Warning(17548): VHDL warning at <VHDL file>: magnitude comparator on user-encoded values can create simulation-synthesis differences

Due to a problem in the Quartus® Prime Pro Edition Software version 17.1 and earlier you may see this warning during synthesis. This problem occurs in designs using VHDL and the 'pos attribute.

It is not safe to ignore this warning and the logic produced is functionally incorrect.

To work around this problem, either do not use the 'pos attribute or add this assignment to your  .qsf (Quartus Settings File).

set_global_assignment -name ENABLE_STATE_MACHINE_INFERENCE OFF

This will mean that your state machines will not be inferred with one-hot encoding.

This problem is scheduled to fixed in a future release of the Quartus® Prime Pro Edition Software and future instances of a simulation-synthesis difference are scheduled to become an error rather than a warning.