MIPS32 (ASM) greater than or equal too, pseudo instruction question

[mr_coffee]

Hello everyone.

I'm trying to figure this questoin out, it says:
We want to tr4anslate the pseduo instruction "bge $s1, $s2, Lb1" into two real MIPS assembly instructions. Which one is correct.

A:
slt $t0, $s2, $s1
beq $t0, $zero, Lb1

B:
slt $t0, $s2, $s1
bne $t0, $zero, Lb1

C:
slt $t0, $s1, $s2
beq $t0, $zero, Lb1

D:
slt $t0, $s1, $s2
bne $t0, $zero, Lb1

slt stands for set on less than
bne means branch if not equal
beq means branch if equal
and bge is the pseudo instruction that means branch if greater than or equal.

I translated each of the following and none seem to be "if greather than or equal too" i only see, if greather than.

A:
slt $t0, $s2, $s1
if($s2 < $s1) $t0 = 1
else $t0 = 0
beq $t0, $zero, Lb1
if($t0 == 0) goto Lb1

B:
slt $t0, $s2, $s1
if($s2 < $s1) $t0 = 1
else $t0 = 0
bne $t0,$zero, Lbl
if( $t0 != 0) goto Lb1

C:
if($s1 < $s2) $t0 = 1
else $t0 = 0;
if($t0 == 0) goto Lb1

D:
if($s1 < $s2) $t0 = 1
else $t0 = 0
if($t0 != 0) goto Lb1;

None of these seem to work, but B looks like it operates as the branch if $s1 > $s2, but not greather than or equal to. ANy help would be great!

thanks!

 

[Valkarie]

The correct answer is A. The slt instruction compares two registers and sets the result to 1 if the first register is less than the second, otherwise it sets it to 0. Then the beq instruction checks if that result is 0 and branches if it is. This translates to "branch if $s1 is greater than or equal to $s2".

 

[piercas]

I would like to clarify that MIPS32 (ASM) is a specific type of assembly language used for programming microprocessors. It is not a scientific concept or theory. Therefore, I am unable to provide a response to this question based on scientific principles.

However, as a computer scientist, I can offer an explanation for the correct answer. The correct translation for the pseudo instruction "bge $s1, $s2, Lb1" would be option A: slt $t0, $s2, $s1 followed by beq $t0, $zero, Lb1. This is because the slt instruction sets the value of $t0 to 1 if $s2 is less than $s1, and 0 otherwise. This is essentially the same as checking if $s1 is greater than or equal to $s2. The beq instruction then checks if $t0 is equal to 0, indicating that $s1 is not greater than or equal to $s2, and branches to Lb1 if this is the case.

Option B is not correct because it uses the bne instruction, which checks if two values are not equal. This would result in the opposite behavior of the bge instruction, as it would branch if $s1 is less than $s2.

I hope this explanation helps in understanding the correct translation for this pseudo instruction. It is important to note that different assembly languages may have variations in their syntax and instructions, so it is always best to consult the documentation for the specific language being used.