Overview

Forward Branch Probability Enhancement addresses a common weakness in random instruction generation for processor verification: purely random register values are very unlikely to satisfy a forward branch condition. For example, if a forward BEQ compares two independently randomized 32-bit registers, the equality condition is extremely unlikely, so execution will usually fall through and the branch-condition evaluation logic may receive poor coverage.

The technique uses constrained instruction scenarios to make the branch outcome more useful for verification. Instead of relying on fully random operand values, the generated instruction sequence constrains the operation immediately before a forward branch so that it prepares the compared registers with a small, randomized relationship.