For smallpt see http://www.kevinbeason.com/smallpt/
For smallptGPU see http://davibu.interfree.it/opencl/smallptgpu2/smallptGPU2.html
These are very dated and not maintained. I have made some changes to make them work on modern systems.
Research Projects for ZJU CS Assembly Language and Microcomputer Interface
For smallpt see http://www.kevinbeason.com/smallpt/
For smallptGPU see http://davibu.interfree.it/opencl/smallptgpu2/smallptGPU2.html
These are very dated and not maintained. I have made some changes to make them work on modern systems.
Research Projects for ZJU CS Assembly Language and Microcomputer Interface