Explain the following with the help of a suitable diagram or an example: – Evaluation stack architecture 5m Dec2005

By | October 28, 2014

Explain the following with the help of a suitable diagram or an example. 

Evaluation stack architecture 5m Dec2005

A stack is a data structure that implements Last-In-First-Out (LIFO) access policy. You could add an entry of data (or value) to the stack with a PUSH (value) Function and remove an entry of data (or value) from the stack with a POP ( ) Function.

No explicit operands are used in ALU instructions, but one operand in PUSH (value) as parameter to be pushed on to the stack and In POP ( ) as return value to be popped from the stack.

Examples of such computers are Burroughs B5500/6500, HP 3000/70 etc.

 

On a stack machine “C = A + B” might be implemented as:

 

PUSH A
 
PUSH B
 
ADD // operator POP operand and PUSH result  (implicit on top of stack)
 
POP C

 

 

Stack Architecture: Pros and Cons

  •  Small instructions (does not need many bits to specify the operation).
  •  Compiler is easy to write.
  •  Lots of memory accesses required – everything that is not on the stack is in memory.

Thus, the result of which the machine performance is poor.