Man Page fesetprec.3m




NAME

     fesetprec, fegetprec - control floating point rounding  pre-
     cision 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 destina-
     tions 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 fol-
     lowing 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  attri-
     butes:










     _________________________________________
    |   ATTRIBUTE TYPE   |   ATTRIBUTE VALUE |
    |____________________|____________________|_
    | Architecture       |  Intel (see below)|
    | Availability       |  SPROm9xs         |
    | Interface Stability|  Stable           |
    | MT-Level           |  MT-Safe          |
    |____________________|___________________|

     These functions are not available on SPARC  systems  because
     SPARC  processors  deliver  intermediate results to destina-
     tions 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  loca-
     tion  in which the compilers are installed (/opt/SUNWspro by
     default).  See the Numerical  Computation  Guide  for  addi-
     tional information about linking with libm9x.