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saxpy_fp32

The saxpy kernel, as the compiler built it for sm_75 at commit 5a313cd: BLOCK = 16, N = 60; a grid of 4 CTAs, 256 threads each.

@autotune(BLOCK in [16, 8192])
kernel saxpy(x: tensor<f32>[N], y: tensor<f32>[N], out: tensor<f32>[N], alpha: f32) {
  let base = ctx.block.x * BLOCK
  out[base :+ BLOCK] = alpha * x[base :+ BLOCK] + y[base :+ BLOCK]
}

examples/saxpy_fp32.ph

The saxpy kernel, stepped through as the compiler built it for sm_75A 4 grid of CTAs with 256 threads each. The drawing shows the tensors x, y, out in global memory with the picked CTA's current boxes, shared memory as a byte ruler of 128 bytes with each buffer at its planned offset, the barriers kept and elided, and how the CTA's threads and warp 0's lanes take part. The readout below describes each step.

CTA 0
  • global memory
  • shared memory
  • threads and lanes
  • extra 128-byte lines, masked elements

Keys: left and right arrows step, space plays and pauses; play runs on from the last step to the first. The address of this page keeps the step, the CTA and the zoom.