A.2.24.1 Values

The -fns option can have the following values.

Defaults

If -fns is not specified, the nonstandard floating point mode is not enabled automatically. Standard IEEE 754 floating-point computation takes place, that is, underflows are gradual.

If only –fns is specified, –fns=yes is assumed.

Examples

In the following example, -fast expands to several options, one of which is -fns=yes which selects nonstandard floating-point mode. The subsequent -fns=no option overrides the initial setting and selects floating-point mode.

example% CC foo.cc -fast -fns=no

Warnings

When nonstandard mode is enabled, floating-point arithmetic can produce results that do not conform to the requirements of the IEEE 754 standard.

If you compile one routine with the -fns option, then compile all routines of the program with the –fns option; otherwise, you might get unexpected results.

This option is effective only on SPARC devices, and only if used when compiling the main program. On x86 devices, the option is ignored.

Use of the –fns=yes (or -fns) option might generate the following message if your program experiences a floating-point error normally managed by the IEEE floating-point trap handlers:

See also

Numerical Computation Guide, ieee_sun(3M)