1) /bin/cc is based on the USL cc, not the Microsoft cc that shipped with earlier SCO products. This is actually a respectable compiler. It generates very good code, has a reliable optimizer, and is pretty quick and solid. You can control optimizations with the -O flags and can fine tune the optimizations with the -K options.

2) icc ships with the SCO DS and is based on the Intel Reference Compiler. This compiler can generate amazing code and very good warnings and diagnostics about your source. It can generate Pentium Pro specific optimizations. The price you pay for all this optimization is high in terms of compile time. It can be slow to build your program.

3) gcc is part of the GNU ds. It generates code that is comparable to the quality of the /bin/cc output. The warnings and diagnostics are good. Optimizations can be controlled via the -O, -m, and -f flags.

4) UDK compiler. See the below for more information on the developement kits available for SCO OS's.

http://www.sco.com/developers/products/devkits.html

All three compilers are ANSI C by default, with options to fall back to K&R.

If you're looking for a "magic bullet" from the compiler to speed up your program by an order of magnitude, just by using a different one or by wiggling some compiler switches, don't. Only after you've highly tuned your algorithms and implementation should you even worry about compiler performance. Even then, you should be prepared to stare at the compiler output and run extensive tests before making an informed decision.

robertlipe@usa.net, gerberb@zenez.com