lib/lz4.c - platform/external/u-boot - Gitiles

 // SPDX-License-Identifier: GPL 2.0+ OR BSD-2-Clause
 /*
  * LZ4 - Fast LZ compression algorithm
  * Copyright (C) 2011 - 2016, Yann Collet.
  * BSD 2 - Clause License (http://www.opensource.org/licenses/bsd - license.php)
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *	* Redistributions of source code must retain the above copyright
  *	  notice, this list of conditions and the following disclaimer.
  *	* Redistributions in binary form must reproduce the above
  * copyright notice, this list of conditions and the following disclaimer
  * in the documentation and/or other materials provided with the
  * distribution.
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  * You can contact the author at :
  *	- LZ4 homepage : http://www.lz4.org
  *	- LZ4 source repository : https://github.com/lz4/lz4
  */
 #include <common.h>
 #include <compiler.h>
 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/bug.h>
 #include <asm/unaligned.h>
 #include <u-boot/lz4.h>

 #define FORCE_INLINE inline __attribute__((always_inline))

 static FORCE_INLINE u16 LZ4_readLE16(const void *src)
 {
 	return get_unaligned_le16(src);
 }

 static FORCE_INLINE void LZ4_copy8(void *dst, const void *src)
 {
 	put_unaligned(get_unaligned((const u64 *)src), (u64 *)dst);
 }

 typedef  uint8_t BYTE;
 typedef uint16_t U16;
 typedef uint32_t U32;
 typedef  int32_t S32;
 typedef uint64_t U64;
 typedef uintptr_t uptrval;

 static FORCE_INLINE void LZ4_write32(void *memPtr, U32 value)
 {
 	put_unaligned(value, (U32 *)memPtr);
 }

 /**************************************
 *  Reading and writing into memory
 **************************************/

 /* customized version of memcpy, which may overwrite up to 7 bytes beyond dstEnd */
 static void LZ4_wildCopy(void* dstPtr, const void* srcPtr, void* dstEnd)
 {
     BYTE* d = (BYTE*)dstPtr;
     const BYTE* s = (const BYTE*)srcPtr;
     BYTE* e = (BYTE*)dstEnd;
     do { LZ4_copy8(d,s); d+=8; s+=8; } while (d<e);
 }


 /**************************************
 *  Common Constants
 **************************************/
 #define MINMATCH 4

 #define WILDCOPYLENGTH 8
 #define LASTLITERALS 5
 #define MFLIMIT (WILDCOPYLENGTH + MINMATCH)

 /*
  * ensure it's possible to write 2 x wildcopyLength
  * without overflowing output buffer
  */
 #define MATCH_SAFEGUARD_DISTANCE  ((2 * WILDCOPYLENGTH) - MINMATCH)

 #define KB (1 <<10)

 #define MAXD_LOG 16
 #define MAX_DISTANCE ((1 << MAXD_LOG) - 1)

 #define ML_BITS  4
 #define ML_MASK  ((1U<<ML_BITS)-1)
 #define RUN_BITS (8-ML_BITS)
 #define RUN_MASK ((1U<<RUN_BITS)-1)

 #define LZ4_STATIC_ASSERT(c)	BUILD_BUG_ON(!(c))

 /**************************************
 *  Local Structures and types
 **************************************/
 typedef enum { noDict = 0, withPrefix64k, usingExtDict } dict_directive;
 typedef enum { endOnOutputSize = 0, endOnInputSize = 1 } endCondition_directive;
 typedef enum { decode_full_block = 0, partial_decode = 1 } earlyEnd_directive;

 #define DEBUGLOG(l, ...) {}	/* disabled */

 #ifndef assert
 #define assert(condition) ((void)0)
 #endif

 /*
  * LZ4_decompress_generic() :
  * This generic decompression function covers all use cases.
  * It shall be instantiated several times, using different sets of directives.
  * Note that it is important for performance that this function really get inlined,
  * in order to remove useless branches during compilation optimization.
  */
 static FORCE_INLINE int LZ4_decompress_generic(
 	 const char * const src,
 	 char * const dst,
 	 int srcSize,
 		/*
 		 * If endOnInput == endOnInputSize,
 		 * this value is `dstCapacity`
 		 */
 	 int outputSize,
 	 /* endOnOutputSize, endOnInputSize */
 	 endCondition_directive endOnInput,
 	 /* full, partial */
 	 earlyEnd_directive partialDecoding,
 	 /* noDict, withPrefix64k, usingExtDict */
 	 dict_directive dict,
 	 /* always <= dst, == dst when no prefix */
 	 const BYTE * const lowPrefix,
 	 /* only if dict == usingExtDict */
 	 const BYTE * const dictStart,
 	 /* note : = 0 if noDict */
 	 const size_t dictSize
 	 )
 {
 	const BYTE *ip = (const BYTE *) src;
 	const BYTE * const iend = ip + srcSize;

 	BYTE *op = (BYTE *) dst;
 	BYTE * const oend = op + outputSize;
 	BYTE *cpy;

 	const BYTE * const dictEnd = (const BYTE *)dictStart + dictSize;
 	static const unsigned int inc32table[8] = {0, 1, 2, 1, 0, 4, 4, 4};
 	static const int dec64table[8] = {0, 0, 0, -1, -4, 1, 2, 3};

 	const int safeDecode = (endOnInput == endOnInputSize);
 	const int checkOffset = ((safeDecode) && (dictSize < (int)(64 * KB)));

 	/* Set up the "end" pointers for the shortcut. */
 	const BYTE *const shortiend = iend -
 		(endOnInput ? 14 : 8) /*maxLL*/ - 2 /*offset*/;
 	const BYTE *const shortoend = oend -
 		(endOnInput ? 14 : 8) /*maxLL*/ - 18 /*maxML*/;

 	DEBUGLOG(5, "%s (srcSize:%i, dstSize:%i)", __func__,
 		 srcSize, outputSize);

 	/* Special cases */
 	assert(lowPrefix <= op);
 	assert(src != NULL);

 	/* Empty output buffer */
 	if ((endOnInput) && (unlikely(outputSize == 0)))
 		return ((srcSize == 1) && (*ip == 0)) ? 0 : -1;

 	if ((!endOnInput) && (unlikely(outputSize == 0)))
 		return (*ip == 0 ? 1 : -1);

 	if ((endOnInput) && unlikely(srcSize == 0))
 		return -1;

 	/* Main Loop : decode sequences */
 	while (1) {
 		size_t length;
 		const BYTE *match;
 		size_t offset;

 		/* get literal length */
 		unsigned int const token = *ip++;
 		length = token>>ML_BITS;

 		/* ip < iend before the increment */
 		assert(!endOnInput || ip <= iend);

 		/*
 		 * A two-stage shortcut for the most common case:
 		 * 1) If the literal length is 0..14, and there is enough
 		 * space, enter the shortcut and copy 16 bytes on behalf
 		 * of the literals (in the fast mode, only 8 bytes can be
 		 * safely copied this way).
 		 * 2) Further if the match length is 4..18, copy 18 bytes
 		 * in a similar manner; but we ensure that there's enough
 		 * space in the output for those 18 bytes earlier, upon
 		 * entering the shortcut (in other words, there is a
 		 * combined check for both stages).
 		 *
 		 * The & in the likely() below is intentionally not && so that
 		 * some compilers can produce better parallelized runtime code
 		 */
 		if ((endOnInput ? length != RUN_MASK : length <= 8)
 		   /*
 		    * strictly "less than" on input, to re-enter
 		    * the loop with at least one byte
 		    */
 		   && likely((endOnInput ? ip < shortiend : 1) &
 			     (op <= shortoend))) {
 			/* Copy the literals */
 			memcpy(op, ip, endOnInput ? 16 : 8);
 			op += length; ip += length;

 			/*
 			 * The second stage:
 			 * prepare for match copying, decode full info.
 			 * If it doesn't work out, the info won't be wasted.
 			 */
 			length = token & ML_MASK; /* match length */
 			offset = LZ4_readLE16(ip);
 			ip += 2;
 			match = op - offset;
 			assert(match <= op); /* check overflow */

 			/* Do not deal with overlapping matches. */
 			if ((length != ML_MASK) &&
 			    (offset >= 8) &&
 			    (dict == withPrefix64k || match >= lowPrefix)) {
 				/* Copy the match. */
 				memcpy(op + 0, match + 0, 8);
 				memcpy(op + 8, match + 8, 8);
 				memcpy(op + 16, match + 16, 2);
 				op += length + MINMATCH;
 				/* Both stages worked, load the next token. */
 				continue;
 			}

 			/*
 			 * The second stage didn't work out, but the info
 			 * is ready. Propel it right to the point of match
 			 * copying.
 			 */
 			goto _copy_match;
 		}

 		/* decode literal length */
 		if (length == RUN_MASK) {
 			unsigned int s;

 			if (unlikely(endOnInput ? ip >= iend - RUN_MASK : 0)) {
 				/* overflow detection */
 				goto _output_error;
 			}
 			do {
 				s = *ip++;
 				length += s;
 			} while (likely(endOnInput
 				? ip < iend - RUN_MASK
 				: 1) & (s == 255));

 			if ((safeDecode)
 			    && unlikely((uptrval)(op) +
 					length < (uptrval)(op))) {
 				/* overflow detection */
 				goto _output_error;
 			}
 			if ((safeDecode)
 			    && unlikely((uptrval)(ip) +
 					length < (uptrval)(ip))) {
 				/* overflow detection */
 				goto _output_error;
 			}
 		}

 		/* copy literals */
 		cpy = op + length;
 		LZ4_STATIC_ASSERT(MFLIMIT >= WILDCOPYLENGTH);

 		if (((endOnInput) && ((cpy > oend - MFLIMIT)
 			|| (ip + length > iend - (2 + 1 + LASTLITERALS))))
 			|| ((!endOnInput) && (cpy > oend - WILDCOPYLENGTH))) {
 			if (partialDecoding) {
 				if (cpy > oend) {
 					/*
 					 * Partial decoding :
 					 * stop in the middle of literal segment
 					 */
 					cpy = oend;
 					length = oend - op;
 				}
 				if ((endOnInput)
 					&& (ip + length > iend)) {
 					/*
 					 * Error :
 					 * read attempt beyond
 					 * end of input buffer
 					 */
 					goto _output_error;
 				}
 			} else {
 				if ((!endOnInput)
 					&& (cpy != oend)) {
 					/*
 					 * Error :
 					 * block decoding must
 					 * stop exactly there
 					 */
 					goto _output_error;
 				}
 				if ((endOnInput)
 					&& ((ip + length != iend)
 					|| (cpy > oend))) {
 					/*
 					 * Error :
 					 * input must be consumed
 					 */
 					goto _output_error;
 				}
 			}

 			/*
 			 * supports overlapping memory regions; only matters
 			 * for in-place decompression scenarios
 			 */
 			memmove(op, ip, length);
 			ip += length;
 			op += length;

 			/* Necessarily EOF, due to parsing restrictions */
 			if (!partialDecoding || (cpy == oend))
 				break;
 		} else {
 			/* may overwrite up to WILDCOPYLENGTH beyond cpy */
 			LZ4_wildCopy(op, ip, cpy);
 			ip += length;
 			op = cpy;
 		}

 		/* get offset */
 		offset = LZ4_readLE16(ip);
 		ip += 2;
 		match = op - offset;

 		/* get matchlength */
 		length = token & ML_MASK;

 _copy_match:
 		if ((checkOffset) && (unlikely(match + dictSize < lowPrefix))) {
 			/* Error : offset outside buffers */
 			goto _output_error;
 		}

 		/* costs ~1%; silence an msan warning when offset == 0 */
 		/*
 		 * note : when partialDecoding, there is no guarantee that
 		 * at least 4 bytes remain available in output buffer
 		 */
 		if (!partialDecoding) {
 			assert(oend > op);
 			assert(oend - op >= 4);

 			LZ4_write32(op, (U32)offset);
 		}

 		if (length == ML_MASK) {
 			unsigned int s;

 			do {
 				s = *ip++;

 				if ((endOnInput) && (ip > iend - LASTLITERALS))
 					goto _output_error;

 				length += s;
 			} while (s == 255);

 			if ((safeDecode)
 				&& unlikely(
 					(uptrval)(op) + length < (uptrval)op)) {
 				/* overflow detection */
 				goto _output_error;
 			}
 		}

 		length += MINMATCH;

 		/* match starting within external dictionary */
 		if ((dict == usingExtDict) && (match < lowPrefix)) {
 			if (unlikely(op + length > oend - LASTLITERALS)) {
 				/* doesn't respect parsing restriction */
 				if (!partialDecoding)
 					goto _output_error;
 				length = min(length, (size_t)(oend - op));
 			}

 			if (length <= (size_t)(lowPrefix - match)) {
 				/*
 				 * match fits entirely within external
 				 * dictionary : just copy
 				 */
 				memmove(op, dictEnd - (lowPrefix - match),
 					length);
 				op += length;
 			} else {
 				/*
 				 * match stretches into both external
 				 * dictionary and current block
 				 */
 				size_t const copySize = (size_t)(lowPrefix - match);
 				size_t const restSize = length - copySize;

 				memcpy(op, dictEnd - copySize, copySize);
 				op += copySize;
 				if (restSize > (size_t)(op - lowPrefix)) {
 					/* overlap copy */
 					BYTE * const endOfMatch = op + restSize;
 					const BYTE *copyFrom = lowPrefix;

 					while (op < endOfMatch)
 						*op++ = *copyFrom++;
 				} else {
 					memcpy(op, lowPrefix, restSize);
 					op += restSize;
 				}
 			}
 			continue;
 		}

 		/* copy match within block */
 		cpy = op + length;

 		/*
 		 * partialDecoding :
 		 * may not respect endBlock parsing restrictions
 		 */
 		assert(op <= oend);
 		if (partialDecoding &&
 		    (cpy > oend - MATCH_SAFEGUARD_DISTANCE)) {
 			size_t const mlen = min(length, (size_t)(oend - op));
 			const BYTE * const matchEnd = match + mlen;
 			BYTE * const copyEnd = op + mlen;

 			if (matchEnd > op) {
 				/* overlap copy */
 				while (op < copyEnd)
 					*op++ = *match++;
 			} else {
 				memcpy(op, match, mlen);
 			}
 			op = copyEnd;
 			if (op == oend)
 				break;
 			continue;
 		}

 		if (unlikely(offset < 8)) {
 			op[0] = match[0];
 			op[1] = match[1];
 			op[2] = match[2];
 			op[3] = match[3];
 			match += inc32table[offset];
 			memcpy(op + 4, match, 4);
 			match -= dec64table[offset];
 		} else {
 			LZ4_copy8(op, match);
 			match += 8;
 		}

 		op += 8;

 		if (unlikely(cpy > oend - MATCH_SAFEGUARD_DISTANCE)) {
 			BYTE * const oCopyLimit = oend - (WILDCOPYLENGTH - 1);

 			if (cpy > oend - LASTLITERALS) {
 				/*
 				 * Error : last LASTLITERALS bytes
 				 * must be literals (uncompressed)
 				 */
 				goto _output_error;
 			}

 			if (op < oCopyLimit) {
 				LZ4_wildCopy(op, match, oCopyLimit);
 				match += oCopyLimit - op;
 				op = oCopyLimit;
 			}
 			while (op < cpy)
 				*op++ = *match++;
 		} else {
 			LZ4_copy8(op, match);
 			if (length > 16)
 				LZ4_wildCopy(op + 8, match + 8, cpy);
 		}
 		op = cpy; /* wildcopy correction */
 	}

 	/* end of decoding */
 	if (endOnInput) {
 		/* Nb of output bytes decoded */
 		return (int) (((char *)op) - dst);
 	} else {
 		/* Nb of input bytes read */
 		return (int) (((const char *)ip) - src);
 	}

 	/* Overflow error detected */
 _output_error:
 	return (int) (-(((const char *)ip) - src)) - 1;
 }

 int LZ4_decompress_safe(const char *source, char *dest,
 	int compressedSize, int maxDecompressedSize)
 {
 	return LZ4_decompress_generic(source, dest,
 				      compressedSize, maxDecompressedSize,
 				      endOnInputSize, decode_full_block,
 				      noDict, (BYTE *)dest, NULL, 0);
 }

 int LZ4_decompress_safe_partial(const char *src, char *dst,
 	int compressedSize, int targetOutputSize, int dstCapacity)
 {
 	dstCapacity = min(targetOutputSize, dstCapacity);
 	return LZ4_decompress_generic(src, dst, compressedSize, dstCapacity,
 				      endOnInputSize, partial_decode,
 				      noDict, (BYTE *)dst, NULL, 0);
 }
	// SPDX-License-Identifier: GPL 2.0+ OR BSD-2-Clause
	/*
	* LZ4 - Fast LZ compression algorithm
	* Copyright (C) 2011 - 2016, Yann Collet.
	* BSD 2 - Clause License (http://www.opensource.org/licenses/bsd - license.php)
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are
	* met:
	* * Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* * Redistributions in binary form must reproduce the above
	* copyright notice, this list of conditions and the following disclaimer
	* in the documentation and/or other materials provided with the
	* distribution.
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	* You can contact the author at :
	* - LZ4 homepage : http://www.lz4.org
	* - LZ4 source repository : https://github.com/lz4/lz4
	*/
	#include <common.h>
	#include <compiler.h>
	#include <linux/kernel.h>
	#include <linux/types.h>
	#include <linux/bug.h>
	#include <asm/unaligned.h>
	#include <u-boot/lz4.h>

	#define FORCE_INLINE inline __attribute__((always_inline))

	static FORCE_INLINE u16 LZ4_readLE16(const void *src)
	{
	return get_unaligned_le16(src);
	}

	static FORCE_INLINE void LZ4_copy8(void dst, const void src)
	{
	put_unaligned(get_unaligned((const u64 )src), (u64 )dst);
	}

	typedef uint8_t BYTE;
	typedef uint16_t U16;
	typedef uint32_t U32;
	typedef int32_t S32;
	typedef uint64_t U64;
	typedef uintptr_t uptrval;

	static FORCE_INLINE void LZ4_write32(void *memPtr, U32 value)
	{
	put_unaligned(value, (U32 *)memPtr);
	}

	/**************************************
	* Reading and writing into memory
	**************************************/

	/* customized version of memcpy, which may overwrite up to 7 bytes beyond dstEnd */
	static void LZ4_wildCopy(void* dstPtr, const void* srcPtr, void* dstEnd)
	{
	BYTE* d = (BYTE*)dstPtr;
	const BYTE* s = (const BYTE*)srcPtr;
	BYTE* e = (BYTE*)dstEnd;
	do { LZ4_copy8(d,s); d+=8; s+=8; } while (d<e);
	}


	/**************************************
	* Common Constants
	**************************************/
	#define MINMATCH 4

	#define WILDCOPYLENGTH 8
	#define LASTLITERALS 5
	#define MFLIMIT (WILDCOPYLENGTH + MINMATCH)

	/*
	* ensure it's possible to write 2 x wildcopyLength
	* without overflowing output buffer
	*/
	#define MATCH_SAFEGUARD_DISTANCE ((2 * WILDCOPYLENGTH) - MINMATCH)

	#define KB (1 <<10)

	#define MAXD_LOG 16
	#define MAX_DISTANCE ((1 << MAXD_LOG) - 1)

	#define ML_BITS 4
	#define ML_MASK ((1U<<ML_BITS)-1)
	#define RUN_BITS (8-ML_BITS)
	#define RUN_MASK ((1U<<RUN_BITS)-1)

	#define LZ4_STATIC_ASSERT(c) BUILD_BUG_ON(!(c))

	/**************************************
	* Local Structures and types
	**************************************/
	typedef enum { noDict = 0, withPrefix64k, usingExtDict } dict_directive;
	typedef enum { endOnOutputSize = 0, endOnInputSize = 1 } endCondition_directive;
	typedef enum { decode_full_block = 0, partial_decode = 1 } earlyEnd_directive;

	#define DEBUGLOG(l, ...) {} /* disabled */

	#ifndef assert
	#define assert(condition) ((void)0)
	#endif

	/*
	* LZ4_decompress_generic() :
	* This generic decompression function covers all use cases.
	* It shall be instantiated several times, using different sets of directives.
	* Note that it is important for performance that this function really get inlined,
	* in order to remove useless branches during compilation optimization.
	*/
	static FORCE_INLINE int LZ4_decompress_generic(
	const char * const src,
	char * const dst,
	int srcSize,
	/*
	* If endOnInput == endOnInputSize,
	* this value is `dstCapacity`
	*/
	int outputSize,
	/* endOnOutputSize, endOnInputSize */
	endCondition_directive endOnInput,
	/* full, partial */
	earlyEnd_directive partialDecoding,
	/* noDict, withPrefix64k, usingExtDict */
	dict_directive dict,
	/* always <= dst, == dst when no prefix */
	const BYTE * const lowPrefix,
	/* only if dict == usingExtDict */
	const BYTE * const dictStart,
	/* note : = 0 if noDict */
	const size_t dictSize
	)
	{
	const BYTE ip = (const BYTE ) src;
	const BYTE * const iend = ip + srcSize;

	BYTE op = (BYTE ) dst;
	BYTE * const oend = op + outputSize;
	BYTE *cpy;

	const BYTE * const dictEnd = (const BYTE *)dictStart + dictSize;
	static const unsigned int inc32table[8] = {0, 1, 2, 1, 0, 4, 4, 4};
	static const int dec64table[8] = {0, 0, 0, -1, -4, 1, 2, 3};

	const int safeDecode = (endOnInput == endOnInputSize);
	const int checkOffset = ((safeDecode) && (dictSize < (int)(64 * KB)));

	/* Set up the "end" pointers for the shortcut. */
	const BYTE *const shortiend = iend -
	(endOnInput ? 14 : 8) /maxLL/ - 2 /offset/;
	const BYTE *const shortoend = oend -
	(endOnInput ? 14 : 8) /maxLL/ - 18 /maxML/;

	DEBUGLOG(5, "%s (srcSize:%i, dstSize:%i)", __func__,
	srcSize, outputSize);

	/* Special cases */
	assert(lowPrefix <= op);
	assert(src != NULL);

	/* Empty output buffer */
	if ((endOnInput) && (unlikely(outputSize == 0)))
	return ((srcSize == 1) && (*ip == 0)) ? 0 : -1;

	if ((!endOnInput) && (unlikely(outputSize == 0)))
	return (*ip == 0 ? 1 : -1);

	if ((endOnInput) && unlikely(srcSize == 0))
	return -1;

	/* Main Loop : decode sequences */
	while (1) {
	size_t length;
	const BYTE *match;
	size_t offset;

	/* get literal length */
	unsigned int const token = *ip++;
	length = token>>ML_BITS;

	/* ip < iend before the increment */
	assert(!endOnInput \|\| ip <= iend);

	/*
	* A two-stage shortcut for the most common case:
	* 1) If the literal length is 0..14, and there is enough
	* space, enter the shortcut and copy 16 bytes on behalf
	* of the literals (in the fast mode, only 8 bytes can be
	* safely copied this way).
	* 2) Further if the match length is 4..18, copy 18 bytes
	* in a similar manner; but we ensure that there's enough
	* space in the output for those 18 bytes earlier, upon
	* entering the shortcut (in other words, there is a
	* combined check for both stages).
	*
	* The & in the likely() below is intentionally not && so that
	* some compilers can produce better parallelized runtime code
	*/
	if ((endOnInput ? length != RUN_MASK : length <= 8)
	/*
	* strictly "less than" on input, to re-enter
	* the loop with at least one byte
	*/
	&& likely((endOnInput ? ip < shortiend : 1) &
	(op <= shortoend))) {
	/* Copy the literals */
	memcpy(op, ip, endOnInput ? 16 : 8);
	op += length; ip += length;

	/*
	* The second stage:
	* prepare for match copying, decode full info.
	* If it doesn't work out, the info won't be wasted.
	*/
	length = token & ML_MASK; /* match length */
	offset = LZ4_readLE16(ip);
	ip += 2;
	match = op - offset;
	assert(match <= op); /* check overflow */

	/* Do not deal with overlapping matches. */
	if ((length != ML_MASK) &&
	(offset >= 8) &&
	(dict == withPrefix64k \|\| match >= lowPrefix)) {
	/* Copy the match. */
	memcpy(op + 0, match + 0, 8);
	memcpy(op + 8, match + 8, 8);
	memcpy(op + 16, match + 16, 2);
	op += length + MINMATCH;
	/* Both stages worked, load the next token. */
	continue;
	}

	/*
	* The second stage didn't work out, but the info
	* is ready. Propel it right to the point of match
	* copying.
	*/
	goto _copy_match;
	}

	/* decode literal length */
	if (length == RUN_MASK) {
	unsigned int s;

	if (unlikely(endOnInput ? ip >= iend - RUN_MASK : 0)) {
	/* overflow detection */
	goto _output_error;
	}
	do {
	s = *ip++;
	length += s;
	} while (likely(endOnInput
	? ip < iend - RUN_MASK
	: 1) & (s == 255));

	if ((safeDecode)
	&& unlikely((uptrval)(op) +
	length < (uptrval)(op))) {
	/* overflow detection */
	goto _output_error;
	}
	if ((safeDecode)
	&& unlikely((uptrval)(ip) +
	length < (uptrval)(ip))) {
	/* overflow detection */
	goto _output_error;
	}
	}

	/* copy literals */
	cpy = op + length;
	LZ4_STATIC_ASSERT(MFLIMIT >= WILDCOPYLENGTH);

	if (((endOnInput) && ((cpy > oend - MFLIMIT)
	\|\| (ip + length > iend - (2 + 1 + LASTLITERALS))))
	\|\| ((!endOnInput) && (cpy > oend - WILDCOPYLENGTH))) {
	if (partialDecoding) {
	if (cpy > oend) {
	/*
	* Partial decoding :
	* stop in the middle of literal segment
	*/
	cpy = oend;
	length = oend - op;
	}
	if ((endOnInput)
	&& (ip + length > iend)) {
	/*
	* Error :
	* read attempt beyond
	* end of input buffer
	*/
	goto _output_error;
	}
	} else {
	if ((!endOnInput)
	&& (cpy != oend)) {
	/*
	* Error :
	* block decoding must
	* stop exactly there
	*/
	goto _output_error;
	}
	if ((endOnInput)
	&& ((ip + length != iend)
	\|\| (cpy > oend))) {
	/*
	* Error :
	* input must be consumed
	*/
	goto _output_error;
	}
	}

	/*
	* supports overlapping memory regions; only matters
	* for in-place decompression scenarios
	*/
	memmove(op, ip, length);
	ip += length;
	op += length;

	/* Necessarily EOF, due to parsing restrictions */
	if (!partialDecoding \|\| (cpy == oend))
	break;
	} else {
	/* may overwrite up to WILDCOPYLENGTH beyond cpy */
	LZ4_wildCopy(op, ip, cpy);
	ip += length;
	op = cpy;
	}

	/* get offset */
	offset = LZ4_readLE16(ip);
	ip += 2;
	match = op - offset;

	/* get matchlength */
	length = token & ML_MASK;

	_copy_match:
	if ((checkOffset) && (unlikely(match + dictSize < lowPrefix))) {
	/* Error : offset outside buffers */
	goto _output_error;
	}

	/* costs ~1%; silence an msan warning when offset == 0 */
	/*
	* note : when partialDecoding, there is no guarantee that
	* at least 4 bytes remain available in output buffer
	*/
	if (!partialDecoding) {
	assert(oend > op);
	assert(oend - op >= 4);

	LZ4_write32(op, (U32)offset);
	}

	if (length == ML_MASK) {
	unsigned int s;

	do {
	s = *ip++;

	if ((endOnInput) && (ip > iend - LASTLITERALS))
	goto _output_error;

	length += s;
	} while (s == 255);

	if ((safeDecode)
	&& unlikely(
	(uptrval)(op) + length < (uptrval)op)) {
	/* overflow detection */
	goto _output_error;
	}
	}

	length += MINMATCH;

	/* match starting within external dictionary */
	if ((dict == usingExtDict) && (match < lowPrefix)) {
	if (unlikely(op + length > oend - LASTLITERALS)) {
	/* doesn't respect parsing restriction */
	if (!partialDecoding)
	goto _output_error;
	length = min(length, (size_t)(oend - op));
	}

	if (length <= (size_t)(lowPrefix - match)) {
	/*
	* match fits entirely within external
	* dictionary : just copy
	*/
	memmove(op, dictEnd - (lowPrefix - match),
	length);
	op += length;
	} else {
	/*
	* match stretches into both external
	* dictionary and current block
	*/
	size_t const copySize = (size_t)(lowPrefix - match);
	size_t const restSize = length - copySize;

	memcpy(op, dictEnd - copySize, copySize);
	op += copySize;
	if (restSize > (size_t)(op - lowPrefix)) {
	/* overlap copy */
	BYTE * const endOfMatch = op + restSize;
	const BYTE *copyFrom = lowPrefix;

	while (op < endOfMatch)
	op++ = copyFrom++;
	} else {
	memcpy(op, lowPrefix, restSize);
	op += restSize;
	}
	}
	continue;
	}

	/* copy match within block */
	cpy = op + length;

	/*
	* partialDecoding :
	* may not respect endBlock parsing restrictions
	*/
	assert(op <= oend);
	if (partialDecoding &&
	(cpy > oend - MATCH_SAFEGUARD_DISTANCE)) {
	size_t const mlen = min(length, (size_t)(oend - op));
	const BYTE * const matchEnd = match + mlen;
	BYTE * const copyEnd = op + mlen;

	if (matchEnd > op) {
	/* overlap copy */
	while (op < copyEnd)
	op++ = match++;
	} else {
	memcpy(op, match, mlen);
	}
	op = copyEnd;
	if (op == oend)
	break;
	continue;
	}

	if (unlikely(offset < 8)) {
	op[0] = match[0];
	op[1] = match[1];
	op[2] = match[2];
	op[3] = match[3];
	match += inc32table[offset];
	memcpy(op + 4, match, 4);
	match -= dec64table[offset];
	} else {
	LZ4_copy8(op, match);
	match += 8;
	}

	op += 8;

	if (unlikely(cpy > oend - MATCH_SAFEGUARD_DISTANCE)) {
	BYTE * const oCopyLimit = oend - (WILDCOPYLENGTH - 1);

	if (cpy > oend - LASTLITERALS) {
	/*
	* Error : last LASTLITERALS bytes
	* must be literals (uncompressed)
	*/
	goto _output_error;
	}

	if (op < oCopyLimit) {
	LZ4_wildCopy(op, match, oCopyLimit);
	match += oCopyLimit - op;
	op = oCopyLimit;
	}
	while (op < cpy)
	op++ = match++;
	} else {
	LZ4_copy8(op, match);
	if (length > 16)
	LZ4_wildCopy(op + 8, match + 8, cpy);
	}
	op = cpy; /* wildcopy correction */
	}

	/* end of decoding */
	if (endOnInput) {
	/* Nb of output bytes decoded */
	return (int) (((char *)op) - dst);
	} else {
	/* Nb of input bytes read */
	return (int) (((const char *)ip) - src);
	}

	/* Overflow error detected */
	_output_error:
	return (int) (-(((const char *)ip) - src)) - 1;
	}

	int LZ4_decompress_safe(const char source, char dest,
	int compressedSize, int maxDecompressedSize)
	{
	return LZ4_decompress_generic(source, dest,
	compressedSize, maxDecompressedSize,
	endOnInputSize, decode_full_block,
	noDict, (BYTE *)dest, NULL, 0);
	}

	int LZ4_decompress_safe_partial(const char src, char dst,
	int compressedSize, int targetOutputSize, int dstCapacity)
	{
	dstCapacity = min(targetOutputSize, dstCapacity);
	return LZ4_decompress_generic(src, dst, compressedSize, dstCapacity,
	endOnInputSize, partial_decode,
	noDict, (BYTE *)dst, NULL, 0);
	}