NAME

fesetprec, fegetprec − control floating point rounding precision modes

SYNOPSIS

cc [ flag ... ] file ... -R/opt/SUNWspro/lib -L/opt/SUNWspro/lib -lm9x [ library ... ]

#include <fenv.h>

int fesetprec(int prec);

int fegetprec(void);

DESCRIPTION

The IEEE 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. 

fesetprec(prec) sets the current rounding precision to the precision specified by prec, which must be one of the following values (defined in <fenv.h>):

FE_FLTPREC round to single precision

FE_DBLPREC round to double precision

FE_LDBLPREC round to extended double precision

The default precision is FE_LDBLPREC (unless it is changed by the -fprecision compiler flag). 

fegetprec() returns the current rounding precision. 

RETURN VALUES

fesetprec returns a nonzero value if the requested rounding precision is established and returns zero otherwise. 

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

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. 

SEE ALSO

fegetenv(3M), fesetround(3M), attributes(5)

Numerical Computation Guide

NOTES

As shown in the synopsis, the recommended way to link with libm9x using cc is to specify

-Rinstall-path/lib -Linstall-path/lib -lm9x

on the command line, where install-path refers to the location in which the compilers are installed (/opt/SUNWspro by default).  See the Numerical Computation Guide or the READMEs/math_libraries file in the compiler installation area for additional information about linking with libm9x. 

SunOS 5.0  —  Last change: 06/25/97