What you're describing is OpenCL, yes it exists, both Xilinx and Intel produce toolsets. No they aren't sane by software standards, but they're fantastic compared to hardware engineering. A card will cost you ~$10k for something you'd actually get acceleration from (https://www.xilinx.com/products/boards-and-kits/alveo/u250.h...) and you'll still need a degree in electronic engineering to produce something that convincingly accelerates your task.