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|
/* $OpenBSD: fcnvfx.c,v 1.5 2001/03/29 03:58:18 mickey Exp $ */
/*
* Copyright 1996 1995 by Open Software Foundation, Inc.
* All Rights Reserved
*
* Permission to use, copy, modify, and distribute this software and
* its documentation for any purpose and without fee is hereby granted,
* provided that the above copyright notice appears in all copies and
* that both the copyright notice and this permission notice appear in
* supporting documentation.
*
* OSF DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE.
*
* IN NO EVENT SHALL OSF BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
* LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
* NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
* WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
*/
/*
* pmk1.1
*/
/*
* (c) Copyright 1986 HEWLETT-PACKARD COMPANY
*
* To anyone who acknowledges that this file is provided "AS IS"
* without any express or implied warranty:
* permission to use, copy, modify, and distribute this file
* for any purpose is hereby granted without fee, provided that
* the above copyright notice and this notice appears in all
* copies, and that the name of Hewlett-Packard Company not be
* used in advertising or publicity pertaining to distribution
* of the software without specific, written prior permission.
* Hewlett-Packard Company makes no representations about the
* suitability of this software for any purpose.
*/
#include "../spmath/float.h"
#include "../spmath/sgl_float.h"
#include "../spmath/dbl_float.h"
#include "../spmath/cnv_float.h"
/*
* Single Floating-point to Single Fixed-point
*/
/*ARGSUSED*/
int
sgl_to_sgl_fcnvfx(srcptr,dstptr,status)
sgl_floating_point *srcptr;
int *dstptr;
unsigned int *status;
{
register unsigned int src, temp;
register int src_exponent, result;
register int inexact = FALSE;
src = *srcptr;
src_exponent = Sgl_exponent(src) - SGL_BIAS;
/*
* Test for overflow
*/
if (src_exponent > SGL_FX_MAX_EXP) {
/* check for MININT */
if ((src_exponent > SGL_FX_MAX_EXP + 1) ||
Sgl_isnotzero_mantissa(src) || Sgl_iszero_sign(src)) {
/*
* Since source is a number which cannot be
* represented in fixed-point format, return
* largest (or smallest) fixed-point number.
*/
Sgl_return_overflow(src,dstptr);
}
}
/*
* Generate result
*/
if (src_exponent >= 0) {
temp = src;
Sgl_clear_signexponent_set_hidden(temp);
Int_from_sgl_mantissa(temp,src_exponent);
if (Sgl_isone_sign(src)) result = -Sgl_all(temp);
else result = Sgl_all(temp);
/* check for inexact */
if (Sgl_isinexact_to_fix(src,src_exponent)) {
inexact = TRUE;
/* round result */
switch (Rounding_mode()) {
case ROUNDPLUS:
if (Sgl_iszero_sign(src)) result++;
break;
case ROUNDMINUS:
if (Sgl_isone_sign(src)) result--;
break;
case ROUNDNEAREST:
if (Sgl_isone_roundbit(src,src_exponent)) {
if (Sgl_isone_stickybit(src,src_exponent)
|| (Sgl_isone_lowmantissa(temp))) {
if (Sgl_iszero_sign(src)) result++;
else result--;
}
}
}
}
}
else {
result = 0;
/* check for inexact */
if (Sgl_isnotzero_exponentmantissa(src)) {
inexact = TRUE;
/* round result */
switch (Rounding_mode()) {
case ROUNDPLUS:
if (Sgl_iszero_sign(src)) result++;
break;
case ROUNDMINUS:
if (Sgl_isone_sign(src)) result--;
break;
case ROUNDNEAREST:
if (src_exponent == -1)
if (Sgl_isnotzero_mantissa(src)) {
if (Sgl_iszero_sign(src)) result++;
else result--;
}
}
}
}
*dstptr = result;
if (inexact) {
if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
else Set_inexactflag();
}
return(NOEXCEPTION);
}
/*
* Single Floating-point to Double Fixed-point
*/
/*ARGSUSED*/
int
sgl_to_dbl_fcnvfx(srcptr,dstptr,status)
sgl_floating_point *srcptr;
dbl_integer *dstptr;
unsigned int *status;
{
register int src_exponent, resultp1;
register unsigned int src, temp, resultp2;
register int inexact = FALSE;
src = *srcptr;
src_exponent = Sgl_exponent(src) - SGL_BIAS;
/*
* Test for overflow
*/
if (src_exponent > DBL_FX_MAX_EXP) {
/* check for MININT */
if ((src_exponent > DBL_FX_MAX_EXP + 1) ||
Sgl_isnotzero_mantissa(src) || Sgl_iszero_sign(src)) {
/*
* Since source is a number which cannot be
* represented in fixed-point format, return
* largest (or smallest) fixed-point number.
*/
Sgl_return_overflow_dbl(src,dstptr);
}
Dint_set_minint(resultp1,resultp2);
Dint_copytoptr(resultp1,resultp2,dstptr);
return(NOEXCEPTION);
}
/*
* Generate result
*/
if (src_exponent >= 0) {
temp = src;
Sgl_clear_signexponent_set_hidden(temp);
Dint_from_sgl_mantissa(temp,src_exponent,resultp1,resultp2);
if (Sgl_isone_sign(src)) {
Dint_setone_sign(resultp1,resultp2);
}
/* check for inexact */
if (Sgl_isinexact_to_fix(src,src_exponent)) {
inexact = TRUE;
/* round result */
switch (Rounding_mode()) {
case ROUNDPLUS:
if (Sgl_iszero_sign(src)) {
Dint_increment(resultp1,resultp2);
}
break;
case ROUNDMINUS:
if (Sgl_isone_sign(src)) {
Dint_decrement(resultp1,resultp2);
}
break;
case ROUNDNEAREST:
if (Sgl_isone_roundbit(src,src_exponent))
if (Sgl_isone_stickybit(src,src_exponent) ||
(Dint_isone_lowp2(resultp2))) {
if (Sgl_iszero_sign(src)) {
Dint_increment(resultp1,resultp2);
}
else {
Dint_decrement(resultp1,resultp2);
}
}
}
}
}
else {
Dint_setzero(resultp1,resultp2);
/* check for inexact */
if (Sgl_isnotzero_exponentmantissa(src)) {
inexact = TRUE;
/* round result */
switch (Rounding_mode()) {
case ROUNDPLUS:
if (Sgl_iszero_sign(src)) {
Dint_increment(resultp1,resultp2);
}
break;
case ROUNDMINUS:
if (Sgl_isone_sign(src)) {
Dint_decrement(resultp1,resultp2);
}
break;
case ROUNDNEAREST:
if (src_exponent == -1)
if (Sgl_isnotzero_mantissa(src)) {
if (Sgl_iszero_sign(src)) {
Dint_increment(resultp1,resultp2);
}
else {
Dint_decrement(resultp1,resultp2);
}
}
}
}
}
Dint_copytoptr(resultp1,resultp2,dstptr);
if (inexact) {
if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
else Set_inexactflag();
}
return(NOEXCEPTION);
}
/*
* Double Floating-point to Single Fixed-point
*/
/*ARGSUSED*/
int
dbl_to_sgl_fcnvfx(srcptr,dstptr,status)
dbl_floating_point *srcptr;
int *dstptr;
unsigned int *status;
{
register unsigned int srcp1,srcp2, tempp1,tempp2;
register int src_exponent, result;
register int inexact = FALSE;
Dbl_copyfromptr(srcptr,srcp1,srcp2);
src_exponent = Dbl_exponent(srcp1) - DBL_BIAS;
/*
* Test for overflow
*/
if (src_exponent > SGL_FX_MAX_EXP) {
/* check for MININT */
if (Dbl_isoverflow_to_int(src_exponent,srcp1,srcp2)) {
/*
* Since source is a number which cannot be
* represented in fixed-point format, return
* largest (or smallest) fixed-point number.
*/
Dbl_return_overflow(srcp1,srcp2,dstptr);
}
}
/*
* Generate result
*/
if (src_exponent >= 0) {
tempp1 = srcp1;
tempp2 = srcp2;
Dbl_clear_signexponent_set_hidden(tempp1);
Int_from_dbl_mantissa(tempp1,tempp2,src_exponent);
if (Dbl_isone_sign(srcp1) && (src_exponent <= SGL_FX_MAX_EXP))
result = -Dbl_allp1(tempp1);
else result = Dbl_allp1(tempp1);
/* check for inexact */
if (Dbl_isinexact_to_fix(srcp1,srcp2,src_exponent)) {
inexact = TRUE;
/* round result */
switch (Rounding_mode()) {
case ROUNDPLUS:
if (Dbl_iszero_sign(srcp1)) result++;
break;
case ROUNDMINUS:
if (Dbl_isone_sign(srcp1)) result--;
break;
case ROUNDNEAREST:
if (Dbl_isone_roundbit(srcp1,srcp2,src_exponent))
if (Dbl_isone_stickybit(srcp1,srcp2,src_exponent) ||
(Dbl_isone_lowmantissap1(tempp1))) {
if (Dbl_iszero_sign(srcp1)) result++;
else result--;
}
}
/* check for overflow */
if ((Dbl_iszero_sign(srcp1) && result < 0) ||
(Dbl_isone_sign(srcp1) && result > 0)) {
Dbl_return_overflow(srcp1,srcp2,dstptr);
}
}
}
else {
result = 0;
/* check for inexact */
if (Dbl_isnotzero_exponentmantissa(srcp1,srcp2)) {
inexact = TRUE;
/* round result */
switch (Rounding_mode()) {
case ROUNDPLUS:
if (Dbl_iszero_sign(srcp1)) result++;
break;
case ROUNDMINUS:
if (Dbl_isone_sign(srcp1)) result--;
break;
case ROUNDNEAREST:
if (src_exponent == -1)
if (Dbl_isnotzero_mantissa(srcp1,srcp2)) {
if (Dbl_iszero_sign(srcp1)) result++;
else result--;
}
}
}
}
*dstptr = result;
if (inexact) {
if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
else Set_inexactflag();
}
return(NOEXCEPTION);
}
/*
* Double Floating-point to Double Fixed-point
*/
/*ARGSUSED*/
int
dbl_to_dbl_fcnvfx(srcptr,dstptr,status)
dbl_floating_point *srcptr;
dbl_integer *dstptr;
unsigned int *status;
{
register int src_exponent, resultp1;
register unsigned int srcp1, srcp2, tempp1, tempp2, resultp2;
register int inexact = FALSE;
Dbl_copyfromptr(srcptr,srcp1,srcp2);
src_exponent = Dbl_exponent(srcp1) - DBL_BIAS;
/*
* Test for overflow
*/
if (src_exponent > DBL_FX_MAX_EXP) {
/* check for MININT */
if ((src_exponent > DBL_FX_MAX_EXP + 1) ||
Dbl_isnotzero_mantissa(srcp1,srcp2) || Dbl_iszero_sign(srcp1)) {
/*
* Since source is a number which cannot be
* represented in fixed-point format, return
* largest (or smallest) fixed-point number.
*/
Dbl_return_overflow_dbl(srcp1,srcp2,dstptr);
}
}
/*
* Generate result
*/
if (src_exponent >= 0) {
tempp1 = srcp1;
tempp2 = srcp2;
Dbl_clear_signexponent_set_hidden(tempp1);
Dint_from_dbl_mantissa(tempp1,tempp2,src_exponent,
resultp1, resultp2);
if (Dbl_isone_sign(srcp1)) {
Dint_setone_sign(resultp1,resultp2);
}
/* check for inexact */
if (Dbl_isinexact_to_fix(srcp1,srcp2,src_exponent)) {
inexact = TRUE;
/* round result */
switch (Rounding_mode()) {
case ROUNDPLUS:
if (Dbl_iszero_sign(srcp1)) {
Dint_increment(resultp1,resultp2);
}
break;
case ROUNDMINUS:
if (Dbl_isone_sign(srcp1)) {
Dint_decrement(resultp1,resultp2);
}
break;
case ROUNDNEAREST:
if (Dbl_isone_roundbit(srcp1,srcp2,src_exponent))
if (Dbl_isone_stickybit(srcp1,srcp2,src_exponent) ||
(Dint_isone_lowp2(resultp2))) {
if (Dbl_iszero_sign(srcp1)) {
Dint_increment(resultp1,resultp2);
}
else {
Dint_decrement(resultp1,resultp2);
}
}
}
}
}
else {
Dint_setzero(resultp1,resultp2);
/* check for inexact */
if (Dbl_isnotzero_exponentmantissa(srcp1,srcp2)) {
inexact = TRUE;
/* round result */
switch (Rounding_mode()) {
case ROUNDPLUS:
if (Dbl_iszero_sign(srcp1)) {
Dint_increment(resultp1,resultp2);
}
break;
case ROUNDMINUS:
if (Dbl_isone_sign(srcp1)) {
Dint_decrement(resultp1,resultp2);
}
break;
case ROUNDNEAREST:
if (src_exponent == -1)
if (Dbl_isnotzero_mantissa(srcp1,srcp2)) {
if (Dbl_iszero_sign(srcp1)) {
Dint_increment(resultp1,resultp2);
}
else {
Dint_decrement(resultp1,resultp2);
}
}
}
}
}
Dint_copytoptr(resultp1,resultp2,dstptr);
if (inexact) {
if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
else Set_inexactflag();
}
return(NOEXCEPTION);
}
|
