- 根目录:
- arch
- parisc
- math-emu
- fcnvfx.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);
}