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?

PUSH 4
PUSH 7
PUSH 8
ADD
PUSH 10
SUB
MUL

Answer 1

After performing the given stack operations, only the element -20 remains on the stack of the stack-oriented processor.

Step-by-step explanation:

The question involves a stack-oriented processor and the execution of stack operations including PUSH, POP, ADD, SUB, and MUL. Starting with an empty stack, the following operations are performed sequentially:

• PUSH 4: Stack now contains [4].
• PUSH 7: Stack now contains [7, 4].
• PUSH 8: Stack now contains [8, 7, 4].
• ADD: Pops the top two elements (8 and 7), adds them (15), and pushes the result: Stack now contains [15, 4].
• PUSH 10: Stack now contains [10, 15, 4].
• SUB: Pops the top two elements (10 and 15), subtracts them (-5), and pushes the result: Stack now contains [-5, 4].
• MUL: Pops the top two elements (-5 and 4), multiplies them (-20), and pushes the result: Stack now contains [-20].

After these instructions are executed, only the element -20 remains on the stack.