A calculation of PI using integrals which runs on the GPU (CUDA).
NVIDIA GPUs with compute capabilty of 6.0 or higher.
For GPUs with compute capabilty 8.6 (arch=sm_86) you can use the prebuilts.
To build it yourself, use the following command: nvcc pi_approx_gpu.cu -arch=sm_{your compute capability here} -o pi_approx_gpu, for example, if your GPU has a 7.5 compute capability, run: nvcc pi_approx_gpu.cu -arch=sm_75 -o pi_approx_gpu.
After compiling / using the prebuilts, just run the .exe file (pi_approx_gpu.exe) and enter the amount of iterations you want to perform (higher means higher accuracy, and if you entered 30, it will run 2^30 iterations).
The code calculates the integral of sqrt(1-x^2) in the range -1, 1 which gives you pi/2, by calculating the size of many rectangles bellow this function, and the "iterations" you enter are acctualy the number of recantgles to calculate.