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fcnvfxt.c revision 1.1
      1  1.1  fredette /*	$NetBSD: fcnvfxt.c,v 1.1 2002/06/05 01:04:25 fredette Exp $	*/
      2  1.1  fredette 
      3  1.1  fredette /*	$OpenBSD: fcnvfxt.c,v 1.5 2001/03/29 03:58:18 mickey Exp $	*/
      4  1.1  fredette 
      5  1.1  fredette /*
      6  1.1  fredette  * Copyright 1996 1995 by Open Software Foundation, Inc.
      7  1.1  fredette  *              All Rights Reserved
      8  1.1  fredette  *
      9  1.1  fredette  * Permission to use, copy, modify, and distribute this software and
     10  1.1  fredette  * its documentation for any purpose and without fee is hereby granted,
     11  1.1  fredette  * provided that the above copyright notice appears in all copies and
     12  1.1  fredette  * that both the copyright notice and this permission notice appear in
     13  1.1  fredette  * supporting documentation.
     14  1.1  fredette  *
     15  1.1  fredette  * OSF DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
     16  1.1  fredette  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
     17  1.1  fredette  * FOR A PARTICULAR PURPOSE.
     18  1.1  fredette  *
     19  1.1  fredette  * IN NO EVENT SHALL OSF BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
     20  1.1  fredette  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
     21  1.1  fredette  * LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
     22  1.1  fredette  * NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
     23  1.1  fredette  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
     24  1.1  fredette  *
     25  1.1  fredette  */
     26  1.1  fredette /*
     27  1.1  fredette  * pmk1.1
     28  1.1  fredette  */
     29  1.1  fredette /*
     30  1.1  fredette  * (c) Copyright 1986 HEWLETT-PACKARD COMPANY
     31  1.1  fredette  *
     32  1.1  fredette  * To anyone who acknowledges that this file is provided "AS IS"
     33  1.1  fredette  * without any express or implied warranty:
     34  1.1  fredette  *     permission to use, copy, modify, and distribute this file
     35  1.1  fredette  * for any purpose is hereby granted without fee, provided that
     36  1.1  fredette  * the above copyright notice and this notice appears in all
     37  1.1  fredette  * copies, and that the name of Hewlett-Packard Company not be
     38  1.1  fredette  * used in advertising or publicity pertaining to distribution
     39  1.1  fredette  * of the software without specific, written prior permission.
     40  1.1  fredette  * Hewlett-Packard Company makes no representations about the
     41  1.1  fredette  * suitability of this software for any purpose.
     42  1.1  fredette  */
     43  1.1  fredette 
     44  1.1  fredette #include "../spmath/float.h"
     45  1.1  fredette #include "../spmath/sgl_float.h"
     46  1.1  fredette #include "../spmath/dbl_float.h"
     47  1.1  fredette #include "../spmath/cnv_float.h"
     48  1.1  fredette 
     49  1.1  fredette /*
     50  1.1  fredette  *  Convert single floating-point to single fixed-point format
     51  1.1  fredette  *  with truncated result
     52  1.1  fredette  */
     53  1.1  fredette /*ARGSUSED*/
     54  1.1  fredette int
     55  1.1  fredette sgl_to_sgl_fcnvfxt(srcptr,dstptr,status)
     56  1.1  fredette 
     57  1.1  fredette sgl_floating_point *srcptr;
     58  1.1  fredette int *dstptr;
     59  1.1  fredette unsigned int *status;
     60  1.1  fredette {
     61  1.1  fredette 	register unsigned int src, temp;
     62  1.1  fredette 	register int src_exponent, result;
     63  1.1  fredette 
     64  1.1  fredette 	src = *srcptr;
     65  1.1  fredette 	src_exponent = Sgl_exponent(src) - SGL_BIAS;
     66  1.1  fredette 
     67  1.1  fredette 	/*
     68  1.1  fredette 	 * Test for overflow
     69  1.1  fredette 	 */
     70  1.1  fredette 	if (src_exponent > SGL_FX_MAX_EXP) {
     71  1.1  fredette 		/* check for MININT */
     72  1.1  fredette 		if ((src_exponent > SGL_FX_MAX_EXP + 1) ||
     73  1.1  fredette 		Sgl_isnotzero_mantissa(src) || Sgl_iszero_sign(src)) {
     74  1.1  fredette 			/*
     75  1.1  fredette 			 * Since source is a number which cannot be
     76  1.1  fredette 			 * represented in fixed-point format, return
     77  1.1  fredette 			 * largest (or smallest) fixed-point number.
     78  1.1  fredette 			 */
     79  1.1  fredette 			Sgl_return_overflow(src,dstptr);
     80  1.1  fredette 		}
     81  1.1  fredette 	}
     82  1.1  fredette 	/*
     83  1.1  fredette 	 * Generate result
     84  1.1  fredette 	 */
     85  1.1  fredette 	if (src_exponent >= 0) {
     86  1.1  fredette 		temp = src;
     87  1.1  fredette 		Sgl_clear_signexponent_set_hidden(temp);
     88  1.1  fredette 		Int_from_sgl_mantissa(temp,src_exponent);
     89  1.1  fredette 		if (Sgl_isone_sign(src))  result = -Sgl_all(temp);
     90  1.1  fredette 		else result = Sgl_all(temp);
     91  1.1  fredette 		*dstptr = result;
     92  1.1  fredette 
     93  1.1  fredette 		/* check for inexact */
     94  1.1  fredette 		if (Sgl_isinexact_to_fix(src,src_exponent)) {
     95  1.1  fredette 			if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
     96  1.1  fredette 			else Set_inexactflag();
     97  1.1  fredette 		}
     98  1.1  fredette 	}
     99  1.1  fredette 	else {
    100  1.1  fredette 		*dstptr = 0;
    101  1.1  fredette 
    102  1.1  fredette 		/* check for inexact */
    103  1.1  fredette 		if (Sgl_isnotzero_exponentmantissa(src)) {
    104  1.1  fredette 			if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
    105  1.1  fredette 			else Set_inexactflag();
    106  1.1  fredette 		}
    107  1.1  fredette 	}
    108  1.1  fredette 	return(NOEXCEPTION);
    109  1.1  fredette }
    110  1.1  fredette 
    111  1.1  fredette /*
    112  1.1  fredette  *  Single Floating-point to Double Fixed-point
    113  1.1  fredette  */
    114  1.1  fredette /*ARGSUSED*/
    115  1.1  fredette int
    116  1.1  fredette sgl_to_dbl_fcnvfxt(srcptr,dstptr,status)
    117  1.1  fredette 
    118  1.1  fredette sgl_floating_point *srcptr;
    119  1.1  fredette dbl_integer *dstptr;
    120  1.1  fredette unsigned int *status;
    121  1.1  fredette {
    122  1.1  fredette 	register int src_exponent, resultp1;
    123  1.1  fredette 	register unsigned int src, temp, resultp2;
    124  1.1  fredette 
    125  1.1  fredette 	src = *srcptr;
    126  1.1  fredette 	src_exponent = Sgl_exponent(src) - SGL_BIAS;
    127  1.1  fredette 
    128  1.1  fredette 	/*
    129  1.1  fredette 	 * Test for overflow
    130  1.1  fredette 	 */
    131  1.1  fredette 	if (src_exponent > DBL_FX_MAX_EXP) {
    132  1.1  fredette 		/* check for MININT */
    133  1.1  fredette 		if ((src_exponent > DBL_FX_MAX_EXP + 1) ||
    134  1.1  fredette 		Sgl_isnotzero_mantissa(src) || Sgl_iszero_sign(src)) {
    135  1.1  fredette 			/*
    136  1.1  fredette 			 * Since source is a number which cannot be
    137  1.1  fredette 			 * represented in fixed-point format, return
    138  1.1  fredette 			 * largest (or smallest) fixed-point number.
    139  1.1  fredette 			 */
    140  1.1  fredette 			Sgl_return_overflow_dbl(src,dstptr);
    141  1.1  fredette 		}
    142  1.1  fredette 		Dint_set_minint(resultp1,resultp2);
    143  1.1  fredette 		Dint_copytoptr(resultp1,resultp2,dstptr);
    144  1.1  fredette 		return(NOEXCEPTION);
    145  1.1  fredette 	}
    146  1.1  fredette 	/*
    147  1.1  fredette 	 * Generate result
    148  1.1  fredette 	 */
    149  1.1  fredette 	if (src_exponent >= 0) {
    150  1.1  fredette 		temp = src;
    151  1.1  fredette 		Sgl_clear_signexponent_set_hidden(temp);
    152  1.1  fredette 		Dint_from_sgl_mantissa(temp,src_exponent,resultp1,resultp2);
    153  1.1  fredette 		if (Sgl_isone_sign(src)) {
    154  1.1  fredette 			Dint_setone_sign(resultp1,resultp2);
    155  1.1  fredette 		}
    156  1.1  fredette 		Dint_copytoptr(resultp1,resultp2,dstptr);
    157  1.1  fredette 
    158  1.1  fredette 		/* check for inexact */
    159  1.1  fredette 		if (Sgl_isinexact_to_fix(src,src_exponent)) {
    160  1.1  fredette 			if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
    161  1.1  fredette 			else Set_inexactflag();
    162  1.1  fredette 		}
    163  1.1  fredette 	}
    164  1.1  fredette 	else {
    165  1.1  fredette 		Dint_setzero(resultp1,resultp2);
    166  1.1  fredette 		Dint_copytoptr(resultp1,resultp2,dstptr);
    167  1.1  fredette 
    168  1.1  fredette 		/* check for inexact */
    169  1.1  fredette 		if (Sgl_isnotzero_exponentmantissa(src)) {
    170  1.1  fredette 			if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
    171  1.1  fredette 			else Set_inexactflag();
    172  1.1  fredette 		}
    173  1.1  fredette 	}
    174  1.1  fredette 	return(NOEXCEPTION);
    175  1.1  fredette }
    176  1.1  fredette 
    177  1.1  fredette /*
    178  1.1  fredette  *  Double Floating-point to Single Fixed-point
    179  1.1  fredette  */
    180  1.1  fredette /*ARGSUSED*/
    181  1.1  fredette int
    182  1.1  fredette dbl_to_sgl_fcnvfxt(srcptr,dstptr,status)
    183  1.1  fredette 
    184  1.1  fredette dbl_floating_point *srcptr;
    185  1.1  fredette int *dstptr;
    186  1.1  fredette unsigned int *status;
    187  1.1  fredette {
    188  1.1  fredette 	register unsigned int srcp1, srcp2, tempp1, tempp2;
    189  1.1  fredette 	register int src_exponent, result;
    190  1.1  fredette 
    191  1.1  fredette 	Dbl_copyfromptr(srcptr,srcp1,srcp2);
    192  1.1  fredette 	src_exponent = Dbl_exponent(srcp1) - DBL_BIAS;
    193  1.1  fredette 
    194  1.1  fredette 	/*
    195  1.1  fredette 	 * Test for overflow
    196  1.1  fredette 	 */
    197  1.1  fredette 	if (src_exponent > SGL_FX_MAX_EXP) {
    198  1.1  fredette 		/* check for MININT */
    199  1.1  fredette 		if (Dbl_isoverflow_to_int(src_exponent,srcp1,srcp2)) {
    200  1.1  fredette 			Dbl_return_overflow(srcp1,srcp2,dstptr);
    201  1.1  fredette 		}
    202  1.1  fredette 	}
    203  1.1  fredette 	/*
    204  1.1  fredette 	 * Generate result
    205  1.1  fredette 	 */
    206  1.1  fredette 	if (src_exponent >= 0) {
    207  1.1  fredette 		tempp1 = srcp1;
    208  1.1  fredette 		tempp2 = srcp2;
    209  1.1  fredette 		Dbl_clear_signexponent_set_hidden(tempp1);
    210  1.1  fredette 		Int_from_dbl_mantissa(tempp1,tempp2,src_exponent);
    211  1.1  fredette 		if (Dbl_isone_sign(srcp1) && (src_exponent <= SGL_FX_MAX_EXP))
    212  1.1  fredette 			result = -Dbl_allp1(tempp1);
    213  1.1  fredette 		else result = Dbl_allp1(tempp1);
    214  1.1  fredette 		*dstptr = result;
    215  1.1  fredette 
    216  1.1  fredette 		/* check for inexact */
    217  1.1  fredette 		if (Dbl_isinexact_to_fix(srcp1,srcp2,src_exponent)) {
    218  1.1  fredette 			if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
    219  1.1  fredette 			else Set_inexactflag();
    220  1.1  fredette 		}
    221  1.1  fredette 	}
    222  1.1  fredette 	else {
    223  1.1  fredette 		*dstptr = 0;
    224  1.1  fredette 
    225  1.1  fredette 		/* check for inexact */
    226  1.1  fredette 		if (Dbl_isnotzero_exponentmantissa(srcp1,srcp2)) {
    227  1.1  fredette 			if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
    228  1.1  fredette 			else Set_inexactflag();
    229  1.1  fredette 		}
    230  1.1  fredette 	}
    231  1.1  fredette 	return(NOEXCEPTION);
    232  1.1  fredette }
    233  1.1  fredette 
    234  1.1  fredette /*
    235  1.1  fredette  *  Double Floating-point to Double Fixed-point
    236  1.1  fredette  */
    237  1.1  fredette /*ARGSUSED*/
    238  1.1  fredette int
    239  1.1  fredette dbl_to_dbl_fcnvfxt(srcptr,dstptr,status)
    240  1.1  fredette 
    241  1.1  fredette dbl_floating_point *srcptr;
    242  1.1  fredette dbl_integer *dstptr;
    243  1.1  fredette unsigned int *status;
    244  1.1  fredette {
    245  1.1  fredette 	register int src_exponent, resultp1;
    246  1.1  fredette 	register unsigned int srcp1, srcp2, tempp1, tempp2, resultp2;
    247  1.1  fredette 
    248  1.1  fredette 	Dbl_copyfromptr(srcptr,srcp1,srcp2);
    249  1.1  fredette 	src_exponent = Dbl_exponent(srcp1) - DBL_BIAS;
    250  1.1  fredette 
    251  1.1  fredette 	/*
    252  1.1  fredette 	 * Test for overflow
    253  1.1  fredette 	 */
    254  1.1  fredette 	if (src_exponent > DBL_FX_MAX_EXP) {
    255  1.1  fredette 		/* check for MININT */
    256  1.1  fredette 		if ((src_exponent > DBL_FX_MAX_EXP + 1) ||
    257  1.1  fredette 		Dbl_isnotzero_mantissa(srcp1,srcp2) || Dbl_iszero_sign(srcp1)) {
    258  1.1  fredette 			/*
    259  1.1  fredette 			 * Since source is a number which cannot be
    260  1.1  fredette 			 * represented in fixed-point format, return
    261  1.1  fredette 			 * largest (or smallest) fixed-point number.
    262  1.1  fredette 			 */
    263  1.1  fredette 			Dbl_return_overflow_dbl(srcp1,srcp2,dstptr);
    264  1.1  fredette 		}
    265  1.1  fredette 	}
    266  1.1  fredette 	/*
    267  1.1  fredette 	 * Generate result
    268  1.1  fredette 	 */
    269  1.1  fredette 	if (src_exponent >= 0) {
    270  1.1  fredette 		tempp1 = srcp1;
    271  1.1  fredette 		tempp2 = srcp2;
    272  1.1  fredette 		Dbl_clear_signexponent_set_hidden(tempp1);
    273  1.1  fredette 		Dint_from_dbl_mantissa(tempp1,tempp2,src_exponent,
    274  1.1  fredette 		resultp1,resultp2);
    275  1.1  fredette 		if (Dbl_isone_sign(srcp1)) {
    276  1.1  fredette 			Dint_setone_sign(resultp1,resultp2);
    277  1.1  fredette 		}
    278  1.1  fredette 		Dint_copytoptr(resultp1,resultp2,dstptr);
    279  1.1  fredette 
    280  1.1  fredette 		/* check for inexact */
    281  1.1  fredette 		if (Dbl_isinexact_to_fix(srcp1,srcp2,src_exponent)) {
    282  1.1  fredette 			if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
    283  1.1  fredette 			else Set_inexactflag();
    284  1.1  fredette 		}
    285  1.1  fredette 	}
    286  1.1  fredette 	else {
    287  1.1  fredette 		Dint_setzero(resultp1,resultp2);
    288  1.1  fredette 		Dint_copytoptr(resultp1,resultp2,dstptr);
    289  1.1  fredette 
    290  1.1  fredette 		/* check for inexact */
    291  1.1  fredette 		if (Dbl_isnotzero_exponentmantissa(srcp1,srcp2)) {
    292  1.1  fredette 			if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
    293  1.1  fredette 			else Set_inexactflag();
    294  1.1  fredette 		}
    295  1.1  fredette 	}
    296  1.1  fredette 	return(NOEXCEPTION);
    297  1.1  fredette }
    298