Register Pressure and Spills
Balancing reuse against occupancy.
Registers Are Precious
Registers are the fastest storage a thread has, but each SM holds only so many. How heavily a kernel uses them is called register pressure.
A Shared, Fixed Pool
Every resident thread draws from one register file per SM. The more registers each thread needs, the fewer threads can stay resident together.
All lessons in this course
- Instruction-Level Parallelism
- Loop Unrolling with #pragma unroll
- Vectorized Loads with float4
- Register Pressure and Spills