MIPS Assembly

Questions Is it correct to write this instruction? add $s0, $s1, $s2, $s3 No. Can only take two for add, produce one

Questions Is it correct to write this instruction? add $s0, $s0, $s0 Yes

Questions How to use only one instruction to set $t0 to 0? Add $t0, $0, $0

Questions Is it correct to write this instruction? lw $s0, 100($s0) Yes

Questions Is it correct to write this instruction? lw $s0, $s1($s0) No. The number must be a constant

Questions Is it correct to write this instruction? add $s0, 100($s1), $s2 No. The two numbers to be added must be registers, not from memory

Questions Suppose memory at address 1000 to 1028 are storing 1,2,…,8 (in each 4 bytes). Suppose $t0 is 1000. What will be in $t0 after this instruction? lw $t0, 16($t0) 5

Exercise Suppose we have the address of A[i] in $t0, where A is an integer array. Write instructions to swap A[i] and A[i+1]. lw $t1, 0(t0) lw $t2, 4(t0) sw $t2, 0(t0) sw $t1, 4(t0)

Processor Memory Address t1 100 Assume the values are 100 and 101 100 t0 t2 xxxxxxxxxx 101 t0+4 lw $t1, 0(t0) lw $t2, 4(t0) sw $t2, 0(t0) sw $t1, 4(t0) t1 100 100 t0 t2 101 101 t0+4 t1 100 101 t0 t2 101 101 t0+4 t1 100 101 t0 t2 101 100 t0+4