'\" t
.\" @(#)fesetprec.3m 1.5 00/01/01 SMI
.TH fesetprec 3M  "01/01/00"
.SH NAME
fesetprec, fegetprec \- control floating point rounding precision 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 fesetprec(int " prec );
.LP
.BI "int fegetprec(void);"
.SH DESCRIPTION
.IX "fesetprec function" "" "\fLfesetprec()\fP function"
.IX "fegetprec function" "" "\fLfegetprec()\fP function"
.LP
The \s-1IEEE\s0 754 standard defines rounding precision modes for systems
that always deliver intermediate results to destinations in extended double
precision format.  These modes allow such systems to deliver correctly
rounded single and double precision results (in the absence of underflow
and overflow) with only one rounding.
.LP
\f3fesetprec(\f2prec\f3)\f1 sets the current rounding precision to the
precision specified by \f2prec\f1, which must be one of the following
values (defined in \f3<fenv.h>\f1):
.LP
.RS
.PD 0
.TP 20
\s-1FE_FLTPREC\s0
round to single precision
.TP
\s-1FE_DBLPREC\s0
round to double precision
.TP
\s-1FE_LDBLPREC\s0
round to extended double precision
.PD
.RE
.LP
The default precision is \s-1FE_LDBLPREC\s0 (unless it is changed by the
\f3-fprecision\f1 compiler flag).
.LP
\f3fegetprec(\|)\f1 returns the current rounding precision.
.LP
.SH "RETURN VALUES"
\f3fesetprec\f1 returns a nonzero value if the requested rounding precision
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
=
Architecture	Intel (see below)
Availability	SPROm9xs
Interface Stability	Stable
MT-Level	MT-Safe
.TE
.LP
These functions are not available on SPARC systems because SPARC processors
deliver intermediate results to destinations in single or double format as
determined by each floating point instruction.
.SH "SEE ALSO"
.BR fegetenv (3M),
.BR fesetround (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
\f2Numerical Computation Guide\f1 for additional information about linking
with libm9x.