524 lines
11 KiB
C
524 lines
11 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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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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/*
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* BEGIN_DESC
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*
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* File:
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* @(#) pa/spmath/fcnvfu.c $Revision: 1.1 $
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*
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* Purpose:
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* Floating-point to Unsigned Fixed-point Converts
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*
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* External Interfaces:
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* dbl_to_dbl_fcnvfu(srcptr,nullptr,dstptr,status)
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* dbl_to_sgl_fcnvfu(srcptr,nullptr,dstptr,status)
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* sgl_to_dbl_fcnvfu(srcptr,nullptr,dstptr,status)
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* sgl_to_sgl_fcnvfu(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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* Floating-point to Unsigned Fixed-point Converts *
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************************************************************************/
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/*
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* Single Floating-point to Single Unsigned Fixed
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*/
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/*ARGSUSED*/
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int
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sgl_to_sgl_fcnvfu(
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sgl_floating_point *srcptr,
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unsigned int *nullptr,
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unsigned int *dstptr,
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unsigned int *status)
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{
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register unsigned int src, result;
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register int src_exponent;
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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 + 1) {
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if (Sgl_isone_sign(src)) {
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result = 0;
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} else {
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result = 0xffffffff;
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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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*dstptr = result;
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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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/*
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* Check sign.
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* If negative, trap unimplemented.
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*/
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if (Sgl_isone_sign(src)) {
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result = 0;
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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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Sgl_clear_signexponent_set_hidden(src);
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Suint_from_sgl_mantissa(src,src_exponent,result);
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/* check for inexact */
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if (Sgl_isinexact_to_unsigned(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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result++;
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break;
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case ROUNDMINUS: /* never negative */
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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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(Sgl_isone_stickybit(src,src_exponent) ||
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(result & 1))) {
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result++;
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}
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break;
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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)) {
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result++;
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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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result = 0;
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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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inexact = FALSE;
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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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Sgl_isnotzero_mantissa(src)) {
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if (Sgl_isone_sign(src)) {
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result = 0;
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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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inexact = FALSE;
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}
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else result++;
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}
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break;
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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 Unsigned Fixed
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*/
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/*ARGSUSED*/
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int
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sgl_to_dbl_fcnvfu(
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sgl_floating_point *srcptr,
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unsigned int *nullptr,
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dbl_unsigned *dstptr,
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unsigned int *status)
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{
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register int src_exponent;
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register unsigned int src, resultp1, 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 + 1) {
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if (Sgl_isone_sign(src)) {
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resultp1 = resultp2 = 0;
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} else {
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resultp1 = resultp2 = 0xffffffff;
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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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Duint_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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/*
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* Check sign.
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* If negative, trap unimplemented.
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*/
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if (Sgl_isone_sign(src)) {
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resultp1 = resultp2 = 0;
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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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Duint_copytoptr(resultp1,resultp2,dstptr);
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return(NOEXCEPTION);
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}
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Sgl_clear_signexponent_set_hidden(src);
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Duint_from_sgl_mantissa(src,src_exponent,resultp1,resultp2);
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/* check for inexact */
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if (Sgl_isinexact_to_unsigned(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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Duint_increment(resultp1,resultp2);
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break;
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case ROUNDMINUS: /* never negative */
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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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(Sgl_isone_stickybit(src,src_exponent) ||
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Duint_isone_lowp2(resultp2))) {
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Duint_increment(resultp1,resultp2);
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}
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break;
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}
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}
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} else {
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Duint_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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Duint_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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resultp1 = resultp2 = 0;
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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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inexact = FALSE;
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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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Sgl_isnotzero_mantissa(src)) {
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if (Sgl_isone_sign(src)) {
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resultp1 = 0;
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resultp2 = 0;
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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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inexact = FALSE;
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}
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else Duint_increment(resultp1,resultp2);
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}
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}
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}
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}
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Duint_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 Unsigned Fixed
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*/
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/*ARGSUSED*/
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int
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dbl_to_sgl_fcnvfu (dbl_floating_point * srcptr, unsigned int *nullptr,
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unsigned int *dstptr, unsigned int *status)
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{
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register unsigned int srcp1, srcp2, result;
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register int src_exponent;
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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 + 1) {
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if (Dbl_isone_sign(srcp1)) {
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result = 0;
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} else {
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result = 0xffffffff;
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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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*dstptr = result;
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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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/*
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* Check sign.
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* If negative, trap unimplemented.
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*/
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if (Dbl_isone_sign(srcp1)) {
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result = 0;
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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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Dbl_clear_signexponent_set_hidden(srcp1);
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Suint_from_dbl_mantissa(srcp1,srcp2,src_exponent,result);
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/* check for inexact */
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if (Dbl_isinexact_to_unsigned(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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result++;
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break;
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case ROUNDMINUS: /* never negative */
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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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(Dbl_isone_stickybit(srcp1,srcp2,src_exponent)||
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result&1))
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result++;
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break;
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}
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/* check for overflow */
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if (result == 0) {
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result = 0xffffffff;
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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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} 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)) {
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result = 0;
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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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inexact = FALSE;
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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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Dbl_isnotzero_mantissa(srcp1,srcp2))
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if (Dbl_isone_sign(srcp1)) {
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result = 0;
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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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inexact = FALSE;
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}
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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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* Double Floating-point to Double Unsigned Fixed
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*/
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/*ARGSUSED*/
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int
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dbl_to_dbl_fcnvfu (dbl_floating_point * srcptr, unsigned int *nullptr,
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dbl_unsigned * dstptr, unsigned int *status)
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{
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register int src_exponent;
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register unsigned int srcp1, srcp2, resultp1, resultp2;
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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 > DBL_FX_MAX_EXP + 1) {
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if (Dbl_isone_sign(srcp1)) {
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resultp1 = resultp2 = 0;
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} else {
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resultp1 = resultp2 = 0xffffffff;
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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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Duint_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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/*
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* Check sign.
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* If negative, trap unimplemented.
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*/
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if (Dbl_isone_sign(srcp1)) {
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resultp1 = resultp2 = 0;
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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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Duint_copytoptr(resultp1,resultp2,dstptr);
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return(NOEXCEPTION);
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}
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Dbl_clear_signexponent_set_hidden(srcp1);
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Duint_from_dbl_mantissa(srcp1,srcp2,src_exponent,resultp1,
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resultp2);
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/* check for inexact */
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if (Dbl_isinexact_to_unsigned(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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Duint_increment(resultp1,resultp2);
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break;
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case ROUNDMINUS: /* never negative */
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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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Duint_isone_lowp2(resultp2))
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Duint_increment(resultp1,resultp2);
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}
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}
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} else {
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Duint_setzero(resultp1,resultp2);
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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)) {
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Duint_increment(resultp1,resultp2);
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}
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break;
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case ROUNDMINUS:
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if (Dbl_isone_sign(srcp1)) {
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resultp1 = resultp2 = 0;
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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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inexact = FALSE;
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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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Dbl_isnotzero_mantissa(srcp1,srcp2))
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if (Dbl_iszero_sign(srcp1)) {
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Duint_increment(resultp1,resultp2);
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} else {
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resultp1 = 0;
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resultp2 = 0;
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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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inexact = FALSE;
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}
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}
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}
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}
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Duint_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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