Optimizing code may introduce bugs to software that runs perfectly when non-optimized. Also, the level of performance gain depends highly on the internal structure of the source code. LISP is a language in which you can easily write programs that create or modify functions at runtime. This use of the language by definition contradicts compile-time optimization.
The VLISP compiler analyzes the code it compiles and links, then it creates a report pointing you to all source code segments that may cause problems when optimized. If you do not receive any optimization warning messages, you can assume optimization did not introduce new problems to your code.
The compiler is able to detect most problematic situations in AutoLISP code. However, there are situations in which it is impossible to detect code that may become incorrect during the optimization. If your program uses one of the following constructs, the compiler will not be able to prove correctness of the optimized code definitively:
Remember that any optimization will change program semantics. The compiler intends to preserve the behavior of project components relative to one another. The compiler cannot guarantee unchanged behavior between your project and external procedures. Typical effects of optimization include the following: