31条MIPS指令集
| 助记符 | 指令格式 | 示例 | 示例含义 | 操作及其解释 | ||||||
| Bit # | 31..26 | 25..21 | 20..16 | 15..11 | 10..6 | 5..0 | ||||
| R-type | op | rs | rt | rd | shamt | func | ||||
| add | 000000 | rs | rt | rd | 00000 | 100000 | add $1,$2,$3 | $1=$2+$3 | rd <- rs + rt 其中rs＝$2，rt=$3, rd=$1 |
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| addu | 000000 | rs | rt | rd | 00000 | 100001 | addu $1,$2,$3 | $1=$2+$3 | rd <- rs + rt 其中rs＝$2，rt=$3, rd=$1,无符号数 |
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| sub | 000000 | rs | rt | rd | 00000 | 100010 | sub $1,$2,$3 | $1=$2-$3 | rd <- rs - rt 其中rs＝$2，rt=$3, rd=$1 |
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| subu | 000000 | rs | rt | rd | 00000 | 100011 | subu $1,$2,$3 | $1=$2-$3 | rd <- rs - rt 其中rs＝$2，rt=$3, rd=$1,无符号数 |
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| and | 000000 | rs | rt | rd | 00000 | 100100 | and $1,$2,$3 | $1=$2 & $3 | rd <- rs & rt 其中rs＝$2，rt=$3, rd=$1 |
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| or | 000000 | rs | rt | rd | 00000 | 100101 | or $1,$2,$3 | $1=$2 | $3 | rd <- rs | rt 其中rs＝$2，rt=$3, rd=$1 |
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| xor | 000000 | rs | rt | rd | 00000 | 100110 | xor $1,$2,$3 | $1=$2 ^ $3 | rd <- rs xor rt 其中rs＝$2，rt=$3, rd=$1(异或） |
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| nor | 000000 | rs | rt | rd | 00000 | 100111 | nor $1,$2,$3 | $1=~($2 | $3) | rd <- not(rs | rt) 其中rs＝$2，rt=$3, rd=$1(或非） |
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| slt | 000000 | rs | rt | rd | 00000 | 101010 | slt $1,$2,$3 | if($2<$3) $1=1 else $1=0 |
if (rs < rt) rd=1 else rd=0 其中rs＝$2，rt=$3, rd=$1 |
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| sltu | 000000 | rs | rt | rd | 00000 | 101011 | sltu $1,$2,$3 | if($2<$3) $1=1 else $1=0 |
if (rs < rt) rd=1 else rd=0 其中rs＝$2，rt=$3, rd=$1 (无符号数） |
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| sll | 000000 | 00000 | rt | rd | shamt | 000000 | sll $1,$2,10 | $1=$2<<10 | rd <- rt << shamt shamt存放移位的位数,也就是指令中的立即数 其中rt=$2, rd=$1 |
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| srl | 000000 | 00000 | rt | rd | shamt | 000010 | srl $1,$2,10 | $1=$2>>10 | rd <- rt >> shamt (logical) 其中rt=$2, rd=$1 |
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| sra | 000000 | 00000 | rt | rd | shamt | 000011 | sra $1,$2,10 | $1=$2>>10 | rd <- rt >> shamt (arithmetic) 注意符号位保留 其中rt=$2, rd=$1 |
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| sllv | 000000 | rs | rt | rd | 00000 | 000100 | sllv $1,$2,$3 | $1=$2<<$3 | rd <- rt << rs 其中rs＝$3，rt=$2, rd=$1 |
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| srlv | 000000 | rs | rt | rd | 00000 | 000110 | srlv $1,$2,$3 | $1=$2>>$3 | rd <- rt >> rs (logical) 其中rs＝$3，rt=$2, rd=$1 |
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| srav | 000000 | rs | rt | rd | 00000 | 000111 | srav $1,$2,$3 | $1=$2>>$3 | rd <- rt >> rs (arithmetic) 注意符号位保留 其中rs＝$3，rt=$2, rd=$1 |
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| jr | 000000 | rs | 00000 | 00000 | 00000 | 001000 | jr $31 | goto $31 | PC <- rs | |
| I-type | op | rs | rt | immediate | immediate | immediate | ||||
| addi | 001000 | rs | rt | immediate | immediate | immediate | addi $1,$2,100 | $1=$2+100 | rt <- rs + (sign-extend)immediate 其中rt=$1,rs=$2 |
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| addiu | 001001 | rs | rt | immediate | immediate | immediate | addiu $1,$2,100 | $1=$2+100 | rt <- rs + (zero-extend)immediate 其中rt=$1,rs=$2 |
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| andi | 001100 | rs | rt | immediate | immediate | immediate | andi $1,$2,10 | $1=$2 & 10 | rt <- rs & (zero-extend)immediate 其中rt=$1,rs=$2 |
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| ori | 001101 | rs | rt | immediate | immediate | immediate | andi $1,$2,10 | $1=$2 | 10 | rt <- rs | (zero-extend)immediate 其中rt=$1,rs=$2 |
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| xori | 001110 | rs | rt | immediate | immediate | immediate | andi $1,$2,10 | $1=$2 ^ 10 | rt <- rs xor (zero-extend)immediate 其中rt=$1,rs=$2 |
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| lui | 001111 | rs | rt | immediate | immediate | immediate | lui $1,100 | $1=100*65536 | rt <- immediate*65536 将16位立即数放到目标寄存器高16位，目标寄存器的低16位填0 |
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| lw | 100011 | rs | rt | immediate | immediate | immediate | lw $1,10($2) | $1=memory[$2+10] | rt <- memory[rs + (sign-extend)immediate] rt=$1,rs=$2 |
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| sw | 101011 | rs | rt | immediate | immediate | immediate | sw $1,10($2) | memory[$2+10]=$1 | memory[rs + (sign-extend)immediate] <- rt rt=$1,rs=$2 |
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| beq | 000100 | rs | rt | immediate | immediate | immediate | beq $1,$2,10 | if($1==$2) goto PC+4+40 |
if (rs == rt) PC <- PC+4 + (sign-extend)immediate<<2 |
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| bne | 000101 | rs | rt | immediate | immediate | immediate | bne $1,$2,10 | if($1!=$2) goto PC+4+40 |
if (rs != rt) PC <- PC+4 + (sign-extend)immediate<<2 |
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| slti | 001010 | rs | rt | immediate | immediate | immediate | slti $1,$2,10 | if($2<10) $1=1 else $1=0 |
if (rs <(sign-extend)immediate) rt=1 else rt=0 其中rs＝$2，rt=$1 |
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| sltiu | 001011 | rs | rt | immediate | immediate | immediate | sltiu $1,$2,10 | if($2<10) $1=1 else $1=0 |
if (rs <(zero-extend)immediate) rt=1 else rt=0 其中rs＝$2，rt=$1 |
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| J-type | op | address | address | address | address | address | ||||
| j | 000010 | address | address | address | address | address | j 10000 | goto 10000 | PC <- (PC+4)[31..28] address,0,0 address=10000/4 |
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| jal | 000011 | address | address | address | address | address | jal 10000 | $31<-PC+4; goto 10000 |
$31<-PC+4 PC <- (PC+4)[31..28] address,0,0 address=10000/4 |
