NAME

OpenCL - Open Computing Language Bindings

SYNOPSIS

use OpenCL;

DESCRIPTION

This is an early release which might be useful, but hasn't seen much testing.

OpenCL FROM 10000 FEET HEIGHT

Here is a high level overview of OpenCL:

First you need to find one or more OpenCL::Platforms (kind of like vendors) - usually there is only one.

Each platform gives you access to a number of OpenCL::Device objects, e.g. your graphics card.

From a platform and some device(s), you create an OpenCL::Context, which is a very central object in OpenCL: Once you have a context you can create most other objects:

OpenCL::Program objects, which store source code and, after building for a specific device ("compiling and linking"), also binary programs. For each kernel function in a program you can then create an OpenCL::Kernel object which represents basically a function call with argument values.

OpenCL::Memory objects of various flavours: OpenCL::Buffer objects (flat memory areas, think arrays or structs) and OpenCL::Image objects (think 2d or 3d array) for bulk data and input and output for kernels.

OpenCL::Sampler objects, which are kind of like texture filter modes in OpenGL.

OpenCL::Queue objects - command queues, which allow you to submit memory reads, writes and copies, as well as kernel calls to your devices. They also offer a variety of methods to synchronise request execution, for example with barriers or OpenCL::Event objects.

OpenCL::Event objects are used to signal when something is complete.

HELPFUL RESOURCES

The OpenCL specs used to develop this module:

http://www.khronos.org/registry/cl/specs/opencl-1.1.pdf
http://www.khronos.org/registry/cl/specs/opencl-1.2.pdf
http://www.khronos.org/registry/cl/specs/opencl-1.2-extensions.pdf

OpenCL manpages:

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/
http://www.khronos.org/registry/cl/sdk/1.2/docs/man/xhtml/

If you are into UML class diagrams, the following diagram might help - if not, it will be mildly confusing (also, the class hierarchy of this module is much more fine-grained):

http://www.khronos.org/registry/cl/sdk/1.2/docs/man/xhtml/classDiagram.html

Here's a tutorial from AMD (very AMD-centric, too), not sure how useful it is, but at least it's free of charge:

http://developer.amd.com/zones/OpenCLZone/courses/Documents/Introduction_to_OpenCL_Programming%20Training_Guide%20%28201005%29.pdf

And here's NVIDIA's OpenCL Best Practises Guide:

http://developer.download.nvidia.com/compute/cuda/3_2/toolkit/docs/OpenCL_Best_Practices_Guide.pdf

BASIC WORKFLOW

To get something done, you basically have to do this once (refer to the examples below for actual code, this is just a high-level description):

Find some platform (e.g. the first one) and some device(s) (e.g. the first device of the platform), and create a context from those.

Create program objects from your OpenCL source code, then build (compile) the programs for each device you want to run them on.

Create kernel objects for all kernels you want to use (surprisingly, these are not device-specific).

Then, to execute stuff, you repeat these steps, possibly resuing or sharing some buffers:

Create some input and output buffers from your context. Set these as arguments to your kernel.

Enqueue buffer writes to initialise your input buffers (when not initialised at creation time).

Enqueue the kernel execution.

Enqueue buffer reads for your output buffer to read results.

EXAMPLES

Enumerate all devices and get contexts for them.

Best run this once to get a feel for the platforms and devices in your system.

for my $platform (OpenCL::platforms) {
   printf "platform: %s\n", $platform->name;
   printf "extensions: %s\n", $platform->extensions;
   for my $device ($platform->devices) {
      printf "+ device: %s\n", $device->name;
      my $ctx = $platform->context (undef, [$device]);
      # do stuff
   }
}

Get a useful context and a command queue.

This is a useful boilerplate for any OpenCL program that only wants to use one device,

my ($platform) = OpenCL::platforms; # find first platform
my ($dev) = $platform->devices;     # find first device of platform
my $ctx = $platform->context (undef, [$dev]); # create context out of those
my $queue = $ctx->queue ($dev);     # create a command queue for the device

Print all supported image formats of a context.

Best run this once for your context, to see whats available and how to gather information.

for my $type (OpenCL::MEM_OBJECT_IMAGE2D, OpenCL::MEM_OBJECT_IMAGE3D) {
   print "supported image formats for ", OpenCL::enum2str $type, "\n";
   
   for my $f ($ctx->supported_image_formats (0, $type)) {
      printf "  %-10s %-20s\n", OpenCL::enum2str $f->[0], OpenCL::enum2str $f->[1];
   }
}

Create a buffer with some predefined data, read it back synchronously, then asynchronously.

my $buf = $ctx->buffer_sv (OpenCL::MEM_COPY_HOST_PTR, "helmut");

$queue->read_buffer ($buf, 1, 1, 3, my $data);
print "$data\n";

my $ev = $queue->read_buffer ($buf, 0, 1, 3, my $data);
$ev->wait;
print "$data\n"; # prints "elm"

Create and build a program, then create a kernel out of one of its functions.

my $src = '
   kernel void
   squareit (global float *input, global float *output)
   {
     $id = get_global_id (0);
     output [id] = input [id] * input [id];
   }
';

my $prog = $ctx->build_program ($src);
my $kernel = $prog->kernel ("squareit");

Create some input and output float buffers, then call the 'squareit' kernel on them.

my $input  = $ctx->buffer_sv (OpenCL::MEM_COPY_HOST_PTR, pack "f*", 1, 2, 3, 4.5);
my $output = $ctx->buffer (0, OpenCL::SIZEOF_FLOAT * 5);

# set buffer
$kernel->set_buffer (0, $input);
$kernel->set_buffer (1, $output);

# execute it for all 4 numbers
$queue->nd_range_kernel ($kernel, undef, [4], undef);

# enqueue a synchronous read
$queue->read_buffer ($output, 1, 0, OpenCL::SIZEOF_FLOAT * 4, my $data);

# print the results:
printf "%s\n", join ", ", unpack "f*", $data;

The same enqueue operations as before, but assuming an out-of-order queue, showing off barriers.

# execute it for all 4 numbers
$queue->nd_range_kernel ($kernel, undef, [4], undef);

# enqueue a barrier to ensure in-order execution
$queue->barrier;

# enqueue an async read
$queue->read_buffer ($output, 0, 0, OpenCL::SIZEOF_FLOAT * 4, my $data);

# wait for all requests to finish
$queue->finish;

The same enqueue operations as before, but assuming an out-of-order queue, showing off event objects and wait lists.

# execute it for all 4 numbers
my $ev = $queue->nd_range_kernel ($kernel, undef, [4], undef);

# enqueue an async read
$ev = $queue->read_buffer ($output, 0, 0, OpenCL::SIZEOF_FLOAT * 4, my $data, $ev);

# wait for the last event to complete
$ev->wait;

This is quite a long example to get you going - you can download it from http://cvs.schmorp.de/OpenCL/examples/juliaflight.

use OpenGL ":all";
use OpenCL;

my $S = $ARGV[0] || 256; # window/texture size, smaller is faster

# open a window and create a gl texture
OpenGL::glpOpenWindow width => $S, height => $S;
my $texid = glGenTextures_p 1;
glBindTexture GL_TEXTURE_2D, $texid;
glTexImage2D_c GL_TEXTURE_2D, 0, GL_RGBA8, $S, $S, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0;

# find and use the first opencl device that let's us get a shared opengl context
my $platform;
my $dev;
my $ctx;

for (OpenCL::platforms) {
   $platform = $_;
   for ($platform->devices) {
      $dev = $_;
      $ctx = $platform->context ([OpenCL::GLX_DISPLAY_KHR, undef, OpenCL::GL_CONTEXT_KHR, undef], [$dev])
         and last;
   }
}

$ctx
   or die "cannot find suitable OpenCL device\n";

my $queue = $ctx->queue ($dev);

# now attach an opencl image2d object to the opengl texture
my $tex = $ctx->gl_texture2d (OpenCL::MEM_WRITE_ONLY, GL_TEXTURE_2D, 0, $texid);

# now the boring opencl code
my $src = <<EOF;
kernel void
juliatunnel (write_only image2d_t img, float time)
{
  int2 xy = (int2)(get_global_id (0), get_global_id (1));
  float2 p = convert_float2 (xy) / $S.f * 2.f - 1.f;

  float2 m = (float2)(1.f, p.y) / fabs (p.x); // tunnel
  m.x = fabs (fmod (m.x + time * 0.05f, 4.f) - 2.f);

  float2 z = m;
  float2 c = (float2)(sin (time * 0.01133f), cos (time * 0.02521f));

  for (int i = 0; i < 25 && dot (z, z) < 4.f; ++i) // standard julia
    z = (float2)(z.x * z.x - z.y * z.y, 2.f * z.x * z.y) + c;

  float3 colour = (float3)(z.x, z.y, atan2 (z.y, z.x));
  write_imagef (img, xy, (float4)(colour * p.x * p.x, 1.));
}
EOF

my $prog = $ctx->build_program ($src);
my $kernel = $prog->kernel ("juliatunnel");

# program compiled, kernel ready, now draw and loop

for (my $time; ; ++$time) {
   # acquire objects from opengl
   $queue->acquire_gl_objects ([$tex]);

   # configure and run our kernel
   $kernel->setf ("mf", $tex, $time*2); # mf = memory object, float
   $queue->nd_range_kernel ($kernel, undef, [$S, $S], undef);

   # release objects to opengl again
   $queue->release_gl_objects ([$tex]);

   # wait
   $queue->finish;

   # now draw the texture, the defaults should be all right
   glTexParameterf GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST;

   glEnable GL_TEXTURE_2D;
   glBegin GL_QUADS;
      glTexCoord2f 0, 1; glVertex3i -1, -1, -1;
      glTexCoord2f 0, 0; glVertex3i  1, -1, -1;
      glTexCoord2f 1, 0; glVertex3i  1,  1, -1;
      glTexCoord2f 1, 1; glVertex3i -1,  1, -1;
   glEnd;

   glXSwapBuffers;

   select undef, undef, undef, 1/60;
}

For those poor souls with only a sucky CPU OpenCL implementation, you currently have to read the image into some perl scalar, and then modify a texture or use glDrawPixels or so).

First, when you don't need gl sharing, you can create the context much simpler:

$ctx = $platform->context (undef, [$dev])

To use a texture, you would modify the above example by creating an OpenCL::Image manually instead of deriving it from a texture:

my $tex = $ctx->image2d (OpenCL::MEM_WRITE_ONLY, OpenCL::RGBA, OpenCL::UNORM_INT8, $S, $S);

And in the darw loop, intead of acquire_gl_objects/release_gl_objects, you would read the image2d after the kernel has written it:

$queue->read_image ($tex, 0, 0, 0, 0, $S, $S, 1, 0, 0, my $data);

And then you would upload the pixel data to the texture (or use glDrawPixels):

glTexSubImage2D_s GL_TEXTURE_2D, 0, 0, 0, $S, $S, GL_RGBA, GL_UNSIGNED_BYTE, $data;

The fully modified example can be found at http://cvs.schmorp.de/OpenCL/examples/juliaflight-nosharing.

DOCUMENTATION

BASIC CONVENTIONS

This is not a one-to-one C-style translation of OpenCL to Perl - instead I attempted to make the interface as type-safe as possible by introducing object syntax where it makes sense. There are a number of important differences between the OpenCL C API and this module:

Object lifetime managament is automatic - there is no need to free objects explicitly (clReleaseXXX), the release function is called automatically once all Perl references to it go away.
OpenCL uses CamelCase for function names (e.g. clGetPlatformIDs, clGetPlatformInfo), while this module uses underscores as word separator and often leaves out prefixes (OpenCL::platforms, $platform->info).
OpenCL often specifies fixed vector function arguments as short arrays (size_t origin[3]), while this module explicitly expects the components as separate arguments ($orig_x, $orig_y, $orig_z) in function calls.
Structures are often specified by flattening out their components as with short vectors, and returned as arrayrefs.
When enqueuing commands, the wait list is specified by adding extra arguments to the function - anywhere a $wait_events... argument is documented this can be any number of event objects. As an extsnion implemented by this module, undef values will be ignored in the event list.
When enqueuing commands, if the enqueue method is called in void context, no event is created. In all other contexts an event is returned by the method.
This module expects all functions to return CL_SUCCESS. If any other status is returned the function will throw an exception, so you don't normally have to to any error checking.

PERL AND OPENCL TYPES

This handy(?) table lists OpenCL types and their perl, PDL and pack/unpack format equivalents:

OpenCL    perl   PDL       pack/unpack
char      IV     -         c
uchar     IV     byte      C
short     IV     short     s
ushort    IV     ushort    S
int       IV     long?     l
uint      IV     -         L
long      IV     longlong  q
ulong     IV     -         Q
float     NV     float     f
half      IV     ushort    S
double    NV     double    d

GLX SUPPORT

Due to the sad state that OpenGL support is in in Perl (mostly the OpenGL module, which has little to no documentation and has little to no support for glX), this module, as a special extension, treats context creation properties OpenCL::GLX_DISPLAY_KHR and OpenCL::GL_CONTEXT_KHR specially: If either or both of these are undef, then the OpenCL module tries to dynamically resolve glXGetCurrentDisplay and glXGetCurrentContext, call these functions and use their return values instead.

For this to work, the OpenGL library must be loaded, a GLX context must have been created and be made current, and dlsym must be available and capable of finding the function via RTLD_DEFAULT.

EVENT SYSTEM

OpenCL can generate a number of (potentially) asynchronous events, for example, after compiling a program, to signal a context-related error or, perhaps most important, to signal completion of queued jobs (by setting callbacks on OpenCL::Event objects).

To facilitate this, this module maintains an event queue - each time an asynchronous event happens, it is queued, and perl will be interrupted. This is implemented via the Async::Interrupt module. In addition, this module has AnyEvent support, so it can seamlessly integrate itself into many event loops.

Since this module is a bit hard to understand, here are some case examples:

Don't use callbacks.

When your program never uses any callbacks, then there will never be any notifications you need to take care of, and therefore no need to worry about all this.

You can achieve a great deal by explicitly waiting for events, or using barriers and flush calls. In many programs, there is no need at all to tinker with asynchronous events.

Use AnyEvent

This module automatically registers a watcher that invokes all outstanding event callbacks when AnyEvent is initialised (and block asynchronous interruptions). Using this mode of operations is the safest and most recommended one.

To use this, simply use AnyEvent and this module normally, make sure you have an event loop running:

use Gtk2 -init;
use AnyEvent;

# initialise AnyEvent, by creating a watcher, or:
AnyEvent::detect;

my $e = $queue->marker;
$e->cb (sub {
   warn "opencl is finished\n";
})

main Gtk2;

Note that this module will not initialise AnyEvent for you. Before AnyEvent is initialised, the module will asynchronously interrupt perl instead. To avoid any surprises, it's best to explicitly initialise AnyEvent.

You can temporarily enable asynchronous interruptions (see next paragraph) by calling $OpenCL::INTERRUPT-unblock> and disable them again by calling $OpenCL::INTERRUPT-block>.

Let yourself be interrupted at any time

This mode is the default unless AnyEvent is loaded and initialised. In this mode, OpenCL asynchronously interrupts a running perl program. The emphasis is on both asynchronously and running here.

Asynchronously means that perl might execute your callbacks at any time. For example, in the following code (THAT YOU SHOULD NOT COPY), the until loop following the marker call will be interrupted by the callback:

my $e = $queue->marker;
my $flag;
$e->cb (sub { $flag = 1 });
1 until $flag;
# $flag is now 1

The reason why you shouldn't blindly copy the above code is that busy waiting is a really really bad thing, and really really bad for performance.

While at first this asynchronous business might look exciting, it can be really hard, because you need to be prepared for the callback code to be executed at any time, which limits the amount of things the callback code can do safely.

This can be mitigated somewhat by using $OpenCL::INTERRUPT->scope_block (see the Async::Interrupt documentation for details).

The other problem is that your program must be actively running to be interrupted. When you calculate stuff, your program is running. When you hang in some C functions or other block execution (by calling sleep, select, running an event loop and so on), your program is waiting, not running.

One way around that would be to attach a read watcher to your event loop, listening for events on $OpenCL::INTERRUPT->pipe_fileno, using a dummy callback (sub { }) to temporarily execute some perl code.

That is then awfully close to using the built-in AnyEvent support above, though, so consider that one instead.

Be creative

OpenCL exports the Async::Interrupt object it uses in the global variable $OpenCL::INTERRUPT. You can configure it in any way you like.

So if you want to feel like a real pro, err, wait, if you feel no risk menas no fun, you can experiment by implementing your own mode of operations.

THE OpenCL PACKAGE

$int = OpenCL::errno

The last error returned by a function - it's only valid after an error occured and before calling another OpenCL function.

$str = OpenCL::err2str [$errval]

Converts an error value into a human readable string. IF no error value is given, then the last error will be used (as returned by OpenCL::errno).

$str = OpenCL::enum2str $enum

Converts most enum values (of parameter names, image format constants, object types, addressing and filter modes, command types etc.) into a human readable string. When confronted with some random integer it can be very helpful to pass it through this function to maybe get some readable string out of it.

@platforms = OpenCL::platforms

Returns all available OpenCL::Platform objects.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clGetPlatformIDs.html

$ctx = OpenCL::context_from_type $properties, $type = OpenCL::DEVICE_TYPE_DEFAULT, $callback->($err, $pvt) = $print_stderr

Tries to create a context from a default device and platform type - never worked for me.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clCreateContextFromType.html

$ctx = OpenCL::context $properties, \@devices, $callback->($err, $pvt) = $print_stderr)

Create a new OpenCL::Context object using the given device object(s). This function isn't implemented yet, use $platform->context instead.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clCreateContext.html

OpenCL::wait_for_events $wait_events...

Waits for all events to complete.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clWaitForEvents.html

OpenCL::poll

Checks if there are any outstanding events (see "EVENT SYSTEM") and invokes their callbacks.

$OpenCL::INTERRUPT

The Async::Interrupt object used to signal asynchronous events (see "EVENT SYSTEM").

$OpenCL::WATCHER

The AnyEvent watcher object used to watch for asynchronous events (see "EVENT SYSTEM"). This variable is undef until AnyEvent has been loaded and initialised (e.g. by calling AnyEvent::detect).

THE OpenCL::Object CLASS

This is the base class for all objects in the OpenCL module. The only method it implements is the id method, which is only useful if you want to interface to OpenCL on the C level.

$iv = $obj->id: OpenCL objects are represented by pointers or integers on the C level. If you want to interface to an OpenCL object directly on the C level, then you need this value, which is returned by this method. You should use an IV type in your code and cast that to the correct type.

THE OpenCL::Platform CLASS

@devices = $platform->devices ($type = OpenCL::DEVICE_TYPE_ALL)

Returns a list of matching OpenCL::Device objects.

$ctx = $platform->context_from_type ($properties, $type = OpenCL::DEVICE_TYPE_DEFAULT, $callback->($err, $pvt) = $print_stderr)

Tries to create a context. Never worked for me, and you need devices explicitly anyway.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clCreateContextFromType.html

$ctx = $platform->context ($properties, \@devices, $callback->($err, $pvt) = $print_stderr)

Create a new OpenCL::Context object using the given device object(s)- a CL_CONTEXT_PLATFORM property is supplied automatically.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clCreateContext.html

$packed_value = $platform->info ($name)

Calls clGetPlatformInfo and returns the packed, raw value - for strings, this will be the string (possibly including terminating \0), for other values you probably need to use the correct unpack.

It's best to avoid this method and use one of the following convenience wrappers.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clGetPlatformInfo.html

$platform->unload_compiler

Attempts to unload the compiler for this platform, for endless profit. Does nothing on OpenCL 1.1.

http://www.khronos.org/registry/cl/sdk/1.2/docs/man/xhtml/clUnloadPlatformCompiler.html

$string = $platform->profile

Calls clGetPlatformInfo with CL_PLATFORM_PROFILE and returns the result.

$string = $platform->version

Calls clGetPlatformInfo with CL_PLATFORM_VERSION and returns the result.

$string = $platform->name

Calls clGetPlatformInfo with CL_PLATFORM_NAME and returns the result.

$string = $platform->vendor

Calls clGetPlatformInfo with CL_PLATFORM_VENDOR and returns the result.

$string = $platform->extensions

Calls clGetPlatformInfo with CL_PLATFORM_EXTENSIONS and returns the result.

THE OpenCL::Device CLASS

$packed_value = $device->info ($name)

See $platform->info for details.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clGetDeviceInfo.html

$device_type = $device->type

Calls clGetDeviceInfo with CL_DEVICE_TYPE and returns the result.

$uint = $device->vendor_id

Calls clGetDeviceInfo with CL_DEVICE_VENDOR_ID and returns the result.

$uint = $device->max_compute_units

Calls clGetDeviceInfo with CL_DEVICE_MAX_COMPUTE_UNITS and returns the result.

$uint = $device->max_work_item_dimensions

Calls clGetDeviceInfo with CL_DEVICE_MAX_WORK_ITEM_DIMENSIONS and returns the result.

$int = $device->max_work_group_size

Calls clGetDeviceInfo with CL_DEVICE_MAX_WORK_GROUP_SIZE and returns the result.

@ints = $device->max_work_item_sizes

Calls clGetDeviceInfo with CL_DEVICE_MAX_WORK_ITEM_SIZES and returns the result.

$uint = $device->preferred_vector_width_char

Calls clGetDeviceInfo with CL_DEVICE_PREFERRED_VECTOR_WIDTH_CHAR and returns the result.

$uint = $device->preferred_vector_width_short

Calls clGetDeviceInfo with CL_DEVICE_PREFERRED_VECTOR_WIDTH_SHORT and returns the result.

$uint = $device->preferred_vector_width_int

Calls clGetDeviceInfo with CL_DEVICE_PREFERRED_VECTOR_WIDTH_INT and returns the result.

$uint = $device->preferred_vector_width_long

Calls clGetDeviceInfo with CL_DEVICE_PREFERRED_VECTOR_WIDTH_LONG and returns the result.

$uint = $device->preferred_vector_width_float

Calls clGetDeviceInfo with CL_DEVICE_PREFERRED_VECTOR_WIDTH_FLOAT and returns the result.

$uint = $device->preferred_vector_width_double

Calls clGetDeviceInfo with CL_DEVICE_PREFERRED_VECTOR_WIDTH_DOUBLE and returns the result.

$uint = $device->max_clock_frequency

Calls clGetDeviceInfo with CL_DEVICE_MAX_CLOCK_FREQUENCY and returns the result.

$bitfield = $device->address_bits

Calls clGetDeviceInfo with CL_DEVICE_ADDRESS_BITS and returns the result.

$uint = $device->max_read_image_args

Calls clGetDeviceInfo with CL_DEVICE_MAX_READ_IMAGE_ARGS and returns the result.

$uint = $device->max_write_image_args

Calls clGetDeviceInfo with CL_DEVICE_MAX_WRITE_IMAGE_ARGS and returns the result.

$ulong = $device->max_mem_alloc_size

Calls clGetDeviceInfo with CL_DEVICE_MAX_MEM_ALLOC_SIZE and returns the result.

$int = $device->image2d_max_width

Calls clGetDeviceInfo with CL_DEVICE_IMAGE2D_MAX_WIDTH and returns the result.

$int = $device->image2d_max_height

Calls clGetDeviceInfo with CL_DEVICE_IMAGE2D_MAX_HEIGHT and returns the result.

$int = $device->image3d_max_width

Calls clGetDeviceInfo with CL_DEVICE_IMAGE3D_MAX_WIDTH and returns the result.

$int = $device->image3d_max_height

Calls clGetDeviceInfo with CL_DEVICE_IMAGE3D_MAX_HEIGHT and returns the result.

$int = $device->image3d_max_depth

Calls clGetDeviceInfo with CL_DEVICE_IMAGE3D_MAX_DEPTH and returns the result.

$uint = $device->image_support

Calls clGetDeviceInfo with CL_DEVICE_IMAGE_SUPPORT and returns the result.

$int = $device->max_parameter_size

Calls clGetDeviceInfo with CL_DEVICE_MAX_PARAMETER_SIZE and returns the result.

$uint = $device->max_samplers

Calls clGetDeviceInfo with CL_DEVICE_MAX_SAMPLERS and returns the result.

$uint = $device->mem_base_addr_align

Calls clGetDeviceInfo with CL_DEVICE_MEM_BASE_ADDR_ALIGN and returns the result.

$uint = $device->min_data_type_align_size

Calls clGetDeviceInfo with CL_DEVICE_MIN_DATA_TYPE_ALIGN_SIZE and returns the result.

$device_fp_config = $device->single_fp_config

Calls clGetDeviceInfo with CL_DEVICE_SINGLE_FP_CONFIG and returns the result.

$device_mem_cache_type = $device->global_mem_cache_type

Calls clGetDeviceInfo with CL_DEVICE_GLOBAL_MEM_CACHE_TYPE and returns the result.

$uint = $device->global_mem_cacheline_size

Calls clGetDeviceInfo with CL_DEVICE_GLOBAL_MEM_CACHELINE_SIZE and returns the result.

$ulong = $device->global_mem_cache_size

Calls clGetDeviceInfo with CL_DEVICE_GLOBAL_MEM_CACHE_SIZE and returns the result.

$ulong = $device->global_mem_size

Calls clGetDeviceInfo with CL_DEVICE_GLOBAL_MEM_SIZE and returns the result.

$ulong = $device->max_constant_buffer_size

Calls clGetDeviceInfo with CL_DEVICE_MAX_CONSTANT_BUFFER_SIZE and returns the result.

$uint = $device->max_constant_args

Calls clGetDeviceInfo with CL_DEVICE_MAX_CONSTANT_ARGS and returns the result.

$device_local_mem_type = $device->local_mem_type

Calls clGetDeviceInfo with CL_DEVICE_LOCAL_MEM_TYPE and returns the result.

$ulong = $device->local_mem_size

Calls clGetDeviceInfo with CL_DEVICE_LOCAL_MEM_SIZE and returns the result.

$boolean = $device->error_correction_support

Calls clGetDeviceInfo with CL_DEVICE_ERROR_CORRECTION_SUPPORT and returns the result.

$int = $device->profiling_timer_resolution

Calls clGetDeviceInfo with CL_DEVICE_PROFILING_TIMER_RESOLUTION and returns the result.

$boolean = $device->endian_little

Calls clGetDeviceInfo with CL_DEVICE_ENDIAN_LITTLE and returns the result.

$boolean = $device->available

Calls clGetDeviceInfo with CL_DEVICE_AVAILABLE and returns the result.

$boolean = $device->compiler_available

Calls clGetDeviceInfo with CL_DEVICE_COMPILER_AVAILABLE and returns the result.

$device_exec_capabilities = $device->execution_capabilities

Calls clGetDeviceInfo with CL_DEVICE_EXECUTION_CAPABILITIES and returns the result.

$command_queue_properties = $device->properties

Calls clGetDeviceInfo with CL_DEVICE_QUEUE_PROPERTIES and returns the result.

$ = $device->platform

Calls clGetDeviceInfo with CL_DEVICE_PLATFORM and returns the result.

$string = $device->name

Calls clGetDeviceInfo with CL_DEVICE_NAME and returns the result.

$string = $device->vendor

Calls clGetDeviceInfo with CL_DEVICE_VENDOR and returns the result.

$string = $device->driver_version

Calls clGetDeviceInfo with CL_DRIVER_VERSION and returns the result.

$string = $device->profile

Calls clGetDeviceInfo with CL_DEVICE_PROFILE and returns the result.

$string = $device->version

Calls clGetDeviceInfo with CL_DEVICE_VERSION and returns the result.

$string = $device->extensions

Calls clGetDeviceInfo with CL_DEVICE_EXTENSIONS and returns the result.

$uint = $device->preferred_vector_width_half

Calls clGetDeviceInfo with CL_DEVICE_PREFERRED_VECTOR_WIDTH_HALF and returns the result.

$uint = $device->native_vector_width_char

Calls clGetDeviceInfo with CL_DEVICE_NATIVE_VECTOR_WIDTH_CHAR and returns the result.

$uint = $device->native_vector_width_short

Calls clGetDeviceInfo with CL_DEVICE_NATIVE_VECTOR_WIDTH_SHORT and returns the result.

$uint = $device->native_vector_width_int

Calls clGetDeviceInfo with CL_DEVICE_NATIVE_VECTOR_WIDTH_INT and returns the result.

$uint = $device->native_vector_width_long

Calls clGetDeviceInfo with CL_DEVICE_NATIVE_VECTOR_WIDTH_LONG and returns the result.

$uint = $device->native_vector_width_float

Calls clGetDeviceInfo with CL_DEVICE_NATIVE_VECTOR_WIDTH_FLOAT and returns the result.

$uint = $device->native_vector_width_double

Calls clGetDeviceInfo with CL_DEVICE_NATIVE_VECTOR_WIDTH_DOUBLE and returns the result.

$uint = $device->native_vector_width_half

Calls clGetDeviceInfo with CL_DEVICE_NATIVE_VECTOR_WIDTH_HALF and returns the result.

$device_fp_config = $device->double_fp_config

Calls clGetDeviceInfo with CL_DEVICE_DOUBLE_FP_CONFIG and returns the result.

$device_fp_config = $device->half_fp_config

Calls clGetDeviceInfo with CL_DEVICE_HALF_FP_CONFIG and returns the result.

$boolean = $device->host_unified_memory

Calls clGetDeviceInfo with CL_DEVICE_HOST_UNIFIED_MEMORY and returns the result.

$device = $device->parent_device_ext

Calls clGetDeviceInfo with CL_DEVICE_PARENT_DEVICE_EXT and returns the result.

@device_partition_property_exts = $device->partition_types_ext

Calls clGetDeviceInfo with CL_DEVICE_PARTITION_TYPES_EXT and returns the result.

@device_partition_property_exts = $device->affinity_domains_ext

Calls clGetDeviceInfo with CL_DEVICE_AFFINITY_DOMAINS_EXT and returns the result.

$uint = $device->reference_count_ext

Calls clGetDeviceInfo with CL_DEVICE_REFERENCE_COUNT_EXT and returns the result.

@device_partition_property_exts = $device->partition_style_ext

Calls clGetDeviceInfo with CL_DEVICE_PARTITION_STYLE_EXT and returns the result.

THE OpenCL::Context CLASS

$prog = $ctx->build_program ($program, $options = "")

This convenience function tries to build the program on all devices in the context. If the build fails, then the function will croak with the build log. Otherwise ti returns the program object.

The $program can either be a OpenCL::Program object or a string containing the program. In the latter case, a program objetc will be created automatically.

$queue = $ctx->queue ($device, $properties)

Create a new OpenCL::Queue object from the context and the given device.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clCreateCommandQueue.html

Example: create an out-of-order queue.

$queue = $ctx->queue ($device, OpenCL::QUEUE_OUT_OF_ORDER_EXEC_MODE_ENABLE);

$ev = $ctx->user_event

Creates a new OpenCL::UserEvent object.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clCreateUserEvent.html

$buf = $ctx->buffer ($flags, $len)

Creates a new OpenCL::Buffer (actually OpenCL::BufferObj) object with the given flags and octet-size.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clCreateBuffer.html

$buf = $ctx->buffer_sv ($flags, $data)

Creates a new OpenCL::Buffer (actually OpenCL::BufferObj) object and initialise it with the given data values.

$img = $ctx->image ($self, $flags, $channel_order, $channel_type, $type, $width, $height, $depth = 0, $array_size = 0, $row_pitch = 0, $slice_pitch = 0, $num_mip_level = 0, $num_samples = 0, $*data = &PL_sv_undef)

Creates a new OpenCL::Image object and optionally initialises it with the given data values.

http://www.khronos.org/registry/cl/sdk/1.2/docs/man/xhtml/clCreateImage.html

$img = $ctx->image2d ($flags, $channel_order, $channel_type, $width, $height, $row_pitch = 0, $data = undef)

Creates a new OpenCL::Image2D object and optionally initialises it with the given data values.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clCreateImage2D.html

$img = $ctx->image3d ($flags, $channel_order, $channel_type, $width, $height, $depth, $row_pitch = 0, $slice_pitch = 0, $data = undef)

Creates a new OpenCL::Image3D object and optionally initialises it with the given data values.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clCreateImage3D.html

$buffer = $ctx->gl_buffer ($flags, $bufobj)

Creates a new OpenCL::Buffer (actually OpenCL::BufferObj) object that refers to the given OpenGL buffer object.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clCreateFromGLBuffer.html

$img = $ctx->gl_texture ($flags, $target, $miplevel, $texture)

Creates a new OpenCL::Image object that refers to the given OpenGL texture object or buffer.

http://www.khronos.org/registry/cl/sdk/1.2/docs/man/xhtml/clCreateFromGLTexture.html

$img = $ctx->gl_texture2d ($flags, $target, $miplevel, $texture)

Creates a new OpenCL::Image2D object that refers to the given OpenGL 2D texture object.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clCreateFromGLTexture2D.html

$img = $ctx->gl_texture3d ($flags, $target, $miplevel, $texture)

Creates a new OpenCL::Image3D object that refers to the given OpenGL 3D texture object.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clCreateFromGLTexture3D.html

$ctx->gl_renderbuffer ($flags, $renderbuffer)

Creates a new OpenCL::Image2D object that refers to the given OpenGL render buffer.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clCreateFromGLRenderbuffer.html

@formats = $ctx->supported_image_formats ($flags, $image_type)

Returns a list of matching image formats - each format is an arrayref with two values, $channel_order and $channel_type, in it.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clGetSupportedImageFormats.html

$sampler = $ctx->sampler ($normalized_coords, $addressing_mode, $filter_mode)

Creates a new OpenCL::Sampler object.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clCreateSampler.html

$program = $ctx->program_with_source ($string)

Creates a new OpenCL::Program object from the given source code.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clCreateProgramWithSource.html

($program, \@status) = $ctx->program_with_binary (\@devices, \@binaries)

Creates a new OpenCL::Program object from the given binaries.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clCreateProgramWithBinary.html

Example: clone an existing program object that contains a successfully compiled program, no matter how useless this is.

my $clone = $ctx->program_with_binary ([$prog->devices], [$prog->binaries]);

$packed_value = $ctx->info ($name)

See $platform->info for details.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clGetContextInfo.html

$uint = $context->reference_count

Calls clGetContextInfo with CL_CONTEXT_REFERENCE_COUNT and returns the result.

@devices = $context->devices

Calls clGetContextInfo with CL_CONTEXT_DEVICES and returns the result.

@property_ints = $context->properties

Calls clGetContextInfo with CL_CONTEXT_PROPERTIES and returns the result.

$uint = $context->num_devices

Calls clGetContextInfo with CL_CONTEXT_NUM_DEVICES and returns the result.

THE OpenCL::Queue CLASS

An OpenCL::Queue represents an execution queue for OpenCL. You execute requests by calling their respective method and waiting for it to complete in some way.

Most methods that enqueue some request return an event object that can be used to wait for completion (optionally using a callback), unless the method is called in void context, in which case no event object is created.

They also allow you to specify any number of other event objects that this request has to wait for before it starts executing, by simply passing the event objects as extra parameters to the enqueue methods. To simplify program design, this module ignores any undef values in the list of events. This makes it possible to code operations such as this, without having to put a valid event object into $event first:

$event = $queue->xxx (..., $event);

Queues execute in-order by default, without any parallelism, so in most cases (i.e. you use only one queue) it's not necessary to wait for or create event objects, althoguh an our of order queue is often a bit faster.

$ev = $queue->read_buffer ($buffer, $blocking, $offset, $len, $data, $wait_events...)

Reads data from buffer into the given string.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clEnqueueReadBuffer.html

$ev = $queue->write_buffer ($buffer, $blocking, $offset, $data, $wait_events...)

Writes data to buffer from the given string.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clEnqueueWriteBuffer.html

$ev = $queue->copy_buffer ($src, $dst, $src_offset, $dst_offset, $len, $wait_events...)

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clEnqueueCopyBuffer.html

$ev = $queue->read_buffer_rect (OpenCL::Memory buf, cl_bool blocking, $buf_x, $buf_y, $buf_z, $host_x, $host_y, $host_z, $width, $height, $depth, $buf_row_pitch, $buf_slice_pitch, $host_row_pitch, $host_slice_pitch, $data, $wait_events...)

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clEnqueueReadBufferRect.html

$ev = $queue->write_buffer_rect (OpenCL::Memory buf, cl_bool blocking, $buf_x, $buf_y, $buf_z, $host_x, $host_y, $host_z, $width, $height, $depth, $buf_row_pitch, $buf_slice_pitch, $host_row_pitch, $host_slice_pitch, $data, $wait_events...)

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clEnqueueWriteBufferRect.html

$ev = $queue->copy_buffer_to_image ($src_buffer, $dst_image, $src_offset, $dst_x, $dst_y, $dst_z, $width, $height, $depth, $wait_events...)

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clEnqueueCopyBufferToImage.html

$ev = $queue->read_image ($src, $blocking, $x, $y, $z, $width, $height, $depth, $row_pitch, $slice_pitch, $data, $wait_events...)

$row_pitch (and $slice_pitch) can be 0, in which case the OpenCL module uses the image width (and height) to supply default values.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clEnqueueReadImage.html

$ev = $queue->write_image ($src, $blocking, $x, $y, $z, $width, $height, $depth, $row_pitch, $slice_pitch, $data, $wait_events...)

$row_pitch (and $slice_pitch) can be 0, in which case the OpenCL module uses the image width (and height) to supply default values. http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clEnqueueWriteImage.html

$ev = $queue->copy_image ($src_image, $dst_image, $src_x, $src_y, $src_z, $dst_x, $dst_y, $dst_z, $width, $height, $depth, $wait_events...)

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clEnqueueCopyImage.html

$ev = $queue->copy_image_to_buffer ($src_image, $dst_image, $src_x, $src_y, $src_z, $width, $height, $depth, $dst_offset, $wait_events...)

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clEnqueueCopyImageToBuffer.html

$ev = $queue->copy_buffer_rect ($src, $dst, $src_x, $src_y, $src_z, $dst_x, $dst_y, $dst_z, $width, $height, $depth, $src_row_pitch, $src_slice_pitch, $dst_row_pitch, $dst_slice_pitch, $wait_event...)

Yeah.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clEnqueueCopyBufferToImage.html.

$ev = $queue->fill_buffer ($mem, $pattern, $offset, $size, ...)

Fills the given buffer object with repeated applications of $pattern, starting at $offset for $size octets.

http://www.khronos.org/registry/cl/sdk/1.2/docs/man/xhtml/clEnqueueFillBuffer.html

$ev = $queue->fill_image ($img, $r, $g, $b, $a, $x, $y, $z, $width, $height, $depth, ...)

Fills the given image area with the given rgba colour components. The components are normally floating point values between 0 and 1, except when the image channel data type is a signe dor unsigned unnormalised format, in which case the range is determined by the format.

http://www.khronos.org/registry/cl/sdk/1.2/docs/man/xhtml/clEnqueueFillImage.html

$ev = $queue->task ($kernel, $wait_events...)

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clEnqueueTask.html

$ev = $queue->nd_range_kernel ($kernel, \@global_work_offset, \@global_work_size, \@local_work_size, $wait_events...)

Enqueues a kernel execution.

\@global_work_size must be specified as a reference to an array of integers specifying the work sizes (element counts).

\@global_work_offset must be either undef (in which case all offsets are 0), or a reference to an array of work offsets, with the same number of elements as \@global_work_size.

\@local_work_size must be either undef (in which case the implementation is supposed to choose good local work sizes), or a reference to an array of local work sizes, with the same number of elements as \@global_work_size.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clEnqueueNDRangeKernel.html

$ev = $queue->acquire_gl_objects ([object, ...], $wait_events...)

Enqueues a list (an array-ref of OpenCL::Memory objects) to be acquired for subsequent OpenCL usage.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clEnqueueAcquireGLObjects.html

$ev = $queue->release_gl_objects ([object, ...], $wait_events...)

Enqueues a list (an array-ref of OpenCL::Memory objects) to be released for subsequent OpenGL usage.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clEnqueueReleaseGLObjects.html

$ev = $queue->wait_for_events ($wait_events...)

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clEnqueueWaitForEvents.html

$ev = $queue->marker ($wait_events...)

http://www.khronos.org/registry/cl/sdk/1.2/docs/man/xhtml/clEnqueueMarkerWithWaitList.html

$ev = $queue->barrier ($wait_events...)

http://www.khronos.org/registry/cl/sdk/1.2/docs/man/xhtml/clEnqueueBarrierWithWaitList.html

$queue->flush

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clFlush.html

$queue->finish

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clFinish.html

$packed_value = $queue->info ($name)

See $platform->info for details.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clGetCommandQueueInfo.html

$ctx = $command_queue->context

Calls clGetCommandQueueInfo with CL_QUEUE_CONTEXT and returns the result.

$device = $command_queue->device

Calls clGetCommandQueueInfo with CL_QUEUE_DEVICE and returns the result.

$uint = $command_queue->reference_count

Calls clGetCommandQueueInfo with CL_QUEUE_REFERENCE_COUNT and returns the result.

$command_queue_properties = $command_queue->properties

Calls clGetCommandQueueInfo with CL_QUEUE_PROPERTIES and returns the result.

MEMORY MAPPED BUFFERS

OpenCL allows you to map buffers and images to host memory (read: perl scalars). This is done much like reading or copying a buffer, by enqueuing a map or unmap operation on the command queue.

The map operations return an OpenCL::Mapped object - see "THE OpenCL::Mapped CLASS" section for details on what to do with these objects.

The object will be unmapped automatically when the mapped object is destroyed (you can use a barrier to make sure the unmap has finished, before using the buffer in a kernel), but you can also enqueue an unmap operation manually.

$mapped_buffer = $queue->map_buffer ($buf, $blocking=1, $map_flags=OpenCL::MAP_READ|OpenCL::MAP_WRITE, $offset=0, $size=undef, $wait_events...)

Maps the given buffer into host memory and returns an OpenCL::MappedBuffer object. If $size is specified as undef, then the map will extend to the end of the buffer.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clEnqueueMapBuffer.html

Example: map the buffer $buf fully and replace the first 4 bytes by "abcd", then unmap.

{
  my $mapped = $queue->map_buffer ($buf, 1, OpenCL::MAP_WRITE);
  substr $$mapped, 0, 4, "abcd";
} # asynchronously unmap because $mapped is destroyed

$mapped_image = $queue->map_image ($img, $blocking=1, $map_flags=OpenCL::MAP_READ|OpenCL::MAP_WRITE, $x=0, $y=0, $z=0, $width=undef, $height=undef, $depth=undef, $wait_events...)

Maps the given image area into host memory and return an OpenCL::MappedImage object.

If any of $width, $height and/or $depth are undef then they will be replaced by the maximum possible value.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clEnqueueMapImage.html

Example: map an image (with OpenCL::UNSIGNED_INT8 channel type) and set the first channel of the leftmost column to 5, then explicitly unmap it. You are not necessarily meant to do it this way, this example just shows you the accessors to use :)

my $mapped = $queue->map_image ($image, 1, OpenCL::MAP_WRITE);

$mapped->set ($_ * $mapped->row_pitch, pack "C", 5)
   for 0..$image->height;

$mapped->unmap;.
$mapped->wait; # only needed for out of order queues normally

$ev = $queue->unmap ($mapped, $wait_events...)

Unmaps the data from host memory. You must not call any methods that modify the data, or modify the data scalar directly, after calling this method.

The mapped event object will always be passed as part of the $wait_events. The mapped event object will be replaced by the new event object that this request creates.

THE OpenCL::Memory CLASS

This the superclass of all memory objects - OpenCL::Buffer, OpenCL::Image, OpenCL::Image2D and OpenCL::Image3D.

$packed_value = $memory->info ($name)

See $platform->info for details.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clGetMemObjectInfo.html

$mem_object_type = $mem->type

Calls clGetMemObjectInfo with CL_MEM_TYPE and returns the result.

$mem_flags = $mem->flags

Calls clGetMemObjectInfo with CL_MEM_FLAGS and returns the result.

$int = $mem->size

Calls clGetMemObjectInfo with CL_MEM_SIZE and returns the result.

$ptr_value = $mem->host_ptr

Calls clGetMemObjectInfo with CL_MEM_HOST_PTR and returns the result.

$uint = $mem->map_count

Calls clGetMemObjectInfo with CL_MEM_MAP_COUNT and returns the result.

$uint = $mem->reference_count

Calls clGetMemObjectInfo with CL_MEM_REFERENCE_COUNT and returns the result.

$ctx = $mem->context

Calls clGetMemObjectInfo with CL_MEM_CONTEXT and returns the result.

$mem = $mem->associated_memobject

Calls clGetMemObjectInfo with CL_MEM_ASSOCIATED_MEMOBJECT and returns the result.

$int = $mem->offset

Calls clGetMemObjectInfo with CL_MEM_OFFSET and returns the result.

($type, $name) = $mem->gl_object_info

Returns the OpenGL object type (e.g. OpenCL::GL_OBJECT_TEXTURE2D) and the object "name" (e.g. the texture name) used to create this memory object.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clGetGLObjectInfo.html

THE OpenCL::Buffer CLASS

This is a subclass of OpenCL::Memory, and the superclass of OpenCL::BufferObj. Its purpose is simply to distinguish between buffers and sub-buffers.

THE OpenCL::BufferObj CLASS

This is a subclass of OpenCL::Buffer and thus OpenCL::Memory. It exists because one cna create sub buffers of OpenLC::BufferObj objects, but not sub buffers from these sub buffers.

$subbuf = $buf_obj->sub_buffer_region ($flags, $origin, $size)

Creates an OpenCL::Buffer objects from this buffer and returns it. The buffer_create_type is assumed to be CL_BUFFER_CREATE_TYPE_REGION.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clCreateSubBuffer.html

THE OpenCL::Image CLASS

This is the superclass of all image objects - OpenCL::Image1D, OpenCL::Image1DArray, OpenCL::Image1DBuffer, OpenCL::Image2D, OpenCL::Image2DArray and OpenCL::Image3D.

$packed_value = $image->image_info ($name)

See $platform->info for details.

The reason this method is not called info is that there already is an ->info method inherited from OpenCL::Memory.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clGetImageInfo.html

($channel_order, $channel_data_type) = $image->format

Returns the channel order and type used to create the image by calling clGetImageInfo with CL_IMAGE_FORMAT.

$int = $image->element_size

Calls clGetImageInfo with CL_IMAGE_ELEMENT_SIZE and returns the result.

$int = $image->row_pitch

Calls clGetImageInfo with CL_IMAGE_ROW_PITCH and returns the result.

$int = $image->slice_pitch

Calls clGetImageInfo with CL_IMAGE_SLICE_PITCH and returns the result.

$int = $image->width

Calls clGetImageInfo with CL_IMAGE_WIDTH and returns the result.

$int = $image->height

Calls clGetImageInfo with CL_IMAGE_HEIGHT and returns the result.

$int = $image->depth

Calls clGetImageInfo with CL_IMAGE_DEPTH and returns the result.

$GLenum = $gl_texture->target

Calls clGetGLTextureInfo with CL_GL_TEXTURE_TARGET and returns the result.

$GLint = $gl_texture->gl_mipmap_level

Calls clGetGLTextureInfo with CL_GL_MIPMAP_LEVEL and returns the result.

THE OpenCL::Sampler CLASS

$packed_value = $sampler->info ($name)

See $platform->info for details.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clGetSamplerInfo.html

$uint = $sampler->reference_count

Calls clGetSamplerInfo with CL_SAMPLER_REFERENCE_COUNT and returns the result.

$ctx = $sampler->context

Calls clGetSamplerInfo with CL_SAMPLER_CONTEXT and returns the result.

$addressing_mode = $sampler->normalized_coords

Calls clGetSamplerInfo with CL_SAMPLER_NORMALIZED_COORDS and returns the result.

$filter_mode = $sampler->addressing_mode

Calls clGetSamplerInfo with CL_SAMPLER_ADDRESSING_MODE and returns the result.

$boolean = $sampler->filter_mode

Calls clGetSamplerInfo with CL_SAMPLER_FILTER_MODE and returns the result.

THE OpenCL::Program CLASS

$program->build (\@devices = undef, $options = "", $cb->($program) = undef)

Tries to build the program with the given options. See also the $ctx-build> convenience function.

If a callback is specified, then it will be called when compilation is finished. Note that many OpenCL implementations block your program while compiling whether you use a callback or not. See build_async if you want to make sure the build is done in the background.

Note that some OpenCL implementations act up badly, and don't call the callback in some error cases (but call it in others). This implementation assumes the callback will always be called, and leaks memory if this is not so. So best make sure you don't pass in invalid values.

Some implementations fail with OpenCL::INVALID_BINARY when the compilation state is successful but some later stage fails.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clBuildProgram.html

$program->build_async (\@devices = undef, $options = "", $cb->($program) = undef)

Similar to ->build, except it starts a thread, and never fails (you need to check the compilation status form the callback, or by polling).

$packed_value = $program->build_info ($device, $name)

Similar to $platform->info, but returns build info for a previous build attempt for the given device.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clGetBuildInfo.html

$kernel = $program->kernel ($function_name)

Creates an OpenCL::Kernel object out of the named __kernel function in the program.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clCreateKernel.html

@kernels = $program->kernels_in_program

Returns all kernels successfully compiled for all devices in program.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clCreateKernelsInProgram.html

$build_status = $program->build_status ($device)

Calls clGetProgramBuildInfo with CL_PROGRAM_BUILD_STATUS and returns the result.

$string = $program->build_options ($device)

Calls clGetProgramBuildInfo with CL_PROGRAM_BUILD_OPTIONS and returns the result.

$string = $program->build_log ($device)

Calls clGetProgramBuildInfo with CL_PROGRAM_BUILD_LOG and returns the result.

$packed_value = $program->info ($name)

See $platform->info for details.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clGetProgramInfo.html

$uint = $program->reference_count

Calls clGetProgramInfo with CL_PROGRAM_REFERENCE_COUNT and returns the result.

$ctx = $program->context

Calls clGetProgramInfo with CL_PROGRAM_CONTEXT and returns the result.

$uint = $program->num_devices

Calls clGetProgramInfo with CL_PROGRAM_NUM_DEVICES and returns the result.

@devices = $program->devices

Calls clGetProgramInfo with CL_PROGRAM_DEVICES and returns the result.

$string = $program->source

Calls clGetProgramInfo with CL_PROGRAM_SOURCE and returns the result.

@ints = $program->binary_sizes

Calls clGetProgramInfo with CL_PROGRAM_BINARY_SIZES and returns the result.

@blobs = $program->binaries

Returns a string for the compiled binary for every device associated with the program, empty strings indicate missing programs, and an empty result means no program binaries are available.

These "binaries" are often, in fact, informative low-level assembly sources.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clGetProgramInfo.html

THE OpenCL::Kernel CLASS

$packed_value = $kernel->info ($name)

See $platform->info for details.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clGetKernelInfo.html

$string = $kernel->function_name

Calls clGetKernelInfo with CL_KERNEL_FUNCTION_NAME and returns the result.

$uint = $kernel->num_args

Calls clGetKernelInfo with CL_KERNEL_NUM_ARGS and returns the result.

$uint = $kernel->reference_count

Calls clGetKernelInfo with CL_KERNEL_REFERENCE_COUNT and returns the result.

$ctx = $kernel->context

Calls clGetKernelInfo with CL_KERNEL_CONTEXT and returns the result.

$program = $kernel->program

Calls clGetKernelInfo with CL_KERNEL_PROGRAM and returns the result.

$packed_value = $kernel->work_group_info ($device, $name)

See $platform->info for details.

The reason this method is not called info is that there already is an ->info method.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clGetKernelWorkGroupInfo.html

$int = $kernel->work_group_size ($device)

Calls clGetKernelWorkGroupInfo with CL_KERNEL_WORK_GROUP_SIZE and returns the result.

@ints = $kernel->compile_work_group_size ($device)

Calls clGetKernelWorkGroupInfo with CL_KERNEL_COMPILE_WORK_GROUP_SIZE and returns the result.

$ulong = $kernel->local_mem_size ($device)

Calls clGetKernelWorkGroupInfo with CL_KERNEL_LOCAL_MEM_SIZE and returns the result.

$int = $kernel->preferred_work_group_size_multiple ($device)

Calls clGetKernelWorkGroupInfo with CL_KERNEL_PREFERRED_WORK_GROUP_SIZE_MULTIPLE and returns the result.

$ulong = $kernel->private_mem_size ($device)

Calls clGetKernelWorkGroupInfo with CL_KERNEL_PRIVATE_MEM_SIZE and returns the result.

$kernel->setf ($format, ...)

Sets the arguments of a kernel. Since OpenCL 1.1 doesn't have a generic way to set arguments (and with OpenCL 1.2 it might be rather slow), you need to specify a format argument, much as with printf, to tell OpenCL what type of argument it is.

The format arguments are single letters:

c   char
C   unsigned char
s   short
S   unsigned short
i   int
I   unsigned int
l   long
L   unsigned long

h   half float (0..65535)
f   float
d   double

z   local (octet size)

m   memory object (buffer or image)
a   sampler
e   event

Space characters in the format string are ignored.

Example: set the arguments for a kernel that expects an int, two floats, a buffer and an image.

$kernel->setf ("i ff mm", 5, 0.5, 3, $buffer, $image);

$kernel->set_TYPE ($index, $value)

$kernel->set_char ($index, $value)

$kernel->set_uchar ($index, $value)

$kernel->set_short ($index, $value)

$kernel->set_ushort ($index, $value)

$kernel->set_int ($index, $value)

$kernel->set_uint ($index, $value)

$kernel->set_long ($index, $value)

$kernel->set_ulong ($index, $value)

$kernel->set_half ($index, $value)

$kernel->set_float ($index, $value)

$kernel->set_double ($index, $value)

$kernel->set_memory ($index, $value)

$kernel->set_buffer ($index, $value)

$kernel->set_image ($index, $value)

$kernel->set_sampler ($index, $value)

$kernel->set_local ($index, $value)

$kernel->set_event ($index, $value)

This is a family of methods to set the kernel argument with the number $index to the give $value.

Chars and integers (including the half type) are specified as integers, float and double as floating point values, memory/buffer/image must be an object of that type or undef, local-memory arguments are set by specifying the size, and sampler and event must be objects of that type.

Note that set_memory works for all memory objects (all types of buffers and images) - the main purpose of the more specific set_TYPE functions is type checking.

Setting an argument for a kernel does NOT keep a reference to the object - for example, if you set an argument to some image object, free the image, and call the kernel, you will run into undefined behaviour.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clSetKernelArg.html

THE OpenCL::Event CLASS

This is the superclass for all event objects (including OpenCL::UserEvent objects).

$ev->wait

Waits for the event to complete.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clWaitForEvents.html

$ev->cb ($exec_callback_type, $callback->($event, $event_command_exec_status))

Adds a callback to the callback stack for the given event type. There is no way to remove a callback again.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clSetEventCallback.html

$packed_value = $ev->info ($name)

See $platform->info for details.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clGetEventInfo.html

$queue = $event->command_queue

Calls clGetEventInfo with CL_EVENT_COMMAND_QUEUE and returns the result.

$command_type = $event->command_type

Calls clGetEventInfo with CL_EVENT_COMMAND_TYPE and returns the result.

$uint = $event->reference_count

Calls clGetEventInfo with CL_EVENT_REFERENCE_COUNT and returns the result.

$uint = $event->command_execution_status

Calls clGetEventInfo with CL_EVENT_COMMAND_EXECUTION_STATUS and returns the result.

$ctx = $event->context

Calls clGetEventInfo with CL_EVENT_CONTEXT and returns the result.

$packed_value = $ev->profiling_info ($name)

See $platform->info for details.

The reason this method is not called info is that there already is an ->info method.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clGetProfilingInfo.html

$ulong = $event->profiling_command_queued

Calls clGetEventProfilingInfo with CL_PROFILING_COMMAND_QUEUED and returns the result.

$ulong = $event->profiling_command_submit

Calls clGetEventProfilingInfo with CL_PROFILING_COMMAND_SUBMIT and returns the result.

$ulong = $event->profiling_command_start

Calls clGetEventProfilingInfo with CL_PROFILING_COMMAND_START and returns the result.

$ulong = $event->profiling_command_end

Calls clGetEventProfilingInfo with CL_PROFILING_COMMAND_END and returns the result.

THE OpenCL::UserEvent CLASS

This is a subclass of OpenCL::Event.

$ev->set_status ($execution_status)

Sets the execution status of the user event. Can only be called once, either with OpenCL::COMPLETE or a negative number as status.

http://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/clSetUserEventStatus.html

THE OpenCL::Mapped CLASS

This class represents objects mapped into host memory. They are represented by a blessed string scalar. The string data is the mapped memory area, that is, if you read or write it, then the mapped object is accessed directly.

You must only ever use operations that modify the string in-place - for example, a substr that doesn't change the length, or maybe a regex that doesn't change the length. Any other operation might cause the data to be copied.

When the object is destroyed it will enqueue an implicit unmap operation on the queue that was used to create it.

Keep in mind that you need to unmap (or destroy) mapped objects before OpenCL sees the changes, even if some implementations don't need this sometimes.

Example, replace the first two floats in the mapped buffer by 1 and 2.

my $mapped = $queue->map_buffer ($buf, ...
$mapped->event->wait; # make sure it's there

# now replace first 8 bytes by new data, which is exactly 8 bytes long
# we blindly assume device endianness to equal host endianness
# (and of course, we assume iee 754 single precision floats :)
substr $$mapped, 0, 8, pack "f*", 1, 2;

$ev = $mapped->unmap ($wait_events...)

Unmaps the mapped memory object, using the queue originally used to create it, quite similarly to $queue->unmap ($mapped, ...).

$bool = $mapped->mapped

Returns whether the object is still mapped - true before an unmap is enqueued, false afterwards.

$ev = $mapped->event

Return the event object associated with the mapped object. Initially, this will be the event object created when mapping the object, and after an unmap, this will be the event object that the unmap operation created.

$mapped->wait

Same as $mapped->event->wait - makes sure no operations on this mapped object are outstanding.

$bytes = $mapped->size

Returns the size of the mapped area, in bytes. Same as length $$mapped.

$ptr = $mapped->ptr

Returns the raw memory address of the mapped area.

$mapped->set ($offset, $data)

Replaces the data at the given $offset in the memory area by the new $data. This method is safer than direct manipulation of $mapped because it does bounds-checking, but also slower.

$data = $mapped->get ($offset, $length)

Returns (without copying) a scalar representing the data at the given $offset and $length in the mapped memory area. This is the same as the following substr, except much slower;

$data = substr $$mapped, $offset, $length

THE OpenCL::MappedBuffer CLASS

This is a subclass of OpenCL::Mapped, representing mapped buffers.

THE OpenCL::MappedImage CLASS

This is a subclass of OpenCL::Mapped, representing mapped images.

$bytes = $mapped->row_pitch
$bytes = $mapped->slice_pitch: Return the row or slice pitch of the image that has been mapped.

AUTHOR

Marc Lehmann <schmorp@schmorp.de>
http://home.schmorp.de/

To install OpenCL, copy and paste the appropriate command in to your terminal.

cpanm

cpanm OpenCL

CPAN shell

perl -MCPAN -e shell
install OpenCL

For more information on module installation, please visit the detailed CPAN module installation guide.

	Global
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`?`	Bring up this help dialog

	GitHub
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`g` `i`	Go to GitHub issues (only if GitHub is preferred repository)

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`g` `c`	Go to changes
`g` `i`	Go to issues
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NAME

SYNOPSIS

DESCRIPTION

OpenCL FROM 10000 FEET HEIGHT

HELPFUL RESOURCES

BASIC WORKFLOW

EXAMPLES

Enumerate all devices and get contexts for them.

Get a useful context and a command queue.

Print all supported image formats of a context.

Create a buffer with some predefined data, read it back synchronously, then asynchronously.

Create and build a program, then create a kernel out of one of its functions.

Create some input and output float buffers, then call the 'squareit' kernel on them.

The same enqueue operations as before, but assuming an out-of-order queue, showing off barriers.

The same enqueue operations as before, but assuming an out-of-order queue, showing off event objects and wait lists.

Use the OpenGL module to share a texture between OpenCL and OpenGL and draw some julia set tunnel effect.

How to modify the previous example to not rely on GL sharing.

DOCUMENTATION

BASIC CONVENTIONS

PERL AND OPENCL TYPES

GLX SUPPORT

EVENT SYSTEM

Don't use callbacks.

Use AnyEvent

Let yourself be interrupted at any time

Be creative

THE OpenCL PACKAGE

THE OpenCL::Object CLASS

THE OpenCL::Platform CLASS

THE OpenCL::Device CLASS

THE OpenCL::Context CLASS

THE OpenCL::Queue CLASS

MEMORY MAPPED BUFFERS

THE OpenCL::Memory CLASS

THE OpenCL::Buffer CLASS

THE OpenCL::BufferObj CLASS

THE OpenCL::Image CLASS

THE OpenCL::Sampler CLASS

THE OpenCL::Program CLASS

THE OpenCL::Kernel CLASS

THE OpenCL::Event CLASS

THE OpenCL::UserEvent CLASS

THE OpenCL::Mapped CLASS

THE OpenCL::MappedBuffer CLASS

THE OpenCL::MappedImage CLASS

AUTHOR

Module Install Instructions