Killing Warp Divergence
Reindexing to keep warps busy.
Warps Run in Lockstep
A warp is 32 threads that execute the same instruction together. When their paths agree, the hardware runs at full speed.
What Divergence Costs
If threads in a warp take different branches, that is divergence. The hardware runs each path serially, leaving some lanes idle and wasting cycles.
All lessons in this course
- The Reduction Tree Idea
- Killing Warp Divergence
- Sequential Addressing
- Multi-Block Final Reduction