Tail Duplication

Tail duplication is the technique of duplicating a basic block so that the diamond pattern is changed into a tree. Besides the instruction scheduling advantages, this technique is of particular interest to Contech for reducing instrumentation costs. The immediate benefit is removing the overhead of a basic block store / instrumentation complete. Of greater interest is whether the two blocks use a common set of memory addresses. If so, the Redundant Memory Address Calculation support will further elide storing these memory operations.

The initial work is in place. Further testing will be required to verify its efficacy or other improvements.

Suggestion is to split blocks to create a partial block that meets the requirements and would provide benefit when tail duplication is applied.