1/* GENERATED SOURCE. DO NOT MODIFY. */
2// © 2016 and later: Unicode, Inc. and others.
3// License & terms of use: http://www.unicode.org/copyright.html#License
4/*
5*******************************************************************************
6* Copyright (C) 2010-2015, International Business Machines
7* Corporation and others.  All Rights Reserved.
8*******************************************************************************
9* Collation.java, ported from collation.h/.cpp
10*
11* C++ version created on: 2010oct27
12* created by: Markus W. Scherer
13*/
14
15package android.icu.impl.coll;
16
17/**
18 * Collation v2 basic definitions and static helper functions.
19 *
20 * Data structures except for expansion tables store 32-bit CEs which are
21 * either specials (see tags below) or are compact forms of 64-bit CEs.
22 * @hide Only a subset of ICU is exposed in Android
23 */
24public final class Collation {
25    /** UChar32 U_SENTINEL.
26     * TODO: Create a common, public constant?
27     */
28    public static final int SENTINEL_CP = -1;
29
30    // ICU4C compare() API returns enum UCollationResult values (with UCOL_ prefix).
31    // ICU4J just returns int. We use these constants for ease of porting.
32    public static final int LESS = -1;
33    public static final int EQUAL = 0;
34    public static final int GREATER = 1;
35
36    // Special sort key bytes for all levels.
37    public static final int TERMINATOR_BYTE = 0;
38    public static final int LEVEL_SEPARATOR_BYTE = 1;
39
40    /** The secondary/tertiary lower limit for tailoring before any root elements. */
41    static final int BEFORE_WEIGHT16 = 0x100;
42
43    /**
44     * Merge-sort-key separator.
45     * Same as the unique primary and identical-level weights of U+FFFE.
46     * Must not be used as primary compression low terminator.
47     * Otherwise usable.
48     */
49    public static final int MERGE_SEPARATOR_BYTE = 2;
50    public static final long MERGE_SEPARATOR_PRIMARY = 0x02000000;  // U+FFFE
51    static final int MERGE_SEPARATOR_CE32 = 0x02000505;  // U+FFFE
52
53    /**
54     * Primary compression low terminator, must be greater than MERGE_SEPARATOR_BYTE.
55     * Reserved value in primary second byte if the lead byte is compressible.
56     * Otherwise usable in all CE weight bytes.
57     */
58    public static final int PRIMARY_COMPRESSION_LOW_BYTE = 3;
59    /**
60     * Primary compression high terminator.
61     * Reserved value in primary second byte if the lead byte is compressible.
62     * Otherwise usable in all CE weight bytes.
63     */
64    public static final int PRIMARY_COMPRESSION_HIGH_BYTE = 0xff;
65
66    /** Default secondary/tertiary weight lead byte. */
67    static final int COMMON_BYTE = 5;
68    public static final int COMMON_WEIGHT16 = 0x0500;
69    /** Middle 16 bits of a CE with a common secondary weight. */
70    static final int COMMON_SECONDARY_CE = 0x05000000;
71    /** Lower 16 bits of a CE with a common tertiary weight. */
72    static final int COMMON_TERTIARY_CE = 0x0500;
73    /** Lower 32 bits of a CE with common secondary and tertiary weights. */
74    public static final int COMMON_SEC_AND_TER_CE = 0x05000500;
75
76    static final int SECONDARY_MASK = 0xffff0000;
77    public static final int CASE_MASK = 0xc000;
78    static final int SECONDARY_AND_CASE_MASK = SECONDARY_MASK | CASE_MASK;
79    /** Only the 2*6 bits for the pure tertiary weight. */
80    public static final int ONLY_TERTIARY_MASK = 0x3f3f;
81    /** Only the secondary & tertiary bits; no case, no quaternary. */
82    static final int ONLY_SEC_TER_MASK = SECONDARY_MASK | ONLY_TERTIARY_MASK;
83    /** Case bits and tertiary bits. */
84    static final int CASE_AND_TERTIARY_MASK = CASE_MASK | ONLY_TERTIARY_MASK;
85    public static final int QUATERNARY_MASK = 0xc0;
86    /** Case bits and quaternary bits. */
87    public static final int CASE_AND_QUATERNARY_MASK = CASE_MASK | QUATERNARY_MASK;
88
89    static final int UNASSIGNED_IMPLICIT_BYTE = 0xfe;  // compressible
90    /**
91     * First unassigned: AlphabeticIndex overflow boundary.
92     * We want a 3-byte primary so that it fits into the root elements table.
93     *
94     * This 3-byte primary will not collide with
95     * any unassigned-implicit 4-byte primaries because
96     * the first few hundred Unicode code points all have real mappings.
97     */
98    static final long FIRST_UNASSIGNED_PRIMARY = 0xfe040200L;
99
100    static final int TRAIL_WEIGHT_BYTE = 0xff;  // not compressible
101    static final long FIRST_TRAILING_PRIMARY = 0xff020200L;  // [first trailing]
102    public static final long MAX_PRIMARY = 0xffff0000L;  // U+FFFF
103    static final int MAX_REGULAR_CE32 = 0xffff0505;  // U+FFFF
104
105    // CE32 value for U+FFFD as well as illegal UTF-8 byte sequences (which behave like U+FFFD).
106    // We use the third-highest primary weight for U+FFFD (as in UCA 6.3+).
107    public static final long FFFD_PRIMARY = MAX_PRIMARY - 0x20000;
108    static final int FFFD_CE32 = MAX_REGULAR_CE32 - 0x20000;
109
110    /**
111     * A CE32 is special if its low byte is this or greater.
112     * Impossible case bits 11 mark special CE32s.
113     * This value itself is used to indicate a fallback to the base collator.
114     */
115    static final int SPECIAL_CE32_LOW_BYTE = 0xc0;
116    static final int FALLBACK_CE32 = SPECIAL_CE32_LOW_BYTE;
117    /**
118     * Low byte of a long-primary special CE32.
119     */
120    static final int LONG_PRIMARY_CE32_LOW_BYTE = 0xc1;  // SPECIAL_CE32_LOW_BYTE | LONG_PRIMARY_TAG
121
122    static final int UNASSIGNED_CE32 = 0xffffffff;  // Compute an unassigned-implicit CE.
123
124    static final int NO_CE32 = 1;
125
126    /** No CE: End of input. Only used in runtime code, not stored in data. */
127    static final long NO_CE_PRIMARY = 1;  // not a left-adjusted weight
128    static final int NO_CE_WEIGHT16 = 0x0100;  // weight of LEVEL_SEPARATOR_BYTE
129    public static final long NO_CE = 0x101000100L;  // NO_CE_PRIMARY, NO_CE_WEIGHT16, NO_CE_WEIGHT16
130
131    /** Sort key levels. */
132
133    /** Unspecified level. */
134    public static final int NO_LEVEL = 0;
135    public static final int PRIMARY_LEVEL = 1;
136    public static final int SECONDARY_LEVEL = 2;
137    public static final int CASE_LEVEL = 3;
138    public static final int TERTIARY_LEVEL = 4;
139    public static final int QUATERNARY_LEVEL = 5;
140    public static final int IDENTICAL_LEVEL = 6;
141    /** Beyond sort key bytes. */
142    public static final int ZERO_LEVEL = 7;
143
144    /**
145     * Sort key level flags: xx_FLAG = 1 << xx_LEVEL.
146     * In Java, use enum Level with flag() getters, or use EnumSet rather than hand-made bit sets.
147     */
148    static final int NO_LEVEL_FLAG = 1;
149    static final int PRIMARY_LEVEL_FLAG = 2;
150    static final int SECONDARY_LEVEL_FLAG = 4;
151    static final int CASE_LEVEL_FLAG = 8;
152    static final int TERTIARY_LEVEL_FLAG = 0x10;
153    static final int QUATERNARY_LEVEL_FLAG = 0x20;
154    static final int IDENTICAL_LEVEL_FLAG = 0x40;
155    static final int ZERO_LEVEL_FLAG = 0x80;
156
157    /**
158     * Special-CE32 tags, from bits 3..0 of a special 32-bit CE.
159     * Bits 31..8 are available for tag-specific data.
160     * Bits  5..4: Reserved. May be used in the future to indicate lccc!=0 and tccc!=0.
161     */
162
163    /**
164     * Fall back to the base collator.
165     * This is the tag value in SPECIAL_CE32_LOW_BYTE and FALLBACK_CE32.
166     * Bits 31..8: Unused, 0.
167     */
168    static final int FALLBACK_TAG = 0;
169    /**
170     * Long-primary CE with COMMON_SEC_AND_TER_CE.
171     * Bits 31..8: Three-byte primary.
172     */
173    static final int LONG_PRIMARY_TAG = 1;
174    /**
175     * Long-secondary CE with zero primary.
176     * Bits 31..16: Secondary weight.
177     * Bits 15.. 8: Tertiary weight.
178     */
179    static final int LONG_SECONDARY_TAG = 2;
180    /**
181     * Unused.
182     * May be used in the future for single-byte secondary CEs (SHORT_SECONDARY_TAG),
183     * storing the secondary in bits 31..24, the ccc in bits 23..16,
184     * and the tertiary in bits 15..8.
185     */
186    static final int RESERVED_TAG_3 = 3;
187    /**
188     * Latin mini expansions of two simple CEs [pp, 05, tt] [00, ss, 05].
189     * Bits 31..24: Single-byte primary weight pp of the first CE.
190     * Bits 23..16: Tertiary weight tt of the first CE.
191     * Bits 15.. 8: Secondary weight ss of the second CE.
192     */
193    static final int LATIN_EXPANSION_TAG = 4;
194    /**
195     * Points to one or more simple/long-primary/long-secondary 32-bit CE32s.
196     * Bits 31..13: Index into int table.
197     * Bits 12.. 8: Length=1..31.
198     */
199    static final int EXPANSION32_TAG = 5;
200    /**
201     * Points to one or more 64-bit CEs.
202     * Bits 31..13: Index into CE table.
203     * Bits 12.. 8: Length=1..31.
204     */
205    static final int EXPANSION_TAG = 6;
206    /**
207     * Builder data, used only in the CollationDataBuilder, not in runtime data.
208     *
209     * If bit 8 is 0: Builder context, points to a list of context-sensitive mappings.
210     * Bits 31..13: Index to the builder's list of ConditionalCE32 for this character.
211     * Bits 12.. 9: Unused, 0.
212     *
213     * If bit 8 is 1 (IS_BUILDER_JAMO_CE32): Builder-only jamoCE32 value.
214     * The builder fetches the Jamo CE32 from the trie.
215     * Bits 31..13: Jamo code point.
216     * Bits 12.. 9: Unused, 0.
217     */
218    static final int BUILDER_DATA_TAG = 7;
219    /**
220     * Points to prefix trie.
221     * Bits 31..13: Index into prefix/contraction data.
222     * Bits 12.. 8: Unused, 0.
223     */
224    static final int PREFIX_TAG = 8;
225    /**
226     * Points to contraction data.
227     * Bits 31..13: Index into prefix/contraction data.
228     * Bits 12..11: Unused, 0.
229     * Bit      10: CONTRACT_TRAILING_CCC flag.
230     * Bit       9: CONTRACT_NEXT_CCC flag.
231     * Bit       8: CONTRACT_SINGLE_CP_NO_MATCH flag.
232     */
233    static final int CONTRACTION_TAG = 9;
234    /**
235     * Decimal digit.
236     * Bits 31..13: Index into int table for non-numeric-collation CE32.
237     * Bit      12: Unused, 0.
238     * Bits 11.. 8: Digit value 0..9.
239     */
240    static final int DIGIT_TAG = 10;
241    /**
242     * Tag for U+0000, for moving the NUL-termination handling
243     * from the regular fastpath into specials-handling code.
244     * Bits 31..8: Unused, 0.
245     */
246    static final int U0000_TAG = 11;
247    /**
248     * Tag for a Hangul syllable.
249     * Bits 31..9: Unused, 0.
250     * Bit      8: HANGUL_NO_SPECIAL_JAMO flag.
251     */
252    static final int HANGUL_TAG = 12;
253    /**
254     * Tag for a lead surrogate code unit.
255     * Optional optimization for UTF-16 string processing.
256     * Bits 31..10: Unused, 0.
257     *       9.. 8: =0: All associated supplementary code points are unassigned-implict.
258     *              =1: All associated supplementary code points fall back to the base data.
259     *              else: (Normally 2) Look up the data for the supplementary code point.
260     */
261    static final int LEAD_SURROGATE_TAG = 13;
262    /**
263     * Tag for CEs with primary weights in code point order.
264     * Bits 31..13: Index into CE table, for one data "CE".
265     * Bits 12.. 8: Unused, 0.
266     *
267     * This data "CE" has the following bit fields:
268     * Bits 63..32: Three-byte primary pppppp00.
269     *      31.. 8: Start/base code point of the in-order range.
270     *           7: Flag isCompressible primary.
271     *       6.. 0: Per-code point primary-weight increment.
272     */
273    static final int OFFSET_TAG = 14;
274    /**
275     * Implicit CE tag. Compute an unassigned-implicit CE.
276     * All bits are set (UNASSIGNED_CE32=0xffffffff).
277     */
278    static final int IMPLICIT_TAG = 15;
279
280    static boolean isAssignedCE32(int ce32) {
281        return ce32 != FALLBACK_CE32 && ce32 != UNASSIGNED_CE32;
282    }
283
284    /**
285     * We limit the number of CEs in an expansion
286     * so that we can use a small number of length bits in the data structure,
287     * and so that an implementation can copy CEs at runtime without growing a destination buffer.
288     */
289    static final int MAX_EXPANSION_LENGTH = 31;
290    static final int MAX_INDEX = 0x7ffff;
291
292    /**
293     * Set if there is no match for the single (no-suffix) character itself.
294     * This is only possible if there is a prefix.
295     * In this case, discontiguous contraction matching cannot add combining marks
296     * starting from an empty suffix.
297     * The default CE32 is used anyway if there is no suffix match.
298     */
299    static final int CONTRACT_SINGLE_CP_NO_MATCH = 0x100;
300    /** Set if the first character of every contraction suffix has lccc!=0. */
301    static final int CONTRACT_NEXT_CCC = 0x200;
302    /** Set if any contraction suffix ends with lccc!=0. */
303    static final int CONTRACT_TRAILING_CCC = 0x400;
304
305    /** For HANGUL_TAG: None of its Jamo CE32s isSpecialCE32(). */
306    static final int HANGUL_NO_SPECIAL_JAMO = 0x100;
307
308    static final int LEAD_ALL_UNASSIGNED = 0;
309    static final int LEAD_ALL_FALLBACK = 0x100;
310    static final int LEAD_MIXED = 0x200;
311    static final int LEAD_TYPE_MASK = 0x300;
312
313    static int makeLongPrimaryCE32(long p) { return (int)(p | LONG_PRIMARY_CE32_LOW_BYTE); }
314
315    /** Turns the long-primary CE32 into a primary weight pppppp00. */
316    static long primaryFromLongPrimaryCE32(int ce32) {
317        return (long)ce32 & 0xffffff00L;
318    }
319    static long ceFromLongPrimaryCE32(int ce32) {
320        return ((long)(ce32 & 0xffffff00) << 32) | COMMON_SEC_AND_TER_CE;
321    }
322
323    static int makeLongSecondaryCE32(int lower32) {
324        return lower32 | SPECIAL_CE32_LOW_BYTE | LONG_SECONDARY_TAG;
325    }
326    static long ceFromLongSecondaryCE32(int ce32) {
327        return (long)ce32 & 0xffffff00L;
328    }
329
330    /** Makes a special CE32 with tag, index and length. */
331    static int makeCE32FromTagIndexAndLength(int tag, int index, int length) {
332        return (index << 13) | (length << 8) | SPECIAL_CE32_LOW_BYTE | tag;
333    }
334    /** Makes a special CE32 with only tag and index. */
335    static int makeCE32FromTagAndIndex(int tag, int index) {
336        return (index << 13) | SPECIAL_CE32_LOW_BYTE | tag;
337    }
338
339    static boolean isSpecialCE32(int ce32) {
340        return (ce32 & 0xff) >= SPECIAL_CE32_LOW_BYTE;
341    }
342
343    static int tagFromCE32(int ce32) {
344        return ce32 & 0xf;
345    }
346
347    static boolean hasCE32Tag(int ce32, int tag) {
348        return isSpecialCE32(ce32) && tagFromCE32(ce32) == tag;
349    }
350
351    static boolean isLongPrimaryCE32(int ce32) {
352        return hasCE32Tag(ce32, LONG_PRIMARY_TAG);
353    }
354
355    static boolean isSimpleOrLongCE32(int ce32) {
356        return !isSpecialCE32(ce32) ||
357                tagFromCE32(ce32) == LONG_PRIMARY_TAG ||
358                tagFromCE32(ce32) == LONG_SECONDARY_TAG;
359    }
360
361    /**
362     * @return true if the ce32 yields one or more CEs without further data lookups
363     */
364    static boolean isSelfContainedCE32(int ce32) {
365        return !isSpecialCE32(ce32) ||
366                tagFromCE32(ce32) == LONG_PRIMARY_TAG ||
367                tagFromCE32(ce32) == LONG_SECONDARY_TAG ||
368                tagFromCE32(ce32) == LATIN_EXPANSION_TAG;
369    }
370
371    static boolean isPrefixCE32(int ce32) {
372        return hasCE32Tag(ce32, PREFIX_TAG);
373    }
374
375    static boolean isContractionCE32(int ce32) {
376        return hasCE32Tag(ce32, CONTRACTION_TAG);
377    }
378
379    static boolean ce32HasContext(int ce32) {
380        return isSpecialCE32(ce32) &&
381                (tagFromCE32(ce32) == PREFIX_TAG ||
382                tagFromCE32(ce32) == CONTRACTION_TAG);
383    }
384
385    /**
386     * Get the first of the two Latin-expansion CEs encoded in ce32.
387     * @see LATIN_EXPANSION_TAG
388     */
389    static long latinCE0FromCE32(int ce32) {
390        return ((long)(ce32 & 0xff000000) << 32) | COMMON_SECONDARY_CE | ((ce32 & 0xff0000) >> 8);
391    }
392
393    /**
394     * Get the second of the two Latin-expansion CEs encoded in ce32.
395     * @see LATIN_EXPANSION_TAG
396     */
397    static long latinCE1FromCE32(int ce32) {
398        return (((long)ce32 & 0xff00) << 16) | COMMON_TERTIARY_CE;
399    }
400
401    /**
402     * Returns the data index from a special CE32.
403     */
404    static int indexFromCE32(int ce32) {
405        return ce32 >>> 13;
406    }
407
408    /**
409     * Returns the data length from a ce32.
410     */
411    static int lengthFromCE32(int ce32) {
412        return (ce32 >> 8) & 31;
413    }
414
415    /**
416     * Returns the digit value from a DIGIT_TAG ce32.
417     */
418    static char digitFromCE32(int ce32) {
419        return (char)((ce32 >> 8) & 0xf);
420    }
421
422    /** Returns a 64-bit CE from a simple CE32 (not special). */
423    static long ceFromSimpleCE32(int ce32) {
424        // normal form ppppsstt -> pppp0000ss00tt00
425        assert (ce32 & 0xff) < SPECIAL_CE32_LOW_BYTE;
426        return ((long)(ce32 & 0xffff0000) << 32) | ((long)(ce32 & 0xff00) << 16) | ((ce32 & 0xff) << 8);
427    }
428
429    /** Returns a 64-bit CE from a simple/long-primary/long-secondary CE32. */
430    static long ceFromCE32(int ce32) {
431        int tertiary = ce32 & 0xff;
432        if(tertiary < SPECIAL_CE32_LOW_BYTE) {
433            // normal form ppppsstt -> pppp0000ss00tt00
434            return ((long)(ce32 & 0xffff0000) << 32) | ((long)(ce32 & 0xff00) << 16) | (tertiary << 8);
435        } else {
436            ce32 -= tertiary;
437            if((tertiary & 0xf) == LONG_PRIMARY_TAG) {
438                // long-primary form ppppppC1 -> pppppp00050000500
439                return ((long)ce32 << 32) | COMMON_SEC_AND_TER_CE;
440            } else {
441                // long-secondary form ssssttC2 -> 00000000sssstt00
442                assert (tertiary & 0xf) == LONG_SECONDARY_TAG;
443                return ce32 & 0xffffffffL;
444            }
445        }
446    }
447
448    /** Creates a CE from a primary weight. */
449    public static long makeCE(long p) {
450        return (p << 32) | COMMON_SEC_AND_TER_CE;
451    }
452    /**
453     * Creates a CE from a primary weight,
454     * 16-bit secondary/tertiary weights, and a 2-bit quaternary.
455     */
456    static long makeCE(long p, int s, int t, int q) {
457        return (p << 32) | ((long)s << 16) | t | (q << 6);
458    }
459
460    /**
461     * Increments a 2-byte primary by a code point offset.
462     */
463    public static long incTwoBytePrimaryByOffset(long basePrimary, boolean isCompressible,
464                                              int offset) {
465        // Extract the second byte, minus the minimum byte value,
466        // plus the offset, modulo the number of usable byte values, plus the minimum.
467        // Reserve the PRIMARY_COMPRESSION_LOW_BYTE and high byte if necessary.
468        long primary;
469        if(isCompressible) {
470            offset += ((int)(basePrimary >> 16) & 0xff) - 4;
471            primary = ((offset % 251) + 4) << 16;
472            offset /= 251;
473        } else {
474            offset += ((int)(basePrimary >> 16) & 0xff) - 2;
475            primary = ((offset % 254) + 2) << 16;
476            offset /= 254;
477        }
478        // First byte, assume no further overflow.
479        return primary | ((basePrimary & 0xff000000L) + ((long)offset << 24));
480    }
481
482    /**
483     * Increments a 3-byte primary by a code point offset.
484     */
485    public static long incThreeBytePrimaryByOffset(long basePrimary, boolean isCompressible,
486                                                int offset) {
487        // Extract the third byte, minus the minimum byte value,
488        // plus the offset, modulo the number of usable byte values, plus the minimum.
489        offset += ((int)(basePrimary >> 8) & 0xff) - 2;
490        long primary = ((offset % 254) + 2) << 8;
491        offset /= 254;
492        // Same with the second byte,
493        // but reserve the PRIMARY_COMPRESSION_LOW_BYTE and high byte if necessary.
494        if(isCompressible) {
495            offset += ((int)(basePrimary >> 16) & 0xff) - 4;
496            primary |= ((offset % 251) + 4) << 16;
497            offset /= 251;
498        } else {
499            offset += ((int)(basePrimary >> 16) & 0xff) - 2;
500            primary |= ((offset % 254) + 2) << 16;
501            offset /= 254;
502        }
503        // First byte, assume no further overflow.
504        return primary | ((basePrimary & 0xff000000L) + ((long)offset << 24));
505    }
506
507    /**
508     * Decrements a 2-byte primary by one range step (1..0x7f).
509     */
510    static long decTwoBytePrimaryByOneStep(long basePrimary, boolean isCompressible, int step) {
511        // Extract the second byte, minus the minimum byte value,
512        // minus the step, modulo the number of usable byte values, plus the minimum.
513        // Reserve the PRIMARY_COMPRESSION_LOW_BYTE and high byte if necessary.
514        // Assume no further underflow for the first byte.
515        assert(0 < step && step <= 0x7f);
516        int byte2 = ((int)(basePrimary >> 16) & 0xff) - step;
517        if(isCompressible) {
518            if(byte2 < 4) {
519                byte2 += 251;
520                basePrimary -= 0x1000000;
521            }
522        } else {
523            if(byte2 < 2) {
524                byte2 += 254;
525                basePrimary -= 0x1000000;
526            }
527        }
528        return (basePrimary & 0xff000000L) | (byte2 << 16);
529    }
530
531    /**
532     * Decrements a 3-byte primary by one range step (1..0x7f).
533     */
534    static long decThreeBytePrimaryByOneStep(long basePrimary, boolean isCompressible, int step) {
535        // Extract the third byte, minus the minimum byte value,
536        // minus the step, modulo the number of usable byte values, plus the minimum.
537        assert(0 < step && step <= 0x7f);
538        int byte3 = ((int)(basePrimary >> 8) & 0xff) - step;
539        if(byte3 >= 2) {
540            return (basePrimary & 0xffff0000L) | (byte3 << 8);
541        }
542        byte3 += 254;
543        // Same with the second byte,
544        // but reserve the PRIMARY_COMPRESSION_LOW_BYTE and high byte if necessary.
545        int byte2 = ((int)(basePrimary >> 16) & 0xff) - 1;
546        if(isCompressible) {
547            if(byte2 < 4) {
548                byte2 = 0xfe;
549                basePrimary -= 0x1000000;
550            }
551        } else {
552            if(byte2 < 2) {
553                byte2 = 0xff;
554                basePrimary -= 0x1000000;
555            }
556        }
557        // First byte, assume no further underflow.
558        return (basePrimary & 0xff000000L) | (byte2 << 16) | (byte3 << 8);
559    }
560
561    /**
562     * Computes a 3-byte primary for c's OFFSET_TAG data "CE".
563     */
564    static long getThreeBytePrimaryForOffsetData(int c, long dataCE) {
565        long p = dataCE >>> 32;  // three-byte primary pppppp00
566        int lower32 = (int)dataCE;  // base code point b & step s: bbbbbbss (bit 7: isCompressible)
567        int offset = (c - (lower32 >> 8)) * (lower32 & 0x7f);  // delta * increment
568        boolean isCompressible = (lower32 & 0x80) != 0;
569        return Collation.incThreeBytePrimaryByOffset(p, isCompressible, offset);
570    }
571
572    /**
573     * Returns the unassigned-character implicit primary weight for any valid code point c.
574     */
575    static long unassignedPrimaryFromCodePoint(int c) {
576        // Create a gap before U+0000. Use c=-1 for [first unassigned].
577        ++c;
578        // Fourth byte: 18 values, every 14th byte value (gap of 13).
579        long primary = 2 + (c % 18) * 14;
580        c /= 18;
581        // Third byte: 254 values.
582        primary |= (2 + (c % 254)) << 8;
583        c /= 254;
584        // Second byte: 251 values 04..FE excluding the primary compression bytes.
585        primary |= (4 + (c % 251)) << 16;
586        // One lead byte covers all code points (c < 0x1182B4 = 1*251*254*18).
587        return primary | ((long)UNASSIGNED_IMPLICIT_BYTE << 24);
588    }
589
590    static long unassignedCEFromCodePoint(int c) {
591        return makeCE(unassignedPrimaryFromCodePoint(c));
592    }
593
594    // private Collation()  // No instantiation.
595}
596