Write a program to evaluate the following expression using an accumulator machine: A = B + C * D * E + F 7m jun2006
Accumulator Architecture:
An accumulator is a specially designated register that supplies one instruction operand and receives the result. The instructions in such machines are normally one-address instructions. The popular architectures were IBM 7090, DEC PDP-8 etc.
Accumulator Architecture: Pros and Cons
- Implicit use of accumulator saves instruction bits.
- Result is ready for immediate reuse, but has to be saved in memory.
- More memory accesses required than stack.
Consider a program to do the expression:
A = B + C * D * E + F
Programs |
Comments |
LOAD C | Load C in AC |
MULT D | Multiply D in AC (i.e C * D) |
MULT E | Multiply E in AC (i.e C * D * E) |
ADD B | Add B in AC (i.e B + C * D * E) |
ADD F | Add F in AC (i.e B + C * D * E +F) |
STORE A | Store Result in A |