I tried the FixedPointCalculations example sketch included with FixedPoints library V1.0.4 and it gives compile errors.
But you can try this yourself. In the IDE, install support for the Arduino Due:
Tools > Board: > Boards Manager
Install: Arduino SAM Boards (32-bits ARM Cortex-M3) by Arduino
Tools > Board: > Arduino Due (Programming Port)
Tools > Board: > Arduino Due (Native USB Port)
File > Examples > FixedPoints > FixedPointsCalculations
Try to compile it.
I don’t have a Due, so if you get a clean compile I won’t be able to test it. I do have a SparkFun SAMD21 Mini Breakout and a Rabid Prototypes Tau, which are both SAMD21 ARM Cortex-M0+ based. I get (the same?) compile errors with them but I can test them if you get a clean compile.