xref: /XiangShan/src/main/scala/xiangshan/backend/decode/DecodeUnit.scala (revision f320e0f01bd645f0a3045a8a740e60dd770734a9)
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.decode
18
19import chipsalliance.rocketchip.config.Parameters
20import chisel3._
21import chisel3.util._
22import freechips.rocketchip.util.{UIntIsOneOf, uintToBitPat}
23import xiangshan._
24import utils._
25import xiangshan.backend._
26import xiangshan.backend.decode.Instructions._
27
28/**
29 * Abstract trait giving defaults and other relevant values to different Decode constants/
30 */
31abstract trait DecodeConstants {
32  def X = BitPat("b?")
33  def N = BitPat("b0")
34  def Y = BitPat("b1")
35
36  def decodeDefault: List[BitPat] = // illegal instruction
37    //   srcType(0)     srcType(1)     srcType(2)     fuType      fuOpType    rfWen
38    //   |            |            |            |           |           |  fpWen
39    //   |            |            |            |           |           |  |  isXSTrap
40    //   |            |            |            |           |           |  |  |  noSpecExec
41    //   |            |            |            |           |           |  |  |  |  blockBackward
42    //   |            |            |            |           |           |  |  |  |  |  flushPipe
43    //   |            |            |            |           |           |  |  |  |  |  |  isRVF
44    //   |            |            |            |           |           |  |  |  |  |  |  |  selImm
45    List(SrcType.DC, SrcType.DC, SrcType.DC, FuType.alu, ALUOpType.sll, N, N, N, N, N, N, N, SelImm.INVALID_INSTR) // Use SelImm to indicate invalid instr
46
47    val table: Array[(BitPat, List[BitPat])]
48}
49
50trait DecodeUnitConstants
51{
52  // abstract out instruction decode magic numbers
53  val RD_MSB  = 11
54  val RD_LSB  = 7
55  val RS1_MSB = 19
56  val RS1_LSB = 15
57  val RS2_MSB = 24
58  val RS2_LSB = 20
59  val RS3_MSB = 31
60  val RS3_LSB = 27
61}
62
63/**
64 * Decoded control signals
65 * See xiangshan/package.scala, xiangshan/backend/package.scala, Bundle.scala
66 */
67
68/**
69 * Decode constants for RV64
70 */
71object X64Decode extends DecodeConstants {
72  val table: Array[(BitPat, List[BitPat])] = Array(
73    LD      -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.ld, Y, N, N, N, N, N, N, SelImm.IMM_I),
74    LWU     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lwu, Y, N, N, N, N, N, N, SelImm.IMM_I),
75    SD      -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.stu, LSUOpType.sd, N, N, N, N, N, N, N, SelImm.IMM_S),
76
77    SLLI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sll, Y, N, N, N, N, N, N, SelImm.IMM_I),
78    SRLI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.srl, Y, N, N, N, N, N, N, SelImm.IMM_I),
79    SRAI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sra, Y, N, N, N, N, N, N, SelImm.IMM_I),
80
81    ADDIW   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.addw, Y, N, N, N, N, N, N, SelImm.IMM_I),
82    SLLIW   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sllw, Y, N, N, N, N, N, N, SelImm.IMM_I),
83    SRAIW   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sraw, Y, N, N, N, N, N, N, SelImm.IMM_I),
84    SRLIW   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.srlw, Y, N, N, N, N, N, N, SelImm.IMM_I),
85
86    ADDW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.addw, Y, N, N, N, N, N, N, SelImm.IMM_X),
87    SUBW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.subw, Y, N, N, N, N, N, N, SelImm.IMM_X),
88    SLLW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sllw, Y, N, N, N, N, N, N, SelImm.IMM_X),
89    SRAW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sraw, Y, N, N, N, N, N, N, SelImm.IMM_X),
90    SRLW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.srlw, Y, N, N, N, N, N, N, SelImm.IMM_X)
91  )
92}
93
94/**
95 * Overall Decode constants
96 */
97object XDecode extends DecodeConstants {
98  val table: Array[(BitPat, List[BitPat])] = Array(
99    LW      -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lw, Y, N, N, N, N, N, N, SelImm.IMM_I),
100    LH      -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lh, Y, N, N, N, N, N, N, SelImm.IMM_I),
101    LHU     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lhu, Y, N, N, N, N, N, N, SelImm.IMM_I),
102    LB      -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lb, Y, N, N, N, N, N, N, SelImm.IMM_I),
103    LBU     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lbu, Y, N, N, N, N, N, N, SelImm.IMM_I),
104
105    SW      -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.stu, LSUOpType.sw, N, N, N, N, N, N, N, SelImm.IMM_S),
106    SH      -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.stu, LSUOpType.sh, N, N, N, N, N, N, N, SelImm.IMM_S),
107    SB      -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.stu, LSUOpType.sb, N, N, N, N, N, N, N, SelImm.IMM_S),
108
109    LUI     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.add, Y, N, N, N, N, N, N, SelImm.IMM_U),
110
111    ADDI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.add, Y, N, N, N, N, N, N, SelImm.IMM_I),
112    ANDI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.and, Y, N, N, N, N, N, N, SelImm.IMM_I),
113    ORI     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.or, Y, N, N, N, N, N, N, SelImm.IMM_I),
114    XORI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.xor, Y, N, N, N, N, N, N, SelImm.IMM_I),
115    SLTI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.slt, Y, N, N, N, N, N, N, SelImm.IMM_I),
116    SLTIU   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sltu, Y, N, N, N, N, N, N, SelImm.IMM_I),
117
118    SLL     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sll, Y, N, N, N, N, N, N, SelImm.IMM_X),
119    ADD     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.add, Y, N, N, N, N, N, N, SelImm.IMM_X),
120    SUB     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sub, Y, N, N, N, N, N, N, SelImm.IMM_X),
121    SLT     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.slt, Y, N, N, N, N, N, N, SelImm.IMM_X),
122    SLTU    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sltu, Y, N, N, N, N, N, N, SelImm.IMM_X),
123    AND     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.and, Y, N, N, N, N, N, N, SelImm.IMM_X),
124    OR      -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.or, Y, N, N, N, N, N, N, SelImm.IMM_X),
125    XOR     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.xor, Y, N, N, N, N, N, N, SelImm.IMM_X),
126    SRA     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sra, Y, N, N, N, N, N, N, SelImm.IMM_X),
127    SRL     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.srl, Y, N, N, N, N, N, N, SelImm.IMM_X),
128
129    MUL     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mul, MDUOpType.mul, Y, N, N, N, N, N, N, SelImm.IMM_X),
130    MULH    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mul, MDUOpType.mulh, Y, N, N, N, N, N, N, SelImm.IMM_X),
131    MULHU   -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mul, MDUOpType.mulhu, Y, N, N, N, N, N, N, SelImm.IMM_X),
132    MULHSU  -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mul, MDUOpType.mulhsu, Y, N, N, N, N, N, N, SelImm.IMM_X),
133    MULW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mul, MDUOpType.mulw, Y, N, N, N, N, N, N, SelImm.IMM_X),
134
135    DIV     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.div, Y, N, N, N, N, N, N, SelImm.IMM_X),
136    DIVU    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.divu, Y, N, N, N, N, N, N, SelImm.IMM_X),
137    REM     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.rem, Y, N, N, N, N, N, N, SelImm.IMM_X),
138    REMU    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.remu, Y, N, N, N, N, N, N, SelImm.IMM_X),
139    DIVW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.divw, Y, N, N, N, N, N, N, SelImm.IMM_X),
140    DIVUW   -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.divuw, Y, N, N, N, N, N, N, SelImm.IMM_X),
141    REMW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.remw, Y, N, N, N, N, N, N, SelImm.IMM_X),
142    REMUW   -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.remuw, Y, N, N, N, N, N, N, SelImm.IMM_X),
143
144    AUIPC   -> List(SrcType.pc , SrcType.imm, SrcType.DC, FuType.jmp, JumpOpType.auipc, Y, N, N, N, N, N, N, SelImm.IMM_U),
145    JAL     -> List(SrcType.pc , SrcType.imm, SrcType.DC, FuType.jmp, JumpOpType.jal, Y, N, N, N, N, N, N, SelImm.IMM_UJ),
146    JALR    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.jmp, JumpOpType.jalr, Y, N, N, N, N, N, N, SelImm.IMM_I),
147    BEQ     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.beq, N, N, N, N, N, N, N, SelImm.IMM_SB),
148    BNE     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.bne, N, N, N, N, N, N, N, SelImm.IMM_SB),
149    BGE     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.bge, N, N, N, N, N, N, N, SelImm.IMM_SB),
150    BGEU    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.bgeu, N, N, N, N, N, N, N, SelImm.IMM_SB),
151    BLT     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.blt, N, N, N, N, N, N, N, SelImm.IMM_SB),
152    BLTU    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.bltu, N, N, N, N, N, N, N, SelImm.IMM_SB),
153
154    // I-type, the immediate12 holds the CSR register.
155    CSRRW   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.wrt, Y, N, N, Y, Y, N, N, SelImm.IMM_I),
156    CSRRS   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.set, Y, N, N, Y, Y, N, N, SelImm.IMM_I),
157    CSRRC   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.clr, Y, N, N, Y, Y, N, N, SelImm.IMM_I),
158
159    CSRRWI  -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.wrti, Y, N, N, Y, Y, N, N, SelImm.IMM_Z),
160    CSRRSI  -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.seti, Y, N, N, Y, Y, N, N, SelImm.IMM_Z),
161    CSRRCI  -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.clri, Y, N, N, Y, Y, N, N, SelImm.IMM_Z),
162
163    SFENCE_VMA->List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.fence, FenceOpType.sfence, N, N, N, Y, Y, Y, N, SelImm.IMM_X),
164    ECALL   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.jmp, Y, N, N, Y, Y, N, N, SelImm.IMM_I),
165    SRET    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.jmp, Y, N, N, Y, Y, N, N, SelImm.IMM_I),
166    MRET    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.jmp, Y, N, N, Y, Y, N, N, SelImm.IMM_I),
167
168    WFI     -> List(SrcType.pc, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sll, Y, N, N, N, N, N, N, SelImm.IMM_X),
169
170    FENCE_I -> List(SrcType.pc, SrcType.imm, SrcType.DC, FuType.fence, FenceOpType.fencei, N, N, N, Y, Y, Y, N, SelImm.IMM_X),
171    FENCE   -> List(SrcType.pc, SrcType.imm, SrcType.DC, FuType.fence, FenceOpType.fence, N, N, N, Y, Y, Y, N, SelImm.IMM_X),
172
173    // A-type
174    AMOADD_W-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoadd_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
175    AMOXOR_W-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoxor_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
176    AMOSWAP_W->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoswap_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
177    AMOAND_W-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoand_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
178    AMOOR_W -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoor_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
179    AMOMIN_W-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomin_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
180    AMOMINU_W->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amominu_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
181    AMOMAX_W-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomax_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
182    AMOMAXU_W->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomaxu_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
183
184    AMOADD_D-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoadd_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
185    AMOXOR_D-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoxor_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
186    AMOSWAP_D->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoswap_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
187    AMOAND_D-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoand_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
188    AMOOR_D -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoor_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
189    AMOMIN_D-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomin_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
190    AMOMINU_D->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amominu_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
191    AMOMAX_D-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomax_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
192    AMOMAXU_D->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomaxu_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
193
194    LR_W    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.mou, LSUOpType.lr_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
195    LR_D    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.mou, LSUOpType.lr_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
196    SC_W    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.sc_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
197    SC_D    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.sc_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X)
198  )
199}
200
201/**
202 * FP Decode constants
203 */
204object FDecode extends DecodeConstants{
205  val table: Array[(BitPat, List[BitPat])] = Array(
206
207  FLW     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lw, N, Y, N, N, N, N, Y, SelImm.IMM_I),
208  FLD     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.ld, N, Y, N, N, N, N, N, SelImm.IMM_I),
209  FSW     -> List(SrcType.reg, SrcType.fp, SrcType.DC, FuType.stu, LSUOpType.sw, N, N, N, N, N, N, Y, SelImm.IMM_S),
210  FSD     -> List(SrcType.reg, SrcType.fp, SrcType.DC, FuType.stu, LSUOpType.sd, N, N, N, N, N, N, N, SelImm.IMM_S),
211
212  FCLASS_S-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, Y, SelImm.IMM_X),
213  FCLASS_D-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, N, SelImm.IMM_X),
214
215  FMV_D_X -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
216  FMV_X_D -> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, N, SelImm.IMM_X),
217  FMV_X_W -> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, Y, SelImm.IMM_X),
218  FMV_W_X -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
219
220  FSGNJ_S -> List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
221  FSGNJ_D -> List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
222  FSGNJX_S-> List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
223  FSGNJX_D-> List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
224  FSGNJN_S-> List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
225  FSGNJN_D-> List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
226
227  // FP to FP
228  FCVT_S_D-> List(SrcType.fp, SrcType.imm, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
229  FCVT_D_S-> List(SrcType.fp, SrcType.imm, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
230
231  // Int to FP
232  FCVT_S_W-> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
233  FCVT_S_WU->List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
234  FCVT_S_L-> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
235  FCVT_S_LU->List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
236
237  FCVT_D_W-> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
238  FCVT_D_WU->List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
239  FCVT_D_L-> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
240  FCVT_D_LU->List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
241
242  // FP to Int
243  FCVT_W_S-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, Y, SelImm.IMM_X),
244  FCVT_WU_S->List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, Y, SelImm.IMM_X),
245  FCVT_L_S-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, Y, SelImm.IMM_X),
246  FCVT_LU_S->List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, Y, SelImm.IMM_X),
247
248  FCVT_W_D-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, N, SelImm.IMM_X),
249  FCVT_WU_D->List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, N, SelImm.IMM_X),
250  FCVT_L_D-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, N, SelImm.IMM_X),
251  FCVT_LU_D->List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, N, SelImm.IMM_X),
252
253  // "fp_single" is used for wb_data formatting (and debugging)
254  FEQ_S    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, Y, SelImm.IMM_X),
255  FLT_S    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, Y, SelImm.IMM_X),
256  FLE_S    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, Y, SelImm.IMM_X),
257
258  FEQ_D    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, N, SelImm.IMM_X),
259  FLT_D    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, N, SelImm.IMM_X),
260  FLE_D    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, N, SelImm.IMM_X),
261
262  FMIN_S   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
263  FMAX_S   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
264  FMIN_D   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
265  FMAX_D   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
266
267  FADD_S   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmac, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
268  FSUB_S   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmac, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
269  FMUL_S   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmac, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
270  FADD_D   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmac, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
271  FSUB_D   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmac, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
272  FMUL_D   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmac, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
273
274  FMADD_S  ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
275  FMSUB_S  ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
276  FNMADD_S ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
277  FNMSUB_S ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
278  FMADD_D  ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
279  FMSUB_D  ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
280  FNMADD_D ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
281  FNMSUB_D ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, X, N, Y, N, N, N, N, N, SelImm.IMM_X)
282  )
283}
284
285/**
286 * FP Divide SquareRoot Constants
287 */
288object FDivSqrtDecode extends DecodeConstants {
289  val table: Array[(BitPat, List[BitPat])] = Array(
290  FDIV_S    ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
291  FDIV_D    ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
292  FSQRT_S   ->List(SrcType.fp,  SrcType.imm, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
293  FSQRT_D   ->List(SrcType.fp,  SrcType.imm, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, N, SelImm.IMM_X)
294  )
295}
296
297/**
298 * XiangShan Trap Decode constants
299 */
300object XSTrapDecode extends DecodeConstants {
301  // calculate as ADDI => addi zero, a0, 0
302  // replace rs '?????' with '01010'(a0) in decode stage
303  def lsrc1 = "b01010".U // $a0
304  val table: Array[(BitPat, List[BitPat])] = Array(
305    TRAP    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.add, Y, N, Y, Y, Y, N, N, SelImm.IMM_I)
306  )
307}
308
309//object Imm32Gen {
310//  def apply(sel: UInt, inst: UInt) = {
311//    val sign = Mux(sel === SelImm.IMM_Z, 0.S, inst(31).asSInt)
312//    val b30_20 = Mux(sel === SelImm.IMM_U, inst(30,20).asSInt, sign)
313//    val b19_12 = Mux(sel =/= SelImm.IMM_U && sel =/= SelImm.IMM_UJ, sign, inst(19,12).asSInt)
314//    val b11 = Mux(sel === SelImm.IMM_U || sel === SelImm.IMM_Z, 0.S,
315//              Mux(sel === SelImm.IMM_UJ, inst(20).asSInt,
316//              Mux(sel === SelImm.IMM_SB, inst(7).asSInt, sign)))
317//    val b10_5 = Mux(sel === SelImm.IMM_U || sel === SelImm.IMM_Z, 0.U(1.W), inst(30,25))
318//    val b4_1 = Mux(sel === SelImm.IMM_U, 0.U(1.W),
319//               Mux(sel === SelImm.IMM_S || sel === SelImm.IMM_SB, inst(11,8),
320//               Mux(sel === SelImm.IMM_Z, inst(19,16), inst(24,21))))
321//    val b0 = Mux(sel === SelImm.IMM_S, inst(7),
322//             Mux(sel === SelImm.IMM_I, inst(20),
323//             Mux(sel === SelImm.IMM_Z, inst(15), 0.U(1.W))))
324//
325//    Cat(sign, b30_20, b19_12, b11, b10_5, b4_1, b0)
326//  }
327//}
328
329abstract class Imm(val len: Int) extends Bundle {
330  def toImm32(minBits: UInt): UInt = do_toImm32(minBits(len - 1, 0))
331  def do_toImm32(minBits: UInt): UInt
332  def minBitsFromInstr(instr: UInt): UInt
333}
334
335case class Imm_I() extends Imm(12) {
336  override def do_toImm32(minBits: UInt): UInt = SignExt(minBits, 32)
337
338  override def minBitsFromInstr(instr: UInt): UInt =
339    Cat(instr(31, 20))
340}
341
342case class Imm_S() extends Imm(12) {
343  override def do_toImm32(minBits: UInt): UInt = SignExt(minBits, 32)
344
345  override def minBitsFromInstr(instr: UInt): UInt =
346    Cat(instr(31, 25), instr(11, 7))
347}
348
349case class Imm_B() extends Imm(12) {
350  override def do_toImm32(minBits: UInt): UInt = SignExt(Cat(minBits, 0.U(1.W)), 32)
351
352  override def minBitsFromInstr(instr: UInt): UInt =
353    Cat(instr(31), instr(7), instr(30, 25), instr(11, 8))
354}
355
356case class Imm_U() extends Imm(20){
357  override def do_toImm32(minBits: UInt): UInt = Cat(minBits, 0.U(12.W))
358
359  override def minBitsFromInstr(instr: UInt): UInt = {
360    instr(31, 12)
361  }
362}
363
364case class Imm_J() extends Imm(20){
365  override def do_toImm32(minBits: UInt): UInt = SignExt(Cat(minBits, 0.U(1.W)), 32)
366
367  override def minBitsFromInstr(instr: UInt): UInt = {
368    Cat(instr(31), instr(19, 12), instr(20), instr(30, 25), instr(24, 21))
369  }
370}
371
372case class Imm_Z() extends Imm(12 + 5){
373  override def do_toImm32(minBits: UInt): UInt = minBits
374
375  override def minBitsFromInstr(instr: UInt): UInt = {
376    Cat(instr(19, 15), instr(31, 20))
377  }
378}
379
380object ImmUnion {
381  val I = Imm_I()
382  val S = Imm_S()
383  val B = Imm_B()
384  val U = Imm_U()
385  val J = Imm_J()
386  val Z = Imm_Z()
387  val imms = Seq(I, S, B, U, J, Z)
388  val maxLen = imms.maxBy(_.len).len
389  val immSelMap = Seq(
390    SelImm.IMM_I,
391    SelImm.IMM_S,
392    SelImm.IMM_SB,
393    SelImm.IMM_U,
394    SelImm.IMM_UJ,
395    SelImm.IMM_Z
396  ).zip(imms)
397  println(s"ImmUnion max len: $maxLen")
398}
399
400
401/**
402 * IO bundle for the Decode unit
403 */
404class DecodeUnitIO(implicit p: Parameters) extends XSBundle {
405  val enq = new Bundle { val ctrl_flow = Input(new CtrlFlow) }
406  val deq = new Bundle { val cf_ctrl = Output(new CfCtrl) }
407}
408
409/**
410 * Decode unit that takes in a single CtrlFlow and generates a CfCtrl.
411 */
412class DecodeUnit(implicit p: Parameters) extends XSModule with DecodeUnitConstants {
413  val io = IO(new DecodeUnitIO)
414
415  val ctrl_flow = Wire(new CtrlFlow) // input with RVC Expanded
416  val cf_ctrl = Wire(new CfCtrl)
417
418  ctrl_flow := io.enq.ctrl_flow
419
420  var decode_table = XDecode.table ++ FDecode.table ++ FDivSqrtDecode.table ++ X64Decode.table ++ XSTrapDecode.table
421
422  // output
423  cf_ctrl.cf := ctrl_flow
424  val cs = Wire(new CtrlSignals()).decode(ctrl_flow.instr, decode_table)
425
426  val fpDecoder = Module(new FPDecoder)
427  fpDecoder.io.instr := ctrl_flow.instr
428  cs.fpu := fpDecoder.io.fpCtrl
429
430  // read src1~3 location
431  cs.lsrc(0) := Mux(ctrl_flow.instr === LUI, 0.U,ctrl_flow.instr(RS1_MSB,RS1_LSB))
432  cs.lsrc(1) := ctrl_flow.instr(RS2_MSB,RS2_LSB)
433  cs.lsrc(2) := ctrl_flow.instr(RS3_MSB,RS3_LSB)
434  // read dest location
435  cs.ldest := Mux(cs.fpWen || cs.rfWen, ctrl_flow.instr(RD_MSB,RD_LSB), 0.U)
436
437  // fill in exception vector
438  cf_ctrl.cf.exceptionVec := io.enq.ctrl_flow.exceptionVec
439  cf_ctrl.cf.exceptionVec(illegalInstr) := cs.selImm === SelImm.INVALID_INSTR
440
441  // fix frflags
442  //                           fflags    zero csrrs rd    csr
443  val isFrflags = BitPat("b000000000001_00000_010_?????_1110011") === ctrl_flow.instr
444  when (cs.fuType === FuType.csr && isFrflags) {
445    cs.blockBackward := false.B
446  }
447
448  // fix isXSTrap
449  when (cs.isXSTrap) {
450    cs.lsrc(0) := XSTrapDecode.lsrc1
451  }
452
453  cs.imm := LookupTree(cs.selImm, ImmUnion.immSelMap.map(
454    x => {
455      val minBits = x._2.minBitsFromInstr(ctrl_flow.instr)
456      require(minBits.getWidth == x._2.len)
457      x._1 -> minBits
458    }
459  ))
460
461  cs.isMove := BitPat("b000000000000_?????_000_?????_0010011") === ctrl_flow.instr
462
463  cf_ctrl.ctrl := cs
464
465  // TODO: do we still need this?
466  // fix ret and call
467//  when (cs.fuType === FuType.jmp) {
468//    def isLink(reg: UInt) = (reg === 1.U || reg === 5.U)
469//    when (isLink(cs.ldest) && cs.fuOpType === JumpOpType.jal) { cf_ctrl.ctrl.fuOpType := JumpOpType.call }
470//    when (cs.fuOpType === JumpOpType.jalr) {
471//      when (isLink(cs.lsrc(0))) { cf_ctrl.ctrl.fuOpType := JumpOpType.ret  }
472//      when (isLink(cs.ldest)) { cf_ctrl.ctrl.fuOpType := JumpOpType.call }
473//    }
474//  }
475
476  io.deq.cf_ctrl := cf_ctrl
477
478  //-------------------------------------------------------------
479  // Debug Info
480  XSDebug("in:  instr=%x pc=%x excepVec=%b intrVec=%b crossPageIPFFix=%d\n",
481    io.enq.ctrl_flow.instr, io.enq.ctrl_flow.pc, io.enq.ctrl_flow.exceptionVec.asUInt,
482    io.enq.ctrl_flow.intrVec.asUInt, io.enq.ctrl_flow.crossPageIPFFix)
483  XSDebug("out: srcType(0)=%b srcType(1)=%b srcType(2)=%b lsrc(0)=%d lsrc(1)=%d lsrc(2)=%d ldest=%d fuType=%b fuOpType=%b\n",
484    io.deq.cf_ctrl.ctrl.srcType(0), io.deq.cf_ctrl.ctrl.srcType(1), io.deq.cf_ctrl.ctrl.srcType(2),
485    io.deq.cf_ctrl.ctrl.lsrc(0), io.deq.cf_ctrl.ctrl.lsrc(1), io.deq.cf_ctrl.ctrl.lsrc(2),
486    io.deq.cf_ctrl.ctrl.ldest, io.deq.cf_ctrl.ctrl.fuType, io.deq.cf_ctrl.ctrl.fuOpType)
487  XSDebug("out: rfWen=%d fpWen=%d isXSTrap=%d noSpecExec=%d isBlocked=%d flushPipe=%d isRVF=%d imm=%x\n",
488    io.deq.cf_ctrl.ctrl.rfWen, io.deq.cf_ctrl.ctrl.fpWen, io.deq.cf_ctrl.ctrl.isXSTrap,
489    io.deq.cf_ctrl.ctrl.noSpecExec, io.deq.cf_ctrl.ctrl.blockBackward, io.deq.cf_ctrl.ctrl.flushPipe,
490    io.deq.cf_ctrl.ctrl.isRVF, io.deq.cf_ctrl.ctrl.imm)
491  XSDebug("out: excepVec=%b intrVec=%b\n",
492    io.deq.cf_ctrl.cf.exceptionVec.asUInt, io.deq.cf_ctrl.cf.intrVec.asUInt)
493}
494