'\" t
.\" @(#)fesetround.3m 1.4 97/06/25 SMI
.TH fesetround 3M  "06/25/97"
.SH NAME
fesetround, fegetround \- control floating point rounding direction modes
.SH SYNOPSIS
.LP
.B cc
.RI "[ " "flag" " \|.\|.\|. ] " "file" " \|.\|.\|."
.B -R/opt/SUNWspro/lib -L/opt/SUNWspro/lib -lm9x
.RI "[ " "library" " \|.\|.\|. ]"
.LP
.B #include <fenv.h>
.LP
.BI "int fesetround(int " round );
.LP
.BI "int fegetround(void);"
.LP
.B #include <fenv96.h>
.LP
.BI "int fesetround96(int " round );
.LP
.BI "int fegetround96(void);"
.SH DESCRIPTION
.IX "fesetround function" "" "\fLfesetround()\fP function"
.IX "fegetround function" "" "\fLfegetround()\fP function"
.IX "fesetround96 function" "" "\fLfesetround96()\fP function"
.IX "fegetround96 function" "" "\fLfegetround96()\fP function"
.LP
\f3fesetround(\f2round\f3)\f1 sets the current rounding direction to the
direction specified by \f2round\f1, which must be one of the following
values (defined in \f3<fenv.h>\f1):
.LP
.RS
.PD 0
.TP 20
\s-1FE_TONEAREST\s0
round to nearest
.TP
\s-1FE_UPWARD\s0
round toward positive infinity
.TP
\s-1FE_DOWNWARD\s0
round toward negative infinity
.TP
\s-1FE_TOWARDZERO\s0
round toward zero
.PD
.RE
.LP
The default direction is \s-1FE_TONEAREST\s0 (unless it is changed by the
\f3-fround\f1 compiler flag).
.LP
\f3fegetround(\|)\f1 returns the current rounding direction.
.SH "RETURN VALUES"
\f3fesetround\f1 returns a nonzero value if the requested rounding mode
is established and returns zero otherwise.
.SH ATTRIBUTES
See
.BR attributes (5)
for descriptions of the following attributes:
.sp
.ne 10
.TS
box;
cbp-1 | cbp-1
l | l .
ATTRIBUTE TYPE	ATTRIBUTE VALUE
=
Availability	SPROm9xs
Interface Stability	Stable (see below)
MT-Level	MT-Safe
.TE
.LP
The \f3fegetround\f1 and \f3fesetround\f1 functions are defined by the C9X
draft standard.  Should the final standard change the definitions of these
functions, new conforming implementations will be provided in a subsequent
major release.  Therefore, these functions should currently be considered
Evolving.
.LP
To maintain compatibility with the present C9X definitions, programs may
instead use the \f3fegetround96\f1 and \f3fesetround96\f1 functions.  Each
of these functions performs the same operation as its counterpart without
the \f396\f1 suffix.  The suffixed functions, however, will retain their
present definitions regardless of changes to the C9X draft.  These functions
are Stable.
.LP
Note that \f3<fenv.h>\f1 currently redefines the names of the standard
functions to their suffixed counterparts so that compiled programs will
invoke the suffixed functions.  Once the C9X draft is adopted as a standard,
those redefinitions will be removed from \f3<fenv.h>\f1.  Any program
recompiled thereafter that uses the standard, unsuffixed names will then
invoke the standard functions (with their final definitions), but previously
compiled programs will be unaffected.
.SH "SEE ALSO"
.BR fegetenv (3M),
.BR fesetprec (3M),
.BR attributes (5)
.LP
.I Numerical Computation Guide
.SH NOTES
As shown in the synopsis, the recommended way to link with libm9x using
\f3cc\f1 is to specify
.LP
.RS
.BI -R install-path "/lib -L" install-path "/lib -lm9x"
.RE
.LP
on the command line, where \f2install-path\f1 refers to the location in
which the compilers are installed (/opt/SUNWspro by default).  See the
\f3Numerical Computation Guide\f1 or the READMEs/math_libraries file in
the compiler installation area for additional information about linking
with libm9x.