Warnings

If you compile and link in separate steps, the -fast option must appear in both the compile command and the link command.

Code that is compiled with the -fast option is not portable. For example, using the following command on an UltraSPARC III system generates a binary that will not execute on an UltraSPARC II system.

example% CC -fast test.cc

Do not use this option for programs that depend on IEEE standard floating-point arithmetic; different numerical results, premature program termination, or unexpected SIGFPE signals can occur.

In previous SPARC releases, the -fast macro expanded to -fsimple=1. Now it expands to -fsimple=2.

In previous releases, the -fast macro expanded to -xO4. Now it expands to -xO5.

In previous SPARC releases, the –fast macro option included –fnonstd; now it does not. Nonstandard floating-point mode is not initialized by –fast. See the Numerical Computation Guide, ieee_sun(3M).