data flow analysis

programming A process to discover the dependencies between

different data items manipulated by a program. The order of

execution in a data driven language is determined solely by

the data dependencies. For example, given the equations

1. X = A + B

2. B = 2 + 2

3. A = 3 + 4

a data-flow analysis would find that 2 and 3 must be evaluated

before 1. Since there are no data dependencies between 2 and

3, they may be evaluated in any order, including in parallel.

This technique is implemented in hardware in some

pipelined processors with multiple functional units. It

allows instructions to be executed as soon as their inputs are

available, independent of the original program order.

(1996-05-13)