Failed to map instruction style information

Your code is probably too complex for Altera's compiler, I would specifically advise against using large switch/case blocks. If you expect the switch/case block to be implemented as an FSM by the compiler (like it would in HDL), it will most likely not happen; instead, the compiler will probably try to pipeline the operation by creating a different path for each case statement and then insert extra registers to unify the latency of all the paths.

You should report compiler crashes like this directly to Altera, they are the only ones who can tell you what is wrong.

P.S. If you are reporting it to Altera, don't forget to include the "defines.h" file so that they can reproduce the crash.