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MIPS 指令集(共31条）
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助记符
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指令格式
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示例
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示例含义
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操作及其解释
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Bit #
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31..26
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25..21
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20..16
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15..11
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10..6
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5..0
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R-type
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op
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rs
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rt
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rd
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shamt
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func
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add
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000000
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rs
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rt
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rd
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00000
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100000
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add $1,$2,$3
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$1=$2+$3
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rd <- rs + rt ；其中rs＝$2，rt=$3, rd=$1
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addu
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000000
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rs
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rt
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rd
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00000
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100001
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addu $1,$2,$3
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$1=$2+$3
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rd <- rs + rt ；其中rs＝$2，rt=$3, rd=$1,无符号数
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sub
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000000
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rs
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rt
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rd
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00000
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100010
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sub $1,$2,$3
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$1=$2-$3
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rd <- rs - rt ；其中rs＝$2，rt=$3, rd=$1
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subu
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000000
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rs
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rt
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rd
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00000
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100011
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subu $1,$2,$3
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$1=$2-$3
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rd <- rs - rt ；其中rs＝$2，rt=$3, rd=$1,无符号数
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and
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000000
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rs
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rt
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rd
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00000
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100100
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and $1,$2,$3
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$1=$2 & $3
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rd <- rs & rt ；其中rs＝$2，rt=$3, rd=$1
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or
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000000
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rs
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rt
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rd
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00000
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100101
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or $1,$2,$3
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$1=$2 | $3
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rd <- rs | rt ；其中rs＝$2，rt=$3, rd=$1
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xor
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000000
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rs
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rt
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rd
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00000
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100110
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xor $1,$2,$3
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$1=$2 ^ $3
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rd <- rs xor rt ；其中rs＝$2，rt=$3, rd=$1(异或）
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nor
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000000
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rs
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rt
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rd
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00000
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100111
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nor $1,$2,$3
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$1=~($2 | $3)
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rd <- not(rs | rt) ；其中rs＝$2，rt=$3, rd=$1(或非）
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slt
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000000
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rs
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rt
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rd
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00000
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101010
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slt $1,$2,$3
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if($2<$3)
$1=1 else
$1=0
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if (rs < rt) rd=1 else rd=0 ；其中rs＝$2，rt=$3, rd=$1
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sltu
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000000
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rs
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rt
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rd
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00000
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101011
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sltu $1,$2,$3
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if($2<$3)
$1=1 else
$1=0
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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
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000000
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00000
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rt
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rd
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shamt
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000000
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sll $1,$2,10
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$1=$2<<10
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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
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000000
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00000
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rt
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rd
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shamt
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000010
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srl $1,$2,10
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$1=$2>>10
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rd <- rt >> shamt ；(logical) ，其中rt=$2, rd=$1
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sra
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000000
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00000
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rt
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rd
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shamt
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000011
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sra $1,$2,10
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$1=$2>>10
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rd <- rt >> shamt ；(arithmetic) 注意符号位保留
其中rt=$2, rd=$1
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sllv
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000000
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rs
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rt
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rd
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00000
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000100
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sllv $1,$2,$3
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$1=$2<<$3
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rd <- rt << rs ；其中rs＝$3，rt=$2, rd=$1
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srlv
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000000
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rs
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rt
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rd
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00000
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000110
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srlv $1,$2,$3
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$1=$2>>$3
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rd <- rt >> rs ；(logical)其中rs＝$3，rt=$2, rd=$1
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srav
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000000
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rs
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rt
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rd
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00000
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000111
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srav $1,$2,$3
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$1=$2>>$3
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rd <- rt >> rs ；(arithmetic) 注意符号位保留
其中rs＝$3，rt=$2, rd=$1
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jr
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000000
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rs
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00000
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00000
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00000
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001000
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jr $31
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goto $31
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PC <- rs
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I-type
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op
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rs
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rt
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immediate
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addi
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001000
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rs
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rt
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immediate
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addi $1,$2,100
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$1=$2+100
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rt <- rs + (sign-extend)immediate ；其中rt=$1,rs=$2
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addiu
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001001
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rs
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rt
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immediate
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addiu $1,$2,100
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$1=$2+100
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rt <- rs + (zero-extend)immediate ；其中rt=$1,rs=$2
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andi
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001100
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rs
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rt
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immediate
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andi $1,$2,10
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$1=$2 & 10
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rt <- rs & (zero-extend)immediate ；其中rt=$1,rs=$2
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ori
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001101
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rs
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rt
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immediate
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andi $1,$2,10
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$1=$2 | 10
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rt <- rs | (zero-extend)immediate ；其中rt=$1,rs=$2
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xori
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001110
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rs
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rt
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immediate
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andi $1,$2,10
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$1=$2 ^ 10
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rt <- rs xor (zero-extend)immediate ；其中rt=$1,rs=$2
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lui
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001111
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00000
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rt
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immediate
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lui $1,100
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$1=100*65536
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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
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100011
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rs
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rt
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immediate
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lw $1,10($2)
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$1=memory[$2
+10]
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rt <- memory[rs + (sign-extend)immediate] ；rt=$1,rs=$2
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sw
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101011
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rs
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rt
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immediate
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sw $1,10($2)
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memory[$2+10]
=$1
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memory[rs + (sign-extend)immediate] <- rt ；rt=$1,rs=$2
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beq
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000100
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rs
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rt
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immediate
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beq $1,$2,10
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if($1==$2)
goto PC+4+40
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if (rs == rt) PC <- PC+4 + (sign-extend)immediate<<2
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bne
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000101
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rs
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rt
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immediate
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bne $1,$2,10
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if($1!=$2)
goto PC+4+40
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if (rs != rt) PC <- PC+4 + (sign-extend)immediate<<2
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slti
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001010
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rs
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rt
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immediate
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slti $1,$2,10
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if($2<10)
$1=1 else
$1=0
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if (rs <(sign-extend)immediate) rt=1 else rt=0 ；
其中rs＝$2，rt=$1
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sltiu
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001011
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rs
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rt
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immediate
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sltiu $1,$2,10
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if($2<10)
$1=1 else
$1=0
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if (rs <(zero-extend)immediate) rt=1 else rt=0 ；
其中rs＝$2，rt=$1
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J-type
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op
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address
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j
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000010
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address
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j 10000
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goto 10000
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PC <- (PC+4)[31..28],address,0,0 ；address=10000/4
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jal
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000011
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address
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jal 10000
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$31<-PC+4;
goto 10000
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$31<-PC+4；PC <- (PC+4)[31..28],address,0,0
；address=10000/4
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注意：因为MIPS16只有16个16位的寄存器，所以JAL指令中$31改成$15, 所有立即数均无需扩展，LUI指令直接就是将立即数付给RT寄存器。
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