SPRUI04F july 2015 – april 2023
advice #30001: Loop at line 18 cannot be scheduled efficiently, as it
contains conversion from "type-a" to "type-b".
Try to use "suggested" type.
The compiler can insert calls to special functions in the run-time support library (RTS) to support operations that are not natively supported by the ISA. For instance, while floating-point ISAs support instructions to convert between floating-point and signed integer values, they don't support conversion between floating-point and unsigned integer values. If you use unsigned variables in floating point expressions, the compiler will generate a call to an RTS routine to carry out this function. Such a call will disable software pipelining.
You can change the unsigned variables in your code to signed variables and prevent this from happening. The compiler will then be able to use the native hardware instead of adding the special function call, so you may get better performance.