In addition to sibling comments, two more oddballs are MSP430 floats and DSPs. MSP430-style floats are common in industrial automation and such, since many sen

In addition to sibling comments, two more oddballs are MSP430 floats and DSPs. MSP430-style floats are common in industrial automation and such, since many sensors either use or used to use MSP430s to collect data. And, of course, in that field, legacy carries more inertia than a 50,000-ton press.... Newer DSPs tend to use IEEE-754 floats, but this was not always the case. Older DSPs used every trick in the book to go faster, and "compatibility with standard floating-point formats" was never in their product requirements. So you can guess at what manner of horrors came out of that! Fortunately, their customers are mostly the sort of people who (1) didn't mind changing to standard floats, since it's not like things were stable before; and (2) are very, very comfortable writing this stuff directly in assembly. So they definitely know whether their architecture has an instruction to take the absolute value, needs a short branching program, or just needs a single bit-operation.