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	/*
	* Copyright (c) 2015, 2020, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	/*
	******************************************************************************
	*
	* Copyright (C) 2009-2014, International Business Machines
	* Corporation and others. All Rights Reserved.
	*
	******************************************************************************
	*/

	package jdk.internal.icu.impl;

	import jdk.internal.icu.text.UnicodeSet.SpanCondition;
	import jdk.internal.icu.util.OutputInt;

	/**
	* Helper class for frozen UnicodeSets, implements contains() and span() optimized for BMP code points.
	*
	* Latin-1: Look up bytes.
	* 2-byte characters: Bits organized vertically.
	* 3-byte characters: Use zero/one/mixed data per 64-block in U+0000..U+FFFF, with mixed for illegal ranges.
	* Supplementary characters: Call contains() on the parent set.
	*/
	public final class BMPSet {

	/**
	* One boolean ('true' or 'false') per Latin-1 character.
	*/
	private boolean[] latin1Contains;

	/**
	* One bit per code point from U+0000..U+07FF. The bits are organized vertically; consecutive code points
	* correspond to the same bit positions in consecutive table words. With code point parts lead=c{10..6}
	* trail=c{5..0} it is set.contains(c)==(table7FF[trail] bit lead)
	*
	* Bits for 0..7F (non-shortest forms) are set to the result of contains(FFFD) for faster validity checking at
	* runtime.
	*/
	private int[] table7FF;

	/**
	* One bit per 64 BMP code points. The bits are organized vertically; consecutive 64-code point blocks
	* correspond to the same bit position in consecutive table words. With code point parts lead=c{15..12}
	* t1=c{11..6} test bits (lead+16) and lead in bmpBlockBits[t1]. If the upper bit is 0, then the lower bit
	* indicates if contains(c) for all code points in the 64-block. If the upper bit is 1, then the block is mixed
	* and set.contains(c) must be called.
	*
	* Bits for 0..7FF (non-shortest forms) and D800..DFFF are set to the result of contains(FFFD) for faster
	* validity checking at runtime.
	*/
	private int[] bmpBlockBits;

	/**
	* Inversion list indexes for restricted binary searches in findCodePoint(), from findCodePoint(U+0800, U+1000,
	* U+2000, .., U+F000, U+10000). U+0800 is the first 3-byte-UTF-8 code point. Code points below U+0800 are
	* always looked up in the bit tables. The last pair of indexes is for finding supplementary code points.
	*/
	private int[] list4kStarts;

	/**
	* The inversion list of the parent set, for the slower contains() implementation for mixed BMP blocks and for
	* supplementary code points. The list is terminated with list[listLength-1]=0x110000.
	*/
	private final int[] list;
	private final int listLength; // length used; list may be longer to minimize reallocs

	public BMPSet(final int[] parentList, int parentListLength) {
	list = parentList;
	listLength = parentListLength;
	latin1Contains = new boolean[0x100];
	table7FF = new int[64];
	bmpBlockBits = new int[64];
	list4kStarts = new int[18];

	/*
	* Set the list indexes for binary searches for U+0800, U+1000, U+2000, .., U+F000, U+10000. U+0800 is the
	* first 3-byte-UTF-8 code point. Lower code points are looked up in the bit tables. The last pair of
	* indexes is for finding supplementary code points.
	*/
	list4kStarts[0] = findCodePoint(0x800, 0, listLength - 1);
	int i;
	for (i = 1; i <= 0x10; ++i) {
	list4kStarts[i] = findCodePoint(i << 12, list4kStarts[i - 1], listLength - 1);
	}
	list4kStarts[0x11] = listLength - 1;

	initBits();
	}

	public boolean contains(int c) {
	if (c <= 0xff) {
	return (latin1Contains[c]);
	} else if (c <= 0x7ff) {
	return ((table7FF[c & 0x3f] & (1 << (c >> 6))) != 0);
	} else if (c < 0xd800 \|\| (c >= 0xe000 && c <= 0xffff)) {
	int lead = c >> 12;
	int twoBits = (bmpBlockBits[(c >> 6) & 0x3f] >> lead) & 0x10001;
	if (twoBits <= 1) {
	// All 64 code points with the same bits 15..6
	// are either in the set or not.
	return (0 != twoBits);
	} else {
	// Look up the code point in its 4k block of code points.
	return containsSlow(c, list4kStarts[lead], list4kStarts[lead + 1]);
	}
	} else if (c <= 0x10ffff) {
	// surrogate or supplementary code point
	return containsSlow(c, list4kStarts[0xd], list4kStarts[0x11]);
	} else {
	// Out-of-range code points get false, consistent with long-standing
	// behavior of UnicodeSet.contains(c).
	return false;
	}
	}

	/**
	* Span the initial substring for which each character c has spanCondition==contains(c). It must be
	* spanCondition==0 or 1.
	*
	* @param start The start index
	* @param outCount If not null: Receives the number of code points in the span.
	* @return the limit (exclusive end) of the span
	*
	* NOTE: to reduce the overhead of function call to contains(c), it is manually inlined here. Check for
	* sufficient length for trail unit for each surrogate pair. Handle single surrogates as surrogate code points
	* as usual in ICU.
	*/
	public final int span(CharSequence s, int start, SpanCondition spanCondition,
	OutputInt outCount) {
	char c, c2;
	int i = start;
	int limit = s.length();
	int numSupplementary = 0;
	if (SpanCondition.NOT_CONTAINED != spanCondition) {
	// span
	while (i < limit) {
	c = s.charAt(i);
	if (c <= 0xff) {
	if (!latin1Contains[c]) {
	break;
	}
	} else if (c <= 0x7ff) {
	if ((table7FF[c & 0x3f] & (1 << (c >> 6))) == 0) {
	break;
	}
	} else if (c < 0xd800 \|\|
	c >= 0xdc00 \|\| (i + 1) == limit \|\| (c2 = s.charAt(i + 1)) < 0xdc00 \|\| c2 >= 0xe000) {
	int lead = c >> 12;
	int twoBits = (bmpBlockBits[(c >> 6) & 0x3f] >> lead) & 0x10001;
	if (twoBits <= 1) {
	// All 64 code points with the same bits 15..6
	// are either in the set or not.
	if (twoBits == 0) {
	break;
	}
	} else {
	// Look up the code point in its 4k block of code points.
	if (!containsSlow(c, list4kStarts[lead], list4kStarts[lead + 1])) {
	break;
	}
	}
	} else {
	// surrogate pair
	int supplementary = UCharacterProperty.getRawSupplementary(c, c2);
	if (!containsSlow(supplementary, list4kStarts[0x10], list4kStarts[0x11])) {
	break;
	}
	++numSupplementary;
	++i;
	}
	++i;
	}
	} else {
	// span not
	while (i < limit) {
	c = s.charAt(i);
	if (c <= 0xff) {
	if (latin1Contains[c]) {
	break;
	}
	} else if (c <= 0x7ff) {
	if ((table7FF[c & 0x3f] & (1 << (c >> 6))) != 0) {
	break;
	}
	} else if (c < 0xd800 \|\|
	c >= 0xdc00 \|\| (i + 1) == limit \|\| (c2 = s.charAt(i + 1)) < 0xdc00 \|\| c2 >= 0xe000) {
	int lead = c >> 12;
	int twoBits = (bmpBlockBits[(c >> 6) & 0x3f] >> lead) & 0x10001;
	if (twoBits <= 1) {
	// All 64 code points with the same bits 15..6
	// are either in the set or not.
	if (twoBits != 0) {
	break;
	}
	} else {
	// Look up the code point in its 4k block of code points.
	if (containsSlow(c, list4kStarts[lead], list4kStarts[lead + 1])) {
	break;
	}
	}
	} else {
	// surrogate pair
	int supplementary = UCharacterProperty.getRawSupplementary(c, c2);
	if (containsSlow(supplementary, list4kStarts[0x10], list4kStarts[0x11])) {
	break;
	}
	++numSupplementary;
	++i;
	}
	++i;
	}
	}
	if (outCount != null) {
	int spanLength = i - start;
	outCount.value = spanLength - numSupplementary; // number of code points
	}
	return i;
	}

	/**
	* Symmetrical with span().
	* Span the trailing substring for which each character c has spanCondition==contains(c). It must be s.length >=
	* limit and spanCondition==0 or 1.
	*
	* @return The string index which starts the span (i.e. inclusive).
	*/
	public final int spanBack(CharSequence s, int limit, SpanCondition spanCondition) {
	char c, c2;

	if (SpanCondition.NOT_CONTAINED != spanCondition) {
	// span
	for (;;) {
	c = s.charAt(--limit);
	if (c <= 0xff) {
	if (!latin1Contains[c]) {
	break;
	}
	} else if (c <= 0x7ff) {
	if ((table7FF[c & 0x3f] & (1 << (c >> 6))) == 0) {
	break;
	}
	} else if (c < 0xd800 \|\|
	c < 0xdc00 \|\| 0 == limit \|\| (c2 = s.charAt(limit - 1)) < 0xd800 \|\| c2 >= 0xdc00) {
	int lead = c >> 12;
	int twoBits = (bmpBlockBits[(c >> 6) & 0x3f] >> lead) & 0x10001;
	if (twoBits <= 1) {
	// All 64 code points with the same bits 15..6
	// are either in the set or not.
	if (twoBits == 0) {
	break;
	}
	} else {
	// Look up the code point in its 4k block of code points.
	if (!containsSlow(c, list4kStarts[lead], list4kStarts[lead + 1])) {
	break;
	}
	}
	} else {
	// surrogate pair
	int supplementary = UCharacterProperty.getRawSupplementary(c2, c);
	if (!containsSlow(supplementary, list4kStarts[0x10], list4kStarts[0x11])) {
	break;
	}
	--limit;
	}
	if (0 == limit) {
	return 0;
	}
	}
	} else {
	// span not
	for (;;) {
	c = s.charAt(--limit);
	if (c <= 0xff) {
	if (latin1Contains[c]) {
	break;
	}
	} else if (c <= 0x7ff) {
	if ((table7FF[c & 0x3f] & (1 << (c >> 6))) != 0) {
	break;
	}
	} else if (c < 0xd800 \|\|
	c < 0xdc00 \|\| 0 == limit \|\| (c2 = s.charAt(limit - 1)) < 0xd800 \|\| c2 >= 0xdc00) {
	int lead = c >> 12;
	int twoBits = (bmpBlockBits[(c >> 6) & 0x3f] >> lead) & 0x10001;
	if (twoBits <= 1) {
	// All 64 code points with the same bits 15..6
	// are either in the set or not.
	if (twoBits != 0) {
	break;
	}
	} else {
	// Look up the code point in its 4k block of code points.
	if (containsSlow(c, list4kStarts[lead], list4kStarts[lead + 1])) {
	break;
	}
	}
	} else {
	// surrogate pair
	int supplementary = UCharacterProperty.getRawSupplementary(c2, c);
	if (containsSlow(supplementary, list4kStarts[0x10], list4kStarts[0x11])) {
	break;
	}
	--limit;
	}
	if (0 == limit) {
	return 0;
	}
	}
	}
	return limit + 1;
	}

	/**
	* Set bits in a bit rectangle in "vertical" bit organization. start<limit<=0x800
	*/
	private static void set32x64Bits(int[] table, int start, int limit) {
	assert (64 == table.length);
	int lead = start >> 6; // Named for UTF-8 2-byte lead byte with upper 5 bits.
	int trail = start & 0x3f; // Named for UTF-8 2-byte trail byte with lower 6 bits.

	// Set one bit indicating an all-one block.
	int bits = 1 << lead;
	if ((start + 1) == limit) { // Single-character shortcut.
	table[trail] \|= bits;
	return;
	}

	int limitLead = limit >> 6;
	int limitTrail = limit & 0x3f;

	if (lead == limitLead) {
	// Partial vertical bit column.
	while (trail < limitTrail) {
	table[trail++] \|= bits;
	}
	} else {
	// Partial vertical bit column,
	// followed by a bit rectangle,
	// followed by another partial vertical bit column.
	if (trail > 0) {
	do {
	table[trail++] \|= bits;
	} while (trail < 64);
	++lead;
	}
	if (lead < limitLead) {
	bits = ~((1 << lead) - 1);
	if (limitLead < 0x20) {
	bits &= (1 << limitLead) - 1;
	}
	for (trail = 0; trail < 64; ++trail) {
	table[trail] \|= bits;
	}
	}
	// limit<=0x800. If limit==0x800 then limitLead=32 and limitTrail=0.
	// In that case, bits=1<<limitLead == 1<<0 == 1
	// (because Java << uses only the lower 5 bits of the shift operand)
	// but the bits value is not used because trail<limitTrail is already false.
	bits = 1 << limitLead;
	for (trail = 0; trail < limitTrail; ++trail) {
	table[trail] \|= bits;
	}
	}
	}

	private void initBits() {
	int start, limit;
	int listIndex = 0;

	// Set latin1Contains[].
	do {
	start = list[listIndex++];
	if (listIndex < listLength) {
	limit = list[listIndex++];
	} else {
	limit = 0x110000;
	}
	if (start >= 0x100) {
	break;
	}
	do {
	latin1Contains[start++] = true;
	} while (start < limit && start < 0x100);
	} while (limit <= 0x100);

	// Set table7FF[].
	while (start < 0x800) {
	set32x64Bits(table7FF, start, limit <= 0x800 ? limit : 0x800);
	if (limit > 0x800) {
	start = 0x800;
	break;
	}

	start = list[listIndex++];
	if (listIndex < listLength) {
	limit = list[listIndex++];
	} else {
	limit = 0x110000;
	}
	}

	// Set bmpBlockBits[].
	int minStart = 0x800;
	while (start < 0x10000) {
	if (limit > 0x10000) {
	limit = 0x10000;
	}

	if (start < minStart) {
	start = minStart;
	}
	if (start < limit) { // Else: Another range entirely in a known mixed-value block.
	if (0 != (start & 0x3f)) {
	// Mixed-value block of 64 code points.
	start >>= 6;
	bmpBlockBits[start & 0x3f] \|= 0x10001 << (start >> 6);
	start = (start + 1) << 6; // Round up to the next block boundary.
	minStart = start; // Ignore further ranges in this block.
	}
	if (start < limit) {
	if (start < (limit & ~0x3f)) {
	// Multiple all-ones blocks of 64 code points each.
	set32x64Bits(bmpBlockBits, start >> 6, limit >> 6);
	}

	if (0 != (limit & 0x3f)) {
	// Mixed-value block of 64 code points.
	limit >>= 6;
	bmpBlockBits[limit & 0x3f] \|= 0x10001 << (limit >> 6);
	limit = (limit + 1) << 6; // Round up to the next block boundary.
	minStart = limit; // Ignore further ranges in this block.
	}
	}
	}

	if (limit == 0x10000) {
	break;
	}

	start = list[listIndex++];
	if (listIndex < listLength) {
	limit = list[listIndex++];
	} else {
	limit = 0x110000;
	}
	}
	}

	/**
	* Same as UnicodeSet.findCodePoint(int c) except that the binary search is restricted for finding code
	* points in a certain range.
	*
	* For restricting the search for finding in the range start..end, pass in lo=findCodePoint(start) and
	* hi=findCodePoint(end) with 0<=lo<=hi<len. findCodePoint(c) defaults to lo=0 and hi=len-1.
	*
	* @param c
	* a character in a subrange of MIN_VALUE..MAX_VALUE
	* @param lo
	* The lowest index to be returned.
	* @param hi
	* The highest index to be returned.
	* @return the smallest integer i in the range lo..hi, inclusive, such that c < list[i]
	*/
	private int findCodePoint(int c, int lo, int hi) {
	/* Examples:
	findCodePoint(c)
	set list[] c=0 1 3 4 7 8
	=== ============== ===========
	[] [110000] 0 0 0 0 0 0
	[\u0000-\u0003] [0, 4, 110000] 1 1 1 2 2 2
	[\u0004-\u0007] [4, 8, 110000] 0 0 0 1 1 2
	[:Any:] [0, 110000] 1 1 1 1 1 1
	*/

	// Return the smallest i such that c < list[i]. Assume
	// list[len - 1] == HIGH and that c is legal (0..HIGH-1).
	if (c < list[lo])
	return lo;
	// High runner test. c is often after the last range, so an
	// initial check for this condition pays off.
	if (lo >= hi \|\| c >= list[hi - 1])
	return hi;
	// invariant: c >= list[lo]
	// invariant: c < list[hi]
	for (;;) {
	int i = (lo + hi) >>> 1;
	if (i == lo) {
	break; // Found!
	} else if (c < list[i]) {
	hi = i;
	} else {
	lo = i;
	}
	}
	return hi;
	}

	private final boolean containsSlow(int c, int lo, int hi) {
	return (0 != (findCodePoint(c, lo, hi) & 1));
	}
	}

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