MagickCore  7.1.0
Convert, Edit, Or Compose Bitmap Images
quantum-private.h
1 /*
2  Copyright @ 1999 ImageMagick Studio LLC, a non-profit organization
3  dedicated to making software imaging solutions freely available.
4 
5  You may not use this file except in compliance with the License. You may
6  obtain a copy of the License at
7 
8  https://imagemagick.org/script/license.php
9 
10  Unless required by applicable law or agreed to in writing, software
11  distributed under the License is distributed on an "AS IS" BASIS,
12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  See the License for the specific language governing permissions and
14  limitations under the License.
15 
16  MagickCore quantum inline methods.
17 */
18 #ifndef MAGICKCORE_QUANTUM_PRIVATE_H
19 #define MAGICKCORE_QUANTUM_PRIVATE_H
20 
21 #include "MagickCore/memory_.h"
22 #include "MagickCore/cache.h"
23 #include "MagickCore/image-private.h"
24 #include "MagickCore/pixel-accessor.h"
25 
26 #if defined(__cplusplus) || defined(c_plusplus)
27 extern "C" {
28 #endif
29 
30 typedef struct _QuantumState
31 {
32  double
33  inverse_scale;
34 
35  unsigned int
36  pixel;
37 
38  size_t
39  bits;
40 
41  const unsigned int
42  *mask;
43 } QuantumState;
44 
45 struct _QuantumInfo
46 {
47  size_t
48  depth,
49  quantum;
50 
51  QuantumFormatType
52  format;
53 
54  double
55  minimum,
56  maximum,
57  scale;
58 
59  size_t
60  pad;
61 
62  MagickBooleanType
63  min_is_white,
64  pack;
65 
66  QuantumAlphaType
67  alpha_type;
68 
69  size_t
70  number_threads;
71 
72  MemoryInfo
73  **pixels;
74 
75  size_t
76  extent;
77 
78  EndianType
79  endian;
80 
81  QuantumState
82  state;
83 
84  SemaphoreInfo
85  *semaphore;
86 
87  size_t
88  signature;
89 };
90 
91 extern MagickPrivate void
92  ResetQuantumState(QuantumInfo *);
93 
94 static inline MagickSizeType GetQuantumRange(const size_t depth)
95 {
96  MagickSizeType
97  one;
98 
99  size_t
100  max_depth;
101 
102  if (depth == 0)
103  return(0);
104  one=1;
105  max_depth=8*sizeof(MagickSizeType);
106  return((MagickSizeType) ((one << (MagickMin(depth,max_depth)-1))+
107  ((one << (MagickMin(depth,max_depth)-1))-1)));
108 }
109 
110 static inline float HalfToSinglePrecision(const unsigned short half)
111 {
112 #define ExponentBias (127-15)
113 #define ExponentMask 0x7c00
114 #define ExponentShift 23
115 #define SignBitShift 31
116 #define SignificandShift 13
117 #define SignificandMask 0x00000400
118 
119  typedef union _SinglePrecision
120  {
121  unsigned int
122  fixed_point;
123 
124  float
125  single_precision;
126  } SinglePrecision;
127 
128  unsigned int
129  exponent,
130  significand,
131  sign_bit;
132 
133  SinglePrecision
134  map;
135 
136  unsigned int
137  value;
138 
139  /*
140  The IEEE 754 standard specifies half precision as having:
141 
142  Sign bit: 1 bit
143  Exponent width: 5 bits
144  Significand precision: 11 (10 explicitly stored)
145  */
146  sign_bit=(unsigned int) ((half >> 15) & 0x00000001);
147  exponent=(unsigned int) ((half >> 10) & 0x0000001f);
148  significand=(unsigned int) (half & 0x000003ff);
149  if (exponent == 0)
150  {
151  if (significand == 0)
152  value=sign_bit << SignBitShift;
153  else
154  {
155  while ((significand & SignificandMask) == 0)
156  {
157  significand<<=1;
158  exponent--;
159  }
160  exponent++;
161  significand&=(~SignificandMask);
162  exponent+=ExponentBias;
163  value=(sign_bit << SignBitShift) | (exponent << ExponentShift) |
164  (significand << SignificandShift);
165  }
166  }
167  else
168  if (exponent == SignBitShift)
169  {
170  value=(sign_bit << SignBitShift) | 0x7f800000;
171  if (significand != 0)
172  value|=(significand << SignificandShift);
173  }
174  else
175  {
176  exponent+=ExponentBias;
177  significand<<=SignificandShift;
178  value=(sign_bit << SignBitShift) | (exponent << ExponentShift) |
179  significand;
180  }
181  map.fixed_point=value;
182  return(map.single_precision);
183 }
184 
185 static inline unsigned char *PopCharPixel(const unsigned char pixel,
186  unsigned char *magick_restrict pixels)
187 {
188  *pixels++=pixel;
189  return(pixels);
190 }
191 
192 static inline unsigned char *PopLongPixel(const EndianType endian,
193  const unsigned int pixel,unsigned char *magick_restrict pixels)
194 {
195  unsigned int
196  quantum;
197 
198  quantum=(unsigned int) pixel;
199  if (endian == LSBEndian)
200  {
201  *pixels++=(unsigned char) (quantum);
202  *pixels++=(unsigned char) (quantum >> 8);
203  *pixels++=(unsigned char) (quantum >> 16);
204  *pixels++=(unsigned char) (quantum >> 24);
205  return(pixels);
206  }
207  *pixels++=(unsigned char) (quantum >> 24);
208  *pixels++=(unsigned char) (quantum >> 16);
209  *pixels++=(unsigned char) (quantum >> 8);
210  *pixels++=(unsigned char) (quantum);
211  return(pixels);
212 }
213 
214 static inline unsigned char *PopShortPixel(const EndianType endian,
215  const unsigned short pixel,unsigned char *magick_restrict pixels)
216 {
217  unsigned int
218  quantum;
219 
220  quantum=pixel;
221  if (endian == LSBEndian)
222  {
223  *pixels++=(unsigned char) (quantum);
224  *pixels++=(unsigned char) (quantum >> 8);
225  return(pixels);
226  }
227  *pixels++=(unsigned char) (quantum >> 8);
228  *pixels++=(unsigned char) (quantum);
229  return(pixels);
230 }
231 
232 static inline const unsigned char *PushCharPixel(
233  const unsigned char *magick_restrict pixels,
234  unsigned char *magick_restrict pixel)
235 {
236  *pixel=(*pixels++);
237  return(pixels);
238 }
239 
240 static inline const unsigned char *PushLongPixel(const EndianType endian,
241  const unsigned char *magick_restrict pixels,
242  unsigned int *magick_restrict pixel)
243 {
244  unsigned int
245  quantum;
246 
247  if (endian == LSBEndian)
248  {
249  quantum=((unsigned int) *pixels++);
250  quantum|=((unsigned int) *pixels++ << 8);
251  quantum|=((unsigned int) *pixels++ << 16);
252  quantum|=((unsigned int) *pixels++ << 24);
253  *pixel=quantum;
254  return(pixels);
255  }
256  quantum=((unsigned int) *pixels++ << 24);
257  quantum|=((unsigned int) *pixels++ << 16);
258  quantum|=((unsigned int) *pixels++ << 8);
259  quantum|=((unsigned int) *pixels++);
260  *pixel=quantum;
261  return(pixels);
262 }
263 
264 static inline const unsigned char *PushShortPixel(const EndianType endian,
265  const unsigned char *magick_restrict pixels,
266  unsigned short *magick_restrict pixel)
267 {
268  unsigned int
269  quantum;
270 
271  if (endian == LSBEndian)
272  {
273  quantum=(unsigned int) *pixels++;
274  quantum|=(unsigned int) (*pixels++ << 8);
275  *pixel=(unsigned short) (quantum & 0xffff);
276  return(pixels);
277  }
278  quantum=(unsigned int) (*pixels++ << 8);
279  quantum|=(unsigned int) *pixels++;
280  *pixel=(unsigned short) (quantum & 0xffff);
281  return(pixels);
282 }
283 
284 static inline const unsigned char *PushFloatPixel(const EndianType endian,
285  const unsigned char *magick_restrict pixels,
286  MagickFloatType *magick_restrict pixel)
287 {
288  union
289  {
290  unsigned int
291  unsigned_value;
292 
293  MagickFloatType
294  float_value;
295  } quantum;
296 
297  if (endian == LSBEndian)
298  {
299  quantum.unsigned_value=((unsigned int) *pixels++);
300  quantum.unsigned_value|=((unsigned int) *pixels++ << 8);
301  quantum.unsigned_value|=((unsigned int) *pixels++ << 16);
302  quantum.unsigned_value|=((unsigned int) *pixels++ << 24);
303  *pixel=quantum.float_value;
304  return(pixels);
305  }
306  quantum.unsigned_value=((unsigned int) *pixels++ << 24);
307  quantum.unsigned_value|=((unsigned int) *pixels++ << 16);
308  quantum.unsigned_value|=((unsigned int) *pixels++ << 8);
309  quantum.unsigned_value|=((unsigned int) *pixels++);
310  *pixel=quantum.float_value;
311  return(pixels);
312 }
313 
314 static inline Quantum ScaleAnyToQuantum(const QuantumAny quantum,
315  const QuantumAny range)
316 {
317  if (quantum > range)
318  return(QuantumRange);
319 #if !defined(MAGICKCORE_HDRI_SUPPORT)
320  return((Quantum) ((double) QuantumRange*(quantum*
321  PerceptibleReciprocal((double) range))+0.5));
322 #else
323  return((Quantum) ((double) QuantumRange*(quantum*
324  PerceptibleReciprocal((double) range))));
325 #endif
326 }
327 
328 static inline QuantumAny ScaleQuantumToAny(const Quantum quantum,
329  const QuantumAny range)
330 {
331 #if !defined(MAGICKCORE_HDRI_SUPPORT)
332  return((QuantumAny) ((double) range*quantum/QuantumRange));
333 #else
334  if ((IsNaN(quantum) != 0) || (quantum <= 0.0))
335  return((QuantumAny) 0UL);
336  if (((double) range*quantum/QuantumRange) >= 18446744073709551615.0)
337  return((QuantumAny) MagickULLConstant(18446744073709551615));
338  return((QuantumAny) ((double) range*quantum/QuantumRange+0.5));
339 #endif
340 }
341 
342 #if (MAGICKCORE_QUANTUM_DEPTH == 8)
343 static inline Quantum ScaleCharToQuantum(const unsigned char value)
344 {
345  return((Quantum) value);
346 }
347 
348 static inline Quantum ScaleLongToQuantum(const unsigned int value)
349 {
350 #if !defined(MAGICKCORE_HDRI_SUPPORT)
351  return((Quantum) ((value)/16843009UL));
352 #else
353  return((Quantum) (value/16843009.0));
354 #endif
355 }
356 
357 static inline Quantum ScaleLongLongToQuantum(const MagickSizeType value)
358 {
359 #if !defined(MAGICKCORE_HDRI_SUPPORT)
360  return((Quantum) (value/MagickULLConstant(72340172838076673)));
361 #else
362  return((Quantum) (value/72340172838076673.0));
363 #endif
364 }
365 
366 static inline Quantum ScaleMapToQuantum(const MagickRealType value)
367 {
368  if (value <= 0.0)
369  return((Quantum) 0);
370  if (value >= MaxMap)
371  return(QuantumRange);
372 #if !defined(MAGICKCORE_HDRI_SUPPORT)
373  return((Quantum) (value+0.5));
374 #else
375  return((Quantum) value);
376 #endif
377 }
378 
379 static inline unsigned int ScaleQuantumToLong(const Quantum quantum)
380 {
381 #if !defined(MAGICKCORE_HDRI_SUPPORT)
382  return((unsigned int) (16843009UL*quantum));
383 #else
384  if ((IsNaN(quantum) != 0) || (quantum <= 0.0))
385  return(0U);
386  if ((16843009.0*quantum) >= 4294967295.0)
387  return(4294967295UL);
388  return((unsigned int) (16843009.0*quantum+0.5));
389 #endif
390 }
391 
392 static inline MagickSizeType ScaleQuantumToLongLong(const Quantum quantum)
393 {
394 #if !defined(MAGICKCORE_HDRI_SUPPORT)
395  return((MagickSizeType) (MagickULLConstant(72340172838076673)*quantum));
396 #else
397  if ((IsNaN(quantum) != 0) || (quantum <= 0.0))
398  return(0UL);
399  if ((72340172838076673.0*quantum) >= 18446744073709551615.0)
400  return(MagickULLConstant(18446744073709551615));
401  return((MagickSizeType) (72340172838076673*quantum+0.5));
402 #endif
403 }
404 
405 static inline unsigned int ScaleQuantumToMap(const Quantum quantum)
406 {
407  if (quantum >= (Quantum) MaxMap)
408  return((unsigned int) MaxMap);
409 #if !defined(MAGICKCORE_HDRI_SUPPORT)
410  return((unsigned int) quantum);
411 #else
412  if ((IsNaN(quantum) != 0) || (quantum <= 0.0))
413  return(0U);
414  return((unsigned int) (quantum+0.5));
415 #endif
416 }
417 
418 static inline unsigned short ScaleQuantumToShort(const Quantum quantum)
419 {
420 #if !defined(MAGICKCORE_HDRI_SUPPORT)
421  return((unsigned short) (257UL*quantum));
422 #else
423  if ((IsNaN(quantum) != 0) || (quantum <= 0.0))
424  return(0);
425  if ((257.0*quantum) >= 65535.0)
426  return(65535);
427  return((unsigned short) (257.0*quantum+0.5));
428 #endif
429 }
430 
431 static inline Quantum ScaleShortToQuantum(const unsigned short value)
432 {
433 #if !defined(MAGICKCORE_HDRI_SUPPORT)
434  return((Quantum) ((value+128U)/257U));
435 #else
436  return((Quantum) (value/257.0));
437 #endif
438 }
439 #elif (MAGICKCORE_QUANTUM_DEPTH == 16)
440 static inline Quantum ScaleCharToQuantum(const unsigned char value)
441 {
442 #if !defined(MAGICKCORE_HDRI_SUPPORT)
443  return((Quantum) (257U*value));
444 #else
445  return((Quantum) (257.0*value));
446 #endif
447 }
448 
449 static inline Quantum ScaleLongToQuantum(const unsigned int value)
450 {
451 #if !defined(MAGICKCORE_HDRI_SUPPORT)
452  return((Quantum) ((value)/MagickULLConstant(65537)));
453 #else
454  return((Quantum) (value/65537.0));
455 #endif
456 }
457 
458 static inline Quantum ScaleLongLongToQuantum(const MagickSizeType value)
459 {
460 #if !defined(MAGICKCORE_HDRI_SUPPORT)
461  return((Quantum) ((value)/MagickULLConstant(281479271743489)));
462 #else
463  return((Quantum) (value/281479271743489.0));
464 #endif
465 }
466 
467 static inline Quantum ScaleMapToQuantum(const MagickRealType value)
468 {
469  if (value <= 0.0)
470  return((Quantum) 0);
471  if (value >= MaxMap)
472  return(QuantumRange);
473 #if !defined(MAGICKCORE_HDRI_SUPPORT)
474  return((Quantum) (value+0.5));
475 #else
476  return((Quantum) value);
477 #endif
478 }
479 
480 static inline unsigned int ScaleQuantumToLong(const Quantum quantum)
481 {
482 #if !defined(MAGICKCORE_HDRI_SUPPORT)
483  return((unsigned int) (65537UL*quantum));
484 #else
485  if ((IsNaN(quantum) != 0) || (quantum <= 0.0))
486  return(0U);
487  if ((65537.0*quantum) >= 4294967295.0)
488  return(4294967295U);
489  return((unsigned int) (65537.0*quantum+0.5));
490 #endif
491 }
492 
493 static inline MagickSizeType ScaleQuantumToLongLong(const Quantum quantum)
494 {
495 #if !defined(MAGICKCORE_HDRI_SUPPORT)
496  return((MagickSizeType) (MagickULLConstant(281479271743489)*quantum));
497 #else
498  if ((IsNaN(quantum) != 0) || (quantum <= 0.0))
499  return(0UL);
500  if ((281479271743489.0*quantum) >= 18446744073709551615.0)
501  return(MagickULLConstant(18446744073709551615));
502  return((MagickSizeType) (281479271743489.0*quantum+0.5));
503 #endif
504 }
505 
506 static inline unsigned int ScaleQuantumToMap(const Quantum quantum)
507 {
508  if (quantum >= (Quantum) MaxMap)
509  return((unsigned int) MaxMap);
510 #if !defined(MAGICKCORE_HDRI_SUPPORT)
511  return((unsigned int) quantum);
512 #else
513  if ((IsNaN(quantum) != 0) || (quantum <= 0.0))
514  return(0U);
515  return((unsigned int) (quantum+0.5));
516 #endif
517 }
518 
519 static inline unsigned short ScaleQuantumToShort(const Quantum quantum)
520 {
521 #if !defined(MAGICKCORE_HDRI_SUPPORT)
522  return((unsigned short) quantum);
523 #else
524  if ((IsNaN(quantum) != 0) || (quantum <= 0.0))
525  return(0);
526  if (quantum >= 65535.0)
527  return(65535);
528  return((unsigned short) (quantum+0.5));
529 #endif
530 }
531 
532 static inline Quantum ScaleShortToQuantum(const unsigned short value)
533 {
534  return((Quantum) value);
535 }
536 #elif (MAGICKCORE_QUANTUM_DEPTH == 32)
537 static inline Quantum ScaleCharToQuantum(const unsigned char value)
538 {
539 #if !defined(MAGICKCORE_HDRI_SUPPORT)
540  return((Quantum) (16843009UL*value));
541 #else
542  return((Quantum) (16843009.0*value));
543 #endif
544 }
545 
546 static inline Quantum ScaleLongToQuantum(const unsigned int value)
547 {
548  return((Quantum) value);
549 }
550 
551 static inline Quantum ScaleLongLongToQuantum(const MagickSizeType value)
552 {
553 #if !defined(MAGICKCORE_HDRI_SUPPORT)
554  return((Quantum) ((value)/MagickULLConstant(4294967297)));
555 #else
556  return((Quantum) (value/4294967297.0));
557 #endif
558 }
559 
560 static inline Quantum ScaleMapToQuantum(const MagickRealType value)
561 {
562  if (value <= 0.0)
563  return((Quantum) 0);
564  if (value >= (Quantum) MaxMap)
565  return(QuantumRange);
566 #if !defined(MAGICKCORE_HDRI_SUPPORT)
567  return((Quantum) (65537.0*value+0.5));
568 #else
569  return((Quantum) (65537.0*value));
570 #endif
571 }
572 
573 static inline unsigned int ScaleQuantumToLong(const Quantum quantum)
574 {
575 #if !defined(MAGICKCORE_HDRI_SUPPORT)
576  return((unsigned int) quantum);
577 #else
578  if ((IsNaN(quantum) != 0) || (quantum <= 0.0))
579  return(0U);
580  if ((quantum) >= 4294967295.0)
581  return(4294967295);
582  return((unsigned int) (quantum+0.5));
583 #endif
584 }
585 
586 static inline MagickSizeType ScaleQuantumToLongLong(const Quantum quantum)
587 {
588 #if !defined(MAGICKCORE_HDRI_SUPPORT)
589  return((MagickSizeType) (MagickULLConstant(4294967297)*quantum));
590 #else
591  if ((IsNaN(quantum) != 0) || (quantum <= 0.0))
592  return(0UL);
593  if ((4294967297.0*quantum) >= 18446744073709551615.0)
594  return(MagickULLConstant(18446744073709551615));
595  return((MagickSizeType) (4294967297.0*quantum+0.5));
596 #endif
597 }
598 
599 static inline unsigned int ScaleQuantumToMap(const Quantum quantum)
600 {
601  if ((quantum/65537) >= (Quantum) MaxMap)
602  return((unsigned int) MaxMap);
603 #if !defined(MAGICKCORE_HDRI_SUPPORT)
604  return((unsigned int) ((quantum+MagickULLConstant(32768))/
605  MagickULLConstant(65537)));
606 #else
607  if ((IsNaN(quantum) != 0) || (quantum <= 0.0))
608  return(0U);
609  return((unsigned int) (quantum/65537.0+0.5));
610 #endif
611 }
612 
613 static inline unsigned short ScaleQuantumToShort(const Quantum quantum)
614 {
615 #if !defined(MAGICKCORE_HDRI_SUPPORT)
616  return((unsigned short) ((quantum+MagickULLConstant(32768))/
617  MagickULLConstant(65537)));
618 #else
619  if ((IsNaN(quantum) != 0) || (quantum <= 0.0))
620  return(0);
621  if ((quantum/65537.0) >= 65535.0)
622  return(65535);
623  return((unsigned short) (quantum/65537.0+0.5));
624 #endif
625 }
626 
627 static inline Quantum ScaleShortToQuantum(const unsigned short value)
628 {
629 #if !defined(MAGICKCORE_HDRI_SUPPORT)
630  return((Quantum) (65537UL*value));
631 #else
632  return((Quantum) (65537.0*value));
633 #endif
634 }
635 #elif (MAGICKCORE_QUANTUM_DEPTH == 64)
636 static inline Quantum ScaleCharToQuantum(const unsigned char value)
637 {
638  return((Quantum) (72340172838076673.0*value));
639 }
640 
641 static inline Quantum ScaleLongToQuantum(const unsigned int value)
642 {
643  return((Quantum) (4294967297.0*value));
644 }
645 
646 static inline Quantum ScaleLongLongToQuantum(const MagickSizeType value)
647 {
648  return((Quantum) (value));
649 }
650 
651 static inline Quantum ScaleMapToQuantum(const MagickRealType value)
652 {
653  if (value <= 0.0)
654  return((Quantum) 0);
655  if (value >= MaxMap)
656  return(QuantumRange);
657  return((Quantum) (281479271743489.0*value));
658 }
659 
660 static inline unsigned int ScaleQuantumToLong(const Quantum quantum)
661 {
662  return((unsigned int) (quantum/4294967297.0+0.5));
663 }
664 
665 static inline MagickSizeType ScaleQuantumToLongLong(const Quantum quantum)
666 {
667 #if !defined(MAGICKCORE_HDRI_SUPPORT)
668  return((MagickSizeType) quantum);
669 #else
670  if ((IsNaN(quantum) != 0) || (quantum <= 0.0))
671  return(0UL);
672  if (quantum >= 18446744073709551615.0)
673  return(MagickULLConstant(18446744073709551615));
674  return((MagickSizeType) (quantum+0.5));
675 #endif
676 }
677 
678 static inline unsigned int ScaleQuantumToMap(const Quantum quantum)
679 {
680  if ((IsNaN(quantum) != 0) || (quantum <= 0.0))
681  return(0U);
682  if ((quantum/281479271743489.0) >= MaxMap)
683  return((unsigned int) MaxMap);
684  return((unsigned int) (quantum/281479271743489.0+0.5));
685 }
686 
687 static inline unsigned short ScaleQuantumToShort(const Quantum quantum)
688 {
689  if ((IsNaN(quantum) != 0) || (quantum <= 0.0))
690  return(0);
691  if ((quantum/281479271743489.0) >= 65535.0)
692  return(65535);
693  return((unsigned short) (quantum/281479271743489.0+0.5));
694 }
695 
696 static inline Quantum ScaleShortToQuantum(const unsigned short value)
697 {
698  return((Quantum) (281479271743489.0*value));
699 }
700 #endif
701 
702 static inline unsigned short SinglePrecisionToHalf(const float value)
703 {
704  typedef union _SinglePrecision
705  {
706  unsigned int
707  fixed_point;
708 
709  float
710  single_precision;
711  } SinglePrecision;
712 
713  int
714  exponent;
715 
716  unsigned int
717  significand,
718  sign_bit;
719 
720  SinglePrecision
721  map;
722 
723  unsigned short
724  half;
725 
726  /*
727  The IEEE 754 standard specifies half precision as having:
728 
729  Sign bit: 1 bit
730  Exponent width: 5 bits
731  Significand precision: 11 (10 explicitly stored)
732  */
733  map.single_precision=value;
734  sign_bit=(map.fixed_point >> 16) & 0x00008000;
735  exponent=(int) ((map.fixed_point >> ExponentShift) & 0x000000ff)-ExponentBias;
736  significand=map.fixed_point & 0x007fffff;
737  if (exponent <= 0)
738  {
739  int
740  shift;
741 
742  if (exponent < -10)
743  return((unsigned short) sign_bit);
744  significand=significand | 0x00800000;
745  shift=(int) (14-exponent);
746  significand=(unsigned int) ((significand+((1 << (shift-1))-1)+
747  ((significand >> shift) & 0x01)) >> shift);
748  return((unsigned short) (sign_bit | significand));
749  }
750  else
751  if (exponent == (0xff-ExponentBias))
752  {
753  if (significand == 0)
754  return((unsigned short) (sign_bit | ExponentMask));
755  else
756  {
757  significand>>=SignificandShift;
758  half=(unsigned short) (sign_bit | significand |
759  (significand == 0) | ExponentMask);
760  return(half);
761  }
762  }
763  significand=significand+((significand >> SignificandShift) & 0x01)+0x00000fff;
764  if ((significand & 0x00800000) != 0)
765  {
766  significand=0;
767  exponent++;
768  }
769  if (exponent > 30)
770  {
771  float
772  alpha;
773 
774  int
775  i;
776 
777  /*
778  Float overflow.
779  */
780  alpha=1.0e10;
781  for (i=0; i < 10; i++)
782  alpha*=alpha;
783  return((unsigned short) (sign_bit | ExponentMask));
784  }
785  half=(unsigned short) (sign_bit | (exponent << 10) |
786  (significand >> SignificandShift));
787  return(half);
788 }
789 
790 #if defined(__cplusplus) || defined(c_plusplus)
791 }
792 #endif
793 
794 #endif
_MemoryInfo
Definition: memory.c:164
_QuantumInfo
Definition: quantum-private.h:46
_QuantumState
Definition: quantum-private.h:31