[Solved] Given the ARM assembly snippet:SUBS R0, R1, R2 BEQ equal_label BNE notequal_labelIf R1 equals R2, which label will the program jump to? | ARM Architecture

ARM Architecture - Control Flow Instructions

Given the ARM assembly snippet:

SUBS R0, R1, R2
BEQ equal_label
BNE notequal_label

If R1 equals R2, which label will the program jump to?

Aequal_label

Bnotequal_label

CNo jump, continue sequentially

DUndefined behavior

Step-by-Step Solution

Solution:

Step 1: Understand the SUBS instruction effect on flags
SUBS subtracts R2 from R1, updates flags including zero flag if result is zero.
Step 2: Check condition when R1 equals R2
If R1 equals R2, subtraction result is zero, so zero flag is set.
Step 3: Determine which branch executes
BEQ branches if zero flag set, so program jumps to equal_label.
Final Answer:
equal_label -> Option A
Quick Check:
Equal inputs set zero flag, BEQ jumps [OK]

Quick Trick: If subtraction zero, BEQ jumps to equal_label [OK]

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