xref: /XiangShan/src/main/scala/xiangshan/backend/decode/DecodeUnit.scala (revision 2225d46ebbe2fd16b9b29963c27a7d0385a42709)
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 chipsalliance.rocketchip.config.Parameters
9import chisel3._
10import chisel3.util._
11import freechips.rocketchip.util.{UIntIsOneOf, uintToBitPat}
12import xiangshan._
13import utils._
14import xiangshan.backend._
15import xiangshan.backend.decode.Instructions._
16
17/**
18 * Abstract trait giving defaults and other relevant values to different Decode constants/
19 */
20abstract trait DecodeConstants {
21  def X = BitPat("b?")
22  def N = BitPat("b0")
23  def Y = BitPat("b1")
24
25  def decodeDefault: List[BitPat] = // illegal instruction
26    //   src1Type     src2Type     src3Type     fuType      fuOpType    rfWen
27    //   |            |            |            |           |           |  fpWen
28    //   |            |            |            |           |           |  |  isXSTrap
29    //   |            |            |            |           |           |  |  |  noSpecExec
30    //   |            |            |            |           |           |  |  |  |  blockBackward
31    //   |            |            |            |           |           |  |  |  |  |  flushPipe
32    //   |            |            |            |           |           |  |  |  |  |  |  isRVF
33    //   |            |            |            |           |           |  |  |  |  |  |  |  selImm
34    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
35
36    val table: Array[(BitPat, List[BitPat])]
37}
38
39trait DecodeUnitConstants
40{
41  // abstract out instruction decode magic numbers
42  val RD_MSB  = 11
43  val RD_LSB  = 7
44  val RS1_MSB = 19
45  val RS1_LSB = 15
46  val RS2_MSB = 24
47  val RS2_LSB = 20
48  val RS3_MSB = 31
49  val RS3_LSB = 27
50}
51
52/**
53 * Decoded control signals
54 * See xiangshan/package.scala, xiangshan/backend/package.scala, Bundle.scala
55 */
56
57/**
58 * Decode constants for RV64
59 */
60object X64Decode extends DecodeConstants {
61  val table: Array[(BitPat, List[BitPat])] = Array(
62    LD      -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.ld, Y, N, N, N, N, N, N, SelImm.IMM_I),
63    LWU     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lwu, Y, N, N, N, N, N, N, SelImm.IMM_I),
64    SD      -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.stu, LSUOpType.sd, N, N, N, N, N, N, N, SelImm.IMM_S),
65
66    SLLI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sll, Y, N, N, N, N, N, N, SelImm.IMM_I),
67    SRLI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.srl, Y, N, N, N, N, N, N, SelImm.IMM_I),
68    SRAI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sra, Y, N, N, N, N, N, N, SelImm.IMM_I),
69
70    ADDIW   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.addw, Y, N, N, N, N, N, N, SelImm.IMM_I),
71    SLLIW   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sllw, Y, N, N, N, N, N, N, SelImm.IMM_I),
72    SRAIW   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sraw, Y, N, N, N, N, N, N, SelImm.IMM_I),
73    SRLIW   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.srlw, Y, N, N, N, N, N, N, SelImm.IMM_I),
74
75    ADDW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.addw, Y, N, N, N, N, N, N, SelImm.IMM_X),
76    SUBW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.subw, Y, N, N, N, N, N, N, SelImm.IMM_X),
77    SLLW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sllw, Y, N, N, N, N, N, N, SelImm.IMM_X),
78    SRAW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sraw, Y, N, N, N, N, N, N, SelImm.IMM_X),
79    SRLW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.srlw, Y, N, N, N, N, N, N, SelImm.IMM_X)
80  )
81}
82
83/**
84 * Overall Decode constants
85 */
86object XDecode extends DecodeConstants {
87  val table: Array[(BitPat, List[BitPat])] = Array(
88    LW      -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lw, Y, N, N, N, N, N, N, SelImm.IMM_I),
89    LH      -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lh, Y, N, N, N, N, N, N, SelImm.IMM_I),
90    LHU     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lhu, Y, N, N, N, N, N, N, SelImm.IMM_I),
91    LB      -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lb, Y, N, N, N, N, N, N, SelImm.IMM_I),
92    LBU     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lbu, Y, N, N, N, N, N, N, SelImm.IMM_I),
93
94    SW      -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.stu, LSUOpType.sw, N, N, N, N, N, N, N, SelImm.IMM_S),
95    SH      -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.stu, LSUOpType.sh, N, N, N, N, N, N, N, SelImm.IMM_S),
96    SB      -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.stu, LSUOpType.sb, N, N, N, N, N, N, N, SelImm.IMM_S),
97
98    LUI     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.add, Y, N, N, N, N, N, N, SelImm.IMM_U),
99
100    ADDI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.add, Y, N, N, N, N, N, N, SelImm.IMM_I),
101    ANDI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.and, Y, N, N, N, N, N, N, SelImm.IMM_I),
102    ORI     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.or, Y, N, N, N, N, N, N, SelImm.IMM_I),
103    XORI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.xor, Y, N, N, N, N, N, N, SelImm.IMM_I),
104    SLTI    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.slt, Y, N, N, N, N, N, N, SelImm.IMM_I),
105    SLTIU   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sltu, Y, N, N, N, N, N, N, SelImm.IMM_I),
106
107    SLL     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sll, Y, N, N, N, N, N, N, SelImm.IMM_X),
108    ADD     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.add, Y, N, N, N, N, N, N, SelImm.IMM_X),
109    SUB     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sub, Y, N, N, N, N, N, N, SelImm.IMM_X),
110    SLT     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.slt, Y, N, N, N, N, N, N, SelImm.IMM_X),
111    SLTU    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sltu, Y, N, N, N, N, N, N, SelImm.IMM_X),
112    AND     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.and, Y, N, N, N, N, N, N, SelImm.IMM_X),
113    OR      -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.or, Y, N, N, N, N, N, N, SelImm.IMM_X),
114    XOR     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.xor, Y, N, N, N, N, N, N, SelImm.IMM_X),
115    SRA     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.sra, Y, N, N, N, N, N, N, SelImm.IMM_X),
116    SRL     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.srl, Y, N, N, N, N, N, N, SelImm.IMM_X),
117
118    MUL     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mul, MDUOpType.mul, Y, N, N, N, N, N, N, SelImm.IMM_X),
119    MULH    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mul, MDUOpType.mulh, Y, N, N, N, N, N, N, SelImm.IMM_X),
120    MULHU   -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mul, MDUOpType.mulhu, Y, N, N, N, N, N, N, SelImm.IMM_X),
121    MULHSU  -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mul, MDUOpType.mulhsu, Y, N, N, N, N, N, N, SelImm.IMM_X),
122    MULW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mul, MDUOpType.mulw, Y, N, N, N, N, N, N, SelImm.IMM_X),
123
124    DIV     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.div, Y, N, N, N, N, N, N, SelImm.IMM_X),
125    DIVU    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.divu, Y, N, N, N, N, N, N, SelImm.IMM_X),
126    REM     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.rem, Y, N, N, N, N, N, N, SelImm.IMM_X),
127    REMU    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.remu, Y, N, N, N, N, N, N, SelImm.IMM_X),
128    DIVW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.divw, Y, N, N, N, N, N, N, SelImm.IMM_X),
129    DIVUW   -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.divuw, Y, N, N, N, N, N, N, SelImm.IMM_X),
130    REMW    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.remw, Y, N, N, N, N, N, N, SelImm.IMM_X),
131    REMUW   -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.div, MDUOpType.remuw, Y, N, N, N, N, N, N, SelImm.IMM_X),
132
133    AUIPC   -> List(SrcType.pc , SrcType.imm, SrcType.DC, FuType.jmp, JumpOpType.auipc, Y, N, N, N, N, N, N, SelImm.IMM_U),
134    JAL     -> List(SrcType.pc , SrcType.imm, SrcType.DC, FuType.jmp, JumpOpType.jal, Y, N, N, N, N, N, N, SelImm.IMM_UJ),
135    JALR    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.jmp, JumpOpType.jalr, Y, N, N, N, N, N, N, SelImm.IMM_I),
136    BEQ     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.beq, N, N, N, N, N, N, N, SelImm.IMM_SB),
137    BNE     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.bne, N, N, N, N, N, N, N, SelImm.IMM_SB),
138    BGE     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.bge, N, N, N, N, N, N, N, SelImm.IMM_SB),
139    BGEU    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.bgeu, N, N, N, N, N, N, N, SelImm.IMM_SB),
140    BLT     -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.blt, N, N, N, N, N, N, N, SelImm.IMM_SB),
141    BLTU    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.alu, ALUOpType.bltu, N, N, N, N, N, N, N, SelImm.IMM_SB),
142
143    // I-type, the immediate12 holds the CSR register.
144    CSRRW   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.wrt, Y, N, N, Y, Y, N, N, SelImm.IMM_I),
145    CSRRS   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.set, Y, N, N, Y, Y, N, N, SelImm.IMM_I),
146    CSRRC   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.clr, Y, N, N, Y, Y, N, N, SelImm.IMM_I),
147
148    CSRRWI  -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.wrti, Y, N, N, Y, Y, N, N, SelImm.IMM_Z),
149    CSRRSI  -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.seti, Y, N, N, Y, Y, N, N, SelImm.IMM_Z),
150    CSRRCI  -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.clri, Y, N, N, Y, Y, N, N, SelImm.IMM_Z),
151
152    SFENCE_VMA->List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.fence, FenceOpType.sfence, N, N, N, Y, Y, Y, N, SelImm.IMM_X),
153    ECALL   -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.jmp, Y, N, N, Y, Y, N, N, SelImm.IMM_I),
154    SRET    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.jmp, Y, N, N, Y, Y, N, N, SelImm.IMM_I),
155    MRET    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.csr, CSROpType.jmp, Y, N, N, Y, Y, N, N, SelImm.IMM_I),
156
157    WFI     -> List(SrcType.pc, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.sll, Y, N, N, N, N, N, N, SelImm.IMM_X),
158
159    FENCE_I -> List(SrcType.pc, SrcType.imm, SrcType.DC, FuType.fence, FenceOpType.fencei, N, N, N, Y, Y, Y, N, SelImm.IMM_X),
160    FENCE   -> List(SrcType.pc, SrcType.imm, SrcType.DC, FuType.fence, FenceOpType.fence, N, N, N, Y, Y, Y, N, SelImm.IMM_X),
161
162    // A-type
163    AMOADD_W-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoadd_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
164    AMOXOR_W-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoxor_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
165    AMOSWAP_W->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoswap_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
166    AMOAND_W-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoand_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
167    AMOOR_W -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoor_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
168    AMOMIN_W-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomin_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
169    AMOMINU_W->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amominu_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
170    AMOMAX_W-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomax_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
171    AMOMAXU_W->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomaxu_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
172
173    AMOADD_D-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoadd_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
174    AMOXOR_D-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoxor_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
175    AMOSWAP_D->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoswap_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
176    AMOAND_D-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoand_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
177    AMOOR_D -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amoor_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
178    AMOMIN_D-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomin_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
179    AMOMINU_D->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amominu_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
180    AMOMAX_D-> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomax_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
181    AMOMAXU_D->List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.amomaxu_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
182
183    LR_W    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.mou, LSUOpType.lr_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
184    LR_D    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.mou, LSUOpType.lr_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
185    SC_W    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.sc_w, Y, N, N, Y, Y, N, N, SelImm.IMM_X),
186    SC_D    -> List(SrcType.reg, SrcType.reg, SrcType.DC, FuType.mou, LSUOpType.sc_d, Y, N, N, Y, Y, N, N, SelImm.IMM_X)
187  )
188}
189
190/**
191 * FP Decode constants
192 */
193object FDecode extends DecodeConstants{
194  val table: Array[(BitPat, List[BitPat])] = Array(
195
196  FLW     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.lw, N, Y, N, N, N, N, Y, SelImm.IMM_I),
197  FLD     -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.ldu, LSUOpType.ld, N, Y, N, N, N, N, N, SelImm.IMM_I),
198  FSW     -> List(SrcType.reg, SrcType.fp, SrcType.DC, FuType.stu, LSUOpType.sw, N, N, N, N, N, N, Y, SelImm.IMM_S),
199  FSD     -> List(SrcType.reg, SrcType.fp, SrcType.DC, FuType.stu, LSUOpType.sd, N, N, N, N, N, N, N, SelImm.IMM_S),
200
201  FCLASS_S-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, Y, SelImm.IMM_X),
202  FCLASS_D-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, N, SelImm.IMM_X),
203
204  FMV_D_X -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
205  FMV_X_D -> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, N, SelImm.IMM_X),
206  FMV_X_W -> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, Y, SelImm.IMM_X),
207  FMV_W_X -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
208
209  FSGNJ_S -> List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
210  FSGNJ_D -> List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
211  FSGNJX_S-> List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
212  FSGNJX_D-> List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
213  FSGNJN_S-> List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
214  FSGNJN_D-> List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
215
216  // FP to FP
217  FCVT_S_D-> List(SrcType.fp, SrcType.imm, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
218  FCVT_D_S-> List(SrcType.fp, SrcType.imm, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
219
220  // Int to FP
221  FCVT_S_W-> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
222  FCVT_S_WU->List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
223  FCVT_S_L-> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
224  FCVT_S_LU->List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
225
226  FCVT_D_W-> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
227  FCVT_D_WU->List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
228  FCVT_D_L-> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
229  FCVT_D_LU->List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.i2f, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
230
231  // FP to Int
232  FCVT_W_S-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, Y, SelImm.IMM_X),
233  FCVT_WU_S->List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, Y, SelImm.IMM_X),
234  FCVT_L_S-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, Y, SelImm.IMM_X),
235  FCVT_LU_S->List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, Y, SelImm.IMM_X),
236
237  FCVT_W_D-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, N, SelImm.IMM_X),
238  FCVT_WU_D->List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, N, SelImm.IMM_X),
239  FCVT_L_D-> List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, N, SelImm.IMM_X),
240  FCVT_LU_D->List(SrcType.fp , SrcType.imm, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, N, SelImm.IMM_X),
241
242  // "fp_single" is used for wb_data formatting (and debugging)
243  FEQ_S    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, Y, SelImm.IMM_X),
244  FLT_S    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, Y, SelImm.IMM_X),
245  FLE_S    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, Y, SelImm.IMM_X),
246
247  FEQ_D    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, N, SelImm.IMM_X),
248  FLT_D    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, N, SelImm.IMM_X),
249  FLE_D    ->List(SrcType.fp , SrcType.fp, SrcType.DC, FuType.fmisc, X, Y, N, N, N, N, N, N, SelImm.IMM_X),
250
251  FMIN_S   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
252  FMAX_S   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
253  FMIN_D   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
254  FMAX_D   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
255
256  FADD_S   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmac, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
257  FSUB_S   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmac, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
258  FMUL_S   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmac, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
259  FADD_D   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmac, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
260  FSUB_D   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmac, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
261  FMUL_D   ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmac, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
262
263  FMADD_S  ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
264  FMSUB_S  ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
265  FNMADD_S ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
266  FNMSUB_S ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
267  FMADD_D  ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
268  FMSUB_D  ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
269  FNMADD_D ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
270  FNMSUB_D ->List(SrcType.fp,  SrcType.fp, SrcType.fp, FuType.fmac, X, N, Y, N, N, N, N, N, SelImm.IMM_X)
271  )
272}
273
274/**
275 * FP Divide SquareRoot Constants
276 */
277object FDivSqrtDecode extends DecodeConstants {
278  val table: Array[(BitPat, List[BitPat])] = Array(
279  FDIV_S    ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
280  FDIV_D    ->List(SrcType.fp,  SrcType.fp, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, N, SelImm.IMM_X),
281  FSQRT_S   ->List(SrcType.fp,  SrcType.imm, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, Y, SelImm.IMM_X),
282  FSQRT_D   ->List(SrcType.fp,  SrcType.imm, SrcType.DC, FuType.fmisc, X, N, Y, N, N, N, N, N, SelImm.IMM_X)
283  )
284}
285
286/**
287 * XiangShan Trap Decode constants
288 */
289object XSTrapDecode extends DecodeConstants {
290  // calculate as ADDI => addi zero, a0, 0
291  // replace rs '?????' with '01010'(a0) in decode stage
292  def lsrc1 = "b01010".U // $a0
293  val table: Array[(BitPat, List[BitPat])] = Array(
294    TRAP    -> List(SrcType.reg, SrcType.imm, SrcType.DC, FuType.alu, ALUOpType.add, Y, N, Y, Y, Y, N, N, SelImm.IMM_I)
295  )
296}
297
298//object Imm32Gen {
299//  def apply(sel: UInt, inst: UInt) = {
300//    val sign = Mux(sel === SelImm.IMM_Z, 0.S, inst(31).asSInt)
301//    val b30_20 = Mux(sel === SelImm.IMM_U, inst(30,20).asSInt, sign)
302//    val b19_12 = Mux(sel =/= SelImm.IMM_U && sel =/= SelImm.IMM_UJ, sign, inst(19,12).asSInt)
303//    val b11 = Mux(sel === SelImm.IMM_U || sel === SelImm.IMM_Z, 0.S,
304//              Mux(sel === SelImm.IMM_UJ, inst(20).asSInt,
305//              Mux(sel === SelImm.IMM_SB, inst(7).asSInt, sign)))
306//    val b10_5 = Mux(sel === SelImm.IMM_U || sel === SelImm.IMM_Z, 0.U(1.W), inst(30,25))
307//    val b4_1 = Mux(sel === SelImm.IMM_U, 0.U(1.W),
308//               Mux(sel === SelImm.IMM_S || sel === SelImm.IMM_SB, inst(11,8),
309//               Mux(sel === SelImm.IMM_Z, inst(19,16), inst(24,21))))
310//    val b0 = Mux(sel === SelImm.IMM_S, inst(7),
311//             Mux(sel === SelImm.IMM_I, inst(20),
312//             Mux(sel === SelImm.IMM_Z, inst(15), 0.U(1.W))))
313//
314//    Cat(sign, b30_20, b19_12, b11, b10_5, b4_1, b0)
315//  }
316//}
317
318abstract class Imm(val len: Int) extends Bundle {
319  def toImm32(minBits: UInt): UInt = do_toImm32(minBits(len - 1, 0))
320  def do_toImm32(minBits: UInt): UInt
321  def minBitsFromInstr(instr: UInt): UInt
322}
323
324case class Imm_I() extends Imm(12) {
325  override def do_toImm32(minBits: UInt): UInt = SignExt(minBits, 32)
326
327  override def minBitsFromInstr(instr: UInt): UInt =
328    Cat(instr(31, 20))
329}
330
331case class Imm_S() extends Imm(12) {
332  override def do_toImm32(minBits: UInt): UInt = SignExt(minBits, 32)
333
334  override def minBitsFromInstr(instr: UInt): UInt =
335    Cat(instr(31, 25), instr(11, 7))
336}
337
338case class Imm_B() extends Imm(12) {
339  override def do_toImm32(minBits: UInt): UInt = SignExt(Cat(minBits, 0.U(1.W)), 32)
340
341  override def minBitsFromInstr(instr: UInt): UInt =
342    Cat(instr(31), instr(7), instr(30, 25), instr(11, 8))
343}
344
345case class Imm_U() extends Imm(20){
346  override def do_toImm32(minBits: UInt): UInt = Cat(minBits, 0.U(12.W))
347
348  override def minBitsFromInstr(instr: UInt): UInt = {
349    instr(31, 12)
350  }
351}
352
353case class Imm_J() extends Imm(20){
354  override def do_toImm32(minBits: UInt): UInt = SignExt(Cat(minBits, 0.U(1.W)), 32)
355
356  override def minBitsFromInstr(instr: UInt): UInt = {
357    Cat(instr(31), instr(19, 12), instr(20), instr(30, 25), instr(24, 21))
358  }
359}
360
361case class Imm_Z() extends Imm(12 + 5){
362  override def do_toImm32(minBits: UInt): UInt = minBits
363
364  override def minBitsFromInstr(instr: UInt): UInt = {
365    Cat(instr(19, 15), instr(31, 20))
366  }
367}
368
369object ImmUnion {
370  val I = Imm_I()
371  val S = Imm_S()
372  val B = Imm_B()
373  val U = Imm_U()
374  val J = Imm_J()
375  val Z = Imm_Z()
376  val imms = Seq(I, S, B, U, J, Z)
377  val maxLen = imms.maxBy(_.len).len
378  val immSelMap = Seq(
379    SelImm.IMM_I,
380    SelImm.IMM_S,
381    SelImm.IMM_SB,
382    SelImm.IMM_U,
383    SelImm.IMM_UJ,
384    SelImm.IMM_Z
385  ).zip(imms)
386  println(s"ImmUnion max len: $maxLen")
387}
388
389
390/**
391 * IO bundle for the Decode unit
392 */
393class DecodeUnitIO(implicit p: Parameters) extends XSBundle {
394  val enq = new Bundle { val ctrl_flow = Input(new CtrlFlow) }
395  val deq = new Bundle { val cf_ctrl = Output(new CfCtrl) }
396}
397
398/**
399 * Decode unit that takes in a single CtrlFlow and generates a CfCtrl.
400 */
401class DecodeUnit(implicit p: Parameters) extends XSModule with DecodeUnitConstants {
402  val io = IO(new DecodeUnitIO)
403
404  val ctrl_flow = Wire(new CtrlFlow) // input with RVC Expanded
405  val cf_ctrl = Wire(new CfCtrl)
406
407  ctrl_flow := io.enq.ctrl_flow
408
409  var decode_table = XDecode.table ++ FDecode.table ++ FDivSqrtDecode.table ++ X64Decode.table ++ XSTrapDecode.table
410
411  // output
412  cf_ctrl.cf := ctrl_flow
413  val cs = Wire(new CtrlSignals()).decode(ctrl_flow.instr, decode_table)
414
415  val fpDecoder = Module(new FPDecoder)
416  fpDecoder.io.instr := ctrl_flow.instr
417  cs.fpu := fpDecoder.io.fpCtrl
418
419  // read src1~3 location
420  cs.lsrc1 := Mux(ctrl_flow.instr === LUI, 0.U,ctrl_flow.instr(RS1_MSB,RS1_LSB))
421  cs.lsrc2 := ctrl_flow.instr(RS2_MSB,RS2_LSB)
422  cs.lsrc3 := ctrl_flow.instr(RS3_MSB,RS3_LSB)
423  // read dest location
424  cs.ldest := Mux(cs.fpWen || cs.rfWen, ctrl_flow.instr(RD_MSB,RD_LSB), 0.U)
425
426  // fill in exception vector
427  cf_ctrl.cf.exceptionVec := io.enq.ctrl_flow.exceptionVec
428  cf_ctrl.cf.exceptionVec(illegalInstr) := cs.selImm === SelImm.INVALID_INSTR
429
430  // fix frflags
431  //                           fflags    zero csrrs rd    csr
432  val isFrflags = BitPat("b000000000001_00000_010_?????_1110011") === ctrl_flow.instr
433  when (cs.fuType === FuType.csr && isFrflags) {
434    cs.blockBackward := false.B
435  }
436
437  // fix isXSTrap
438  when (cs.isXSTrap) {
439    cs.lsrc1 := XSTrapDecode.lsrc1
440  }
441
442  cs.imm := LookupTree(cs.selImm, ImmUnion.immSelMap.map(
443    x => {
444      val minBits = x._2.minBitsFromInstr(ctrl_flow.instr)
445      require(minBits.getWidth == x._2.len)
446      x._1 -> minBits
447    }
448  ))
449
450  cs.isMove := BitPat("b000000000000_?????_000_?????_0010011") === ctrl_flow.instr
451
452  cf_ctrl.ctrl := cs
453
454  // TODO: do we still need this?
455  // fix ret and call
456//  when (cs.fuType === FuType.jmp) {
457//    def isLink(reg: UInt) = (reg === 1.U || reg === 5.U)
458//    when (isLink(cs.ldest) && cs.fuOpType === JumpOpType.jal) { cf_ctrl.ctrl.fuOpType := JumpOpType.call }
459//    when (cs.fuOpType === JumpOpType.jalr) {
460//      when (isLink(cs.lsrc1)) { cf_ctrl.ctrl.fuOpType := JumpOpType.ret  }
461//      when (isLink(cs.ldest)) { cf_ctrl.ctrl.fuOpType := JumpOpType.call }
462//    }
463//  }
464
465  io.deq.cf_ctrl := cf_ctrl
466
467  //-------------------------------------------------------------
468  // Debug Info
469  XSDebug("in:  instr=%x pc=%x excepVec=%b intrVec=%b crossPageIPFFix=%d\n",
470    io.enq.ctrl_flow.instr, io.enq.ctrl_flow.pc, io.enq.ctrl_flow.exceptionVec.asUInt,
471    io.enq.ctrl_flow.intrVec.asUInt, io.enq.ctrl_flow.crossPageIPFFix)
472  XSDebug("out: src1Type=%b src2Type=%b src3Type=%b lsrc1=%d lsrc2=%d lsrc3=%d ldest=%d fuType=%b fuOpType=%b\n",
473    io.deq.cf_ctrl.ctrl.src1Type, io.deq.cf_ctrl.ctrl.src2Type, io.deq.cf_ctrl.ctrl.src3Type,
474    io.deq.cf_ctrl.ctrl.lsrc1, io.deq.cf_ctrl.ctrl.lsrc2, io.deq.cf_ctrl.ctrl.lsrc3,
475    io.deq.cf_ctrl.ctrl.ldest, io.deq.cf_ctrl.ctrl.fuType, io.deq.cf_ctrl.ctrl.fuOpType)
476  XSDebug("out: rfWen=%d fpWen=%d isXSTrap=%d noSpecExec=%d isBlocked=%d flushPipe=%d isRVF=%d imm=%x\n",
477    io.deq.cf_ctrl.ctrl.rfWen, io.deq.cf_ctrl.ctrl.fpWen, io.deq.cf_ctrl.ctrl.isXSTrap,
478    io.deq.cf_ctrl.ctrl.noSpecExec, io.deq.cf_ctrl.ctrl.blockBackward, io.deq.cf_ctrl.ctrl.flushPipe,
479    io.deq.cf_ctrl.ctrl.isRVF, io.deq.cf_ctrl.ctrl.imm)
480  XSDebug("out: excepVec=%b intrVec=%b\n",
481    io.deq.cf_ctrl.cf.exceptionVec.asUInt, io.deq.cf_ctrl.cf.intrVec.asUInt)
482}
483