[INFORMATION]
The compiler has optimized the indicated library function. Depending on the actual function and its arguments, the compiler does replace the function with a simpler one or does even replace the function with the actual code as if the ANSI-C function would have been called. If you want to your a certain actual implementation of this function, disable this optimization with the -oilib option. There is a certain -oilib suboption for every supported ANSI-C function.