1. A method, in a data processing system, for effectively validating execution units within a processor, the method comprising: generating, by a processor, a branch test pattern for execution by an execution unit that is under validation testing; selecting, by the processor, an execution pattern from a set of execution patterns thereby forming a selected execution pattern; loading, by the processor, the selected execution pattern into a condition register; executing, by an execution unit, the branch test pattern based on the selected execution pattern in the condition register; responsive to the branch test pattern ending, comparing, by the processor, values output from the execution unit during execution of the branch test pattern to a set of expected results; responsive to a match of the comparison, repeating, by the processor, the process for each execution pattern in the set of execution patterns; and responsive to a match of the comparison for the execution patterns in the set of execution patterns, validating, by the processor, the execution unit.