502 lines
15 KiB
C
502 lines
15 KiB
C
/*
|
|
* 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/spmath/fcnvfx.c $Revision: 1.1 $
|
|
*
|
|
* Purpose:
|
|
* Single Floating-point to Single Fixed-point
|
|
* Single Floating-point to Double Fixed-point
|
|
* Double Floating-point to Single Fixed-point
|
|
* Double Floating-point to Double Fixed-point
|
|
*
|
|
* External Interfaces:
|
|
* dbl_to_dbl_fcnvfx(srcptr,nullptr,dstptr,status)
|
|
* dbl_to_sgl_fcnvfx(srcptr,nullptr,dstptr,status)
|
|
* sgl_to_dbl_fcnvfx(srcptr,nullptr,dstptr,status)
|
|
* sgl_to_sgl_fcnvfx(srcptr,nullptr,dstptr,status)
|
|
*
|
|
* Internal Interfaces:
|
|
*
|
|
* 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 "cnv_float.h"
|
|
|
|
/*
|
|
* Single Floating-point to Single Fixed-point
|
|
*/
|
|
/*ARGSUSED*/
|
|
int
|
|
sgl_to_sgl_fcnvfx(
|
|
sgl_floating_point *srcptr,
|
|
sgl_floating_point *nullptr,
|
|
int *dstptr,
|
|
sgl_floating_point *status)
|
|
{
|
|
register unsigned int src, temp;
|
|
register int src_exponent, result;
|
|
register boolean 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)) {
|
|
if (Sgl_iszero_sign(src)) result = 0x7fffffff;
|
|
else result = 0x80000000;
|
|
|
|
if (Is_invalidtrap_enabled()) {
|
|
return(INVALIDEXCEPTION);
|
|
}
|
|
Set_invalidflag();
|
|
*dstptr = result;
|
|
return(NOEXCEPTION);
|
|
}
|
|
}
|
|
/*
|
|
* 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(
|
|
sgl_floating_point *srcptr,
|
|
unsigned int *nullptr,
|
|
dbl_integer *dstptr,
|
|
unsigned int *status)
|
|
{
|
|
register int src_exponent, resultp1;
|
|
register unsigned int src, temp, resultp2;
|
|
register boolean 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)) {
|
|
if (Sgl_iszero_sign(src)) {
|
|
resultp1 = 0x7fffffff;
|
|
resultp2 = 0xffffffff;
|
|
}
|
|
else {
|
|
resultp1 = 0x80000000;
|
|
resultp2 = 0;
|
|
}
|
|
if (Is_invalidtrap_enabled()) {
|
|
return(INVALIDEXCEPTION);
|
|
}
|
|
Set_invalidflag();
|
|
Dint_copytoptr(resultp1,resultp2,dstptr);
|
|
return(NOEXCEPTION);
|
|
}
|
|
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(
|
|
dbl_floating_point *srcptr,
|
|
unsigned int *nullptr,
|
|
int *dstptr,
|
|
unsigned int *status)
|
|
{
|
|
register unsigned int srcp1,srcp2, tempp1,tempp2;
|
|
register int src_exponent, result;
|
|
register boolean 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)) {
|
|
if (Dbl_iszero_sign(srcp1)) result = 0x7fffffff;
|
|
else result = 0x80000000;
|
|
|
|
if (Is_invalidtrap_enabled()) {
|
|
return(INVALIDEXCEPTION);
|
|
}
|
|
Set_invalidflag();
|
|
*dstptr = result;
|
|
return(NOEXCEPTION);
|
|
}
|
|
}
|
|
/*
|
|
* 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)) {
|
|
|
|
if (Dbl_iszero_sign(srcp1)) result = 0x7fffffff;
|
|
else result = 0x80000000;
|
|
|
|
if (Is_invalidtrap_enabled()) {
|
|
return(INVALIDEXCEPTION);
|
|
}
|
|
Set_invalidflag();
|
|
*dstptr = result;
|
|
return(NOEXCEPTION);
|
|
}
|
|
}
|
|
}
|
|
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(
|
|
dbl_floating_point *srcptr,
|
|
unsigned int *nullptr,
|
|
dbl_integer *dstptr,
|
|
unsigned int *status)
|
|
{
|
|
register int src_exponent, resultp1;
|
|
register unsigned int srcp1, srcp2, tempp1, tempp2, resultp2;
|
|
register boolean 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)) {
|
|
if (Dbl_iszero_sign(srcp1)) {
|
|
resultp1 = 0x7fffffff;
|
|
resultp2 = 0xffffffff;
|
|
}
|
|
else {
|
|
resultp1 = 0x80000000;
|
|
resultp2 = 0;
|
|
}
|
|
if (Is_invalidtrap_enabled()) {
|
|
return(INVALIDEXCEPTION);
|
|
}
|
|
Set_invalidflag();
|
|
Dint_copytoptr(resultp1,resultp2,dstptr);
|
|
return(NOEXCEPTION);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
}
|