|
MIPS 指令集(共31条）
|
|
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
|
|
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
|
|
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
|
|
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
|
|
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
|
|
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
|
|
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）
|
|
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）
|
|
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
|
|
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）
|
|
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
|
|
srl
|
000000
|
00000
|
rt
|
rd
|
shamt
|
000010
|
srl $1,$2,10
|
$1=$2>>10
|
rd <- rt >> shamt ；(logical) ，其中rt=$2, rd=$1
|
|
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
|
|
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
|
|
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
|
|
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
|
|
jr
|
000000
|
rs
|
00000
|
00000
|
00000
|
001000
|
jr $31
|
goto $31
|
PC <- rs
|
|
I-type
|
op
|
rs
|
rt
|
immediate
|
|
|
|
|
addi
|
001000
|
rs
|
rt
|
immediate
|
addi $1,$2,100
|
$1=$2+100
|
rt <- rs + (sign-extend)immediate ；其中rt=$1,rs=$2
|
|
addiu
|
001001
|
rs
|
rt
|
immediate
|
addiu $1,$2,100
|
$1=$2+100
|
rt <- rs + (zero-extend)immediate ；其中rt=$1,rs=$2
|
|
andi
|
001100
|
rs
|
rt
|
immediate
|
andi $1,$2,10
|
$1=$2 & 10
|
rt <- rs & (zero-extend)immediate ；其中rt=$1,rs=$2
|
|
ori
|
001101
|
rs
|
rt
|
immediate
|
andi $1,$2,10
|
$1=$2 | 10
|
rt <- rs | (zero-extend)immediate ；其中rt=$1,rs=$2
|
|
xori
|
001110
|
rs
|
rt
|
immediate
|
andi $1,$2,10
|
$1=$2 ^ 10
|
rt <- rs xor (zero-extend)immediate ；其中rt=$1,rs=$2
|
|
lui
|
001111
|
00000
|
rt
|
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
|
|
lw
|
100011
|
rs
|
rt
|
immediate
|
lw $1,10($2)
|
$1=memory[$2
+10]
|
rt <- memory[rs + (sign-extend)immediate] ；rt=$1,rs=$2
|
|
sw
|
101011
|
rs
|
rt
|
immediate
|
sw $1,10($2)
|
memory[$2+10]
=$1
|
memory[rs + (sign-extend)immediate] <- rt ；rt=$1,rs=$2
|
|
beq
|
000100
|
rs
|
rt
|
immediate
|
beq $1,$2,10
|
if($1==$2)
goto PC+4+40
|
if (rs == rt) PC <- PC+4 + (sign-extend)immediate<<2
|
|
bne
|
000101
|
rs
|
rt
|
immediate
|
bne $1,$2,10
|
if($1!=$2)
goto PC+4+40
|
if (rs != rt) PC <- PC+4 + (sign-extend)immediate<<2
|
|
slti
|
001010
|
rs
|
rt
|
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
|
|
sltiu
|
001011
|
rs
|
rt
|
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
|
|
J-type
|
op
|
address
|
|
|
|
|
j
|
000010
|
address
|
j 10000
|
goto 10000
|
PC <- (PC+4)[31..28],address,0,0 ；address=10000/4
|
|
jal
|
000011
|
address
|
jal 10000
|
$31<-PC+4;
goto 10000
|
$31<-PC+4；PC <- (PC+4)[31..28],address,0,0
；address=10000/4
|
|
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。 |