Warnings

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

Object binaries compiled with the-fast option are 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.

The expansion of -fast includes -D_MATHERR_ERRNO_DONTCARE.

To display the expansion of —fast on any platform, run the command CC —dryrun —fast

>CC -dryrun -fast
###     command line files and options (expanded):
### -dryrun -xO5 -xarch=sparcvis2 -xcache=64/32/4:1024/64/4 \
-xchip=ultra3i -xmemalign=8s -fsimple=2 -fns=yes -ftrap=%none \
-xlibmil -xlibmopt -xbuiltin=%all -D__MATHERR_ERRNO_DONTCARE