Warp-Level Primitives
Independent Thread Scheduling explained why lockstep-dependent, volatile-based tricks for exchanging data within a warp no longer work, and why the fix is a family of intrinsics that carry explicit synchronization and an explicit participant mask. This page is that family: the shuffle intrinsics for moving values directly between lanes' registers, the vote intrinsics for asking a yes/no question of the whole warp, and the canonical reduction pattern built from them.