About Optimizing for Specific Processors
You can generate optimized code that only runs on a target processor or later processors. The resulting code may use extensions for the target processor, while not providing any conditional code to support processors earlier than the target processor.
If a program compiled with any of these processor-specifc optimization options, listed in the next topic, is executed on a processor that lacks the specified extensions, it can fail with an illegal instruction exception or display other unexpected behavior.
For the target processor, the compiler uses: