philipturner / swift-opencl

Swift bindings for OpenCL

Swift Bindings for OpenCL

A native Swift API for OpenCL, based on the C++ bindings. This package runs on macOS, Linux, Windows, and Android. It detects which OpenCL version you have at runtime.

Naming Conventions

swift-opencl renames the following words in OpenCL macros:

• "Addr" to "Address"
• "Alloc" to "Allocation"
• "Arg" to "Argument"
• "Bitfield" to "BitField"
• "Cacheline" to "CacheLine"
• "Ctor" to "Constructor"
• "Dtor" to "Destructor"
• "Exec" to "Execution"
• "FP" to "FloatingPoint"
• "Mem" to "Memory"
• "Memobject" to "MemoryObject"
• "Ptr" to "Pointer"
• "Rect" to "Rectangle"
• "Spec" to "SpecializationConstant"

This package's source code has numerous comments explaining where its API structure and names differ from the C++ bindings. It lacks much documentation otherwise, because the C++ bindings are extensively documented. Just download opencl.hpp and search for the C++ counterpart to any Swift type.

Tips

Most properties of OpenCL types take a non-negligible time to retrieve, making multiple function calls under the hood. When possible, access them once and reuse the returned value.

import OpenCL

// ❌
func inList(device: CLDevice, names: [String]) -> Bool {
  // Fetches the device name on potentially every iteration through `names`.
  names.contains(where: { $0 == device.name! })
}

// ✅
func inList(device: CLDevice, names: [String]) -> Bool {
  let deviceName = device.name!
  return names.contains(where: { $0 == deviceName })
}

swift-opencl dynamically loads OpenCL symbols at runtime like PythonKit, so it can import OpenCL on macOS without depending on the Objective-C framework. This means swift-opencl's Swift module can be named OpenCL. If you use the module, ensure the system framework named OpenCL is not in your dependency chain.

CLError produces a name collision with Apple’s CoreLocation framework. You can work around it by stating CoreLocation.CLError and OpenCL.CLError explicitly.