osf1 man page for write_rnd

write_rnd(3)						     Library Functions Manual						      write_rnd(3)

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

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

SYNOPSIS
       #include <float.h>

       unsigned int write_rnd(
	       unsigned int  rnd);

       unsigned int read_rnd();

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

RELATED INFORMATION
       Commands: cc(1).

       Files: float.h.

       Assembly Language Programmer's Guide.

       Alpha Architecture Reference Manual.

       IEEE Standard for Binary Floating-Point Arithmetic delim off

																      write_rnd(3)