Question

Question:

Write down the corresponding MIPS machine language of the following assembly language code.

lw $S0, 64($S1)

add $t0,$S0,$S1

sub $t1,$S3,$S4

sw $t1,100($S1)

addi $S4,$S6,100

Answer 1

The machine code of mips instruction is of 32 bit. The converstions and machine codes are as below

1) lw $S0, 64($S1)

Syntax:	lw $t, offset($s)
Encoding:	1000 11ss ssst tttt iiii iiii iiii iiii

$s = $S1 = 17 = 10001

$t = $S0 = 16 = 10000

Offset = 64 = 0000000001000000

Machine code = 1000 1110 0011 0000 0000 0000 0100 0000 = 0x8E300040

So the machine code according to above is 0x8E300040

2) add $t0,$S0,$S1

Syntax:	add $d, $s, $t
Encoding:	0000 00ss ssst tttt dddd d000 0010 0000

$s = $S0 = 16 = 10000

$t = $S1 = 17 = 10001

$d = $t0 = 8 = 01000

Machine code = 0000 0010 0001 0001 0100 0000 0010 0000 = 0x02114020

So the machine code according to above is 0x02114020

3) sub $t1,$S3,$S4

Syntax:	sub $d, $s, $t
Encoding:	0000 00ss ssst tttt dddd d000 0010 0010

$s = $S3 = 19 = 10011

$t = $S4 = 20 = 10100

$d = $t1 = 9 = 01001

Machine code = 0000 0010 0111 0100 0100 1000 0010 0010 = 0x02744822

So the machine code according to above is 0x02744822

4) sw $t1,100($S1)

Syntax:	sw $t, offset($s)
Encoding:	1010 11ss ssst tttt iiii iiii iiii iiii

$s = $S1 = 17 = 10001

$t = $t1 = 19 = 01001

Offset = 100 = 0000000001100100

Machine code = 1010 1110 0010 1001 0000 0000 0110 0100 = 0xAE290064

So the machine code according to above is 0xAE290064

5) addi $S4,$S6,100

Syntax:	addi $t, $s, imm
Encoding:	0010 00ss ssst tttt iiii iiii iiii iiii

$s = $S6 = 22 = 10110

$t = $S4 = 20 = 10100

Offset = 100 = 0000000001100100

Machine code = 0010 0010 1101 0100 0000 0000 0110 0100 = 0x22D40064

So the machine code according to above is 0x22D40064