xref: /XiangShan/src/main/scala/xiangshan/backend/decode/DecodeUnit.scala (revision a63ad672336e5b45e5899e0f37ec319e5dc62b0b)
1package xiangshan.backend.decode
2
3import chisel3._
4import chisel3.util._
5
6import freechips.rocketchip.config.Parameters
7import freechips.rocketchip.rocket.{RVCDecoder, ExpandedInstruction}
8import freechips.rocketchip.rocket.{CSR,Causes}
9import freechips.rocketchip.util.{uintToBitPat,UIntIsOneOf}
10
11import xiangshan._
12import utils._
13import xiangshan.backend._
14import xiangshan.backend.decode.AltInstructions._
15import xiangshan.backend.fu.fpu.FPUOpType
16import freechips.rocketchip.tile.RocketTile
17
18/**
19 * Abstract trait giving defaults and other relevant values to different Decode constants/
20 */
21abstract trait DecodeConstants {
22  def X = BitPat("b?")
23  def N = BitPat("b0")
24  def Y = BitPat("b1")
25
26  def decodeDefault: List[BitPat] = // illegal instruction
27    //   src1Type     src2Type     src3Type     fuType      fuOpType    rfWen
28    //   |            |            |            |           |           |  fpWen
29    //   |            |            |            |           |           |  |  isXSTrap
30    //   |            |            |            |           |           |  |  |  noSpecExec
31    //   |            |            |            |           |           |  |  |  |  blockBackward
32    //   |            |            |            |           |           |  |  |  |  |  flushPipe
33    //   |            |            |            |           |           |  |  |  |  |  |  isRVF
34    //   |            |            |            |           |           |  |  |  |  |  |  |  selImm
35    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
36
37    val table: Array[(BitPat, List[BitPat])]
38}
39
40trait DecodeUnitConstants
41{
42  // abstract out instruction decode magic numbers
43  val RD_MSB  = 11
44  val RD_LSB  = 7
45  val RS1_MSB = 19
46  val RS1_LSB = 15
47  val RS2_MSB = 24
48  val RS2_LSB = 20
49  val RS3_MSB = 31
50  val RS3_LSB = 27
51}
52
53/**
54 * Decoded control signals
55 * See xiangshan/package.scala, xiangshan/backend/package.scala, Bundle.scala
56 */
57
58/**
59 * Decode constants for RV64
60 */
61object X64Decode extends DecodeConstants {
62  val table: Array[(BitPat, List[BitPat])] = Array(
63    LD      -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.ld, Y, N, N, N, N, N, N, SelImm.IMM_I),
64    LWU     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lwu, Y, N, N, N, N, N, N, SelImm.IMM_I),
65    SD      -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.stu, LSUOpType.sd, N, N, N, N, N, N, N, SelImm.IMM_S),
66
67    SLLI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sll, Y, N, N, N, N, N, N, SelImm.IMM_I),
68    SRLI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.srl, Y, N, N, N, N, N, N, SelImm.IMM_I),
69    SRAI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sra, Y, N, N, N, N, N, N, SelImm.IMM_I),
70
71    ADDIW   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.addw, Y, N, N, N, N, N, N, SelImm.IMM_I),
72    SLLIW   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sllw, Y, N, N, N, N, N, N, SelImm.IMM_I),
73    SRAIW   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sraw, Y, N, N, N, N, N, N, SelImm.IMM_I),
74    SRLIW   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.srlw, Y, N, N, N, N, N, N, SelImm.IMM_I),
75
76    ADDW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.addw, Y, N, N, N, N, N, N, SelImm.IMM_X),
77    SUBW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.subw, Y, N, N, N, N, N, N, SelImm.IMM_X),
78    SLLW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sllw, Y, N, N, N, N, N, N, SelImm.IMM_X),
79    SRAW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sraw, Y, N, N, N, N, N, N, SelImm.IMM_X),
80    SRLW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.srlw, Y, N, N, N, N, N, N, SelImm.IMM_X)
81  )
82}
83
84/**
85 * Overall Decode constants
86 */
87object XDecode extends DecodeConstants {
88  val table: Array[(BitPat, List[BitPat])] = Array(
89    LW      -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lw, Y, N, N, N, N, N, N, SelImm.IMM_I),
90    LH      -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lh, Y, N, N, N, N, N, N, SelImm.IMM_I),
91    LHU     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lhu, Y, N, N, N, N, N, N, SelImm.IMM_I),
92    LB      -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lb, Y, N, N, N, N, N, N, SelImm.IMM_I),
93    LBU     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lbu, Y, N, N, N, N, N, N, SelImm.IMM_I),
94
95    SW      -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.stu, LSUOpType.sw, N, N, N, N, N, N, N, SelImm.IMM_S),
96    SH      -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.stu, LSUOpType.sh, N, N, N, N, N, N, N, SelImm.IMM_S),
97    SB      -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.stu, LSUOpType.sb, N, N, N, N, N, N, N, SelImm.IMM_S),
98
99    LUI     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.add, Y, N, N, N, N, N, N, SelImm.IMM_U),
100
101    ADDI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.add, Y, N, N, N, N, N, N, SelImm.IMM_I),
102    ANDI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.and, Y, N, N, N, N, N, N, SelImm.IMM_I),
103    ORI     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.or, Y, N, N, N, N, N, N, SelImm.IMM_I),
104    XORI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.xor, Y, N, N, N, N, N, N, SelImm.IMM_I),
105    SLTI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.slt, Y, N, N, N, N, N, N, SelImm.IMM_I),
106    SLTIU   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sltu, Y, N, N, N, N, N, N, SelImm.IMM_I),
107
108    SLL     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sll, Y, N, N, N, N, N, N, SelImm.IMM_X),
109    ADD     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.add, Y, N, N, N, N, N, N, SelImm.IMM_X),
110    SUB     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sub, Y, N, N, N, N, N, N, SelImm.IMM_X),
111    SLT     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.slt, Y, N, N, N, N, N, N, SelImm.IMM_X),
112    SLTU    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sltu, Y, N, N, N, N, N, N, SelImm.IMM_X),
113    AND     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.and, Y, N, N, N, N, N, N, SelImm.IMM_X),
114    OR      -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.or, Y, N, N, N, N, N, N, SelImm.IMM_X),
115    XOR     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.xor, Y, N, N, N, N, N, N, SelImm.IMM_X),
116    SRA     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sra, Y, N, N, N, N, N, N, SelImm.IMM_X),
117    SRL     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.srl, Y, N, N, N, N, N, N, SelImm.IMM_X),
118
119    MUL     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mul, MDUOpType.mul, Y, N, N, N, N, N, N, SelImm.IMM_X),
120    MULH    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mul, MDUOpType.mulh, Y, N, N, N, N, N, N, SelImm.IMM_X),
121    MULHU   -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mul, MDUOpType.mulhu, Y, N, N, N, N, N, N, SelImm.IMM_X),
122    MULHSU  -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mul, MDUOpType.mulhsu, Y, N, N, N, N, N, N, SelImm.IMM_X),
123    MULW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mul, MDUOpType.mulw, Y, N, N, N, N, N, N, SelImm.IMM_X),
124
125    DIV     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.div, Y, N, N, N, N, N, N, SelImm.IMM_X),
126    DIVU    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.divu, Y, N, N, N, N, N, N, SelImm.IMM_X),
127    REM     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.rem, Y, N, N, N, N, N, N, SelImm.IMM_X),
128    REMU    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.remu, Y, N, N, N, N, N, N, SelImm.IMM_X),
129    DIVW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.divw, Y, N, N, N, N, N, N, SelImm.IMM_X),
130    DIVUW   -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.divuw, Y, N, N, N, N, N, N, SelImm.IMM_X),
131    REMW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.remw, Y, N, N, N, N, N, N, SelImm.IMM_X),
132    REMUW   -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.remuw, Y, N, N, N, N, N, N, SelImm.IMM_X),
133
134    AUIPC   -> List(SrcType.pc, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.add, Y, N, N, N, N, N, N, SelImm.IMM_U),
135    JAL     -> List(SrcType.pc , SrcType.imm, SrcType.DC, FuType.jmp, JumpOpType.jal, Y, N, N, N, N, N, N, SelImm.IMM_UJ),
136    JALR    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.jmp, JumpOpType.jalr, Y, N, N, N, N, N, N, SelImm.IMM_I),
137    BEQ     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.beq, N, N, N, N, N, N, N, SelImm.IMM_SB),
138    BNE     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.bne, N, N, N, N, N, N, N, SelImm.IMM_SB),
139    BGE     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.bge, N, N, N, N, N, N, N, SelImm.IMM_SB),
140    BGEU    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.bgeu, N, N, N, N, N, N, N, SelImm.IMM_SB),
141    BLT     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.blt, N, N, N, N, N, N, N, SelImm.IMM_SB),
142    BLTU    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.bltu, N, N, N, N, N, N, N, SelImm.IMM_SB),
143
144    // I-type, the immediate12 holds the CSR register.
145    CSRRW   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.wrt, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
146    CSRRS   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.set, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
147    CSRRC   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.clr, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
148
149    CSRRWI  -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.wrti, Y, N, N, Y, Y, N, N, SelImm.IMM_Z),
150    CSRRSI  -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.seti, Y, N, N, Y, Y, N, N, SelImm.IMM_Z),
151    CSRRCI  -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.clri, Y, N, N, Y, Y, N, N, SelImm.IMM_Z),
152
153    SFENCE_VMA->List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.fence, FenceOpType.sfence, N, N, N, Y, Y, Y, N, SelImm.IMM_X),
154    ECALL   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.jmp, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
155    SRET    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.jmp, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
156    MRET    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.jmp, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
157
158    WFI     -> List(SrcType.pc, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sll, Y, N, N, N, N, N, N, SelImm.IMM_X),
159
160    FENCE_I -> List(SrcType.pc, SrcType.imm, SrcType.DC, FuType.fence, FenceOpType.fencei, N, N, N, Y, Y, Y, N, SelImm.IMM_X),
161    FENCE   -> List(SrcType.pc, SrcType.imm, SrcType.DC, FuType.fence, FenceOpType.fence, N, N, N, Y, Y, Y, N, SelImm.IMM_X),
162
163    // A-type
164    AMOADD_W-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoadd_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
165    AMOXOR_W-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoxor_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
166    AMOSWAP_W->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoswap_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
167    AMOAND_W-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoand_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
168    AMOOR_W -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoor_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
169    AMOMIN_W-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomin_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
170    AMOMINU_W->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amominu_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
171    AMOMAX_W-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomax_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
172    AMOMAXU_W->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomaxu_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
173
174    AMOADD_D-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoadd_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
175    AMOXOR_D-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoxor_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
176    AMOSWAP_D->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoswap_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
177    AMOAND_D-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoand_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
178    AMOOR_D -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoor_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
179    AMOMIN_D-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomin_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
180    AMOMINU_D->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amominu_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
181    AMOMAX_D-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomax_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
182    AMOMAXU_D->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomaxu_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
183
184    LR_W    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.mou, LSUOpType.lr_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
185    LR_D    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.mou, LSUOpType.lr_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
186    SC_W    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.sc_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
187    SC_D    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.sc_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X)
188  )
189}
190
191/**
192 * FP Decode constants
193 */
194object FDecode extends DecodeConstants{
195  val table: Array[(BitPat, List[BitPat])] = Array(
196
197  FLW     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.flw, N, Y, N, N, N, N, N, SelImm.IMM_I),
198  FLD     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.ld, N, Y, N, N, N, N, N, SelImm.IMM_I),
199  FSW     -> List(SrcType.reg, SrcType.fp, SrcType.DC, FuType.stu, LSUOpType.sw, N, N, N, N, N, N, N, SelImm.IMM_S),
200  FSD     -> List(SrcType.reg, SrcType.fp, SrcType.DC, FuType.stu, LSUOpType.sd, N, N, N, N, N, N, N, SelImm.IMM_S),
201
202  FCLASS_S-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.fclass, Y, N, N, N, N, N, Y, SelImm.IMM_X),
203  FCLASS_D-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.fclass, Y, N, N, N, N, N, N, SelImm.IMM_X),
204
205  FMV_D_X -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, FPUOpType.fmv_i2f, N, Y, N, N, N, N, N, SelImm.IMM_X),
206  FMV_X_D -> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.fmv_f2i, Y, N, N, N, N, N, N, SelImm.IMM_X),
207  FMV_X_W -> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.fmv_f2i, Y, N, N, N, N, N, N, SelImm.IMM_X),
208  FMV_W_X -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, FPUOpType.fmv_i2f, N, Y, N, N, N, N, N, SelImm.IMM_X),
209
210  FSGNJ_S -> List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.fsgnj, N, Y, N, N, N, N, Y, SelImm.IMM_X),
211  FSGNJ_D -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.fmisc, FPUOpType.fsgnj, N, Y, N, N, N, N, N, SelImm.IMM_X),
212  FSGNJX_S-> List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.fsgnjx, N, Y, N, N, N, N, Y, SelImm.IMM_X),
213  FSGNJX_D-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.fmisc, FPUOpType.fsgnjx, N, Y, N, N, N, N, N, SelImm.IMM_X),
214  FSGNJN_S-> List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.fsgnjn, N, Y, N, N, N, N, Y, SelImm.IMM_X),
215  FSGNJN_D-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.fmisc, FPUOpType.fsgnjn, N, Y, N, N, N, N, N, SelImm.IMM_X),
216
217  // FP to FP
218  FCVT_S_D-> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.d2s, N, Y, N, N, N, N, Y, SelImm.IMM_X),
219  FCVT_D_S-> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.s2d, N, Y, N, N, N, N, N, SelImm.IMM_X),
220
221  // Int to FP
222  FCVT_S_W-> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, FPUOpType.w2f, N, Y, N, N, N, N, Y, SelImm.IMM_X),
223  FCVT_S_WU->List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, FPUOpType.wu2f, N, Y, N, N, N, N, Y, SelImm.IMM_X),
224  FCVT_S_L-> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, FPUOpType.l2f, N, Y, N, N, N, N, Y, SelImm.IMM_X),
225  FCVT_S_LU->List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, FPUOpType.lu2f, N, Y, N, N, N, N, Y, SelImm.IMM_X),
226
227  FCVT_D_W-> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, FPUOpType.w2f, N, Y, N, N, N, N, N, SelImm.IMM_X),
228  FCVT_D_WU->List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, FPUOpType.wu2f, N, Y, N, N, N, N, N, SelImm.IMM_X),
229  FCVT_D_L-> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, FPUOpType.l2f, N, Y, N, N, N, N, N, SelImm.IMM_X),
230  FCVT_D_LU->List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, FPUOpType.lu2f, N, Y, N, N, N, N, N, SelImm.IMM_X),
231
232  // FP to Int
233  FCVT_W_S-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.f2w, Y, N, N, N, N, N, Y, SelImm.IMM_X),
234  FCVT_WU_S->List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.f2wu, Y, N, N, N, N, N, Y, SelImm.IMM_X),
235  FCVT_L_S-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.f2l, Y, N, N, N, N, N, Y, SelImm.IMM_X),
236  FCVT_LU_S->List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.f2lu, Y, N, N, N, N, N, Y, SelImm.IMM_X),
237
238  FCVT_W_D-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.f2w, Y, N, N, N, N, N, N, SelImm.IMM_X),
239  FCVT_WU_D->List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.f2wu, Y, N, N, N, N, N, N, SelImm.IMM_X),
240  FCVT_L_D-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.f2l, Y, N, N, N, N, N, N, SelImm.IMM_X),
241  FCVT_LU_D->List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.f2lu, Y, N, N, N, N, N, N, SelImm.IMM_X),
242
243  // "fp_single" is used for wb_data formatting (and debugging)
244  FEQ_S    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.feq, Y, N, N, N, N, N, Y, SelImm.IMM_X),
245  FLT_S    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.flt, Y, N, N, N, N, N, Y, SelImm.IMM_X),
246  FLE_S    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.fle, Y, N, N, N, N, N, Y, SelImm.IMM_X),
247
248  FEQ_D    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.feq, Y, N, N, N, N, N, N, SelImm.IMM_X),
249  FLT_D    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.flt, Y, N, N, N, N, N, N, SelImm.IMM_X),
250  FLE_D    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.fle, Y, N, N, N, N, N, N, SelImm.IMM_X),
251
252  FMIN_S   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.fmin, N, Y, N, N, N, N, Y, SelImm.IMM_X),
253  FMAX_S   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.fmax, N, Y, N, N, N, N, Y, SelImm.IMM_X),
254  FMIN_D   ->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.fmisc, FPUOpType.fmin, N, Y, N, N, N, N, N, SelImm.IMM_X),
255  FMAX_D   ->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.fmisc, FPUOpType.fmax, N, Y, N, N, N, N, N, SelImm.IMM_X),
256
257  FADD_S   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmac, FPUOpType.fadd, N, Y, N, N, N, N, Y, SelImm.IMM_X),
258  FSUB_S   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmac, FPUOpType.fsub, N, Y, N, N, N, N, Y, SelImm.IMM_X),
259  FMUL_S   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmac, FPUOpType.fmul, N, Y, N, N, N, N, Y, SelImm.IMM_X),
260  FADD_D   ->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.fmac, FPUOpType.fadd, N, Y, N, N, N, N, N, SelImm.IMM_X),
261  FSUB_D   ->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.fmac, FPUOpType.fsub, N, Y, N, N, N, N, N, SelImm.IMM_X),
262  FMUL_D   ->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.fmac, FPUOpType.fmul, N, Y, N, N, N, N, N, SelImm.IMM_X),
263
264  FMADD_S  ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, FPUOpType.fmadd, N, Y, N, N, N, N, Y, SelImm.IMM_X),
265  FMSUB_S  ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, FPUOpType.fmsub, N, Y, N, N, N, N, Y, SelImm.IMM_X),
266  FNMADD_S ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, FPUOpType.fnmadd, N, Y, N, N, N, N, Y, SelImm.IMM_X),
267  FNMSUB_S ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, FPUOpType.fnmsub, N, Y, N, N, N, N, Y, SelImm.IMM_X),
268  FMADD_D  ->List(SrcType.reg, SrcType.reg, SrcType.fp, FuType.fmac, FPUOpType.fmadd, N, Y, N, N, N, N, N, SelImm.IMM_X),
269  FMSUB_D  ->List(SrcType.reg, SrcType.reg, SrcType.fp, FuType.fmac, FPUOpType.fmsub, N, Y, N, N, N, N, N, SelImm.IMM_X),
270  FNMADD_D ->List(SrcType.reg, SrcType.reg, SrcType.fp, FuType.fmac, FPUOpType.fnmadd, N, Y, N, N, N, N, N, SelImm.IMM_X),
271  FNMSUB_D ->List(SrcType.reg, SrcType.reg, SrcType.fp, FuType.fmac, FPUOpType.fnmsub, N, Y, N, N, N, N, N, SelImm.IMM_X)
272  )
273}
274
275/**
276 * FP Divide SquareRoot Constants
277 */
278object FDivSqrtDecode extends DecodeConstants {
279  val table: Array[(BitPat, List[BitPat])] = Array(
280  FDIV_S    ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.fdiv, N, Y, N, N, N, N, Y, SelImm.IMM_X),
281  FDIV_D    ->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.fmisc, FPUOpType.fdiv, N, Y, N, N, N, N, N, SelImm.IMM_X),
282  FSQRT_S   ->List(SrcType.fp,  SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.fsqrt, N, Y, N, N, N, N, Y, SelImm.IMM_X),
283  FSQRT_D   ->List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.fsqrt, N, Y, N, N, N, N, N, SelImm.IMM_X)
284  )
285}
286
287/**
288 * XiangShan Trap Decode constants
289 */
290object XSTrapDecode extends DecodeConstants {
291  // calculate as ADDI => addi zero, a0, 0
292  // replace rs '?????' with '01010'(a0) in decode stage
293  def lsrc1 = "b01010".U // $a0
294  val table: Array[(BitPat, List[BitPat])] = Array(
295    TRAP    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.add, Y, N, Y, Y, Y, N, N, SelImm.IMM_I)
296  )
297}
298
299class RVCExpander extends XSModule {
300  val io = IO(new Bundle {
301    val in = Input(UInt(32.W))
302    val out = Output(new ExpandedInstruction)
303    val rvc = Output(Bool())
304  })
305
306  if (HasCExtension) {
307    io.rvc := io.in(1,0) =/= 3.U
308    io.out := new RVCDecoder(io.in, XLEN).decode
309  } else {
310    io.rvc := false.B
311    io.out := new RVCDecoder(io.in, XLEN).passthrough
312  }
313}
314
315object Imm32Gen {
316  def apply(sel: UInt, inst: UInt) = {
317    val sign = Mux(sel === SelImm.IMM_Z, 0.S, inst(31).asSInt)
318    val b30_20 = Mux(sel === SelImm.IMM_U, inst(30,20).asSInt, sign)
319    val b19_12 = Mux(sel =/= SelImm.IMM_U && sel =/= SelImm.IMM_UJ, sign, inst(19,12).asSInt)
320    val b11 = Mux(sel === SelImm.IMM_U || sel === SelImm.IMM_Z, 0.S,
321              Mux(sel === SelImm.IMM_UJ, inst(20).asSInt,
322              Mux(sel === SelImm.IMM_SB, inst(7).asSInt, sign)))
323    val b10_5 = Mux(sel === SelImm.IMM_U || sel === SelImm.IMM_Z, 0.U(1.W), inst(30,25))
324    val b4_1 = Mux(sel === SelImm.IMM_U, 0.U(1.W),
325               Mux(sel === SelImm.IMM_S || sel === SelImm.IMM_SB, inst(11,8),
326               Mux(sel === SelImm.IMM_Z, inst(19,16), inst(24,21))))
327    val b0 = Mux(sel === SelImm.IMM_S, inst(7),
328             Mux(sel === SelImm.IMM_I, inst(20),
329             Mux(sel === SelImm.IMM_Z, inst(15), 0.U(1.W))))
330
331    Cat(sign, b30_20, b19_12, b11, b10_5, b4_1, b0)
332  }
333}
334
335/**
336 * IO bundle for the Decode unit
337 */
338class DecodeUnitIO extends XSBundle {
339  val enq = new Bundle { val ctrl_flow = Input(new CtrlFlow) }
340  val deq = new Bundle { val cf_ctrl = Output(new CfCtrl) }
341}
342
343/**
344 * Decode unit that takes in a single CtrlFlow and generates a CfCtrl.
345 */
346class DecodeUnit extends XSModule with DecodeUnitConstants {
347  val io = IO(new DecodeUnitIO)
348
349  val ctrl_flow = Wire(new CtrlFlow) // input with RVC Expanded
350  val cf_ctrl = Wire(new CfCtrl)
351
352  val exp = Module(new RVCExpander())
353  exp.io.in := io.enq.ctrl_flow.instr
354  ctrl_flow := io.enq.ctrl_flow
355  when (exp.io.rvc) {
356    ctrl_flow.instr := exp.io.out.bits
357  }
358
359  // save rvc decode info
360  val rvc_info = Wire(new ExpandedInstruction())
361  val is_rvc = Wire(Bool())
362  rvc_info := exp.io.out
363  is_rvc := exp.io.rvc
364
365  var decode_table = XDecode.table ++ FDecode.table ++ FDivSqrtDecode.table ++ X64Decode.table ++ XSTrapDecode.table
366
367  // output
368  cf_ctrl.cf := ctrl_flow
369  cf_ctrl.brTag := DontCare
370  val cs = Wire(new CtrlSignals()).decode(ctrl_flow.instr, decode_table)
371
372  when (is_rvc) {
373    cs.lsrc1 := rvc_info.rs1
374    cs.lsrc2 := rvc_info.rs2
375    cs.lsrc3 := rvc_info.rs3
376
377    cs.ldest := rvc_info.rd
378
379  } .otherwise {
380    cs.lsrc1 := ctrl_flow.instr(RS1_MSB,RS1_LSB)
381    cs.lsrc2 := ctrl_flow.instr(RS2_MSB,RS2_LSB)
382    cs.lsrc3 := ctrl_flow.instr(RS3_MSB,RS3_LSB)
383
384    cs.ldest := ctrl_flow.instr(RD_MSB,RD_LSB)
385  }
386
387  // fill in exception vector
388  cf_ctrl.cf.exceptionVec.map(_ := false.B)
389  cf_ctrl.cf.exceptionVec(illegalInstr) := cs.imm === SelImm.INVALID_INSTR
390  cf_ctrl.cf.exceptionVec(instrPageFault) := io.enq.ctrl_flow.exceptionVec(instrPageFault)
391
392  // fix frflags
393  //                           fflags    zero csrrs rd    csr
394  val isFrflags = BitPat("b000000000001_00000_010_?????_1110011") === ctrl_flow.instr
395  when (cs.fuType === FuType.csr && isFrflags) {
396    cs.blockBackward := false.B
397  }
398
399  // fix isXSTrap
400  when (cs.isXSTrap) {
401    cs.lsrc1 := XSTrapDecode.lsrc1
402  }
403
404  cs.imm := SignExt(Imm32Gen(cs.selImm, ctrl_flow.instr), XLEN)
405
406  cf_ctrl.ctrl := cs
407
408  // fix ret and call
409  when (cs.fuType === FuType.jmp) {
410    def isLink(reg: UInt) = (reg === 1.U || reg === 5.U)
411    when (isLink(cs.ldest) && cs.fuOpType === JumpOpType.jal) { cf_ctrl.ctrl.fuOpType := JumpOpType.call }
412    when (cs.fuOpType === JumpOpType.jalr) {
413      when (isLink(cs.lsrc1)) { cf_ctrl.ctrl.fuOpType := JumpOpType.ret  }
414      when (isLink(cs.ldest)) { cf_ctrl.ctrl.fuOpType := JumpOpType.call }
415    }
416  }
417
418  io.deq.cf_ctrl := cf_ctrl
419
420  //-------------------------------------------------------------
421  // Debug Info
422  XSDebug("in:  instr=%x pc=%x excepVec=%b intrVec=%b crossPageIPFFix=%d\n",
423    io.enq.ctrl_flow.instr, io.enq.ctrl_flow.pc, io.enq.ctrl_flow.exceptionVec.asUInt,
424    io.enq.ctrl_flow.intrVec.asUInt, io.enq.ctrl_flow.crossPageIPFFix)
425  XSDebug("out: src1Type=%b src2Type=%b src3Type=%b lsrc1=%d lsrc2=%d lsrc3=%d ldest=%d fuType=%b fuOpType=%b\n",
426    io.deq.cf_ctrl.ctrl.src1Type, io.deq.cf_ctrl.ctrl.src2Type, io.deq.cf_ctrl.ctrl.src3Type,
427    io.deq.cf_ctrl.ctrl.lsrc1, io.deq.cf_ctrl.ctrl.lsrc2, io.deq.cf_ctrl.ctrl.lsrc3,
428    io.deq.cf_ctrl.ctrl.ldest, io.deq.cf_ctrl.ctrl.fuType, io.deq.cf_ctrl.ctrl.fuOpType)
429  XSDebug("out: rfWen=%d fpWen=%d isXSTrap=%d noSpecExec=%d isBlocked=%d flushPipe=%d isRVF=%d imm=%x\n",
430    io.deq.cf_ctrl.ctrl.rfWen, io.deq.cf_ctrl.ctrl.fpWen, io.deq.cf_ctrl.ctrl.isXSTrap,
431    io.deq.cf_ctrl.ctrl.noSpecExec, io.deq.cf_ctrl.ctrl.blockBackward, io.deq.cf_ctrl.ctrl.flushPipe,
432    io.deq.cf_ctrl.ctrl.isRVF, io.deq.cf_ctrl.ctrl.imm)
433}
434