inline DeviceIterator copy_to_device(HostIterator first,
HostIterator last,
DeviceIterator result,
command_queue &queue,
const wait_list &events)
{
typedef typename
std::iterator_traits<DeviceIterator>::value_type
value_type;
typedef typename
std::iterator_traits<DeviceIterator>::difference_type
difference_type;
size_t count = iterator_range_size(first, last);
if(count == 0){
return result;
}
size_t offset = result.get_index();
queue.enqueue_write_buffer(result.get_buffer(),
offset * sizeof(value_type),
count * sizeof(value_type),
::boost::addressof(*first),
events);
return result + static_cast<difference_type>(count);
}
inline event write_single_value(const T &value,
const buffer &buffer,
size_t index,
command_queue &queue)
{
BOOST_ASSERT(index < buffer.size() / sizeof(T));
BOOST_ASSERT(buffer.get_context() == queue.get_context());
return queue.enqueue_write_buffer(buffer,
index * sizeof(T),
sizeof(T),
&value);
}
inline void
dispatch_fill(BufferIterator first,
size_t count,
const T &value,
command_queue &queue,
typename boost::enable_if<
is_valid_fill_buffer_iterator<BufferIterator>
>::type* = 0)
{
typedef typename std::iterator_traits<BufferIterator>::value_type value_type;
if(count == 0){
// nothing to do
return;
}
// check if the device supports OpenCL 1.2 (required for enqueue_fill_buffer)
if(!queue.check_device_version(1, 2)){
return fill_with_copy(first, count, value, queue);
}
value_type pattern = static_cast<value_type>(value);
size_t offset = static_cast<size_t>(first.get_index());
if(count == 1){
// use clEnqueueWriteBuffer() directly when writing a single value
// to the device buffer. this is potentially more efficient and also
// works around a bug in the intel opencl driver.
queue.enqueue_write_buffer(
first.get_buffer(),
offset * sizeof(value_type),
sizeof(value_type),
&pattern
);
}
else {
queue.enqueue_fill_buffer(
first.get_buffer(),
&pattern,
sizeof(value_type),
offset * sizeof(value_type),
count * sizeof(value_type)
);
}
}