FPC(3C)FPC(3C)NAME
fpc: get_fpc_csr, set_fpc_csr, get_fpc_irr, swapRM, swapINX - floating-
point control registers
SYNOPSIS
#include <sys/fpu.h>
int get_fpc_csr(void);
int set_fpc_csr(int csr);
int get_fpc_irr(void);
int swapRM(int x);
int swapINX(int x);
DESCRIPTION
These routines are to get and set the floating-point control registers of
MIPS floating-point units. All of these routines take and or return
their values as 32 bit integers.
The file <sys/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.
All implementations of MIPS floating-point have a control and status
register and a implementation revision register. The control and status
register is returned by get_fpc_csr. The routine set_fpc_csr sets the
control and status register and returns the old value. The
implementation revision register is read-only and is returned by the
routine get_fpc_irr.
The routine swapRM sets only the rounding mode and returns the old
rounding mode. The routine swapINX sets only the sticky inexact bit and
returns the old one. The bits in the arguments and return values to
swapRM and swapINX are right justified.
NOTES
swapRM and swapINX are in libm.a . The link editor searches this library
under the "-lm" option.
ALSO SEE
R4000 Microprocessor User's Manual
Page 1
