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 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 function swapRM sets only the rounding mode and returns the old rounding mode.  The function 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.