Add pnpoly cupy example

Author: bouweandela

examples/cuda/pnpoly_cupy.py

@@ -0,0 +1,90 @@
+#!/usr/bin/env python
+""" Point-in-Polygon host/device code tuner
+
+This program is used for auto-tuning the host and device code of a CUDA program
+for computing the point-in-polygon problem for very large datasets and large
+polygons.
+
+The time measurements used as a basis for tuning include the time spent on
+data transfers between host and device memory. The host code uses device mapped
+host memory to overlap communication between host and device with kernel
+execution on the GPU. Because each input is read only once and each output
+is written only once, this implementation almost fully overlaps all
+communication and the kernel execution time dominates the total execution time.
+
+The code has the option to precompute all polygon line slopes on the CPU and
+reuse those results on the GPU, instead of recomputing them on the GPU all
+the time. The time spent on precomputing these values on the CPU is also
+taken into account by the time measurement in the code.
+
+This code was written for use with the Kernel Tuner. See:
+     https://github.com/benvanwerkhoven/kernel_tuner
+
+Author: Ben van Werkhoven <[email protected]>
+"""
+from collections import OrderedDict
+import json
+import logging
+
+import cupy as cp
+import cupyx as cpx
+import kernel_tuner
+import numpy
+
+
+def allocator(size: int) -> cp.cuda.PinnedMemoryPointer:
+    """Allocate context-portable device mapped host memory."""
+    flags = cp.cuda.runtime.hostAllocPortable | cp.cuda.runtime.hostAllocMapped
+    mem = cp.cuda.PinnedMemory(size, flags=flags)
+    return cp.cuda.PinnedMemoryPointer(mem, offset=0)
+
+
+def tune():
+
+    #set the number of points and the number of vertices
+    size = numpy.int32(2e7)
+    problem_size = (size, 1)
+    vertices = 600
+
+    #allocate context-portable device mapped host memory
+    cp.cuda.set_pinned_memory_allocator(allocator)
+
+    #generate input data
+    points = cpx.empty_pinned(shape=(2*size,), dtype=numpy.float32)
+    points[:] = numpy.random.randn(2*size).astype(numpy.float32)
+
+    bitmap = cpx.zeros_pinned(shape=(size,), dtype=numpy.int32)
+    #as test input we use a circle with radius 1 as polygon and
+    #a large set of normally distributed points around 0,0
+    vertex_seeds = numpy.sort(numpy.random.rand(vertices)*2.0*numpy.pi)[::-1]
+    vertex_x = numpy.cos(vertex_seeds)
+    vertex_y = numpy.sin(vertex_seeds)
+    vertex_xy = cpx.empty_pinned(shape=(2*vertices,), dtype=numpy.float32)
+    vertex_xy[:] = numpy.array( list(zip(vertex_x, vertex_y)) ).astype(numpy.float32).ravel()
+
+    #kernel arguments
+    args = [bitmap, points, vertex_xy, size]
+
+    #setup tunable parameters
+    tune_params = OrderedDict()
+    tune_params["block_size_x"] = [32*i for i in range(1,32)]  #multiple of 32
+    tune_params["tile_size"] = [1] + [2*i for i in range(1,11)]
+    tune_params["between_method"] = [0, 1, 2, 3]
+    tune_params["use_precomputed_slopes"] = [0, 1]
+    tune_params["use_method"] = [0, 1]
+
+    #tell the Kernel Tuner how to compute the grid dimensions from the problem_size
+    grid_div_x = ["block_size_x", "tile_size"]
+
+    #start tuning
+    results = kernel_tuner.tune_kernel("cn_pnpoly_host", ['pnpoly_host.cu', 'pnpoly.cu'],
+        problem_size, args, tune_params,
+        grid_div_x=grid_div_x, lang="C", compiler_options=["-arch=sm_52"], verbose=True, log=logging.DEBUG)
+
+    return results
+
+
+if __name__ == "__main__":
+    results = tune()
+    with open("pnpoly.json", 'w') as fp:
+        json.dump(results, fp)