502 строки
15 KiB
C
502 строки
15 KiB
C
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/*
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* Linux/PA-RISC Project (http://www.parisc-linux.org/)
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*
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* Floating-point emulation code
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* Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2, or (at your option)
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* any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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/*
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* BEGIN_DESC
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*
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* File:
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* @(#) pa/spmath/fcnvfx.c $Revision: 1.1 $
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*
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* Purpose:
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* Single Floating-point to Single Fixed-point
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* Single Floating-point to Double Fixed-point
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* Double Floating-point to Single Fixed-point
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* Double Floating-point to Double Fixed-point
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*
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* External Interfaces:
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* dbl_to_dbl_fcnvfx(srcptr,nullptr,dstptr,status)
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* dbl_to_sgl_fcnvfx(srcptr,nullptr,dstptr,status)
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* sgl_to_dbl_fcnvfx(srcptr,nullptr,dstptr,status)
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* sgl_to_sgl_fcnvfx(srcptr,nullptr,dstptr,status)
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*
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* Internal Interfaces:
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*
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* Theory:
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* <<please update with a overview of the operation of this file>>
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*
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* END_DESC
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*/
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#include "float.h"
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#include "sgl_float.h"
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#include "dbl_float.h"
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#include "cnv_float.h"
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/*
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* Single Floating-point to Single Fixed-point
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*/
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/*ARGSUSED*/
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int
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sgl_to_sgl_fcnvfx(
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sgl_floating_point *srcptr,
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sgl_floating_point *nullptr,
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int *dstptr,
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sgl_floating_point *status)
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{
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register unsigned int src, temp;
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register int src_exponent, result;
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register boolean inexact = FALSE;
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src = *srcptr;
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src_exponent = Sgl_exponent(src) - SGL_BIAS;
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/*
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* Test for overflow
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*/
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if (src_exponent > SGL_FX_MAX_EXP) {
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/* check for MININT */
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if ((src_exponent > SGL_FX_MAX_EXP + 1) ||
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Sgl_isnotzero_mantissa(src) || Sgl_iszero_sign(src)) {
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if (Sgl_iszero_sign(src)) result = 0x7fffffff;
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else result = 0x80000000;
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if (Is_invalidtrap_enabled()) {
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return(INVALIDEXCEPTION);
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}
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Set_invalidflag();
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*dstptr = result;
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return(NOEXCEPTION);
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}
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}
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/*
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* Generate result
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*/
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if (src_exponent >= 0) {
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temp = src;
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Sgl_clear_signexponent_set_hidden(temp);
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Int_from_sgl_mantissa(temp,src_exponent);
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if (Sgl_isone_sign(src)) result = -Sgl_all(temp);
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else result = Sgl_all(temp);
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/* check for inexact */
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if (Sgl_isinexact_to_fix(src,src_exponent)) {
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inexact = TRUE;
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/* round result */
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switch (Rounding_mode()) {
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case ROUNDPLUS:
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if (Sgl_iszero_sign(src)) result++;
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break;
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case ROUNDMINUS:
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if (Sgl_isone_sign(src)) result--;
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break;
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case ROUNDNEAREST:
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if (Sgl_isone_roundbit(src,src_exponent)) {
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if (Sgl_isone_stickybit(src,src_exponent)
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|| (Sgl_isone_lowmantissa(temp)))
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if (Sgl_iszero_sign(src)) result++;
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else result--;
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}
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}
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}
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}
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else {
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result = 0;
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/* check for inexact */
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if (Sgl_isnotzero_exponentmantissa(src)) {
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inexact = TRUE;
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/* round result */
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switch (Rounding_mode()) {
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case ROUNDPLUS:
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if (Sgl_iszero_sign(src)) result++;
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break;
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case ROUNDMINUS:
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if (Sgl_isone_sign(src)) result--;
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break;
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case ROUNDNEAREST:
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if (src_exponent == -1)
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if (Sgl_isnotzero_mantissa(src))
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if (Sgl_iszero_sign(src)) result++;
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else result--;
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}
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}
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}
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*dstptr = result;
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if (inexact) {
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if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
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else Set_inexactflag();
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}
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return(NOEXCEPTION);
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}
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/*
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* Single Floating-point to Double Fixed-point
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*/
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/*ARGSUSED*/
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int
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sgl_to_dbl_fcnvfx(
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sgl_floating_point *srcptr,
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unsigned int *nullptr,
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dbl_integer *dstptr,
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unsigned int *status)
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{
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register int src_exponent, resultp1;
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register unsigned int src, temp, resultp2;
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register boolean inexact = FALSE;
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src = *srcptr;
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src_exponent = Sgl_exponent(src) - SGL_BIAS;
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/*
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* Test for overflow
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*/
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if (src_exponent > DBL_FX_MAX_EXP) {
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/* check for MININT */
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if ((src_exponent > DBL_FX_MAX_EXP + 1) ||
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Sgl_isnotzero_mantissa(src) || Sgl_iszero_sign(src)) {
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if (Sgl_iszero_sign(src)) {
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resultp1 = 0x7fffffff;
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resultp2 = 0xffffffff;
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}
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else {
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resultp1 = 0x80000000;
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resultp2 = 0;
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}
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if (Is_invalidtrap_enabled()) {
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return(INVALIDEXCEPTION);
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}
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Set_invalidflag();
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Dint_copytoptr(resultp1,resultp2,dstptr);
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return(NOEXCEPTION);
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}
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Dint_set_minint(resultp1,resultp2);
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Dint_copytoptr(resultp1,resultp2,dstptr);
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return(NOEXCEPTION);
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}
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/*
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* Generate result
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*/
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if (src_exponent >= 0) {
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temp = src;
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Sgl_clear_signexponent_set_hidden(temp);
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Dint_from_sgl_mantissa(temp,src_exponent,resultp1,resultp2);
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if (Sgl_isone_sign(src)) {
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Dint_setone_sign(resultp1,resultp2);
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}
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/* check for inexact */
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if (Sgl_isinexact_to_fix(src,src_exponent)) {
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inexact = TRUE;
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/* round result */
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switch (Rounding_mode()) {
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case ROUNDPLUS:
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if (Sgl_iszero_sign(src)) {
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Dint_increment(resultp1,resultp2);
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}
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break;
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case ROUNDMINUS:
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if (Sgl_isone_sign(src)) {
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Dint_decrement(resultp1,resultp2);
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}
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break;
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case ROUNDNEAREST:
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if (Sgl_isone_roundbit(src,src_exponent))
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if (Sgl_isone_stickybit(src,src_exponent) ||
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(Dint_isone_lowp2(resultp2)))
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if (Sgl_iszero_sign(src)) {
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Dint_increment(resultp1,resultp2);
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}
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else {
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Dint_decrement(resultp1,resultp2);
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}
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}
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}
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}
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else {
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Dint_setzero(resultp1,resultp2);
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/* check for inexact */
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if (Sgl_isnotzero_exponentmantissa(src)) {
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inexact = TRUE;
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/* round result */
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switch (Rounding_mode()) {
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case ROUNDPLUS:
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if (Sgl_iszero_sign(src)) {
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Dint_increment(resultp1,resultp2);
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}
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break;
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case ROUNDMINUS:
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if (Sgl_isone_sign(src)) {
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Dint_decrement(resultp1,resultp2);
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}
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break;
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case ROUNDNEAREST:
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if (src_exponent == -1)
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if (Sgl_isnotzero_mantissa(src))
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if (Sgl_iszero_sign(src)) {
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Dint_increment(resultp1,resultp2);
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}
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else {
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Dint_decrement(resultp1,resultp2);
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}
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}
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}
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}
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Dint_copytoptr(resultp1,resultp2,dstptr);
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if (inexact) {
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if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
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else Set_inexactflag();
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}
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return(NOEXCEPTION);
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}
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/*
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* Double Floating-point to Single Fixed-point
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*/
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/*ARGSUSED*/
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int
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dbl_to_sgl_fcnvfx(
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dbl_floating_point *srcptr,
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unsigned int *nullptr,
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int *dstptr,
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unsigned int *status)
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{
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register unsigned int srcp1,srcp2, tempp1,tempp2;
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register int src_exponent, result;
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register boolean inexact = FALSE;
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Dbl_copyfromptr(srcptr,srcp1,srcp2);
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src_exponent = Dbl_exponent(srcp1) - DBL_BIAS;
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/*
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* Test for overflow
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*/
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if (src_exponent > SGL_FX_MAX_EXP) {
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/* check for MININT */
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if (Dbl_isoverflow_to_int(src_exponent,srcp1,srcp2)) {
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if (Dbl_iszero_sign(srcp1)) result = 0x7fffffff;
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else result = 0x80000000;
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if (Is_invalidtrap_enabled()) {
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return(INVALIDEXCEPTION);
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}
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Set_invalidflag();
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*dstptr = result;
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return(NOEXCEPTION);
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}
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}
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/*
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* Generate result
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*/
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if (src_exponent >= 0) {
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tempp1 = srcp1;
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tempp2 = srcp2;
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Dbl_clear_signexponent_set_hidden(tempp1);
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Int_from_dbl_mantissa(tempp1,tempp2,src_exponent);
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if (Dbl_isone_sign(srcp1) && (src_exponent <= SGL_FX_MAX_EXP))
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result = -Dbl_allp1(tempp1);
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else result = Dbl_allp1(tempp1);
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/* check for inexact */
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if (Dbl_isinexact_to_fix(srcp1,srcp2,src_exponent)) {
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inexact = TRUE;
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/* round result */
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switch (Rounding_mode()) {
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case ROUNDPLUS:
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if (Dbl_iszero_sign(srcp1)) result++;
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break;
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case ROUNDMINUS:
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if (Dbl_isone_sign(srcp1)) result--;
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break;
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case ROUNDNEAREST:
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if (Dbl_isone_roundbit(srcp1,srcp2,src_exponent))
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if (Dbl_isone_stickybit(srcp1,srcp2,src_exponent) ||
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(Dbl_isone_lowmantissap1(tempp1)))
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if (Dbl_iszero_sign(srcp1)) result++;
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else result--;
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}
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/* check for overflow */
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if ((Dbl_iszero_sign(srcp1) && result < 0) ||
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(Dbl_isone_sign(srcp1) && result > 0)) {
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if (Dbl_iszero_sign(srcp1)) result = 0x7fffffff;
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else result = 0x80000000;
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if (Is_invalidtrap_enabled()) {
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return(INVALIDEXCEPTION);
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}
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Set_invalidflag();
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*dstptr = result;
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return(NOEXCEPTION);
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}
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}
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}
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else {
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result = 0;
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/* check for inexact */
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if (Dbl_isnotzero_exponentmantissa(srcp1,srcp2)) {
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inexact = TRUE;
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/* round result */
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switch (Rounding_mode()) {
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case ROUNDPLUS:
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if (Dbl_iszero_sign(srcp1)) result++;
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break;
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case ROUNDMINUS:
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if (Dbl_isone_sign(srcp1)) result--;
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break;
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case ROUNDNEAREST:
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if (src_exponent == -1)
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if (Dbl_isnotzero_mantissa(srcp1,srcp2))
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if (Dbl_iszero_sign(srcp1)) result++;
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else result--;
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}
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}
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}
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*dstptr = result;
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if (inexact) {
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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);
|
||
|
|
}
|