xref: /XiangShan/src/main/scala/xiangshan/backend/decode/DecodeUnit.scala (revision d70a22729e83ef255c566a9eed5c479baa1c6bf4)
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.AltInstructions._
20import xiangshan.backend.fu.fpu.FPUOpType
21import freechips.rocketchip.tile.RocketTile
22
23/**
24 * Abstract trait giving defaults and other relevant values to different Decode constants/
25 */
26abstract trait DecodeConstants {
27  def X = BitPat("b?")
28  def N = BitPat("b0")
29  def Y = BitPat("b1")
30
31  def decodeDefault: List[BitPat] = // illegal instruction
32    //   src1Type     src2Type     src3Type     fuType      fuOpType    rfWen
33    //   |            |            |            |           |           |  fpWen
34    //   |            |            |            |           |           |  |  isXSTrap
35    //   |            |            |            |           |           |  |  |  noSpecExec
36    //   |            |            |            |           |           |  |  |  |  blockBackward
37    //   |            |            |            |           |           |  |  |  |  |  flushPipe
38    //   |            |            |            |           |           |  |  |  |  |  |  isRVF
39    //   |            |            |            |           |           |  |  |  |  |  |  |  selImm
40    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
41
42    val table: Array[(BitPat, List[BitPat])]
43}
44
45trait DecodeUnitConstants
46{
47  // abstract out instruction decode magic numbers
48  val RD_MSB  = 11
49  val RD_LSB  = 7
50  val RS1_MSB = 19
51  val RS1_LSB = 15
52  val RS2_MSB = 24
53  val RS2_LSB = 20
54  val RS3_MSB = 31
55  val RS3_LSB = 27
56}
57
58/**
59 * Decoded control signals
60 * See xiangshan/package.scala, xiangshan/backend/package.scala, Bundle.scala
61 */
62
63/**
64 * Decode constants for RV64
65 */
66object X64Decode extends DecodeConstants {
67  val table: Array[(BitPat, List[BitPat])] = Array(
68    LD      -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.ld, Y, N, N, N, N, N, N, SelImm.IMM_I),
69    LWU     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lwu, Y, N, N, N, N, N, N, SelImm.IMM_I),
70    SD      -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.stu, LSUOpType.sd, N, N, N, N, N, N, N, SelImm.IMM_S),
71
72    SLLI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sll, Y, N, N, N, N, N, N, SelImm.IMM_I),
73    SRLI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.srl, Y, N, N, N, N, N, N, SelImm.IMM_I),
74    SRAI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sra, Y, N, N, N, N, N, N, SelImm.IMM_I),
75
76    ADDIW   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.addw, Y, N, N, N, N, N, N, SelImm.IMM_I),
77    SLLIW   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sllw, Y, N, N, N, N, N, N, SelImm.IMM_I),
78    SRAIW   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sraw, Y, N, N, N, N, N, N, SelImm.IMM_I),
79    SRLIW   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.srlw, Y, N, N, N, N, N, N, SelImm.IMM_I),
80
81    ADDW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.addw, Y, N, N, N, N, N, N, SelImm.IMM_X),
82    SUBW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.subw, Y, N, N, N, N, N, N, SelImm.IMM_X),
83    SLLW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sllw, Y, N, N, N, N, N, N, SelImm.IMM_X),
84    SRAW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sraw, Y, N, N, N, N, N, N, SelImm.IMM_X),
85    SRLW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.srlw, Y, N, N, N, N, N, N, SelImm.IMM_X)
86  )
87}
88
89/**
90 * Overall Decode constants
91 */
92object XDecode extends DecodeConstants {
93  val table: Array[(BitPat, List[BitPat])] = Array(
94    LW      -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lw, Y, N, N, N, N, N, N, SelImm.IMM_I),
95    LH      -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lh, Y, N, N, N, N, N, N, SelImm.IMM_I),
96    LHU     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lhu, Y, N, N, N, N, N, N, SelImm.IMM_I),
97    LB      -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lb, Y, N, N, N, N, N, N, SelImm.IMM_I),
98    LBU     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lbu, Y, N, N, N, N, N, N, SelImm.IMM_I),
99
100    SW      -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.stu, LSUOpType.sw, N, N, N, N, N, N, N, SelImm.IMM_S),
101    SH      -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.stu, LSUOpType.sh, N, N, N, N, N, N, N, SelImm.IMM_S),
102    SB      -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.stu, LSUOpType.sb, N, N, N, N, N, N, N, SelImm.IMM_S),
103
104    LUI     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.add, Y, N, N, N, N, N, N, SelImm.IMM_U),
105
106    ADDI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.add, Y, N, N, N, N, N, N, SelImm.IMM_I),
107    ANDI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.and, Y, N, N, N, N, N, N, SelImm.IMM_I),
108    ORI     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.or, Y, N, N, N, N, N, N, SelImm.IMM_I),
109    XORI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.xor, Y, N, N, N, N, N, N, SelImm.IMM_I),
110    SLTI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.slt, Y, N, N, N, N, N, N, SelImm.IMM_I),
111    SLTIU   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sltu, Y, N, N, N, N, N, N, SelImm.IMM_I),
112
113    SLL     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sll, Y, N, N, N, N, N, N, SelImm.IMM_X),
114    ADD     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.add, Y, N, N, N, N, N, N, SelImm.IMM_X),
115    SUB     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sub, Y, N, N, N, N, N, N, SelImm.IMM_X),
116    SLT     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.slt, Y, N, N, N, N, N, N, SelImm.IMM_X),
117    SLTU    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sltu, Y, N, N, N, N, N, N, SelImm.IMM_X),
118    AND     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.and, Y, N, N, N, N, N, N, SelImm.IMM_X),
119    OR      -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.or, Y, N, N, N, N, N, N, SelImm.IMM_X),
120    XOR     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.xor, Y, N, N, N, N, N, N, SelImm.IMM_X),
121    SRA     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sra, Y, N, N, N, N, N, N, SelImm.IMM_X),
122    SRL     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.srl, Y, N, N, N, N, N, N, SelImm.IMM_X),
123
124    MUL     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mul, MDUOpType.mul, Y, N, N, N, N, N, N, SelImm.IMM_X),
125    MULH    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mul, MDUOpType.mulh, Y, N, N, N, N, N, N, SelImm.IMM_X),
126    MULHU   -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mul, MDUOpType.mulhu, Y, N, N, N, N, N, N, SelImm.IMM_X),
127    MULHSU  -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mul, MDUOpType.mulhsu, Y, N, N, N, N, N, N, SelImm.IMM_X),
128    MULW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mul, MDUOpType.mulw, Y, N, N, N, N, N, N, SelImm.IMM_X),
129
130    DIV     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.div, Y, N, N, N, N, N, N, SelImm.IMM_X),
131    DIVU    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.divu, Y, N, N, N, N, N, N, SelImm.IMM_X),
132    REM     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.rem, Y, N, N, N, N, N, N, SelImm.IMM_X),
133    REMU    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.remu, Y, N, N, N, N, N, N, SelImm.IMM_X),
134    DIVW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.divw, Y, N, N, N, N, N, N, SelImm.IMM_X),
135    DIVUW   -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.divuw, Y, N, N, N, N, N, N, SelImm.IMM_X),
136    REMW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.remw, Y, N, N, N, N, N, N, SelImm.IMM_X),
137    REMUW   -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.remuw, Y, N, N, N, N, N, N, SelImm.IMM_X),
138
139    AUIPC   -> List(SrcType.pc, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.add, Y, N, N, N, N, N, N, SelImm.IMM_U),
140    JAL     -> List(SrcType.pc , SrcType.imm, SrcType.DC, FuType.jmp, JumpOpType.jal, Y, N, N, N, N, N, N, SelImm.IMM_UJ),
141    JALR    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.jmp, JumpOpType.jalr, Y, N, N, N, N, N, N, SelImm.IMM_I),
142    BEQ     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.beq, N, N, N, N, N, N, N, SelImm.IMM_SB),
143    BNE     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.bne, N, N, N, N, N, N, N, SelImm.IMM_SB),
144    BGE     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.bge, N, N, N, N, N, N, N, SelImm.IMM_SB),
145    BGEU    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.bgeu, N, N, N, N, N, N, N, SelImm.IMM_SB),
146    BLT     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.blt, N, N, N, N, N, N, N, SelImm.IMM_SB),
147    BLTU    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.bltu, N, N, N, N, N, N, N, SelImm.IMM_SB),
148
149    // I-type, the immediate12 holds the CSR register.
150    CSRRW   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.wrt, Y, N, N, Y, Y, N, N, SelImm.IMM_I),
151    CSRRS   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.set, Y, N, N, Y, Y, N, N, SelImm.IMM_I),
152    CSRRC   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.clr, Y, N, N, Y, Y, N, N, SelImm.IMM_I),
153
154    CSRRWI  -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.wrti, Y, N, N, Y, Y, N, N, SelImm.IMM_I),
155    CSRRSI  -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.seti, Y, N, N, Y, Y, N, N, SelImm.IMM_I),
156    CSRRCI  -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.clri, Y, N, N, Y, Y, N, N, SelImm.IMM_I),
157
158    SFENCE_VMA->List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.fence, FenceOpType.sfence, N, N, N, Y, Y, Y, N, SelImm.IMM_X),
159    ECALL   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.jmp, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
160    SRET    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.jmp, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
161    MRET    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.jmp, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
162
163    WFI     -> List(SrcType.pc, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sll, Y, N, N, N, N, N, N, SelImm.IMM_X),
164
165    FENCE_I -> List(SrcType.pc, SrcType.imm, SrcType.DC, FuType.fence, FenceOpType.fencei, N, N, N, Y, Y, Y, N, SelImm.IMM_X),
166    FENCE   -> List(SrcType.pc, SrcType.imm, SrcType.DC, FuType.fence, FenceOpType.fence, N, N, N, Y, Y, Y, N, SelImm.IMM_X),
167
168    // A-type
169    AMOADD_W-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoadd_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
170    AMOXOR_W-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoxor_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
171    AMOSWAP_W->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoswap_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
172    AMOAND_W-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoand_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
173    AMOOR_W -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoor_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
174    AMOMIN_W-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomin_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
175    AMOMINU_W->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amominu_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
176    AMOMAX_W-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomax_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
177    AMOMAXU_W->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomaxu_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
178
179    AMOADD_D-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoadd_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
180    AMOXOR_D-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoxor_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
181    AMOSWAP_D->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoswap_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
182    AMOAND_D-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoand_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
183    AMOOR_D -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoor_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
184    AMOMIN_D-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomin_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
185    AMOMINU_D->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amominu_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
186    AMOMAX_D-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomax_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
187    AMOMAXU_D->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomaxu_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
188
189    LR_W    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.mou, LSUOpType.lr_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
190    LR_D    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.mou, LSUOpType.lr_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
191    SC_W    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.sc_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
192    SC_D    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.sc_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X)
193  )
194}
195
196/**
197 * FP Decode constants
198 */
199object FDecode extends DecodeConstants{
200  val table: Array[(BitPat, List[BitPat])] = Array(
201
202  FLW     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.flw, N, Y, N, N, N, N, Y, SelImm.IMM_I),
203  FLD     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.ld, N, Y, N, N, N, N, N, SelImm.IMM_I),
204  FSW     -> List(SrcType.reg, SrcType.fp, SrcType.DC, FuType.stu, LSUOpType.sw, N, N, N, N, N, N, Y, SelImm.IMM_S),
205  FSD     -> List(SrcType.reg, SrcType.fp, SrcType.DC, FuType.stu, LSUOpType.sd, N, N, N, N, N, N, N, SelImm.IMM_S),
206
207  FCLASS_S-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.fclass, Y, N, N, N, N, N, Y, SelImm.IMM_X),
208  FCLASS_D-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.fclass, Y, N, N, N, N, N, N, SelImm.IMM_X),
209
210  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),
211  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),
212  FMV_X_W -> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.fmv_f2i, Y, N, N, N, N, N, Y, SelImm.IMM_X),
213  FMV_W_X -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, FPUOpType.fmv_i2f, N, Y, N, N, N, N, Y, SelImm.IMM_X),
214
215  FSGNJ_S -> List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.fsgnj, N, Y, N, N, N, N, Y, SelImm.IMM_X),
216  FSGNJ_D -> List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.fsgnj, N, Y, N, N, N, N, N, SelImm.IMM_X),
217  FSGNJX_S-> List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.fsgnjx, N, Y, N, N, N, N, Y, SelImm.IMM_X),
218  FSGNJX_D-> List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.fsgnjx, N, Y, N, N, N, N, N, SelImm.IMM_X),
219  FSGNJN_S-> List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.fsgnjn, N, Y, N, N, N, N, Y, SelImm.IMM_X),
220  FSGNJN_D-> List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.fsgnjn, N, Y, N, N, N, N, N, SelImm.IMM_X),
221
222  // FP to FP
223  FCVT_S_D-> List(SrcType.fp, SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.d2s, N, Y, N, N, N, N, Y, SelImm.IMM_X),
224  FCVT_D_S-> List(SrcType.fp, SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.s2d, N, Y, N, N, N, N, N, SelImm.IMM_X),
225
226  // Int to FP
227  FCVT_S_W-> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, FPUOpType.w2f, N, Y, N, N, N, N, Y, SelImm.IMM_X),
228  FCVT_S_WU->List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, FPUOpType.wu2f, N, Y, N, N, N, N, Y, SelImm.IMM_X),
229  FCVT_S_L-> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, FPUOpType.l2f, N, Y, N, N, N, N, Y, SelImm.IMM_X),
230  FCVT_S_LU->List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, FPUOpType.lu2f, N, Y, N, N, N, N, Y, SelImm.IMM_X),
231
232  FCVT_D_W-> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, FPUOpType.w2f, N, Y, N, N, N, N, N, SelImm.IMM_X),
233  FCVT_D_WU->List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, FPUOpType.wu2f, N, Y, N, N, N, N, N, SelImm.IMM_X),
234  FCVT_D_L-> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, FPUOpType.l2f, N, Y, N, N, N, N, N, SelImm.IMM_X),
235  FCVT_D_LU->List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, FPUOpType.lu2f, N, Y, N, N, N, N, N, SelImm.IMM_X),
236
237  // FP to Int
238  FCVT_W_S-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.f2w, Y, N, N, N, N, N, Y, SelImm.IMM_X),
239  FCVT_WU_S->List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.f2wu, Y, N, N, N, N, N, Y, SelImm.IMM_X),
240  FCVT_L_S-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.f2l, Y, N, N, N, N, N, Y, SelImm.IMM_X),
241  FCVT_LU_S->List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.f2lu, Y, N, N, N, N, N, Y, SelImm.IMM_X),
242
243  FCVT_W_D-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.f2w, Y, N, N, N, N, N, N, SelImm.IMM_X),
244  FCVT_WU_D->List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.f2wu, Y, N, N, N, N, N, N, SelImm.IMM_X),
245  FCVT_L_D-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.f2l, Y, N, N, N, N, N, N, SelImm.IMM_X),
246  FCVT_LU_D->List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.f2lu, Y, N, N, N, N, N, N, SelImm.IMM_X),
247
248  // "fp_single" is used for wb_data formatting (and debugging)
249  FEQ_S    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.feq, Y, N, N, N, N, N, Y, SelImm.IMM_X),
250  FLT_S    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.flt, Y, N, N, N, N, N, Y, SelImm.IMM_X),
251  FLE_S    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.fle, Y, N, N, N, N, N, Y, SelImm.IMM_X),
252
253  FEQ_D    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.feq, Y, N, N, N, N, N, N, SelImm.IMM_X),
254  FLT_D    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.flt, Y, N, N, N, N, N, N, SelImm.IMM_X),
255  FLE_D    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.fle, Y, N, N, N, N, N, N, SelImm.IMM_X),
256
257  FMIN_S   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.fmin, N, Y, N, N, N, N, Y, SelImm.IMM_X),
258  FMAX_S   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.fmax, N, Y, N, N, N, N, Y, SelImm.IMM_X),
259  FMIN_D   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.fmin, N, Y, N, N, N, N, N, SelImm.IMM_X),
260  FMAX_D   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.fmax, N, Y, N, N, N, N, N, SelImm.IMM_X),
261
262  FADD_S   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmac, FPUOpType.fadd, N, Y, N, N, N, N, Y, SelImm.IMM_X),
263  FSUB_S   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmac, FPUOpType.fsub, N, Y, N, N, N, N, Y, SelImm.IMM_X),
264  FMUL_S   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmac, FPUOpType.fmul, N, Y, N, N, N, N, Y, SelImm.IMM_X),
265  FADD_D   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmac, FPUOpType.fadd, N, Y, N, N, N, N, N, SelImm.IMM_X),
266  FSUB_D   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmac, FPUOpType.fsub, N, Y, N, N, N, N, N, SelImm.IMM_X),
267  FMUL_D   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmac, FPUOpType.fmul, N, Y, N, N, N, N, N, SelImm.IMM_X),
268
269  FMADD_S  ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, FPUOpType.fmadd, N, Y, N, N, N, N, Y, SelImm.IMM_X),
270  FMSUB_S  ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, FPUOpType.fmsub, N, Y, N, N, N, N, Y, SelImm.IMM_X),
271  FNMADD_S ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, FPUOpType.fnmadd, N, Y, N, N, N, N, Y, SelImm.IMM_X),
272  FNMSUB_S ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, FPUOpType.fnmsub, N, Y, N, N, N, N, Y, SelImm.IMM_X),
273  FMADD_D  ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, FPUOpType.fmadd, N, Y, N, N, N, N, N, SelImm.IMM_X),
274  FMSUB_D  ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, FPUOpType.fmsub, N, Y, N, N, N, N, N, SelImm.IMM_X),
275  FNMADD_D ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, FPUOpType.fnmadd, N, Y, N, N, N, N, N, SelImm.IMM_X),
276  FNMSUB_D ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, FPUOpType.fnmsub, N, Y, N, N, N, N, N, SelImm.IMM_X)
277  )
278}
279
280/**
281 * FP Divide SquareRoot Constants
282 */
283object FDivSqrtDecode extends DecodeConstants {
284  val table: Array[(BitPat, List[BitPat])] = Array(
285  FDIV_S    ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.fdiv, N, Y, N, N, N, N, Y, SelImm.IMM_X),
286  FDIV_D    ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, FPUOpType.fdiv, N, Y, N, N, N, N, N, SelImm.IMM_X),
287  FSQRT_S   ->List(SrcType.fp,  SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.fsqrt, N, Y, N, N, N, N, Y, SelImm.IMM_X),
288  FSQRT_D   ->List(SrcType.fp,  SrcType.imm, SrcType.DC, FuType.fmisc, FPUOpType.fsqrt, N, Y, N, N, N, N, N, SelImm.IMM_X)
289  )
290}
291
292/**
293 * XiangShan Trap Decode constants
294 */
295object XSTrapDecode extends DecodeConstants {
296  // calculate as ADDI => addi zero, a0, 0
297  // replace rs '?????' with '01010'(a0) in decode stage
298  def lsrc1 = "b01010".U // $a0
299  val table: Array[(BitPat, List[BitPat])] = Array(
300    TRAP    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.add, Y, N, Y, Y, Y, N, N, SelImm.IMM_I)
301  )
302}
303
304class RVCExpander extends XSModule {
305  val io = IO(new Bundle {
306    val in = Input(UInt(32.W))
307    val out = Output(new ExpandedInstruction)
308    val rvc = Output(Bool())
309  })
310
311  if (HasCExtension) {
312    io.rvc := io.in(1,0) =/= 3.U
313    io.out := new RVCDecoder(io.in, XLEN).decode
314  } else {
315    io.rvc := false.B
316    io.out := new RVCDecoder(io.in, XLEN).passthrough
317  }
318}
319
320object Imm32Gen {
321  def apply(sel: UInt, inst: UInt) = {
322    val sign = Mux(sel === SelImm.IMM_Z, 0.S, inst(31).asSInt)
323    val b30_20 = Mux(sel === SelImm.IMM_U, inst(30,20).asSInt, sign)
324    val b19_12 = Mux(sel =/= SelImm.IMM_U && sel =/= SelImm.IMM_UJ, sign, inst(19,12).asSInt)
325    val b11 = Mux(sel === SelImm.IMM_U || sel === SelImm.IMM_Z, 0.S,
326              Mux(sel === SelImm.IMM_UJ, inst(20).asSInt,
327              Mux(sel === SelImm.IMM_SB, inst(7).asSInt, sign)))
328    val b10_5 = Mux(sel === SelImm.IMM_U || sel === SelImm.IMM_Z, 0.U(1.W), inst(30,25))
329    val b4_1 = Mux(sel === SelImm.IMM_U, 0.U(1.W),
330               Mux(sel === SelImm.IMM_S || sel === SelImm.IMM_SB, inst(11,8),
331               Mux(sel === SelImm.IMM_Z, inst(19,16), inst(24,21))))
332    val b0 = Mux(sel === SelImm.IMM_S, inst(7),
333             Mux(sel === SelImm.IMM_I, inst(20),
334             Mux(sel === SelImm.IMM_Z, inst(15), 0.U(1.W))))
335
336    Cat(sign, b30_20, b19_12, b11, b10_5, b4_1, b0)
337  }
338}
339
340/**
341 * IO bundle for the Decode unit
342 */
343class DecodeUnitIO extends XSBundle {
344  val enq = new Bundle { val ctrl_flow = Input(new CtrlFlow) }
345  val deq = new Bundle { val cf_ctrl = Output(new CfCtrl) }
346}
347
348/**
349 * Decode unit that takes in a single CtrlFlow and generates a CfCtrl.
350 */
351class DecodeUnit extends XSModule with DecodeUnitConstants {
352  val io = IO(new DecodeUnitIO)
353
354  val ctrl_flow = Wire(new CtrlFlow) // input with RVC Expanded
355  val cf_ctrl = Wire(new CfCtrl)
356
357  val exp = Module(new RVCExpander())
358  exp.io.in := io.enq.ctrl_flow.instr
359  ctrl_flow := io.enq.ctrl_flow
360  when (exp.io.rvc) {
361    ctrl_flow.instr := exp.io.out.bits
362  }
363
364  // save rvc decode info
365  // TODO maybe rvc_info are useless?
366  val rvc_info = Wire(new ExpandedInstruction())
367  val is_rvc = Wire(Bool())
368  rvc_info := exp.io.out
369  is_rvc := exp.io.rvc
370
371  var decode_table = XDecode.table ++ FDecode.table ++ FDivSqrtDecode.table ++ X64Decode.table ++ XSTrapDecode.table
372
373  // output
374  cf_ctrl.cf := ctrl_flow
375  cf_ctrl.brTag := DontCare
376  val cs = Wire(new CtrlSignals()).decode(ctrl_flow.instr, decode_table)
377
378  // read src1~3 location
379  cs.lsrc1 := Mux(ctrl_flow.instr === LUI || cs.src1Type === SrcType.pc, 0.U, ctrl_flow.instr(RS1_MSB,RS1_LSB))
380  cs.lsrc2 := ctrl_flow.instr(RS2_MSB,RS2_LSB)
381  cs.lsrc3 := ctrl_flow.instr(RS3_MSB,RS3_LSB)
382  // read dest location
383  cs.ldest := Mux(cs.fpWen || cs.rfWen, ctrl_flow.instr(RD_MSB,RD_LSB), 0.U)
384
385  // fill in exception vector
386  cf_ctrl.cf.exceptionVec.map(_ := false.B)
387  cf_ctrl.cf.exceptionVec(illegalInstr) := cs.selImm === SelImm.INVALID_INSTR
388  cf_ctrl.cf.exceptionVec(instrPageFault) := io.enq.ctrl_flow.exceptionVec(instrPageFault)
389  cf_ctrl.cf.exceptionVec(instrAccessFault) := io.enq.ctrl_flow.exceptionVec(instrAccessFault)
390
391  // fix frflags
392  //                           fflags    zero csrrs rd    csr
393  val isFrflags = BitPat("b000000000001_00000_010_?????_1110011") === ctrl_flow.instr
394  when (cs.fuType === FuType.csr && isFrflags) {
395    cs.blockBackward := false.B
396  }
397
398  // fix isXSTrap
399  when (cs.isXSTrap) {
400    cs.lsrc1 := XSTrapDecode.lsrc1
401  }
402
403  cs.imm := SignExt(Imm32Gen(cs.selImm, ctrl_flow.instr), XLEN)
404
405  cf_ctrl.ctrl := cs
406
407  // fix ret and call
408  when (cs.fuType === FuType.jmp) {
409    def isLink(reg: UInt) = (reg === 1.U || reg === 5.U)
410    when (isLink(cs.ldest) && cs.fuOpType === JumpOpType.jal) { cf_ctrl.ctrl.fuOpType := JumpOpType.call }
411    when (cs.fuOpType === JumpOpType.jalr) {
412      when (isLink(cs.lsrc1)) { cf_ctrl.ctrl.fuOpType := JumpOpType.ret  }
413      when (isLink(cs.ldest)) { cf_ctrl.ctrl.fuOpType := JumpOpType.call }
414    }
415  }
416
417  io.deq.cf_ctrl := cf_ctrl
418
419  //-------------------------------------------------------------
420  // Debug Info
421  XSDebug("in:  instr=%x pc=%x excepVec=%b intrVec=%b crossPageIPFFix=%d\n",
422    io.enq.ctrl_flow.instr, io.enq.ctrl_flow.pc, io.enq.ctrl_flow.exceptionVec.asUInt,
423    io.enq.ctrl_flow.intrVec.asUInt, io.enq.ctrl_flow.crossPageIPFFix)
424  XSDebug("out: src1Type=%b src2Type=%b src3Type=%b lsrc1=%d lsrc2=%d lsrc3=%d ldest=%d fuType=%b fuOpType=%b\n",
425    io.deq.cf_ctrl.ctrl.src1Type, io.deq.cf_ctrl.ctrl.src2Type, io.deq.cf_ctrl.ctrl.src3Type,
426    io.deq.cf_ctrl.ctrl.lsrc1, io.deq.cf_ctrl.ctrl.lsrc2, io.deq.cf_ctrl.ctrl.lsrc3,
427    io.deq.cf_ctrl.ctrl.ldest, io.deq.cf_ctrl.ctrl.fuType, io.deq.cf_ctrl.ctrl.fuOpType)
428  XSDebug("out: rfWen=%d fpWen=%d isXSTrap=%d noSpecExec=%d isBlocked=%d flushPipe=%d isRVF=%d imm=%x\n",
429    io.deq.cf_ctrl.ctrl.rfWen, io.deq.cf_ctrl.ctrl.fpWen, io.deq.cf_ctrl.ctrl.isXSTrap,
430    io.deq.cf_ctrl.ctrl.noSpecExec, io.deq.cf_ctrl.ctrl.blockBackward, io.deq.cf_ctrl.ctrl.flushPipe,
431    io.deq.cf_ctrl.ctrl.isRVF, io.deq.cf_ctrl.ctrl.imm)
432  XSDebug("out: excepVec=%b intrVec=%b\n",
433    io.deq.cf_ctrl.cf.exceptionVec.asUInt, io.deq.cf_ctrl.cf.intrVec.asUInt)
434}
435