Exotic architectures the standards committees care about

Question

I know that the C and C++ standards leave many aspects of the language implementation-defined just because if there is an architecture with other characteristics, it would b

Answer 1

IEEE 754 binary representation was uncommon on GPUs until recently, see GPU Floating-Point Paranoia.

EDIT: a question has been raised in the comments whether GPU floating point is relevant to the usual computer programming, unrelated to graphics. Hell, yes! Most high performance thing industrially computed today is done on GPUs; the list includes AI, data mining, neural networks, physical simulations, weather forecast, and much much more. One of the links in the comments shows why: an order of magnitude floating point advantage of GPUs.

Another thing I'd like to add, which is more relevant to the OP question: what did people do 10-15 years ago when GPU floating point was not IEEE and when there was no API such as today's OpenCL or CUDA to program GPUs? Believe it or not, early GPU computing pioneers managed to program GPUs without an API to do that! I met one of them in my company. Here's what he did: he encoded the data he needed to compute as an image with pixels representing the values he was working on, then used OpenGL to perform the operations he needed (such as "gaussian blur" to represent a convolution with a normal distribution, etc), and decoded the resulting image back into an array of results. And this still was faster than using CPU!

Things like that is what prompted NVidia to finally make their internal data binary compatible with IEEE and to introduce an API oriented on computation rather than image manipulation.