GATE CSE 2001 | Question: 2.9

Question

Which is the most appropriate match for the items in the first column with the items in the second column:$$\begin{array}{|cl|cl|} \hline \text{X.} &\text{Indirect Addressing} &  \text{I.} &\text{Array implementation} \\\hline
\text{Y.} &\text{Indexed Addressing} & \text{II.} &\text{Writing relocatable code}  \\\hline 
\text {Z.} &\text{Base Register Addressing}  & \text{III.} &\text{Passing array as parameter}\\\hline  \end{array}$$

• A. (X, III), (Y, I), (Z, II)
• B. (X, II), (Y, III), (Z, I)
• C. (X, III), (Y, II), (Z, I)
• D. (X, I), (Y, III), (Z, II)

Comments

• Indirect Addressing: Matches Passing array as parameter (uses pointers).
• Indexed Addressing: Matches Array implementation (accesses array elements).
• Base Register Addressing: Matches Writing relocatable code (adjusts addresses with a base register).

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Relative, Indexed, Base Register all these three are relocatable code.

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indirect addressing mode -- passing array as an parameter

indexed addressing mode -- array implementation

base register relocatble mode --- writing relocatable code

Answer 1

(A) is the answer.

Array implementation can use Indexed addressing.

While passing array as parameter we can make use of a pointer (as in (C)) and hence can use Indirect addressing.

Base Register addressing can be used to write relocatable code by changing the content of Base Register.

Comments

Thanks@Arjun sir

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Can I say also that, passing array as parameter is also Indexed addressing, because in indexed addressing we're passing base address of the array.

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Yes, that’s what we do while using pass by reference.

Answer 2

In Indirect Addressing mode, Instruction contain address of Effective Address(M-->EA-->operand), So it is used for pointer implementation.

In Index Addressing mode used for array implementation because we can access array by changing the index value in instruction.

For program relocation best addressing mode is relative addressing mode, but we can implement relocation using Base Addressing mode by changing value in Base