NAME    [Toc]    [Back]

       write_rnd, read_rnd - sets and returns IEEE dynamic rounding
 mode for floating-point operations

SYNOPSIS    [Toc]    [Back]

       #include <float.h>

       unsigned int write_rnd(
               unsigned int rnd ); unsigned int read_rnd(
               void );

LIBRARY    [Toc]    [Back]

       Standard C Library (libc.so, libc.a)

DESCRIPTION    [Toc]    [Back]

       The write_rnd() function sets the dynamic rounding mode in
       the floating-point control register (fpcr) for IEEE floating-point
 operations  and  returns  the  previous  dynamic
       rounding  mode.  Dynamic  rounding mode for IEEE floatingpoint
 operations is enabled for code generated  by  the  C
       compiler  by specifying -fprm d to cc(1), and by using the
       d floating-point instruction operator in assembly language
       code.

       Specify  rnd  as one of the following constants defined in
       float.h:

       -------------------------------------------------
       Constant    Meaning
       -------------------------------------------------

       FP_RND_RZ   Round toward zero (chopped rounding)
       FP_RND_RN   Round toward nearest (normal  rounding)

       FP_RND_RP   Round toward plus infinity
       FP_RND_RM   Round toward minus infinity
       -------------------------------------------------

       The read_rnd() function returns the current dynamic rounding
 mode for floating-point operations.

RETURN VALUES    [Toc]    [Back]

       The write_rnd() function returns the previous IEEE  floating-point
  rounding  mode. The read_rnd() function returns
       the current IEEE floating-point rounding mode.

SEE ALSO    [Toc]    [Back]

       Commands: cc(1)

       Files: float.h

       Assembly Language Programmer's Guide

       Alpha Architecture Reference Manual

       IEEE Standard for Binary Floating-Point Arithmetic



                                                     write_rnd(3)