Techniques for reducing serialization in divergent control flow

Abstract

Techniques for executing shader programs with divergent control flow on a single instruction multiple data ('SIMD') processor are disclosed. These techniques includes detecting entry into a divergent section of a shader program and, for the work-items that enter the divergent section, placing a task entry into a task queue associated with the target of each work-item. The target is the destination, in code, of any particular work-item, and is also referred to as a code segment herein. The task queues store task entries for code segments generated by different (or the same) wavefronts. A command processor examines task lists and schedules wavefronts for execution by grouping together tasks in the same task list into wavefronts and launching those wavefronts. By grouping tasks from different wavefronts together for execution in the same front, serialization of execution is greatly reduced or eliminated.