xinyangli
2824efad33
NJU-ProjectN/nemu eb63cf3568dbf4e0c3c6ef462e6ec685550fabbc Merge pull request #76 from rijuyuezhu/master
72 lines
2.3 KiB
C
72 lines
2.3 KiB
C
/***************************************************************************************
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* Copyright (c) 2014-2022 Zihao Yu, Nanjing University
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*
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* NEMU is licensed under Mulan PSL v2.
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* You can use this software according to the terms and conditions of the Mulan PSL v2.
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* You may obtain a copy of Mulan PSL v2 at:
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* http://license.coscl.org.cn/MulanPSL2
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*
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* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
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* EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
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* MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
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*
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* See the Mulan PSL v2 for more details.
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***************************************************************************************/
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#include "local-include/reg.h"
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#include <cpu/cpu.h>
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#include <cpu/ifetch.h>
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#include <cpu/decode.h>
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#define R(i) gpr(i)
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#define Mr vaddr_read
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#define Mw vaddr_write
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enum {
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TYPE_2RI12, TYPE_1RI20,
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TYPE_N, // none
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};
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#define src1R() do { *src1 = R(rj); } while (0)
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#define simm12() do { *imm = SEXT(BITS(i, 21, 10), 12); } while (0)
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#define simm20() do { *imm = SEXT(BITS(i, 24, 5), 20) << 12; } while (0)
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static void decode_operand(Decode *s, int *rd_, word_t *src1, word_t *src2, word_t *imm, int type) {
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uint32_t i = s->isa.inst.val;
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int rj = BITS(i, 9, 5);
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*rd_ = BITS(i, 4, 0);
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switch (type) {
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case TYPE_1RI20: simm20(); src1R(); break;
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case TYPE_2RI12: simm12(); src1R(); break;
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}
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}
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static int decode_exec(Decode *s) {
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int rd = 0;
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word_t src1 = 0, src2 = 0, imm = 0;
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s->dnpc = s->snpc;
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#define INSTPAT_INST(s) ((s)->isa.inst.val)
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#define INSTPAT_MATCH(s, name, type, ... /* execute body */ ) { \
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decode_operand(s, &rd, &src1, &src2, &imm, concat(TYPE_, type)); \
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__VA_ARGS__ ; \
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}
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INSTPAT_START();
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INSTPAT("0001110 ????? ????? ????? ????? ?????" , pcaddu12i, 1RI20 , R(rd) = s->pc + imm);
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INSTPAT("0010100010 ???????????? ????? ?????" , ld.w , 2RI12 , R(rd) = Mr(src1 + imm, 4));
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INSTPAT("0010100110 ???????????? ????? ?????" , st.w , 2RI12 , Mw(src1 + imm, 4, R(rd)));
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INSTPAT("0000 0000 0010 10100 ????? ????? ?????", break , N , NEMUTRAP(s->pc, R(4))); // R(4) is $a0
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INSTPAT("????????????????? ????? ????? ?????" , inv , N , INV(s->pc));
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INSTPAT_END();
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R(0) = 0; // reset $zero to 0
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return 0;
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}
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int isa_exec_once(Decode *s) {
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s->isa.inst.val = inst_fetch(&s->snpc, 4);
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return decode_exec(s);
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}
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