386 | The code executes on 80386, 80486 and Pentium processors. |
486 | Includes instructions that are available only on 80486 and Pentium processors. |
PENTIUM | As for "486", but switches on certain optimizations which improve code speed at the cost of increased code size. None of these optimizations prevent the code running on a 486, but the benefits are not as great as when the code is run on a Pentium. |
Comments:
This directive is only available on SCO UNIX.