std::vector<size_t>
kernel::optimal_block_size(const command_queue &q,
const std::vector<size_t> &grid_size) const {
return factor::find_grid_optimal_factor<size_t>(
q.device().max_threads_per_block(), q.device().max_block_size(),
grid_size);
}
/// Select best launch configuration for the given shared memory requirements.
void config(const command_queue &q, std::function<size_t(size_t)> smem) {
// Select workgroup size that would fit into the device.
size_t ws = q.device().max_threads_per_block() / 2;
size_t max_ws = max_threads_per_block(q);
size_t max_smem = max_shared_memory_per_block(q);
// Reduce workgroup size until it satisfies resource requirements:
while( (ws > max_ws) || (smem(ws) > max_smem) )
ws /= 2;
config(num_workgroups(q), ws);
}
void
kernel::launch(command_queue &q,
const std::vector<size_t> &grid_offset,
const std::vector<size_t> &grid_size,
const std::vector<size_t> &block_size) {
const auto m = program().build(q.device()).binary;
const auto reduced_grid_size =
map(divides(), grid_size, block_size);
void *st = exec.bind(&q, grid_offset);
struct pipe_grid_info info = {};
// The handles are created during exec_context::bind(), so we need make
// sure to call exec_context::bind() before retrieving them.
std::vector<uint32_t *> g_handles = map([&](size_t h) {
return (uint32_t *)&exec.input[h];
}, exec.g_handles);
q.pipe->bind_compute_state(q.pipe, st);
q.pipe->bind_sampler_states(q.pipe, PIPE_SHADER_COMPUTE,
0, exec.samplers.size(),
exec.samplers.data());
q.pipe->set_sampler_views(q.pipe, PIPE_SHADER_COMPUTE, 0,
exec.sviews.size(), exec.sviews.data());
q.pipe->set_compute_resources(q.pipe, 0, exec.resources.size(),
exec.resources.data());
q.pipe->set_global_binding(q.pipe, 0, exec.g_buffers.size(),
exec.g_buffers.data(), g_handles.data());
// Fill information for the launch_grid() call.
info.work_dim = grid_size.size();
copy(pad_vector(q, block_size, 1), info.block);
copy(pad_vector(q, reduced_grid_size, 1), info.grid);
info.pc = find(name_equals(_name), m.syms).offset;
info.input = exec.input.data();
q.pipe->launch_grid(q.pipe, &info);
q.pipe->set_global_binding(q.pipe, 0, exec.g_buffers.size(), NULL, NULL);
q.pipe->set_compute_resources(q.pipe, 0, exec.resources.size(), NULL);
q.pipe->set_sampler_views(q.pipe, PIPE_SHADER_COMPUTE, 0,
exec.sviews.size(), NULL);
q.pipe->bind_sampler_states(q.pipe, PIPE_SHADER_COMPUTE, 0,
exec.samplers.size(), NULL);
q.pipe->memory_barrier(q.pipe, PIPE_BARRIER_GLOBAL_BUFFER);
exec.unbind();
}
void
kernel::launch(command_queue &q,
const std::vector<size_t> &grid_offset,
const std::vector<size_t> &grid_size,
const std::vector<size_t> &block_size) {
const auto m = program().binary(q.device());
const auto reduced_grid_size =
map(divides(), grid_size, block_size);
void *st = exec.bind(&q, grid_offset);
// The handles are created during exec_context::bind(), so we need make
// sure to call exec_context::bind() before retrieving them.
std::vector<uint32_t *> g_handles = map([&](size_t h) {
return (uint32_t *)&exec.input[h];
}, exec.g_handles);
q.pipe->bind_compute_state(q.pipe, st);
q.pipe->bind_sampler_states(q.pipe, PIPE_SHADER_COMPUTE,
0, exec.samplers.size(),
exec.samplers.data());
q.pipe->set_sampler_views(q.pipe, PIPE_SHADER_COMPUTE, 0,
exec.sviews.size(), exec.sviews.data());
q.pipe->set_compute_resources(q.pipe, 0, exec.resources.size(),
exec.resources.data());
q.pipe->set_global_binding(q.pipe, 0, exec.g_buffers.size(),
exec.g_buffers.data(), g_handles.data());
q.pipe->launch_grid(q.pipe,
pad_vector(q, block_size, 1).data(),
pad_vector(q, reduced_grid_size, 1).data(),
find(name_equals(_name), m.syms).offset,
exec.input.data());
q.pipe->set_global_binding(q.pipe, 0, exec.g_buffers.size(), NULL, NULL);
q.pipe->set_compute_resources(q.pipe, 0, exec.resources.size(), NULL);
q.pipe->set_sampler_views(q.pipe, PIPE_SHADER_COMPUTE, 0,
exec.sviews.size(), NULL);
q.pipe->bind_sampler_states(q.pipe, PIPE_SHADER_COMPUTE, 0,
exec.samplers.size(), NULL);
exec.unbind();
}
static inline std::vector<uint>
pad_vector(command_queue &q, const V &v, uint x) {
std::vector<uint> w { v.begin(), v.end() };
w.resize(q.device().max_block_size().size(), x);
return w;
}
/// The size in bytes of shared memory per block available for this kernel.
size_t max_shared_memory_per_block(const command_queue &q) const {
return q.device().max_shared_memory_per_block() -
shared_size_bytes();
}
/// Standard number of workgroups to launch on a device.
static inline size_t num_workgroups(const command_queue &q) {
return 8 * q.device().multiprocessor_count();
}
/// Create and build a program from source string.
inline vex::backend::program build_sources(
const command_queue &queue, const std::string &source,
const std::string &options = ""
)
{
#ifdef VEXCL_SHOW_KERNELS
std::cout << source << std::endl;
#else
if (getenv("VEXCL_SHOW_KERNELS"))
std::cout << source << std::endl;
#endif
std::string compile_options = options + " " + get_compile_options(queue);
queue.context().set_current();
auto cc = queue.device().compute_capability();
std::ostringstream ccstr;
ccstr << std::get<0>(cc) << std::get<1>(cc);
sha1_hasher sha1;
sha1.process(source)
.process(queue.device().name())
.process(compile_options)
.process(ccstr.str())
;
std::string hash = static_cast<std::string>(sha1);
// Write source to a .cu file
std::string basename = program_binaries_path(hash, true) + "kernel";
std::string ptxfile = basename + ".ptx";
if ( !boost::filesystem::exists(ptxfile) ) {
std::string cufile = basename + ".cu";
{
std::ofstream f(cufile);
f << source;
}
// Compile the source to ptx.
std::ostringstream cmdline;
cmdline
<< "nvcc -ptx -O3"
<< " -arch=sm_" << std::get<0>(cc) << std::get<1>(cc)
<< " " << compile_options
<< " -o " << ptxfile << " " << cufile;
if (0 != system(cmdline.str().c_str()) ) {
#ifndef VEXCL_SHOW_KERNELS
std::cerr << source << std::endl;
#endif
vex::detail::print_backtrace();
throw std::runtime_error("nvcc invocation failed");
}
}
// Load the compiled ptx.
CUmodule prg;
cuda_check( cuModuleLoad(&prg, ptxfile.c_str()) );
return program(queue.context(), prg);
}
/// Create command queue on the same context and device as the given one.
inline command_queue duplicate_queue(const command_queue &q) {
return command_queue(q.context(), q.device(), q.flags());
}
/// Returns id of the device associated with the given queue.
inline device_id get_device_id(const command_queue &q) {
return q.device().raw();
}
/// Returns device associated with the given queue.
inline device get_device(const command_queue &q) {
return q.device();
}