swaprm(3) [ultrix man page]

fpc(3)							     Library Functions Manual							    fpc(3)

Name
       fpc, get_fpc_csr, set_fpc_csr, swapRM, swapINX - floating-point control registers

Syntax
       #include <mips/fpu.h>

       int get_fpc_csr()

       int set_fpc_csr(csr)
       int csr;

       int get_fpc_irr()

       int swapRM(x)
       int x;

       int swapINX(x)
       int x;

Description
       These  functions  are  to  get  and set the floating-point control registers of RISC floating-point units.  All of these functions take and
       return their values as 32 bit integers.

       The file <mips/fpu.h> contains unions for each of the control registers. Each union contains a structure that breaks  out  the  bit  fields
       into the logical parts for each control register.  This file also contains constants for fields of the control registers.

       RISC  floating-point  implementations  have  a control and status register and an implementation revision register.  The control and status
       register is returned by The routine sets the control and status register and returns the old value.  The implementation	revision  register
       is read-only and is returned by the routine

       The  function sets only the rounding mode and returns the old rounding mode.  The function sets only the sticky inexact bit and returns the
       old one.  The bits in the arguments and return values to and are right justified.

								       RISC								    fpc(3)

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)