xref: /XiangShan/src/main/scala/xiangshan/backend/decode/DecodeUnit.scala (revision 3e98122d7c1c9f544f8596a195d04abe375fd70c)
1//******************************************************************************
2// Copyright (c) 2015 - 2018, The Regents of the University of California (Regents).
3// All Rights Reserved. See LICENSE and LICENSE.SiFive for license details.
4//------------------------------------------------------------------------------
5
6package xiangshan.backend.decode
7
8import chisel3._
9import chisel3.util._
10
11import freechips.rocketchip.config.Parameters
12import freechips.rocketchip.rocket.{RVCDecoder, ExpandedInstruction}
13import freechips.rocketchip.rocket.{CSR,Causes}
14import freechips.rocketchip.util.{uintToBitPat,UIntIsOneOf}
15
16import xiangshan._
17import utils._
18import xiangshan.backend._
19import xiangshan.backend.decode.Instructions._
20import freechips.rocketchip.tile.RocketTile
21
22/**
23 * Abstract trait giving defaults and other relevant values to different Decode constants/
24 */
25abstract trait DecodeConstants {
26  def X = BitPat("b?")
27  def N = BitPat("b0")
28  def Y = BitPat("b1")
29
30  def decodeDefault: List[BitPat] = // illegal instruction
31    //   src1Type     src2Type     src3Type     fuType      fuOpType    rfWen
32    //   |            |            |            |           |           |  fpWen
33    //   |            |            |            |           |           |  |  isXSTrap
34    //   |            |            |            |           |           |  |  |  noSpecExec
35    //   |            |            |            |           |           |  |  |  |  blockBackward
36    //   |            |            |            |           |           |  |  |  |  |  flushPipe
37    //   |            |            |            |           |           |  |  |  |  |  |  isRVF
38    //   |            |            |            |           |           |  |  |  |  |  |  |  selImm
39    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
40
41    val table: Array[(BitPat, List[BitPat])]
42}
43
44trait DecodeUnitConstants
45{
46  // abstract out instruction decode magic numbers
47  val RD_MSB  = 11
48  val RD_LSB  = 7
49  val RS1_MSB = 19
50  val RS1_LSB = 15
51  val RS2_MSB = 24
52  val RS2_LSB = 20
53  val RS3_MSB = 31
54  val RS3_LSB = 27
55}
56
57/**
58 * Decoded control signals
59 * See xiangshan/package.scala, xiangshan/backend/package.scala, Bundle.scala
60 */
61
62/**
63 * Decode constants for RV64
64 */
65object X64Decode extends DecodeConstants {
66  val table: Array[(BitPat, List[BitPat])] = Array(
67    LD      -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.ld, Y, N, N, N, N, N, N, SelImm.IMM_I),
68    LWU     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lwu, Y, N, N, N, N, N, N, SelImm.IMM_I),
69    SD      -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.stu, LSUOpType.sd, N, N, N, N, N, N, N, SelImm.IMM_S),
70
71    SLLI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sll, Y, N, N, N, N, N, N, SelImm.IMM_I),
72    SRLI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.srl, Y, N, N, N, N, N, N, SelImm.IMM_I),
73    SRAI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sra, Y, N, N, N, N, N, N, SelImm.IMM_I),
74
75    ADDIW   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.addw, Y, N, N, N, N, N, N, SelImm.IMM_I),
76    SLLIW   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sllw, Y, N, N, N, N, N, N, SelImm.IMM_I),
77    SRAIW   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sraw, Y, N, N, N, N, N, N, SelImm.IMM_I),
78    SRLIW   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.srlw, Y, N, N, N, N, N, N, SelImm.IMM_I),
79
80    ADDW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.addw, Y, N, N, N, N, N, N, SelImm.IMM_X),
81    SUBW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.subw, Y, N, N, N, N, N, N, SelImm.IMM_X),
82    SLLW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sllw, Y, N, N, N, N, N, N, SelImm.IMM_X),
83    SRAW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sraw, Y, N, N, N, N, N, N, SelImm.IMM_X),
84    SRLW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.srlw, Y, N, N, N, N, N, N, SelImm.IMM_X)
85  )
86}
87
88/**
89 * Overall Decode constants
90 */
91object XDecode extends DecodeConstants {
92  val table: Array[(BitPat, List[BitPat])] = Array(
93    LW      -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lw, Y, N, N, N, N, N, N, SelImm.IMM_I),
94    LH      -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lh, Y, N, N, N, N, N, N, SelImm.IMM_I),
95    LHU     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lhu, Y, N, N, N, N, N, N, SelImm.IMM_I),
96    LB      -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lb, Y, N, N, N, N, N, N, SelImm.IMM_I),
97    LBU     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lbu, Y, N, N, N, N, N, N, SelImm.IMM_I),
98
99    SW      -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.stu, LSUOpType.sw, N, N, N, N, N, N, N, SelImm.IMM_S),
100    SH      -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.stu, LSUOpType.sh, N, N, N, N, N, N, N, SelImm.IMM_S),
101    SB      -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.stu, LSUOpType.sb, N, N, N, N, N, N, N, SelImm.IMM_S),
102
103    LUI     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.add, Y, N, N, N, N, N, N, SelImm.IMM_U),
104
105    ADDI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.add, Y, N, N, N, N, N, N, SelImm.IMM_I),
106    ANDI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.and, Y, N, N, N, N, N, N, SelImm.IMM_I),
107    ORI     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.or, Y, N, N, N, N, N, N, SelImm.IMM_I),
108    XORI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.xor, Y, N, N, N, N, N, N, SelImm.IMM_I),
109    SLTI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.slt, Y, N, N, N, N, N, N, SelImm.IMM_I),
110    SLTIU   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sltu, Y, N, N, N, N, N, N, SelImm.IMM_I),
111
112    SLL     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sll, Y, N, N, N, N, N, N, SelImm.IMM_X),
113    ADD     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.add, Y, N, N, N, N, N, N, SelImm.IMM_X),
114    SUB     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sub, Y, N, N, N, N, N, N, SelImm.IMM_X),
115    SLT     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.slt, Y, N, N, N, N, N, N, SelImm.IMM_X),
116    SLTU    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sltu, Y, N, N, N, N, N, N, SelImm.IMM_X),
117    AND     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.and, Y, N, N, N, N, N, N, SelImm.IMM_X),
118    OR      -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.or, Y, N, N, N, N, N, N, SelImm.IMM_X),
119    XOR     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.xor, Y, N, N, N, N, N, N, SelImm.IMM_X),
120    SRA     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sra, Y, N, N, N, N, N, N, SelImm.IMM_X),
121    SRL     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.srl, Y, N, N, N, N, N, N, SelImm.IMM_X),
122
123    MUL     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mul, MDUOpType.mul, Y, N, N, N, N, N, N, SelImm.IMM_X),
124    MULH    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mul, MDUOpType.mulh, Y, N, N, N, N, N, N, SelImm.IMM_X),
125    MULHU   -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mul, MDUOpType.mulhu, Y, N, N, N, N, N, N, SelImm.IMM_X),
126    MULHSU  -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mul, MDUOpType.mulhsu, Y, N, N, N, N, N, N, SelImm.IMM_X),
127    MULW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mul, MDUOpType.mulw, Y, N, N, N, N, N, N, SelImm.IMM_X),
128
129    DIV     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.div, Y, N, N, N, N, N, N, SelImm.IMM_X),
130    DIVU    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.divu, Y, N, N, N, N, N, N, SelImm.IMM_X),
131    REM     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.rem, Y, N, N, N, N, N, N, SelImm.IMM_X),
132    REMU    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.remu, Y, N, N, N, N, N, N, SelImm.IMM_X),
133    DIVW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.divw, Y, N, N, N, N, N, N, SelImm.IMM_X),
134    DIVUW   -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.divuw, Y, N, N, N, N, N, N, SelImm.IMM_X),
135    REMW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.remw, Y, N, N, N, N, N, N, SelImm.IMM_X),
136    REMUW   -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.remuw, Y, N, N, N, N, N, N, SelImm.IMM_X),
137
138    AUIPC   -> List(SrcType.pc , SrcType.imm, SrcType.DC, FuType.jmp, JumpOpType.auipc, Y, N, N, N, N, N, N, SelImm.IMM_U),
139    JAL     -> List(SrcType.pc , SrcType.imm, SrcType.DC, FuType.jmp, JumpOpType.jal, Y, N, N, N, N, N, N, SelImm.IMM_UJ),
140    JALR    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.jmp, JumpOpType.jalr, Y, N, N, N, N, N, N, SelImm.IMM_I),
141    BEQ     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.beq, N, N, N, N, N, N, N, SelImm.IMM_SB),
142    BNE     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.bne, N, N, N, N, N, N, N, SelImm.IMM_SB),
143    BGE     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.bge, N, N, N, N, N, N, N, SelImm.IMM_SB),
144    BGEU    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.bgeu, N, N, N, N, N, N, N, SelImm.IMM_SB),
145    BLT     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.blt, N, N, N, N, N, N, N, SelImm.IMM_SB),
146    BLTU    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.bltu, N, N, N, N, N, N, N, SelImm.IMM_SB),
147
148    // I-type, the immediate12 holds the CSR register.
149    CSRRW   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.wrt, Y, N, N, Y, Y, N, N, SelImm.IMM_I),
150    CSRRS   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.set, Y, N, N, Y, Y, N, N, SelImm.IMM_I),
151    CSRRC   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.clr, Y, N, N, Y, Y, N, N, SelImm.IMM_I),
152
153    CSRRWI  -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.wrti, Y, N, N, Y, Y, N, N, SelImm.IMM_Z),
154    CSRRSI  -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.seti, Y, N, N, Y, Y, N, N, SelImm.IMM_Z),
155    CSRRCI  -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.clri, Y, N, N, Y, Y, N, N, SelImm.IMM_Z),
156
157    SFENCE_VMA->List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.fence, FenceOpType.sfence, N, N, N, Y, Y, Y, N, SelImm.IMM_X),
158    ECALL   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.jmp, Y, N, N, Y, Y, N, N, SelImm.IMM_I),
159    SRET    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.jmp, Y, N, N, Y, Y, N, N, SelImm.IMM_I),
160    MRET    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.jmp, Y, N, N, Y, Y, N, N, SelImm.IMM_I),
161
162    WFI     -> List(SrcType.pc, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sll, Y, N, N, N, N, N, N, SelImm.IMM_X),
163
164    FENCE_I -> List(SrcType.pc, SrcType.imm, SrcType.DC, FuType.fence, FenceOpType.fencei, N, N, N, Y, Y, Y, N, SelImm.IMM_X),
165    FENCE   -> List(SrcType.pc, SrcType.imm, SrcType.DC, FuType.fence, FenceOpType.fence, N, N, N, Y, Y, Y, N, SelImm.IMM_X),
166
167    // A-type
168    AMOADD_W-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoadd_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
169    AMOXOR_W-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoxor_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
170    AMOSWAP_W->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoswap_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
171    AMOAND_W-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoand_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
172    AMOOR_W -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoor_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
173    AMOMIN_W-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomin_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
174    AMOMINU_W->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amominu_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
175    AMOMAX_W-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomax_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
176    AMOMAXU_W->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomaxu_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
177
178    AMOADD_D-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoadd_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
179    AMOXOR_D-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoxor_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
180    AMOSWAP_D->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoswap_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
181    AMOAND_D-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoand_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
182    AMOOR_D -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoor_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
183    AMOMIN_D-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomin_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
184    AMOMINU_D->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amominu_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
185    AMOMAX_D-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomax_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
186    AMOMAXU_D->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomaxu_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
187
188    LR_W    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.mou, LSUOpType.lr_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
189    LR_D    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.mou, LSUOpType.lr_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
190    SC_W    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.sc_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
191    SC_D    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.sc_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X)
192  )
193}
194
195/**
196 * FP Decode constants
197 */
198object FDecode extends DecodeConstants{
199  val table: Array[(BitPat, List[BitPat])] = Array(
200
201  FLW     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lw, N, Y, N, N, N, N, Y, SelImm.IMM_I),
202  FLD     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.ld, N, Y, N, N, N, N, N, SelImm.IMM_I),
203  FSW     -> List(SrcType.reg, SrcType.fp, SrcType.DC, FuType.stu, LSUOpType.sw, N, N, N, N, N, N, Y, SelImm.IMM_S),
204  FSD     -> List(SrcType.reg, SrcType.fp, SrcType.DC, FuType.stu, LSUOpType.sd, N, N, N, N, N, N, N, SelImm.IMM_S),
205
206  FCLASS_S-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, Y, SelImm.IMM_X),
207  FCLASS_D-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, N, SelImm.IMM_X),
208
209  FMV_D_X -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
210  FMV_X_D -> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, N, SelImm.IMM_X),
211  FMV_X_W -> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, Y, SelImm.IMM_X),
212  FMV_W_X -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
213
214  FSGNJ_S -> List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
215  FSGNJ_D -> List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
216  FSGNJX_S-> List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
217  FSGNJX_D-> List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
218  FSGNJN_S-> List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
219  FSGNJN_D-> List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
220
221  // FP to FP
222  FCVT_S_D-> List(SrcType.fp, SrcType.imm, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
223  FCVT_D_S-> List(SrcType.fp, SrcType.imm, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
224
225  // Int to FP
226  FCVT_S_W-> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
227  FCVT_S_WU->List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
228  FCVT_S_L-> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
229  FCVT_S_LU->List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
230
231  FCVT_D_W-> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
232  FCVT_D_WU->List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
233  FCVT_D_L-> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
234  FCVT_D_LU->List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
235
236  // FP to Int
237  FCVT_W_S-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, Y, SelImm.IMM_X),
238  FCVT_WU_S->List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, Y, SelImm.IMM_X),
239  FCVT_L_S-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, Y, SelImm.IMM_X),
240  FCVT_LU_S->List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, Y, SelImm.IMM_X),
241
242  FCVT_W_D-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, N, SelImm.IMM_X),
243  FCVT_WU_D->List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, N, SelImm.IMM_X),
244  FCVT_L_D-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, N, SelImm.IMM_X),
245  FCVT_LU_D->List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, N, SelImm.IMM_X),
246
247  // "fp_single" is used for wb_data formatting (and debugging)
248  FEQ_S    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, Y, SelImm.IMM_X),
249  FLT_S    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, Y, SelImm.IMM_X),
250  FLE_S    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, Y, SelImm.IMM_X),
251
252  FEQ_D    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, N, SelImm.IMM_X),
253  FLT_D    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, N, SelImm.IMM_X),
254  FLE_D    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, N, SelImm.IMM_X),
255
256  FMIN_S   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
257  FMAX_S   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
258  FMIN_D   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
259  FMAX_D   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
260
261  FADD_S   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmac, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
262  FSUB_S   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmac, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
263  FMUL_S   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmac, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
264  FADD_D   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmac, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
265  FSUB_D   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmac, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
266  FMUL_D   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmac, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
267
268  FMADD_S  ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
269  FMSUB_S  ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
270  FNMADD_S ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
271  FNMSUB_S ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
272  FMADD_D  ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
273  FMSUB_D  ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
274  FNMADD_D ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
275  FNMSUB_D ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, X, N, Y, N, N, N, N, N, SelImm.IMM_X)
276  )
277}
278
279/**
280 * FP Divide SquareRoot Constants
281 */
282object FDivSqrtDecode extends DecodeConstants {
283  val table: Array[(BitPat, List[BitPat])] = Array(
284  FDIV_S    ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
285  FDIV_D    ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
286  FSQRT_S   ->List(SrcType.fp,  SrcType.imm, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
287  FSQRT_D   ->List(SrcType.fp,  SrcType.imm, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, N, SelImm.IMM_X)
288  )
289}
290
291/**
292 * XiangShan Trap Decode constants
293 */
294object XSTrapDecode extends DecodeConstants {
295  // calculate as ADDI => addi zero, a0, 0
296  // replace rs '?????' with '01010'(a0) in decode stage
297  def lsrc1 = "b01010".U // $a0
298  val table: Array[(BitPat, List[BitPat])] = Array(
299    TRAP    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.add, Y, N, Y, Y, Y, N, N, SelImm.IMM_I)
300  )
301}
302
303//object Imm32Gen {
304//  def apply(sel: UInt, inst: UInt) = {
305//    val sign = Mux(sel === SelImm.IMM_Z, 0.S, inst(31).asSInt)
306//    val b30_20 = Mux(sel === SelImm.IMM_U, inst(30,20).asSInt, sign)
307//    val b19_12 = Mux(sel =/= SelImm.IMM_U && sel =/= SelImm.IMM_UJ, sign, inst(19,12).asSInt)
308//    val b11 = Mux(sel === SelImm.IMM_U || sel === SelImm.IMM_Z, 0.S,
309//              Mux(sel === SelImm.IMM_UJ, inst(20).asSInt,
310//              Mux(sel === SelImm.IMM_SB, inst(7).asSInt, sign)))
311//    val b10_5 = Mux(sel === SelImm.IMM_U || sel === SelImm.IMM_Z, 0.U(1.W), inst(30,25))
312//    val b4_1 = Mux(sel === SelImm.IMM_U, 0.U(1.W),
313//               Mux(sel === SelImm.IMM_S || sel === SelImm.IMM_SB, inst(11,8),
314//               Mux(sel === SelImm.IMM_Z, inst(19,16), inst(24,21))))
315//    val b0 = Mux(sel === SelImm.IMM_S, inst(7),
316//             Mux(sel === SelImm.IMM_I, inst(20),
317//             Mux(sel === SelImm.IMM_Z, inst(15), 0.U(1.W))))
318//
319//    Cat(sign, b30_20, b19_12, b11, b10_5, b4_1, b0)
320//  }
321//}
322
323abstract class Imm(val len: Int) extends Bundle {
324  def toImm32(minBits: UInt): UInt = do_toImm32(minBits(len - 1, 0))
325  def do_toImm32(minBits: UInt): UInt
326  def minBitsFromInstr(instr: UInt): UInt
327}
328
329case class Imm_I() extends Imm(12) {
330  override def do_toImm32(minBits: UInt): UInt = SignExt(minBits, 32)
331
332  override def minBitsFromInstr(instr: UInt): UInt =
333    Cat(instr(31, 20))
334}
335
336case class Imm_S() extends Imm(12) {
337  override def do_toImm32(minBits: UInt): UInt = SignExt(minBits, 32)
338
339  override def minBitsFromInstr(instr: UInt): UInt =
340    Cat(instr(31, 25), instr(11, 7))
341}
342
343case class Imm_B() extends Imm(12) {
344  override def do_toImm32(minBits: UInt): UInt = SignExt(Cat(minBits, 0.U(1.W)), 32)
345
346  override def minBitsFromInstr(instr: UInt): UInt =
347    Cat(instr(31), instr(7), instr(30, 25), instr(11, 8))
348}
349
350case class Imm_U() extends Imm(20){
351  override def do_toImm32(minBits: UInt): UInt = Cat(minBits, 0.U(12.W))
352
353  override def minBitsFromInstr(instr: UInt): UInt = {
354    instr(31, 12)
355  }
356}
357
358case class Imm_J() extends Imm(20){
359  override def do_toImm32(minBits: UInt): UInt = SignExt(Cat(minBits, 0.U(1.W)), 32)
360
361  override def minBitsFromInstr(instr: UInt): UInt = {
362    Cat(instr(31), instr(19, 12), instr(20), instr(30, 25), instr(24, 21))
363  }
364}
365
366case class Imm_Z() extends Imm(12 + 5){
367  override def do_toImm32(minBits: UInt): UInt = minBits
368
369  override def minBitsFromInstr(instr: UInt): UInt = {
370    Cat(instr(19, 15), instr(31, 20))
371  }
372}
373
374object ImmUnion {
375  val I = Imm_I()
376  val S = Imm_S()
377  val B = Imm_B()
378  val U = Imm_U()
379  val J = Imm_J()
380  val Z = Imm_Z()
381  val imms = Seq(I, S, B, U, J, Z)
382  val maxLen = imms.maxBy(_.len).len
383  val immSelMap = Seq(
384    SelImm.IMM_I,
385    SelImm.IMM_S,
386    SelImm.IMM_SB,
387    SelImm.IMM_U,
388    SelImm.IMM_UJ,
389    SelImm.IMM_Z
390  ).zip(imms)
391  println(s"ImmUnion max len: $maxLen")
392}
393
394
395/**
396 * IO bundle for the Decode unit
397 */
398class DecodeUnitIO extends XSBundle {
399  val enq = new Bundle { val ctrl_flow = Input(new CtrlFlow) }
400  val deq = new Bundle { val cf_ctrl = Output(new CfCtrl) }
401}
402
403/**
404 * Decode unit that takes in a single CtrlFlow and generates a CfCtrl.
405 */
406class DecodeUnit extends XSModule with DecodeUnitConstants {
407  val io = IO(new DecodeUnitIO)
408
409  val ctrl_flow = Wire(new CtrlFlow) // input with RVC Expanded
410  val cf_ctrl = Wire(new CfCtrl)
411
412  ctrl_flow := io.enq.ctrl_flow
413
414  var decode_table = XDecode.table ++ FDecode.table ++ FDivSqrtDecode.table ++ X64Decode.table ++ XSTrapDecode.table
415
416  // output
417  cf_ctrl.cf := ctrl_flow
418  cf_ctrl.brTag := DontCare
419  val cs = Wire(new CtrlSignals()).decode(ctrl_flow.instr, decode_table)
420
421  val fpDecoder = Module(new FPDecoder)
422  fpDecoder.io.instr := ctrl_flow.instr
423  cs.fpu := fpDecoder.io.fpCtrl
424
425  // read src1~3 location
426  cs.lsrc1 := Mux(ctrl_flow.instr === LUI || cs.src1Type === SrcType.pc, 0.U, ctrl_flow.instr(RS1_MSB,RS1_LSB))
427  cs.lsrc2 := ctrl_flow.instr(RS2_MSB,RS2_LSB)
428  cs.lsrc3 := ctrl_flow.instr(RS3_MSB,RS3_LSB)
429  // read dest location
430  cs.ldest := Mux(cs.fpWen || cs.rfWen, ctrl_flow.instr(RD_MSB,RD_LSB), 0.U)
431
432  // fill in exception vector
433  cf_ctrl.cf.exceptionVec := io.enq.ctrl_flow.exceptionVec
434  cf_ctrl.cf.exceptionVec(illegalInstr) := cs.selImm === SelImm.INVALID_INSTR
435
436  // fix frflags
437  //                           fflags    zero csrrs rd    csr
438  val isFrflags = BitPat("b000000000001_00000_010_?????_1110011") === ctrl_flow.instr
439  when (cs.fuType === FuType.csr && isFrflags) {
440    cs.blockBackward := false.B
441  }
442
443  // fix isXSTrap
444  when (cs.isXSTrap) {
445    cs.lsrc1 := XSTrapDecode.lsrc1
446  }
447
448  cs.imm := LookupTree(cs.selImm, ImmUnion.immSelMap.map(
449    x => {
450      val minBits = x._2.minBitsFromInstr(ctrl_flow.instr)
451      require(minBits.getWidth == x._2.len)
452      x._1 -> minBits
453    }
454  ))
455
456  cf_ctrl.ctrl := cs
457
458  // TODO: do we still need this?
459  // fix ret and call
460//  when (cs.fuType === FuType.jmp) {
461//    def isLink(reg: UInt) = (reg === 1.U || reg === 5.U)
462//    when (isLink(cs.ldest) && cs.fuOpType === JumpOpType.jal) { cf_ctrl.ctrl.fuOpType := JumpOpType.call }
463//    when (cs.fuOpType === JumpOpType.jalr) {
464//      when (isLink(cs.lsrc1)) { cf_ctrl.ctrl.fuOpType := JumpOpType.ret  }
465//      when (isLink(cs.ldest)) { cf_ctrl.ctrl.fuOpType := JumpOpType.call }
466//    }
467//  }
468
469  io.deq.cf_ctrl := cf_ctrl
470
471  //-------------------------------------------------------------
472  // Debug Info
473  XSDebug("in:  instr=%x pc=%x excepVec=%b intrVec=%b crossPageIPFFix=%d\n",
474    io.enq.ctrl_flow.instr, io.enq.ctrl_flow.pc, io.enq.ctrl_flow.exceptionVec.asUInt,
475    io.enq.ctrl_flow.intrVec.asUInt, io.enq.ctrl_flow.crossPageIPFFix)
476  XSDebug("out: src1Type=%b src2Type=%b src3Type=%b lsrc1=%d lsrc2=%d lsrc3=%d ldest=%d fuType=%b fuOpType=%b\n",
477    io.deq.cf_ctrl.ctrl.src1Type, io.deq.cf_ctrl.ctrl.src2Type, io.deq.cf_ctrl.ctrl.src3Type,
478    io.deq.cf_ctrl.ctrl.lsrc1, io.deq.cf_ctrl.ctrl.lsrc2, io.deq.cf_ctrl.ctrl.lsrc3,
479    io.deq.cf_ctrl.ctrl.ldest, io.deq.cf_ctrl.ctrl.fuType, io.deq.cf_ctrl.ctrl.fuOpType)
480  XSDebug("out: rfWen=%d fpWen=%d isXSTrap=%d noSpecExec=%d isBlocked=%d flushPipe=%d isRVF=%d imm=%x\n",
481    io.deq.cf_ctrl.ctrl.rfWen, io.deq.cf_ctrl.ctrl.fpWen, io.deq.cf_ctrl.ctrl.isXSTrap,
482    io.deq.cf_ctrl.ctrl.noSpecExec, io.deq.cf_ctrl.ctrl.blockBackward, io.deq.cf_ctrl.ctrl.flushPipe,
483    io.deq.cf_ctrl.ctrl.isRVF, io.deq.cf_ctrl.ctrl.imm)
484  XSDebug("out: excepVec=%b intrVec=%b\n",
485    io.deq.cf_ctrl.cf.exceptionVec.asUInt, io.deq.cf_ctrl.cf.intrVec.asUInt)
486}
487