Question

Assume a stack-oriented processor that includes the stack operations PUSH and POP. Arithmetic operations automatically involve the top one or two stack elements. Begin with an empty stack. What stack elements remain after the following instructions are executed?

a. PUSH 9
b. PUSH 6
c. PUSH 3
d. ADD
e. PUSH 2
f. SUB
g. MUL

Answer 1

After executing the sequence of stack operations, the final element remaining on the stack is the number 63. Therefore, the correct answer option is a)

Step-by-step explanation:

The subject in question pertains to a stack-oriented processor and the behavior of stack operations, including PUSH and POP, with a focus on executing a sequence of commands to identify the elements remaining on the stack. Here is the sequence with explanations:

• PUSH 9 - Places the number 9 on the top of the stack.
• PUSH 6 - Places the number 6 on top of the stack, above the 9.
• PUSH 3 - Places the number 3 on top of the stack, above the 6.
• ADD - Pops the top two numbers (which are 3 and 6), adds them (resulting in 9), and pushes the result back on the stack.
• PUSH 2 - Places the number 2 on top of the stack, above the result of the addition (9).
• SUB - Pops the top two numbers (which are 2 and 9), subtracts them (2 from 9, resulting in 7), and pushes the result back on the stack.
• MUL - Pops the top two numbers (which are now 7 and the earlier 9), multiplies them (resulting in 63), and pushes the result back on the stack.

After these instructions are executed on an initially empty stack, the element remaining on the stack is 63.