C++ Fixed Point Maths Class (64-bit precision)

I'm looking for a C++ class that would replace the equivalent 'float' type for hardware that doesn't support it. I don't require it to work the same way as a 'float', I would just like it to use fixed point maths. I have an existing class that uses 32-bit precision (i.e. 16:16 or 20:12 etc...) but I need one that stores 64-bit numbers. I also need to be able to modify the precision - for instance, from 32:32 to 40:24 etc... The class would contain all the standard operators so I can simply typedef the class as a float replacement. Due to the hardware I'm working on the code would have to be completely C++ and have no PC specific assembly code. The hardware only supports 32-bit unsigned integers as well so all larger maths would have to work within those bounds (e.g. the 128-bit result from a multiplication would have to be stored as 4 32-bit integers). ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Deliverables must be in ready-to-run condition, as follows (depending on the nature of the deliverables): a) For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform Standard C++ Class required - no platform specific machine code allowed