What I didn't anderstand is that this option "Support Long long" is: Me as developper indicate to Matlab that my compiler doesn't support long long (or yes it is supported).
I give here the option description (2018a):
"Specify whether the C compiler for production hardware supports long long.
Most C99 compilers support long long."
How can the advisor say that for efficiency the generated code shall use long long? => Hey, use long long, it will not work as you say your compiler doesn't support it but YOLO!
I think matlab belives that my compiler is C99 (I got a warning for simulation advisor that suggest me to select C99 instead of C90). But in fact my compiler is C90 (without long long introduced in C99).
It is in fact a bug in the algorithm for this advise. This shall be reported, and I hope fixed.
I don't know the way to do that.