OpenCL

Installing on Mac OS X

April 2017

Checking Hardware

Open Apple Menu > About This Mac > System Information

Click "Graphics/Displays" on the left hand menu:

Intel Iris Graphics 6100:

  Chipset Model:	Intel Iris Graphics 6100
  Type:	GPU
  Bus:	Built-In
  VRAM (Dynamic, Max):	1536 MB
  Vendor:	Intel (0x8086)
  Device ID:	0x162b
  Revision ID:	0x0009

OpenGL and OpenCL Versions

Apple lists the different graphic cards and the corresponding versions of OpenGL and OpenCL that are compatible here: https://support.apple.com/en-us/HT202823

OpenGL - version 4.1

OpenCL - version 1.2

Intel doesn't provide any Apple drivers, because Apple wants you to go through Apple. Go figure.

Link to OpenCL software for Mac: https://developer.apple.com/opencl/

OpenCL Binary

The openclc binary is located in /System/Library/Frameworks/OpenCL.framework/Libraries/openclc

Hello World

Here's a link to an OpenCL Hello World guide using XCode: [1]

Building from the command line: [2]

Link to the code of OpenCL: [3]

If you just compile it without any flags, it won't work:

$ /System/Library/Frameworks/OpenCL.framework/Libraries/openclc hello.c
In file included from hello.c:61:
In file included from /System/Library/Frameworks/OpenCL.framework/Headers/opencl.h:12:
In file included from /System/Library/Frameworks/OpenCL.framework/Headers/cl.h:28:
/System/Library/Frameworks/OpenCL.framework/Headers/cl_platform.h:357:18: fatal error:
      'xmmintrin.h' file not found
        #include <xmmintrin.h>
                 ^
1 error generated.

The compiler command needs to use the -I flag:

$ cd ~/OpenCL_Hello_World_Example

$ find /System/Library/Frameworks -name "xmmintrin.h"
/System/Library/Frameworks/OpenCL.framework/Versions/A/lib/clang/2.0/include/xmmintrin.h

$ /System/Library/Frameworks/OpenCL.framework/Libraries/openclc -framework OpenCL \
  -I/System/Library/Frameworks/OpenCL.framework/Versions/A/lib/clang/2.0/include  hello.c

$ ./a.out
Computed '1024/1024' correct values!