1. 17 Apr, 2022 1 commit
    • Paul Fultz II's avatar
      Reduce with runtime compilation (#1150) · f9a5b81e
      Paul Fultz II authored
      There is significant improvement on larger tensors with half almost 50% faster:
      
      lens: [1024, 384, 768]
      gpu::code_object[code_object=13832,symbol_name=kernel,global=39321600,local=256,]: 1.16685ms
      gpu::reduce_sum[axes={2}]: 1.73126ms
      Also for non-trivial layouts this can sometimes be over 2x faster:
      
      lens: [64, 1024, 768, 4]
      gpu::code_object[code_object=13832,symbol_name=kernel,global=39321600,local=256,]: 1.1706ms
      gpu::reduce_sum[axes={1}]: 2.63375ms
      Of course if the stride becomes larger this speed improvement diminishes due to poor memory access patterns. A lane_reduce instead of a block_reduce is needed for such type of kernels. I plan to address that in a future PR.
      
      Finally, this also includes a MIGRAPHX_GPU_DUMP_ASM env variable which will print out the assembly when the kernel compiles.
      f9a5b81e