From f9ae670d0563322506490e3fe7f2dae6d432e05f Mon Sep 17 00:00:00 2001 From: Mike Klein Date: Wed, 20 Jun 2018 14:05:05 -0400 Subject: add hello-opencl This is a little hello world for OpenCL. Change-Id: I9502407dab75694a19e97832bcfe33f47cbd97e9 Reviewed-on: https://skia-review.googlesource.com/136223 Commit-Queue: Allan MacKinnon Reviewed-by: Allan MacKinnon --- tools/hello-opencl.cpp | 118 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 118 insertions(+) create mode 100644 tools/hello-opencl.cpp (limited to 'tools/hello-opencl.cpp') diff --git a/tools/hello-opencl.cpp b/tools/hello-opencl.cpp new file mode 100644 index 0000000000..7e57f0b977 --- /dev/null +++ b/tools/hello-opencl.cpp @@ -0,0 +1,118 @@ +/* + * Copyright 2018 Google Inc. + * + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +// This is a simple OpenCL Hello World that tests you have a functioning OpenCL setup. + +#include +#include + +extern "C" { + #include "cl/assert_cl.h" // for cl(), cl_ok() macros + #include "cl/find_cl.h" // for clFindIdsByName +} + +int main(int argc, char** argv) { + // Find any OpenCL platform+device with these substrings. + const char* platform_match = argc > 1 ? argv[1] : ""; + const char* device_match = argc > 2 ? argv[2] : ""; + + cl_platform_id platform_id; + cl_device_id device_id; + + char device_name[256]; + size_t device_name_len; + + // clFindIdsByName will narrate what it's doing when this is set. + bool verbose = true; + + // The cl() macro prepends cl to its argument, calls it, and asserts that it succeeded, + // printing out the file, line, and somewhat readable version of the error code on failure. + // + // It's generally used to call OpenCL APIs, but here we've written clFindIdsByName to match + // the convention, as its error conditions are just going to be passed along from OpenCL. + cl(FindIdsByName(platform_match, device_match, + &platform_id, &device_id, + sizeof(device_name), device_name, &device_name_len, + verbose)); + + printf("picked %.*s\n", (int)device_name_len, device_name); + + // Allan's code is all C using OpenCL's C API, + // but we can mix that freely with the C++ API found in cl.hpp. + // cl_ok() comes in handy here, which is cl() without the extra cl- prefix. + + cl::Device device(device_id); + + std::string name, + vendor, + extensions; + cl_ok(device.getInfo(CL_DEVICE_NAME, &name)); + cl_ok(device.getInfo(CL_DEVICE_VENDOR, &vendor)); + cl_ok(device.getInfo(CL_DEVICE_EXTENSIONS, &extensions)); + + printf("name %s, vendor %s, extensions:\n%s\n", + name.c_str(), vendor.c_str(), extensions.c_str()); + + std::vector devices = { device }; + + // Some APIs can't return their cl_int error but might still fail, + // so they take a pointer. cl_ok() is really handy here too. + cl_int ok; + cl::Context ctx(devices, + nullptr/*optional cl_context_properties*/, + nullptr/*optional error reporting callback*/, + nullptr/*context arguement for error reporting callback*/, + &ok); + cl_ok(ok); + + cl::Program program(ctx, + "__kernel void mul(__global const float* a, " + " __global const float* b, " + " __global float* dst) {" + " int i = get_global_id(0); " + " dst[i] = a[i] * b[i]; " + "} ", + /*and build now*/true, + &ok); + cl_ok(ok); + + std::vector a,b,p; + for (int i = 0; i < 1000; i++) { + a.push_back(+i); + b.push_back(-i); + p.push_back( 0); + } + + cl::Buffer A(ctx, CL_MEM_READ_ONLY | CL_MEM_COPY_HOST_PTR , sizeof(float)*a.size(), a.data()), + B(ctx, CL_MEM_READ_ONLY | CL_MEM_COPY_HOST_PTR , sizeof(float)*b.size(), b.data()), + P(ctx, CL_MEM_WRITE_ONLY| CL_MEM_HOST_READ_ONLY, sizeof(float)*p.size()); + + cl::Kernel mul(program, "mul", &ok); + cl_ok(ok); + cl_ok(mul.setArg(0, A)); + cl_ok(mul.setArg(1, B)); + cl_ok(mul.setArg(2, P)); + + cl::CommandQueue queue(ctx, device); + + cl_ok(queue.enqueueNDRangeKernel(mul, cl::NDRange(0) /*offset*/ + , cl::NDRange(1000) /*size*/)); + + cl_ok(queue.enqueueReadBuffer(P, true/*block until read is done*/ + , 0 /*offset in bytes*/ + , sizeof(float)*p.size() /*size in bytes*/ + , p.data())); + + for (int i = 0; i < 1000; i++) { + if (p[i] != a[i]*b[i]) { + return 1; + } + } + + printf("OpenCL sez: %g x %g = %g\n", a[42], b[42], p[42]); + return 0; +} -- cgit v1.2.3