tags : Floating Point, Computer Architecture
To come back later

finance folks use fixedpoint

GPUs do not implement fixedpoint arithmetic in hardware

I would expect dedicated digital signal processor chips to almost always support a highperformance fixedpoint multiplyadd instruction.

A Tutorial on Data Representation  Integers, Floatingpoint numbers
Deterministic?
 The main appeal of fixed point nowadays is determinism across hardware  so networked games benefit, for instance.
 They are still popular for multiplayer games that has a synced game state. In all clients you want to get exact same results when they run same code which is not possible with fp
Integer Math
 Integer arithmetic is a specialisation of fixedpoint arithmetic in which operands have an exponent of zero. This means that the results of all operations also have an exponent of zero. That obviously simplifies operations themselves, but it also means that the results of those operations can be used in subsequent operations (or recurrently in the same operation) without the need to normalise the exponent, i.e. no bit shifting!
 you can perfectly store integers in FP variables. Even banks could store everything in FP instead of integer variables in the lowest unit they support (for example cents).
 Integers at overflow fail catastrophically, so that also has to be controlled for.
Uses
 very lowlevel network software, radios, and image processing.
 NN inference
 In neural nets, it is usually paired with reduced precision
int8
because in addition to getting more operations per second, you can transfer more weights per byte of L1 cache and per bytepersecond of memory bus. Since navigating those memory limitations is a major part of performance optimization, reducedprecision fixedpoint can help a lot.