linux-sg2042/arch/parisc/math-emu/denormal.c

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/*
* Linux/PA-RISC Project (http://www.parisc-linux.org/)
*
* Floating-point emulation code
* Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* BEGIN_DESC
*
* File:
* @(#) pa/fp/denormal.c $ Revision: $
*
* Purpose:
* <<please update with a synopsis of the functionality provided by this file>>
*
* External Interfaces:
* <<the following list was autogenerated, please review>>
* dbl_denormalize(dbl_opndp1,dbl_opndp2,inexactflag,rmode)
* sgl_denormalize(sgl_opnd,inexactflag,rmode)
*
* Internal Interfaces:
* <<please update>>
*
* Theory:
* <<please update with a overview of the operation of this file>>
*
* END_DESC
*/
#include "float.h"
#include "sgl_float.h"
#include "dbl_float.h"
#include "hppa.h"
#include <linux/kernel.h>
/* #include <machine/sys/mdep_private.h> */
#undef Fpustatus_register
#define Fpustatus_register Fpu_register[0]
void
sgl_denormalize(unsigned int *sgl_opnd, boolean *inexactflag, int rmode)
{
unsigned int opnd;
int sign, exponent;
boolean guardbit = FALSE, stickybit, inexact;
opnd = *sgl_opnd;
stickybit = *inexactflag;
exponent = Sgl_exponent(opnd) - SGL_WRAP;
sign = Sgl_sign(opnd);
Sgl_denormalize(opnd,exponent,guardbit,stickybit,inexact);
if (inexact) {
switch (rmode) {
case ROUNDPLUS:
if (sign == 0) {
Sgl_increment(opnd);
}
break;
case ROUNDMINUS:
if (sign != 0) {
Sgl_increment(opnd);
}
break;
case ROUNDNEAREST:
if (guardbit && (stickybit ||
Sgl_isone_lowmantissa(opnd))) {
Sgl_increment(opnd);
}
break;
}
}
Sgl_set_sign(opnd,sign);
*sgl_opnd = opnd;
*inexactflag = inexact;
return;
}
void
dbl_denormalize(unsigned int *dbl_opndp1,
unsigned int * dbl_opndp2,
boolean *inexactflag,
int rmode)
{
unsigned int opndp1, opndp2;
int sign, exponent;
boolean guardbit = FALSE, stickybit, inexact;
opndp1 = *dbl_opndp1;
opndp2 = *dbl_opndp2;
stickybit = *inexactflag;
exponent = Dbl_exponent(opndp1) - DBL_WRAP;
sign = Dbl_sign(opndp1);
Dbl_denormalize(opndp1,opndp2,exponent,guardbit,stickybit,inexact);
if (inexact) {
switch (rmode) {
case ROUNDPLUS:
if (sign == 0) {
Dbl_increment(opndp1,opndp2);
}
break;
case ROUNDMINUS:
if (sign != 0) {
Dbl_increment(opndp1,opndp2);
}
break;
case ROUNDNEAREST:
if (guardbit && (stickybit ||
Dbl_isone_lowmantissap2(opndp2))) {
Dbl_increment(opndp1,opndp2);
}
break;
}
}
Dbl_set_sign(opndp1,sign);
*dbl_opndp1 = opndp1;
*dbl_opndp2 = opndp2;
*inexactflag = inexact;
return;
}