1
2/*	$OpenBSD: fcnvfx.c,v 1.8 2010/07/30 18:05:23 kettenis Exp $	*/
3
4/*
5 * Copyright 1996 1995 by Open Software Foundation, Inc.
6 *              All Rights Reserved
7 *
8 * Permission to use, copy, modify, and distribute this software and
9 * its documentation for any purpose and without fee is hereby granted,
10 * provided that the above copyright notice appears in all copies and
11 * that both the copyright notice and this permission notice appear in
12 * supporting documentation.
13 *
14 * OSF DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
15 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
16 * FOR A PARTICULAR PURPOSE.
17 *
18 * IN NO EVENT SHALL OSF BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
19 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
20 * LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
21 * NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
22 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
23 *
24 */
25/*
26 * pmk1.1
27 */
28/*
29 * (c) Copyright 1986 HEWLETT-PACKARD COMPANY
30 *
31 * To anyone who acknowledges that this file is provided "AS IS"
32 * without any express or implied warranty:
33 *     permission to use, copy, modify, and distribute this file
34 * for any purpose is hereby granted without fee, provided that
35 * the above copyright notice and this notice appears in all
36 * copies, and that the name of Hewlett-Packard Company not be
37 * used in advertising or publicity pertaining to distribution
38 * of the software without specific, written prior permission.
39 * Hewlett-Packard Company makes no representations about the
40 * suitability of this software for any purpose.
41 */
42
43#include <sys/cdefs.h>
44__KERNEL_RCSID(0, "$NetBSD: fcnvfx.c,v 1.5 2012/01/01 20:04:36 skrll Exp $");
45
46#include "../spmath/float.h"
47#include "../spmath/sgl_float.h"
48#include "../spmath/dbl_float.h"
49#include "../spmath/cnv_float.h"
50
51/*
52 *  Single Floating-point to Single Fixed-point
53 */
54/*ARGSUSED*/
55int
56sgl_to_sgl_fcnvfx(sgl_floating_point *srcptr, int *dstptr,
57    unsigned int *status)
58{
59	register unsigned int src, temp;
60	register int src_exponent, result;
61	register int inexact = false;
62
63	src = *srcptr;
64	src_exponent = Sgl_exponent(src) - SGL_BIAS;
65
66	/*
67	 * Test for overflow
68	 */
69	if (src_exponent > SGL_FX_MAX_EXP) {
70		/* check for MININT */
71		if ((src_exponent > SGL_FX_MAX_EXP + 1) ||
72		Sgl_isnotzero_mantissa(src) || Sgl_iszero_sign(src)) {
73			if (Sgl_iszero_sign(src)) result = 0x7fffffff;
74			else result = 0x80000000;
75
76			if (Is_invalidtrap_enabled()) {
77				return(INVALIDEXCEPTION);
78			}
79			Set_invalidflag();
80			*dstptr = result;
81			return(NOEXCEPTION);
82		}
83	}
84	/*
85	 * Generate result
86	 */
87	if (src_exponent >= 0) {
88		temp = src;
89		Sgl_clear_signexponent_set_hidden(temp);
90		Int_from_sgl_mantissa(temp,src_exponent);
91		if (Sgl_isone_sign(src))  result = -Sgl_all(temp);
92		else result = Sgl_all(temp);
93
94		/* check for inexact */
95		if (Sgl_isinexact_to_fix(src,src_exponent)) {
96			inexact = true;
97			/*  round result  */
98			switch (Rounding_mode()) {
99			case ROUNDPLUS:
100			     if (Sgl_iszero_sign(src)) result++;
101			     break;
102			case ROUNDMINUS:
103			     if (Sgl_isone_sign(src)) result--;
104			     break;
105			case ROUNDNEAREST:
106			     if (Sgl_isone_roundbit(src,src_exponent)) {
107				if (Sgl_isone_stickybit(src,src_exponent)
108				|| (Sgl_isone_lowmantissa(temp))) {
109				   if (Sgl_iszero_sign(src)) result++;
110				   else result--;
111				}
112			     }
113			}
114		}
115	}
116	else {
117		result = 0;
118
119		/* check for inexact */
120		if (Sgl_isnotzero_exponentmantissa(src)) {
121			inexact = true;
122			/*  round result  */
123			switch (Rounding_mode()) {
124			case ROUNDPLUS:
125			     if (Sgl_iszero_sign(src)) result++;
126			     break;
127			case ROUNDMINUS:
128			     if (Sgl_isone_sign(src)) result--;
129			     break;
130			case ROUNDNEAREST:
131			     if (src_exponent == -1)
132				if (Sgl_isnotzero_mantissa(src)) {
133				   if (Sgl_iszero_sign(src)) result++;
134				   else result--;
135				}
136			}
137		}
138	}
139	*dstptr = result;
140	if (inexact) {
141		if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
142		else Set_inexactflag();
143	}
144	return(NOEXCEPTION);
145}
146
147/*
148 *  Single Floating-point to Double Fixed-point
149 */
150/*ARGSUSED*/
151int
152sgl_to_dbl_fcnvfx(sgl_floating_point *srcptr, dbl_integer *dstptr,
153    unsigned int *status)
154{
155	register int src_exponent, resultp1;
156	register unsigned int src, temp, resultp2;
157	register int inexact = false;
158
159	src = *srcptr;
160	src_exponent = Sgl_exponent(src) - SGL_BIAS;
161
162	/*
163	 * Test for overflow
164	 */
165	if (src_exponent > DBL_FX_MAX_EXP) {
166		/* check for MININT */
167		if ((src_exponent > DBL_FX_MAX_EXP + 1) ||
168		Sgl_isnotzero_mantissa(src) || Sgl_iszero_sign(src)) {
169			if (Sgl_iszero_sign(src)) {
170				resultp1 = 0x7fffffff;
171				resultp2 = 0xffffffff;
172			}
173			else {
174				resultp1 = 0x80000000;
175				resultp2 = 0;
176			}
177
178			if (Is_invalidtrap_enabled()) {
179				return(INVALIDEXCEPTION);
180			}
181			Set_invalidflag();
182			Dint_copytoptr(resultp1,resultp2,dstptr);
183			return(NOEXCEPTION);
184		}
185		Dint_set_minint(resultp1,resultp2);
186		Dint_copytoptr(resultp1,resultp2,dstptr);
187		return(NOEXCEPTION);
188	}
189	/*
190	 * Generate result
191	 */
192	if (src_exponent >= 0) {
193		temp = src;
194		Sgl_clear_signexponent_set_hidden(temp);
195		Dint_from_sgl_mantissa(temp,src_exponent,resultp1,resultp2);
196		if (Sgl_isone_sign(src)) {
197			Dint_setone_sign(resultp1,resultp2);
198		}
199
200		/* check for inexact */
201		if (Sgl_isinexact_to_fix(src,src_exponent)) {
202			inexact = true;
203			/*  round result  */
204			switch (Rounding_mode()) {
205			case ROUNDPLUS:
206			     if (Sgl_iszero_sign(src)) {
207				Dint_increment(resultp1,resultp2);
208			     }
209			     break;
210			case ROUNDMINUS:
211			     if (Sgl_isone_sign(src)) {
212				Dint_decrement(resultp1,resultp2);
213			     }
214			     break;
215			case ROUNDNEAREST:
216			     if (Sgl_isone_roundbit(src,src_exponent))
217				if (Sgl_isone_stickybit(src,src_exponent) ||
218				(Dint_isone_lowp2(resultp2))) {
219				   if (Sgl_iszero_sign(src)) {
220				      Dint_increment(resultp1,resultp2);
221				   }
222				   else {
223				      Dint_decrement(resultp1,resultp2);
224				   }
225				}
226			}
227		}
228	}
229	else {
230		Dint_setzero(resultp1,resultp2);
231
232		/* check for inexact */
233		if (Sgl_isnotzero_exponentmantissa(src)) {
234			inexact = true;
235			/*  round result  */
236			switch (Rounding_mode()) {
237			case ROUNDPLUS:
238			     if (Sgl_iszero_sign(src)) {
239				Dint_increment(resultp1,resultp2);
240			     }
241			     break;
242			case ROUNDMINUS:
243			     if (Sgl_isone_sign(src)) {
244				Dint_decrement(resultp1,resultp2);
245			     }
246			     break;
247			case ROUNDNEAREST:
248			     if (src_exponent == -1)
249				if (Sgl_isnotzero_mantissa(src)) {
250				   if (Sgl_iszero_sign(src)) {
251				      Dint_increment(resultp1,resultp2);
252				   }
253				   else {
254				      Dint_decrement(resultp1,resultp2);
255				   }
256				}
257			}
258		}
259	}
260	Dint_copytoptr(resultp1,resultp2,dstptr);
261	if (inexact) {
262		if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
263		else Set_inexactflag();
264	}
265	return(NOEXCEPTION);
266}
267
268/*
269 *  Double Floating-point to Single Fixed-point
270 */
271/*ARGSUSED*/
272int
273dbl_to_sgl_fcnvfx(dbl_floating_point *srcptr, int *dstptr,
274   unsigned int *status)
275{
276	register unsigned int srcp1,srcp2, tempp1,tempp2;
277	register int src_exponent, result;
278	register int inexact = false;
279
280	Dbl_copyfromptr(srcptr,srcp1,srcp2);
281	src_exponent = Dbl_exponent(srcp1) - DBL_BIAS;
282
283	/*
284	 * Test for overflow
285	 */
286	if (src_exponent > SGL_FX_MAX_EXP) {
287		/* check for MININT */
288		if (Dbl_isoverflow_to_int(src_exponent,srcp1,srcp2)) {
289			if (Dbl_iszero_sign(srcp1)) result = 0x7fffffff;
290			else result = 0x80000000;
291
292			if (Is_invalidtrap_enabled()) {
293				return(INVALIDEXCEPTION);
294			}
295			Set_invalidflag();
296			*dstptr = result;
297			return(NOEXCEPTION);
298		}
299	}
300	/*
301	 * Generate result
302	 */
303	if (src_exponent >= 0) {
304		tempp1 = srcp1;
305		tempp2 = srcp2;
306		Dbl_clear_signexponent_set_hidden(tempp1);
307		Int_from_dbl_mantissa(tempp1,tempp2,src_exponent);
308		if (Dbl_isone_sign(srcp1) && (src_exponent <= SGL_FX_MAX_EXP))
309			result = -Dbl_allp1(tempp1);
310		else result = Dbl_allp1(tempp1);
311
312		/* check for inexact */
313		if (Dbl_isinexact_to_fix(srcp1,srcp2,src_exponent)) {
314			inexact = true;
315			/*  round result  */
316			switch (Rounding_mode()) {
317			case ROUNDPLUS:
318				if (Dbl_iszero_sign(srcp1))
319					result++;
320			     break;
321			case ROUNDMINUS:
322			     if (Dbl_isone_sign(srcp1)) result--;
323			     break;
324			case ROUNDNEAREST:
325			     if (Dbl_isone_roundbit(srcp1,srcp2,src_exponent))
326				if (Dbl_isone_stickybit(srcp1,srcp2,src_exponent) ||
327				(Dbl_isone_lowmantissap1(tempp1))) {
328				   if (Dbl_iszero_sign(srcp1)) result++;
329				   else result--;
330				}
331			}
332			/* check for overflow */
333			if ((Dbl_iszero_sign(srcp1) && result < 0) ||
334			    (Dbl_isone_sign(srcp1) && result > 0)) {
335
336				if (Dbl_iszero_sign(srcp1))
337					result = 0x7fffffff;
338				else
339					result = 0x80000000;
340
341			    if (Is_overflowtrap_enabled()) {
342			    if (Is_inexacttrap_enabled())
343			      return(OVERFLOWEXCEPTION|INEXACTEXCEPTION);
344			    else Set_inexactflag();
345			    return(OVERFLOWEXCEPTION);
346			    }
347			  Set_overflowflag();
348			  *dstptr = result;
349			  if (Is_inexacttrap_enabled() )
350				return(INEXACTEXCEPTION);
351			  else Set_inexactflag();
352			  return(NOEXCEPTION);
353			}
354		}
355	}
356	else {
357		result = 0;
358
359		/* check for inexact */
360		if (Dbl_isnotzero_exponentmantissa(srcp1,srcp2)) {
361			inexact = true;
362			/*  round result  */
363			switch (Rounding_mode()) {
364			case ROUNDPLUS:
365			     if (Dbl_iszero_sign(srcp1)) result++;
366			     break;
367			case ROUNDMINUS:
368			     if (Dbl_isone_sign(srcp1)) result--;
369			     break;
370			case ROUNDNEAREST:
371			     if (src_exponent == -1)
372				if (Dbl_isnotzero_mantissa(srcp1,srcp2)) {
373				   if (Dbl_iszero_sign(srcp1)) result++;
374				   else result--;
375				}
376			}
377		}
378	}
379	*dstptr = result;
380	if (inexact) {
381		if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
382		else Set_inexactflag();
383	}
384	return(NOEXCEPTION);
385}
386
387/*
388 *  Double Floating-point to Double Fixed-point
389 */
390/*ARGSUSED*/
391int
392dbl_to_dbl_fcnvfx(dbl_floating_point *srcptr, dbl_integer *dstptr,
393    unsigned int *status)
394{
395	register int src_exponent, resultp1;
396	register unsigned int srcp1, srcp2, tempp1, tempp2, resultp2;
397	register int inexact = false;
398
399	Dbl_copyfromptr(srcptr,srcp1,srcp2);
400	src_exponent = Dbl_exponent(srcp1) - DBL_BIAS;
401
402	/*
403	 * Test for overflow
404	 */
405	if (src_exponent > DBL_FX_MAX_EXP) {
406		/* check for MININT */
407		if ((src_exponent > DBL_FX_MAX_EXP + 1) ||
408		Dbl_isnotzero_mantissa(srcp1,srcp2) || Dbl_iszero_sign(srcp1)) {
409			if (Dbl_iszero_sign(srcp1)) {
410				resultp1 = 0x7fffffff;
411				resultp2 = 0xffffffff;
412			}
413			else {
414				resultp1 = 0x80000000;
415				resultp2 = 0;
416			}
417
418			if (Is_invalidtrap_enabled()) {
419				return(INVALIDEXCEPTION);
420			}
421			Set_invalidflag();
422			Dint_copytoptr(resultp1,resultp2,dstptr);
423			return(NOEXCEPTION);
424		}
425	}
426
427	/*
428	 * Generate result
429	 */
430	if (src_exponent >= 0) {
431		tempp1 = srcp1;
432		tempp2 = srcp2;
433		Dbl_clear_signexponent_set_hidden(tempp1);
434		Dint_from_dbl_mantissa(tempp1,tempp2,src_exponent,
435				       resultp1, resultp2);
436		if (Dbl_isone_sign(srcp1)) {
437			Dint_setone_sign(resultp1,resultp2);
438		}
439
440		/* check for inexact */
441		if (Dbl_isinexact_to_fix(srcp1,srcp2,src_exponent)) {
442			inexact = true;
443			/*  round result  */
444			switch (Rounding_mode()) {
445			case ROUNDPLUS:
446			     if (Dbl_iszero_sign(srcp1)) {
447				Dint_increment(resultp1,resultp2);
448			     }
449			     break;
450			case ROUNDMINUS:
451			     if (Dbl_isone_sign(srcp1)) {
452				Dint_decrement(resultp1,resultp2);
453			     }
454			     break;
455			case ROUNDNEAREST:
456			     if (Dbl_isone_roundbit(srcp1,srcp2,src_exponent))
457				if (Dbl_isone_stickybit(srcp1,srcp2,src_exponent) ||
458				(Dint_isone_lowp2(resultp2))) {
459				   if (Dbl_iszero_sign(srcp1)) {
460				      Dint_increment(resultp1,resultp2);
461				   }
462				   else {
463				      Dint_decrement(resultp1,resultp2);
464				   }
465				}
466			}
467		}
468	}
469	else {
470		Dint_setzero(resultp1,resultp2);
471
472		/* check for inexact */
473		if (Dbl_isnotzero_exponentmantissa(srcp1,srcp2)) {
474			inexact = true;
475			/*  round result  */
476			switch (Rounding_mode()) {
477			case ROUNDPLUS:
478			     if (Dbl_iszero_sign(srcp1)) {
479				Dint_increment(resultp1,resultp2);
480			     }
481			     break;
482			case ROUNDMINUS:
483			     if (Dbl_isone_sign(srcp1)) {
484				Dint_decrement(resultp1,resultp2);
485			     }
486			     break;
487			case ROUNDNEAREST:
488			     if (src_exponent == -1)
489				if (Dbl_isnotzero_mantissa(srcp1,srcp2)) {
490				   if (Dbl_iszero_sign(srcp1)) {
491				      Dint_increment(resultp1,resultp2);
492				   }
493				   else {
494				      Dint_decrement(resultp1,resultp2);
495				   }
496				}
497			}
498		}
499	}
500	Dint_copytoptr(resultp1,resultp2,dstptr);
501	if (inexact) {
502		if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
503		else Set_inexactflag();
504	}
505	return(NOEXCEPTION);
506}
507