq(i) := walkNeedIntDest(i) && !walkIsMove(i) 230 231 // no valid instruction from decode stage || all resources (dispatch1 + both free lists) ready 232 io.in(i).ready := !hasValid || (canOut && allOut) 233 234 uops(i).robIdx := robIdxHead + PopCount(io.in.zip(needRobFlags).take(i).map{ case(in, needRobFlag) => in.valid && in.bits.lastUop && needRobFlag}) 235 uops(i).instrSize := instrSizesVec(i) 236 when(isMove(i)) { 237 uops(i).numUops := 0.U 238 uops(i).numWB := 0.U 239 } 240 if (i > 0) { 241 when(!needRobFlags(i - 1)) { 242 uops(i).firstUop := false.B 243 uops(i).ftqPtr := uops(i - 1).ftqPtr 244 uops(i).ftqOffset := uops(i - 1).ftqOffset 245 uops(i).numUops := instrSizesVec(i) - PopCount(compressMasksVec(i) & Cat(isMove.reverse)) 246 uops(i).numWB := instrSizesVec(i) - PopCount(compressMasksVec(i) & Cat(isMove.reverse)) 247 } 248 } 249 when(!needRobFlags(i)) { 250 uops(i).lastUop := false.B 251 uops(i).numUops := instrSizesVec(i) - PopCount(compressMasksVec(i) & Cat(isMove.reverse)) 252 uops(i).numWB := instrSizesVec(i) - PopCount(compressMasksVec(i) & Cat(isMove.reverse)) 253 } 254 uops(i).wfflags := (compressMasksVec(i) & Cat(io.in.map(_.bits.wfflags).reverse)).orR 255 uops(i).dirtyFs := (compressMasksVec(i) & Cat(io.in.map(_.bits.fpWen).reverse)).orR 256 257 uops(i).psrc(0) := Mux1H(uops(i).srcType(0), Seq(io.intReadPorts(i)(0), io.fpReadPorts(i)(0), io.vecReadPorts(i)(0))) 258 uops(i).psrc(1) := Mux1H(uops(i).srcType(1), Seq(io.intReadPorts(i)(1), io.fpReadPorts(i)(1), io.vecReadPorts(i)(1))) 259 uops(i).psrc(2) := Mux1H(uops(i).srcType(2)(2, 1), Seq(io.fpReadPorts(i)(2), io.vecReadPorts(i)(2))) 260 uops(i).psrc(3) := io.vecReadPorts(i)(3) 261 uops(i).psrc(4) := io.vecReadPorts(i)(4) // Todo: vl read port 262 263 // int psrc2 should be bypassed from next instruction if it is fused 264 if (i < RenameWidth - 1) { 265 when (io.fusionInfo(i).rs2FromRs2 || io.fusionInfo(i).rs2FromRs1) { 266 uops(i).psrc(1) := Mux(io.fusionInfo(i).rs2FromRs2, io.intReadPorts(i + 1)(1), io.intReadPorts(i + 1)(0)) 267 }.elsewhen(io.fusionInfo(i).rs2FromZero) { 268 uops(i).psrc(1) := 0.U 269 } 270 } 271 uops(i).eliminatedMove := isMove(i) 272 273 // update pdest 274 val pdestWire = MuxCase(0.U, Seq( 275 (needIntDest(i) && !isMove(i)) -> intFreeList.io.allocatePhyReg(i), 276 (needFpDest(i) || needVecDest(i)) -> fpFreeList.io.allocatePhyReg(i), 277 )) 278 pdestReg(i) := Mux(io.out(i).fire, pdestWire, pdestReg(i)) 279 uops(i).pdest := Mux(io.out(i).fire, pdestWire, pdestReg(i)) 280 281 // Assign performance counters 282 uops(i).debugInfo.renameTime := GTimer() 283 284 dontTouch(isWaitForward) 285 io.out(i).valid := !isWaitForward(i) && (!io.in(i).bits.waitForward || (io.in(i).bits.waitForward && io.robIsEmpty) ) && outValidMask(i) && io.in(i).valid && io.out(i).ready && intFreeList.io.canAllocate && fpFreeList.io.canAllocate && !io.robCommits.isWalk 286 io.out(i).bits := uops(i) 287 // Todo: move these shit in decode stage 288 // dirty code for fence. The lsrc is passed by imm. 289 when (io.out(i).bits.fuType === FuType.fence.U) { 290 io.out(i).bits.imm := Cat(io.in(i).bits.lsrc(1), io.in(i).bits.lsrc(0)) 291 } 292 293 // dirty code for SoftPrefetch (prefetch.r/prefetch.w) 294// when (io.in(i).bits.isSoftPrefetch) { 295// io.out(i).bits.fuType := FuType.ldu.U 296// io.out(i).bits.fuOpType := Mux(io.in(i).bits.lsrc(1) === 1.U, LSUOpType.prefetch_r, LSUOpType.prefetch_w) 297// io.out(i).bits.selImm := SelImm.IMM_S 298// io.out(i).bits.imm := Cat(io.in(i).bits.imm(io.in(i).bits.imm.getWidth - 1, 5), 0.U(5.W)) 299// } 300 301 // dirty code for lui+addi(w) fusion 302 if (i < RenameWidth - 1) { 303 val fused_lui32 = io.in(i).bits.selImm === SelImm.IMM_LUI32 && io.in(i).bits.fuType === FuType.alu.U 304 when (fused_lui32) { 305 val lui_imm = io.in(i).bits.imm(19, 0) 306 val add_imm = io.in(i + 1).bits.imm(11, 0) 307 io.out(i).bits.imm := Imm_LUI_LOAD().immFromLuiLoad(lui_imm, add_imm) 308 val lsrcWidth = uops(i).lsrc.head.getWidth 309 val lui_imm_in_imm = ImmUnion.maxLen - Imm_I().len 310 val left_lui_imm = Imm_U().len - lui_imm_in_imm 311 require(2 * lsrcWidth >= left_lui_imm, "cannot fused lui and addi(w) with lsrc") 312 io.out(i).bits.lsrc(0) := lui_imm(lui_imm_in_imm + lsrcWidth - 1, lui_imm_in_imm) 313 io.out(i).bits.lsrc(1) := lui_imm(lui_imm.getWidth - 1, lui_imm_in_imm + lsrcWidth) 314 } 315 } 316 317 // write speculative rename table 318 // we update rat later inside commit code 319 intSpecWen(i) := needIntDest(i) && intFreeList.io.canAllocate && intFreeList.io.doAllocate && !io.robCommits.isWalk && !io.redirect.valid 320 fpSpecWen(i) := needFpDest(i) && fpFreeList.io.canAllocate && fpFreeList.io.doAllocate && !io.robCommits.isWalk && !io.redirect.valid 321 vecSpecWen(i) := needVecDest(i) && fpFreeList.io.canAllocate && fpFreeList.io.doAllocate && !io.robCommits.isWalk && !io.redirect.valid 322 io.toDispatchIsFp := fpSpecWen.zip(vecSpecWen).map{ case(fp, vec) => fp || vec } 323 io.toDispatchIsInt := intSpecWen 324 325 if (i < CommitWidth) { 326 walkIntSpecWen(i) := walkNeedIntDest(i) && !io.redirect.valid 327 walkPdest(i) := io.robCommits.info(i).pdest 328 } else { 329 walkPdest(i) := io.out(i).bits.pdest 330 } 331 } 332 333 /** 334 * How to set psrc: 335 * - bypass the pdest to psrc if previous instructions write to the same ldest as lsrc 336 * - default: psrc from RAT 337 * How to set pdest: 338 * - Mux(isMove, psrc, pdest_from_freelist). 339 * 340 * The critical path of rename lies here: 341 * When move elimination is enabled, we need to update the rat with psrc. 342 * However, psrc maybe comes from previous instructions' pdest, which comes from freelist. 343 * 344 * If we expand these logic for pdest(N): 345 * pdest(N) = Mux(isMove(N), psrc(N), freelist_out(N)) 346 * = Mux(isMove(N), Mux(bypass(N, N - 1), pdest(N - 1), 347 * Mux(bypass(N, N - 2), pdest(N - 2), 348 * ... 349 * Mux(bypass(N, 0), pdest(0), 350 * rat_out(N))...)), 351 * freelist_out(N)) 352 */ 353 // a simple functional model for now 354 io.out(0).bits.pdest := Mux(isMove(0), uops(0).psrc.head, uops(0).pdest) 355 356 // psrc(n) + pdest(1) 357 val bypassCond: Vec[MixedVec[UInt]] = Wire(Vec(numRegSrc + 1, MixedVec(List.tabulate(RenameWidth-1)(i => UInt((i+1).W))))) 358 require(io.in(0).bits.srcType.size == io.in(0).bits.numSrc) 359 private val pdestLoc = io.in.head.bits.srcType.size // 2 vector src: v0, vl&vtype 360 println(s"[Rename] idx of pdest in bypassCond $pdestLoc") 361 for (i <- 1 until RenameWidth) { 362 val vecCond = io.in(i).bits.srcType.map(_ === SrcType.vp) :+ needVecDest(i) 363 val fpCond = io.in(i).bits.srcType.map(_ === SrcType.fp) :+ needFpDest(i) 364 val intCond = io.in(i).bits.srcType.map(_ === SrcType.xp) :+ needIntDest(i) 365 val target = io.in(i).bits.lsrc :+ io.in(i).bits.ldest 366 for (((((cond1, cond2), cond3), t), j) <- vecCond.zip(fpCond).zip(intCond).zip(target).zipWithIndex) { 367 val destToSrc = io.in.take(i).zipWithIndex.map { case (in, j) => 368 val indexMatch = in.bits.ldest === t 369 val writeMatch = cond3 && needIntDest(j) || cond2 && needFpDest(j) || cond1 && needVecDest(j) 370 indexMatch && writeMatch 371 } 372 bypassCond(j)(i - 1) := VecInit(destToSrc).asUInt 373 } 374 io.out(i).bits.psrc(0) := io.out.take(i).map(_.bits.pdest).zip(bypassCond(0)(i-1).asBools).foldLeft(uops(i).psrc(0)) { 375 (z, next) => Mux(next._2, next._1, z) 376 } 377 io.out(i).bits.psrc(1) := io.out.take(i).map(_.bits.pdest).zip(bypassCond(1)(i-1).asBools).foldLeft(uops(i).psrc(1)) { 378 (z, next) => Mux(next._2, next._1, z) 379 } 380 io.out(i).bits.psrc(2) := io.out.take(i).map(_.bits.pdest).zip(bypassCond(2)(i-1).asBools).foldLeft(uops(i).psrc(2)) { 381 (z, next) => Mux(next._2, next._1, z) 382 } 383 io.out(i).bits.psrc(3) := io.out.take(i).map(_.bits.pdest).zip(bypassCond(3)(i-1).asBools).foldLeft(uops(i).psrc(3)) { 384 (z, next) => Mux(next._2, next._1, z) 385 } 386 io.out(i).bits.psrc(4) := io.out.take(i).map(_.bits.pdest).zip(bypassCond(4)(i-1).asBools).foldLeft(uops(i).psrc(4)) { 387 (z, next) => Mux(next._2, next._1, z) 388 } 389 io.out(i).bits.pdest := Mux(isMove(i), io.out(i).bits.psrc(0), uops(i).pdest) 390 391 // Todo: better implementation for fields reuse 392 // For fused-lui-load, load.src(0) is replaced by the imm. 393 val last_is_lui = io.in(i - 1).bits.selImm === SelImm.IMM_U && io.in(i - 1).bits.srcType(0) =/= SrcType.pc 394 val this_is_load = io.in(i).bits.fuType === FuType.ldu.U 395 val lui_to_load = io.in(i - 1).valid && io.in(i - 1).bits.ldest === io.in(i).bits.lsrc(0) 396 val fused_lui_load = last_is_lui && this_is_load && lui_to_load 397 when (fused_lui_load) { 398 // The first LOAD operand (base address) is replaced by LUI-imm and stored in {psrc, imm} 399 val lui_imm = io.in(i - 1).bits.imm(19, 0) 400 val ld_imm = io.in(i).bits.imm 401 io.out(i).bits.srcType(0) := SrcType.imm 402 io.out(i).bits.imm := Imm_LUI_LOAD().immFromLuiLoad(lui_imm, ld_imm) 403 val psrcWidth = uops(i).psrc.head.getWidth 404 val lui_imm_in_imm = 20/*Todo: uops(i).imm.getWidth*/ - Imm_I().len 405 val left_lui_imm = Imm_U().len - lui_imm_in_imm 406 require(2 * psrcWidth >= left_lui_imm, "cannot fused lui and load with psrc") 407 io.out(i).bits.psrc(0) := lui_imm(lui_imm_in_imm + psrcWidth - 1, lui_imm_in_imm) 408 io.out(i).bits.psrc(1) := lui_imm(lui_imm.getWidth - 1, lui_imm_in_imm + psrcWidth) 409 } 410 411 } 412 413 val genSnapshot = Cat(io.out.map(out => out.fire && out.bits.snapshot)).orR 414 val snapshotCtr = RegInit((4 * CommitWidth).U) 415 val notInSameSnpt = RegNext(distanceBetween(robIdxHeadNext, io.snptLastEnq.bits) >= CommitWidth.U || !io.snptLastEnq.valid) 416 val allowSnpt = if (EnableRenameSnapshot) !hasInstr && !snapshotCtr.orR && notInSameSnpt && io.in.head.bits.firstUop else false.B 417 io.out.zip(io.in).foreach{ case (out, in) => out.bits.snapshot := allowSnpt && (!in.bits.preDecodeInfo.notCFI || FuType.isJump(in.bits.fuType)) && in.fire } 418 when(genSnapshot) { 419 snapshotCtr := (4 * CommitWidth).U - PopCount(io.out.map(_.fire)) 420 }.elsewhen(io.out.head.fire) { 421 snapshotCtr := Mux(snapshotCtr < PopCount(io.out.map(_.fire)), 0.U, snapshotCtr - PopCount(io.out.map(_.fire))) 422 } 423 424 intFreeList.io.snpt := io.snpt 425 fpFreeList.io.snpt := io.snpt 426 intFreeList.io.snpt.snptEnq := genSnapshot 427 fpFreeList.io.snpt.snptEnq := genSnapshot 428 429 /** 430 * Instructions commit: update freelist and rename table 431 */ 432 for (i <- 0 until CommitWidth) { 433 val commitValid = io.robCommits.isCommit && io.robCommits.commitValid(i) 434 val walkValid = io.robCommits.isWalk && io.robCommits.walkValid(i) 435 436 // I. RAT Update 437 // When redirect happens (mis-prediction), don't update the rename table 438 io.intRenamePorts(i).wen := intSpecWen(i) 439 io.intRenamePorts(i).addr := uops(i).ldest 440 io.intRenamePorts(i).data := io.out(i).bits.pdest 441 442 io.fpRenamePorts(i).wen := fpSpecWen(i) 443 io.fpRenamePorts(i).addr := uops(i).ldest 444 io.fpRenamePorts(i).data := fpFreeList.io.allocatePhyReg(i) 445 446 io.vecRenamePorts(i).wen := vecSpecWen(i) 447 io.vecRenamePorts(i).addr := uops(i).ldest 448 io.vecRenamePorts(i).data := fpFreeList.io.allocatePhyReg(i) 449 450 // II. Free List Update 451 intFreeList.io.freeReq(i) := io.int_need_free(i) 452 intFreeList.io.freePhyReg(i) := RegNext(io.int_old_pdest(i)) 453 fpFreeList.io.freeReq(i) := RegNext(commitValid && (needDestRegCommit(Reg_F, io.robCommits.info(i)) || needDestRegCommit(Reg_V, io.robCommits.info(i)))) 454 fpFreeList.io.freePhyReg(i) := Mux(RegNext(needDestRegCommit(Reg_F, io.robCommits.info(i))), io.fp_old_pdest(i), io.vec_old_pdest(i)) 455 } 456 457 /* 458 Debug and performance counters 459 */ 460 def printRenameInfo(in: DecoupledIO[DecodedInst], out: DecoupledIO[DynInst]) = { 461 XSInfo(out.fire, p"pc:${Hexadecimal(in.bits.pc)} in(${in.valid},${in.ready}) " + 462 p"lsrc(0):${in.bits.lsrc(0)} -> psrc(0):${out.bits.psrc(0)} " + 463 p"lsrc(1):${in.bits.lsrc(1)} -> psrc(1):${out.bits.psrc(1)} " + 464 p"lsrc(2):${in.bits.lsrc(2)} -> psrc(2):${out.bits.psrc(2)} " + 465 p"ldest:${in.bits.ldest} -> pdest:${out.bits.pdest}\n" 466 ) 467 } 468 469 for ((x,y) <- io.in.zip(io.out)) { 470 printRenameInfo(x, y) 471 } 472 473 val debugRedirect = RegEnable(io.redirect.bits, io.redirect.valid) 474 // bad speculation 475 val recStall = io.redirect.valid || io.robCommits.isWalk 476 val ctrlRecStall = Mux(io.redirect.valid, io.redirect.bits.debugIsCtrl, io.robCommits.isWalk && debugRedirect.debugIsCtrl) 477 val mvioRecStall = Mux(io.redirect.valid, io.redirect.bits.debugIsMemVio, io.robCommits.isWalk && debugRedirect.debugIsMemVio) 478 val otherRecStall = recStall && !(ctrlRecStall || mvioRecStall) 479 XSPerfAccumulate("recovery_stall", recStall) 480 XSPerfAccumulate("control_recovery_stall", ctrlRecStall) 481 XSPerfAccumulate("mem_violation_recovery_stall", mvioRecStall) 482 XSPerfAccumulate("other_recovery_stall", otherRecStall) 483 // freelist stall 484 val notRecStall = !io.out.head.valid && !recStall 485 val intFlStall = notRecStall && inHeadValid && !intFreeList.io.canAllocate 486 val fpFlStall = notRecStall && inHeadValid && intFreeList.io.canAllocate && !fpFreeList.io.canAllocate 487 // other stall 488 val otherStall = notRecStall && !intFlStall && !fpFlStall 489 490 io.stallReason.in.backReason.valid := io.stallReason.out.backReason.valid || !io.in.head.ready 491 io.stallReason.in.backReason.bits := Mux(io.stallReason.out.backReason.valid, io.stallReason.out.backReason.bits, 492 MuxCase(TopDownCounters.OtherCoreStall.id.U, Seq( 493 ctrlRecStall -> TopDownCounters.ControlRecoveryStall.id.U, 494 mvioRecStall -> TopDownCounters.MemVioRecoveryStall.id.U, 495 otherRecStall -> TopDownCounters.OtherRecoveryStall.id.U, 496 intFlStall -> TopDownCounters.IntFlStall.id.U, 497 fpFlStall -> TopDownCounters.FpFlStall.id.U 498 ) 499 )) 500 io.stallReason.out.reason.zip(io.stallReason.in.reason).zip(io.in.map(_.valid)).foreach { case ((out, in), valid) => 501 out := Mux(io.stallReason.in.backReason.valid, io.stallReason.in.backReason.bits, in) 502 } 503 504 XSDebug(io.robCommits.isWalk, p"Walk Recovery Enabled\n") 505 XSDebug(io.robCommits.isWalk, p"validVec:${Binary(io.robCommits.walkValid.asUInt)}\n") 506 for (i <- 0 until CommitWidth) { 507 val info = io.robCommits.info(i) 508 XSDebug(io.robCommits.isWalk && io.robCommits.walkValid(i), p"[#$i walk info] pc:${Hexadecimal(info.pc)} " + 509 p"ldest:${info.ldest} rfWen:${info.rfWen} fpWen:${info.fpWen} vecWen:${info.vecWen}") 510 } 511 512 XSDebug(p"inValidVec: ${Binary(Cat(io.in.map(_.valid)))}\n") 513 514 XSPerfAccumulate("in_valid_count", PopCount(io.in.map(_.valid))) 515 XSPerfAccumulate("in_fire_count", PopCount(io.in.map(_.fire))) 516 XSPerfAccumulate("in_valid_not_ready_count", PopCount(io.in.map(x => x.valid && !x.ready))) 517 XSPerfAccumulate("wait_cycle", !io.in.head.valid && io.out.head.ready) 518 519 // These stall reasons could overlap each other, but we configure the priority as fellows. 520 // walk stall > dispatch stall > int freelist stall > fp freelist stall 521 private val inHeadStall = io.in.head match { case x => x.valid && !x.ready } 522 private val stallForWalk = inHeadValid && io.robCommits.isWalk 523 private val stallForDispatch = inHeadValid && !io.robCommits.isWalk && !io.out(0).ready 524 private val stallForIntFL = inHeadValid && !io.robCommits.isWalk && io.out(0).ready && !intFreeList.io.canAllocate 525 private val stallForFpFL = inHeadValid && !io.robCommits.isWalk && io.out(0).ready && intFreeList.io.canAllocate && !fpFreeList.io.canAllocate 526 XSPerfAccumulate("stall_cycle", inHeadStall) 527 XSPerfAccumulate("stall_cycle_walk", stallForWalk) 528 XSPerfAccumulate("stall_cycle_dispatch", stallForDispatch) 529 XSPerfAccumulate("stall_cycle_int", stallForIntFL) 530 XSPerfAccumulate("stall_cycle_fp", stallForFpFL) 531 532 XSPerfHistogram("in_valid_range", PopCount(io.in.map(_.valid)), true.B, 0, DecodeWidth + 1, 1) 533 XSPerfHistogram("in_fire_range", PopCount(io.in.map(_.fire)), true.B, 0, DecodeWidth + 1, 1) 534 XSPerfHistogram("out_valid_range", PopCount(io.out.map(_.valid)), true.B, 0, DecodeWidth + 1, 1) 535 XSPerfHistogram("out_fire_range", PopCount(io.out.map(_.fire)), true.B, 0, DecodeWidth + 1, 1) 536 537 XSPerfAccumulate("move_instr_count", PopCount(io.out.map(out => out.fire && out.bits.isMove))) 538 val is_fused_lui_load = io.out.map(o => o.fire && o.bits.fuType === FuType.ldu.U && o.bits.srcType(0) === SrcType.imm) 539 XSPerfAccumulate("fused_lui_load_instr_count", PopCount(is_fused_lui_load)) 540 541 val renamePerf = Seq( 542 ("rename_in ", PopCount(io.in.map(_.valid & io.in(0).ready )) ), 543 ("rename_waitinstr ", PopCount((0 until RenameWidth).map(i => io.in(i).valid && !io.in(i).ready)) ), 544 ("rename_stall ", inHeadStall), 545 ("rename_stall_cycle_walk ", inHeadValid && io.robCommits.isWalk), 546 ("rename_stall_cycle_dispatch", inHeadValid && !io.robCommits.isWalk && !io.out(0).ready), 547 ("rename_stall_cycle_int ", inHeadValid && !io.robCommits.isWalk && io.out(0).ready && !intFreeList.io.canAllocate), 548 ("rename_stall_cycle_fp ", inHeadValid && !io.robCommits.isWalk && io.out(0).ready && intFreeList.io.canAllocate && !fpFreeList.io.canAllocate), 549 ) 550 val intFlPerf = intFreeList.getPerfEvents 551 val fpFlPerf = fpFreeList.getPerfEvents 552 val perfEvents = renamePerf ++ intFlPerf ++ fpFlPerf 553 generatePerfEvent() 554} 555