Write a program to evaluate the following expression using an accumulator machine: A = B + C * D * E + F 7m jun2006
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
|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|