Slides - Par Lab

SIMD & Control Flow ¡ Nvidia GPU hardware handles control flow divergence and reconvergence § Write scalar SIMD code, the hardware schedules the SIMD execution § One caveat: __syncthreads() can’t appear in a divergent path ▪ This may cause programs to hang § Good performing code will try to keep the execution convergent within a warp ▪ Warp divergence only costs because of a finite instruction cache 35/73