I am writing a marshaling layer to automatically convert values between different domains. When it comes to floating point values this potentially means converting values from one floating point format to another. However, it seems that almost every modern system is using IEEE754, so I'm wondering whether it's actually worth generalising to allow other formats, or just manage marshaling between different IEEE754 formats.
Does anyone know of any commonly used floating point formats other than IEEE754 that I should consider (perhaps on ARM processors or mainframes)? If so, a reference to the format specification would be extremely helpful.
Virtually all relatively modern (within the last 15 years) general purpose computers use IEEE 754. In the very unlikely event that you find system that you need to support which uses a non-IEEE 754 floating point format, there will probably be a library available to convert to/from IEEE 754.
Some non-ancient systems which did not natively use IEEE 754 were the Cray SV1 (1998-2003) and IBM System 360, 370, and 390 prior to Generation 5 (ended 2002). IBM implemented IEEE 754 emulation around 2001 in a software release for prior S/390 hardware.