Questions about MIPS Codes

Question

How to write the following into MIPS instructions?

• $t0=$t1
• if ($t6<$t7) go to Label.

Answer 1

$t0 is not reserved for zero. $t0 is a temporary register that can store any value. The register $zero is reserved/hard-wired to zero. We would want to "branch" to "Label" if $t6 is "less than" $t7, so use the branch on less than instruction blt. The code would look like:

add $t0,$zero,$t1
blt $t6,$t7,Label

Answer 2

your following rubbish:

$t0=$t1

if ($t6 less than $t7) go to Label

would be converted to MIPS like:

move $t0,$t1 # or use instruction instead (add $t0,$zero,$t1)|(addi $t0,$t1,0)

slt $t2,$t6,$t7 # if $t6less than $t7 set $t2=1

bgtz $t2,foo # if $t2=0 goto foo, and foo is the label that you want to move to

Answer 3

Assuming that the registers are already loaded with the right data.

So for $t2 = $t3, adding $t3 to register zero and storing it in $t2 will work so this is how it would look like :

add $t2,$t3,$t0 - assuming $t0 is reserved for zero like most versions of mips.

for if $t4, we need a branch statement, not sure what you want to compare it to, but look at this guide - should give enough instructions about how to write it.