Compiling a file containing long functions with lots of constants -- in this case, one function has 2000 lines and another has almost 13,000 -- without optimisation may abort with a "constant table error" message. The compiler is trying to place constants in among the instructions, which usually leads to more efficient code for ARM Cortex devices, but was unable to do so. Turning off embedded constants inhibits the whole pass, while compiling with optimisation reduces the number of constants.