320 lines
8.0 KiB
C
320 lines
8.0 KiB
C
/* $NetBSD: fcnvff.c,v 1.3 2003/11/01 18:23:38 matt Exp $ */
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/* $OpenBSD: fcnvff.c,v 1.5 2001/03/29 03:58:18 mickey Exp $ */
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/*
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* Copyright 1996 1995 by Open Software Foundation, Inc.
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* All Rights Reserved
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*
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* Permission to use, copy, modify, and distribute this software and
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* its documentation for any purpose and without fee is hereby granted,
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* provided that the above copyright notice appears in all copies and
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* that both the copyright notice and this permission notice appear in
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* supporting documentation.
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*
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* OSF DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
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* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE.
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*
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* IN NO EVENT SHALL OSF BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
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* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
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* LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
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* NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
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* WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*
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*/
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/*
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* pmk1.1
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*/
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/*
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* (c) Copyright 1986 HEWLETT-PACKARD COMPANY
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*
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* To anyone who acknowledges that this file is provided "AS IS"
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* without any express or implied warranty:
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* permission to use, copy, modify, and distribute this file
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* for any purpose is hereby granted without fee, provided that
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* the above copyright notice and this notice appears in all
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* copies, and that the name of Hewlett-Packard Company not be
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* used in advertising or publicity pertaining to distribution
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* of the software without specific, written prior permission.
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* Hewlett-Packard Company makes no representations about the
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* suitability of this software for any purpose.
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: fcnvff.c,v 1.3 2003/11/01 18:23:38 matt Exp $");
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#include "../spmath/float.h"
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#include "../spmath/sgl_float.h"
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#include "../spmath/dbl_float.h"
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#include "../spmath/cnv_float.h"
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/*
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* Single Floating-point to Double Floating-point
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*/
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/*ARGSUSED*/
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int
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sgl_to_dbl_fcnvff(srcptr,dstptr,status)
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sgl_floating_point *srcptr;
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dbl_floating_point *dstptr;
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unsigned int *status;
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{
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register unsigned int src, resultp1, resultp2;
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register int src_exponent;
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src = *srcptr;
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src_exponent = Sgl_exponent(src);
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Dbl_allp1(resultp1) = Sgl_all(src); /* set sign of result */
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/*
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* Test for NaN or infinity
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*/
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if (src_exponent == SGL_INFINITY_EXPONENT) {
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/*
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* determine if NaN or infinity
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*/
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if (Sgl_iszero_mantissa(src)) {
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/*
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* is infinity; want to return double infinity
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*/
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Dbl_setinfinity_exponentmantissa(resultp1,resultp2);
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Dbl_copytoptr(resultp1,resultp2,dstptr);
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return(NOEXCEPTION);
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}
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else {
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/*
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* is NaN; signaling or quiet?
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*/
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if (Sgl_isone_signaling(src)) {
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/* trap if INVALIDTRAP enabled */
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if (Is_invalidtrap_enabled())
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return(INVALIDEXCEPTION);
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/* make NaN quiet */
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else {
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Set_invalidflag();
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Sgl_set_quiet(src);
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}
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}
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/*
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* NaN is quiet, return as double NaN
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*/
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Dbl_setinfinity_exponent(resultp1);
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Sgl_to_dbl_mantissa(src,resultp1,resultp2);
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Dbl_copytoptr(resultp1,resultp2,dstptr);
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return(NOEXCEPTION);
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}
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}
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/*
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* Test for zero or denormalized
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*/
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if (src_exponent == 0) {
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/*
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* determine if zero or denormalized
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*/
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if (Sgl_isnotzero_mantissa(src)) {
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/*
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* is denormalized; want to normalize
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*/
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Sgl_clear_signexponent(src);
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Sgl_leftshiftby1(src);
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Sgl_normalize(src,src_exponent);
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Sgl_to_dbl_exponent(src_exponent,resultp1);
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Sgl_to_dbl_mantissa(src,resultp1,resultp2);
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}
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else {
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Dbl_setzero_exponentmantissa(resultp1,resultp2);
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}
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Dbl_copytoptr(resultp1,resultp2,dstptr);
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return(NOEXCEPTION);
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}
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/*
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* No special cases, just complete the conversion
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*/
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Sgl_to_dbl_exponent(src_exponent, resultp1);
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Sgl_to_dbl_mantissa(Sgl_mantissa(src), resultp1,resultp2);
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Dbl_copytoptr(resultp1,resultp2,dstptr);
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return(NOEXCEPTION);
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}
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/*
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* Double Floating-point to Single Floating-point
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*/
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/*ARGSUSED*/
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int
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dbl_to_sgl_fcnvff(srcptr,dstptr,status)
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dbl_floating_point *srcptr;
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sgl_floating_point *dstptr;
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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, dest_exponent, dest_mantissa;
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register int inexact = FALSE, guardbit = FALSE, stickybit = FALSE;
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register int lsb_odd = FALSE;
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int is_tiny = FALSE;
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Dbl_copyfromptr(srcptr,srcp1,srcp2);
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src_exponent = Dbl_exponent(srcp1);
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Sgl_all(result) = Dbl_allp1(srcp1); /* set sign of result */
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/*
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* Test for NaN or infinity
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*/
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if (src_exponent == DBL_INFINITY_EXPONENT) {
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/*
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* determine if NaN or infinity
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*/
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if (Dbl_iszero_mantissa(srcp1,srcp2)) {
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/*
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* is infinity; want to return single infinity
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*/
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Sgl_setinfinity_exponentmantissa(result);
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*dstptr = result;
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return(NOEXCEPTION);
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}
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/*
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* is NaN; signaling or quiet?
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*/
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if (Dbl_isone_signaling(srcp1)) {
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/* trap if INVALIDTRAP enabled */
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if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION);
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else {
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Set_invalidflag();
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/* make NaN quiet */
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Dbl_set_quiet(srcp1);
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}
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}
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/*
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* NaN is quiet, return as single NaN
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*/
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Sgl_setinfinity_exponent(result);
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Sgl_set_mantissa(result,Dallp1(srcp1)<<3 | Dallp2(srcp2)>>29);
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if (Sgl_iszero_mantissa(result)) Sgl_set_quiet(result);
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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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Dbl_to_sgl_exponent(src_exponent,dest_exponent);
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if (dest_exponent > 0) {
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Dbl_to_sgl_mantissa(srcp1,srcp2,dest_mantissa,inexact,guardbit,
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stickybit,lsb_odd);
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}
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else {
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if (Dbl_iszero_exponentmantissa(srcp1,srcp2)){
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Sgl_setzero_exponentmantissa(result);
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*dstptr = result;
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return(NOEXCEPTION);
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}
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if (Is_underflowtrap_enabled()) {
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Dbl_to_sgl_mantissa(srcp1,srcp2,dest_mantissa,inexact,
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guardbit,stickybit,lsb_odd);
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}
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else {
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/* compute result, determine inexact info,
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* and set Underflowflag if appropriate
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*/
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Dbl_to_sgl_denormalized(srcp1,srcp2,dest_exponent,
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dest_mantissa,inexact,guardbit,stickybit,lsb_odd,
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is_tiny);
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}
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}
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/*
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* Now round result if not exact
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*/
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if (inexact) {
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switch (Rounding_mode()) {
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case ROUNDPLUS:
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if (Sgl_iszero_sign(result)) dest_mantissa++;
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break;
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case ROUNDMINUS:
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if (Sgl_isone_sign(result)) dest_mantissa++;
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break;
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case ROUNDNEAREST:
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if (guardbit) {
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if (stickybit || lsb_odd) dest_mantissa++;
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}
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}
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}
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Sgl_set_exponentmantissa(result,dest_mantissa);
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/*
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* check for mantissa overflow after rounding
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*/
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if ((dest_exponent>0 || Is_underflowtrap_enabled()) &&
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Sgl_isone_hidden(result)) dest_exponent++;
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/*
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* Test for overflow
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*/
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if (dest_exponent >= SGL_INFINITY_EXPONENT) {
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/* trap if OVERFLOWTRAP enabled */
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if (Is_overflowtrap_enabled()) {
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/*
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* Check for gross overflow
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*/
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if (dest_exponent >= SGL_INFINITY_EXPONENT+SGL_WRAP)
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return(UNIMPLEMENTEDEXCEPTION);
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/*
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* Adjust bias of result
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*/
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Sgl_setwrapped_exponent(result,dest_exponent,ovfl);
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*dstptr = result;
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if (inexact) {
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if (Is_inexacttrap_enabled())
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return(OVERFLOWEXCEPTION|INEXACTEXCEPTION);
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else
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Set_inexactflag();
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}
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return(OVERFLOWEXCEPTION);
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}
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Set_overflowflag();
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inexact = TRUE;
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/* set result to infinity or largest number */
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Sgl_setoverflow(result);
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}
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/*
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* Test for underflow
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*/
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else if (dest_exponent <= 0) {
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/* trap if UNDERFLOWTRAP enabled */
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if (Is_underflowtrap_enabled()) {
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/*
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* Check for gross underflow
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*/
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if (dest_exponent <= -(SGL_WRAP))
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return(UNIMPLEMENTEDEXCEPTION);
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/*
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* Adjust bias of result
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*/
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Sgl_setwrapped_exponent(result,dest_exponent,unfl);
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*dstptr = result;
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if (inexact) {
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if (Is_inexacttrap_enabled())
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return(UNDERFLOWEXCEPTION|INEXACTEXCEPTION);
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else
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Set_inexactflag();
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}
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return(UNDERFLOWEXCEPTION);
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}
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/*
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* result is denormalized or signed zero
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*/
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if (inexact && is_tiny) Set_underflowflag();
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}
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else Sgl_set_exponent(result,dest_exponent);
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*dstptr = result;
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/*
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* Trap if inexact trap is enabled
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*/
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if (inexact) {
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if (Is_inexacttrap_enabled())
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return(INEXACTEXCEPTION);
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else
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Set_inexactflag();
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}
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return(NOEXCEPTION);
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}
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