lib/lzo/lzo1x_compress.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  *  LZO1X Compressor from LZO
  *
  *  Copyright (C) 1996-2012 Markus F.X.J. Oberhumer <markus@oberhumer.com>
  *
  *  The full LZO package can be found at:
  *  http://www.oberhumer.com/opensource/lzo/
  *
  *  Changed for Linux kernel use by:
  *  Nitin Gupta <nitingupta910@gmail.com>
  *  Richard Purdie <rpurdie@openedhand.com>
  */

 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/unaligned.h>
 #include <linux/lzo.h>
 #include "lzodefs.h"

 static noinline size_t
 lzo1x_1_do_compress(const unsigned char *in, size_t in_len,
 		    unsigned char *out, size_t *out_len,
 		    size_t ti, void *wrkmem, signed char *state_offset,
 		    const unsigned char bitstream_version)
 {
 	const unsigned char *ip;
 	unsigned char *op;
 	const unsigned char * const in_end = in + in_len;
 	const unsigned char * const ip_end = in + in_len - 20;
 	const unsigned char *ii;
 	lzo_dict_t * const dict = (lzo_dict_t *) wrkmem;

 	op = out;
 	ip = in;
 	ii = ip;
 	ip += ti < 4 ? 4 - ti : 0;

 	for (;;) {
 		const unsigned char *m_pos = NULL;
 		size_t t, m_len, m_off;
 		u32 dv;
 		u32 run_length = 0;
 literal:
 		ip += 1 + ((ip - ii) >> 5);
 next:
 		if (unlikely(ip >= ip_end))
 			break;
 		dv = get_unaligned_le32(ip);

 		if (dv == 0 && bitstream_version) {
 			const unsigned char *ir = ip + 4;
 			const unsigned char *limit = min(ip_end, ip + MAX_ZERO_RUN_LENGTH + 1);
 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && \
 	defined(LZO_FAST_64BIT_MEMORY_ACCESS)
 			u64 dv64;

 			for (; (ir + 32) <= limit; ir += 32) {
 				dv64 = get_unaligned((u64 *)ir);
 				dv64 |= get_unaligned((u64 *)ir + 1);
 				dv64 |= get_unaligned((u64 *)ir + 2);
 				dv64 |= get_unaligned((u64 *)ir + 3);
 				if (dv64)
 					break;
 			}
 			for (; (ir + 8) <= limit; ir += 8) {
 				dv64 = get_unaligned((u64 *)ir);
 				if (dv64) {
 #  if defined(__LITTLE_ENDIAN)
 					ir += __builtin_ctzll(dv64) >> 3;
 #  elif defined(__BIG_ENDIAN)
 					ir += __builtin_clzll(dv64) >> 3;
 #  else
 #    error "missing endian definition"
 #  endif
 					break;
 				}
 			}
 #else
 			while ((ir < (const unsigned char *)
 					ALIGN((uintptr_t)ir, 4)) &&
 					(ir < limit) && (*ir == 0))
 				ir++;
 			if (IS_ALIGNED((uintptr_t)ir, 4)) {
 				for (; (ir + 4) <= limit; ir += 4) {
 					dv = *((u32 *)ir);
 					if (dv) {
 #  if defined(__LITTLE_ENDIAN)
 						ir += __builtin_ctz(dv) >> 3;
 #  elif defined(__BIG_ENDIAN)
 						ir += __builtin_clz(dv) >> 3;
 #  else
 #    error "missing endian definition"
 #  endif
 						break;
 					}
 				}
 			}
 #endif
 			while (likely(ir < limit) && unlikely(*ir == 0))
 				ir++;
 			run_length = ir - ip;
 			if (run_length > MAX_ZERO_RUN_LENGTH)
 				run_length = MAX_ZERO_RUN_LENGTH;
 		} else {
 			t = ((dv * 0x1824429d) >> (32 - D_BITS)) & D_MASK;
 			m_pos = in + dict[t];
 			dict[t] = (lzo_dict_t) (ip - in);
 			if (unlikely(dv != get_unaligned_le32(m_pos)))
 				goto literal;
 		}

 		ii -= ti;
 		ti = 0;
 		t = ip - ii;
 		if (t != 0) {
 			if (t <= 3) {
 				op[*state_offset] |= t;
 				COPY4(op, ii);
 				op += t;
 			} else if (t <= 16) {
 				*op++ = (t - 3);
 				COPY8(op, ii);
 				COPY8(op + 8, ii + 8);
 				op += t;
 			} else {
 				if (t <= 18) {
 					*op++ = (t - 3);
 				} else {
 					size_t tt = t - 18;
 					*op++ = 0;
 					while (unlikely(tt > 255)) {
 						tt -= 255;
 						*op++ = 0;
 					}
 					*op++ = tt;
 				}
 				do {
 					COPY8(op, ii);
 					COPY8(op + 8, ii + 8);
 					op += 16;
 					ii += 16;
 					t -= 16;
 				} while (t >= 16);
 				if (t > 0) do {
 					*op++ = *ii++;
 				} while (--t > 0);
 			}
 		}

 		if (unlikely(run_length)) {
 			ip += run_length;
 			run_length -= MIN_ZERO_RUN_LENGTH;
 			put_unaligned_le32((run_length << 21) | 0xfffc18
 					   | (run_length & 0x7), op);
 			op += 4;
 			run_length = 0;
 			*state_offset = -3;
 			goto finished_writing_instruction;
 		}

 		m_len = 4;
 		{
 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && defined(LZO_USE_CTZ64)
 		u64 v;
 		v = get_unaligned((const u64 *) (ip + m_len)) ^
 		    get_unaligned((const u64 *) (m_pos + m_len));
 		if (unlikely(v == 0)) {
 			do {
 				m_len += 8;
 				v = get_unaligned((const u64 *) (ip + m_len)) ^
 				    get_unaligned((const u64 *) (m_pos + m_len));
 				if (unlikely(ip + m_len >= ip_end))
 					goto m_len_done;
 			} while (v == 0);
 		}
 #  if defined(__LITTLE_ENDIAN)
 		m_len += (unsigned) __builtin_ctzll(v) / 8;
 #  elif defined(__BIG_ENDIAN)
 		m_len += (unsigned) __builtin_clzll(v) / 8;
 #  else
 #    error "missing endian definition"
 #  endif
 #elif defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && defined(LZO_USE_CTZ32)
 		u32 v;
 		v = get_unaligned((const u32 *) (ip + m_len)) ^
 		    get_unaligned((const u32 *) (m_pos + m_len));
 		if (unlikely(v == 0)) {
 			do {
 				m_len += 4;
 				v = get_unaligned((const u32 *) (ip + m_len)) ^
 				    get_unaligned((const u32 *) (m_pos + m_len));
 				if (v != 0)
 					break;
 				m_len += 4;
 				v = get_unaligned((const u32 *) (ip + m_len)) ^
 				    get_unaligned((const u32 *) (m_pos + m_len));
 				if (unlikely(ip + m_len >= ip_end))
 					goto m_len_done;
 			} while (v == 0);
 		}
 #  if defined(__LITTLE_ENDIAN)
 		m_len += (unsigned) __builtin_ctz(v) / 8;
 #  elif defined(__BIG_ENDIAN)
 		m_len += (unsigned) __builtin_clz(v) / 8;
 #  else
 #    error "missing endian definition"
 #  endif
 #else
 		if (unlikely(ip[m_len] == m_pos[m_len])) {
 			do {
 				m_len += 1;
 				if (ip[m_len] != m_pos[m_len])
 					break;
 				m_len += 1;
 				if (ip[m_len] != m_pos[m_len])
 					break;
 				m_len += 1;
 				if (ip[m_len] != m_pos[m_len])
 					break;
 				m_len += 1;
 				if (ip[m_len] != m_pos[m_len])
 					break;
 				m_len += 1;
 				if (ip[m_len] != m_pos[m_len])
 					break;
 				m_len += 1;
 				if (ip[m_len] != m_pos[m_len])
 					break;
 				m_len += 1;
 				if (ip[m_len] != m_pos[m_len])
 					break;
 				m_len += 1;
 				if (unlikely(ip + m_len >= ip_end))
 					goto m_len_done;
 			} while (ip[m_len] == m_pos[m_len]);
 		}
 #endif
 		}
 m_len_done:

 		m_off = ip - m_pos;
 		ip += m_len;
 		if (m_len <= M2_MAX_LEN && m_off <= M2_MAX_OFFSET) {
 			m_off -= 1;
 			*op++ = (((m_len - 1) << 5) | ((m_off & 7) << 2));
 			*op++ = (m_off >> 3);
 		} else if (m_off <= M3_MAX_OFFSET) {
 			m_off -= 1;
 			if (m_len <= M3_MAX_LEN)
 				*op++ = (M3_MARKER | (m_len - 2));
 			else {
 				m_len -= M3_MAX_LEN;
 				*op++ = M3_MARKER | 0;
 				while (unlikely(m_len > 255)) {
 					m_len -= 255;
 					*op++ = 0;
 				}
 				*op++ = (m_len);
 			}
 			*op++ = (m_off << 2);
 			*op++ = (m_off >> 6);
 		} else {
 			m_off -= 0x4000;
 			if (m_len <= M4_MAX_LEN)
 				*op++ = (M4_MARKER | ((m_off >> 11) & 8)
 						| (m_len - 2));
 			else {
 				if (unlikely(((m_off & 0x403f) == 0x403f)
 						&& (m_len >= 261)
 						&& (m_len <= 264))
 						&& likely(bitstream_version)) {
 					// Under lzo-rle, block copies
 					// for 261 <= length <= 264 and
 					// (distance & 0x80f3) == 0x80f3
 					// can result in ambiguous
 					// output. Adjust length
 					// to 260 to prevent ambiguity.
 					ip -= m_len - 260;
 					m_len = 260;
 				}
 				m_len -= M4_MAX_LEN;
 				*op++ = (M4_MARKER | ((m_off >> 11) & 8));
 				while (unlikely(m_len > 255)) {
 					m_len -= 255;
 					*op++ = 0;
 				}
 				*op++ = (m_len);
 			}
 			*op++ = (m_off << 2);
 			*op++ = (m_off >> 6);
 		}
 		*state_offset = -2;
 finished_writing_instruction:
 		ii = ip;
 		goto next;
 	}
 	*out_len = op - out;
 	return in_end - (ii - ti);
 }

 static int lzogeneric1x_1_compress(const unsigned char *in, size_t in_len,
 		     unsigned char *out, size_t *out_len,
 		     void *wrkmem, const unsigned char bitstream_version)
 {
 	const unsigned char *ip = in;
 	unsigned char *op = out;
 	unsigned char *data_start;
 	size_t l = in_len;
 	size_t t = 0;
 	signed char state_offset = -2;
 	unsigned int m4_max_offset;

 	// LZO v0 will never write 17 as first byte (except for zero-length
 	// input), so this is used to version the bitstream
 	if (bitstream_version > 0) {
 		*op++ = 17;
 		*op++ = bitstream_version;
 		m4_max_offset = M4_MAX_OFFSET_V1;
 	} else {
 		m4_max_offset = M4_MAX_OFFSET_V0;
 	}

 	data_start = op;

 	while (l > 20) {
 		size_t ll = min_t(size_t, l, m4_max_offset + 1);
 		uintptr_t ll_end = (uintptr_t) ip + ll;
 		if ((ll_end + ((t + ll) >> 5)) <= ll_end)
 			break;
 		BUILD_BUG_ON(D_SIZE * sizeof(lzo_dict_t) > LZO1X_1_MEM_COMPRESS);
 		memset(wrkmem, 0, D_SIZE * sizeof(lzo_dict_t));
 		t = lzo1x_1_do_compress(ip, ll, op, out_len, t, wrkmem,
 					&state_offset, bitstream_version);
 		ip += ll;
 		op += *out_len;
 		l  -= ll;
 	}
 	t += l;

 	if (t > 0) {
 		const unsigned char *ii = in + in_len - t;

 		if (op == data_start && t <= 238) {
 			*op++ = (17 + t);
 		} else if (t <= 3) {
 			op[state_offset] |= t;
 		} else if (t <= 18) {
 			*op++ = (t - 3);
 		} else {
 			size_t tt = t - 18;
 			*op++ = 0;
 			while (tt > 255) {
 				tt -= 255;
 				*op++ = 0;
 			}
 			*op++ = tt;
 		}
 		if (t >= 16) do {
 			COPY8(op, ii);
 			COPY8(op + 8, ii + 8);
 			op += 16;
 			ii += 16;
 			t -= 16;
 		} while (t >= 16);
 		if (t > 0) do {
 			*op++ = *ii++;
 		} while (--t > 0);
 	}

 	*op++ = M4_MARKER | 1;
 	*op++ = 0;
 	*op++ = 0;

 	*out_len = op - out;
 	return LZO_E_OK;
 }

 int lzo1x_1_compress(const unsigned char *in, size_t in_len,
 		     unsigned char *out, size_t *out_len,
 		     void *wrkmem)
 {
 	return lzogeneric1x_1_compress(in, in_len, out, out_len, wrkmem, 0);
 }

 int lzorle1x_1_compress(const unsigned char *in, size_t in_len,
 		     unsigned char *out, size_t *out_len,
 		     void *wrkmem)
 {
 	return lzogeneric1x_1_compress(in, in_len, out, out_len,
 				       wrkmem, LZO_VERSION);
 }

 EXPORT_SYMBOL_GPL(lzo1x_1_compress);
 EXPORT_SYMBOL_GPL(lzorle1x_1_compress);

 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("LZO1X-1 Compressor");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* LZO1X Compressor from LZO
	*
	* Copyright (C) 1996-2012 Markus F.X.J. Oberhumer <markus@oberhumer.com>
	*
	* The full LZO package can be found at:
	* http://www.oberhumer.com/opensource/lzo/
	*
	* Changed for Linux kernel use by:
	* Nitin Gupta <nitingupta910@gmail.com>
	* Richard Purdie <rpurdie@openedhand.com>
	*/

	#include <linux/module.h>
	#include <linux/kernel.h>
	#include <linux/unaligned.h>
	#include <linux/lzo.h>
	#include "lzodefs.h"

	static noinline size_t
	lzo1x_1_do_compress(const unsigned char *in, size_t in_len,
	unsigned char out, size_t out_len,
	size_t ti, void wrkmem, signed char state_offset,
	const unsigned char bitstream_version)
	{
	const unsigned char *ip;
	unsigned char *op;
	const unsigned char * const in_end = in + in_len;
	const unsigned char * const ip_end = in + in_len - 20;
	const unsigned char *ii;
	lzo_dict_t * const dict = (lzo_dict_t *) wrkmem;

	op = out;
	ip = in;
	ii = ip;
	ip += ti < 4 ? 4 - ti : 0;

	for (;;) {
	const unsigned char *m_pos = NULL;
	size_t t, m_len, m_off;
	u32 dv;
	u32 run_length = 0;
	literal:
	ip += 1 + ((ip - ii) >> 5);
	next:
	if (unlikely(ip >= ip_end))
	break;
	dv = get_unaligned_le32(ip);

	if (dv == 0 && bitstream_version) {
	const unsigned char *ir = ip + 4;
	const unsigned char *limit = min(ip_end, ip + MAX_ZERO_RUN_LENGTH + 1);
	#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && \
	defined(LZO_FAST_64BIT_MEMORY_ACCESS)
	u64 dv64;

	for (; (ir + 32) <= limit; ir += 32) {
	dv64 = get_unaligned((u64 *)ir);
	dv64 \|= get_unaligned((u64 *)ir + 1);
	dv64 \|= get_unaligned((u64 *)ir + 2);
	dv64 \|= get_unaligned((u64 *)ir + 3);
	if (dv64)
	break;
	}
	for (; (ir + 8) <= limit; ir += 8) {
	dv64 = get_unaligned((u64 *)ir);
	if (dv64) {
	# if defined(__LITTLE_ENDIAN)
	ir += __builtin_ctzll(dv64) >> 3;
	# elif defined(__BIG_ENDIAN)
	ir += __builtin_clzll(dv64) >> 3;
	# else
	# error "missing endian definition"
	# endif
	break;
	}
	}
	#else
	while ((ir < (const unsigned char *)
	ALIGN((uintptr_t)ir, 4)) &&
	(ir < limit) && (*ir == 0))
	ir++;
	if (IS_ALIGNED((uintptr_t)ir, 4)) {
	for (; (ir + 4) <= limit; ir += 4) {
	dv = ((u32 )ir);
	if (dv) {
	# if defined(__LITTLE_ENDIAN)
	ir += __builtin_ctz(dv) >> 3;
	# elif defined(__BIG_ENDIAN)
	ir += __builtin_clz(dv) >> 3;
	# else
	# error "missing endian definition"
	# endif
	break;
	}
	}
	}
	#endif
	while (likely(ir < limit) && unlikely(*ir == 0))
	ir++;
	run_length = ir - ip;
	if (run_length > MAX_ZERO_RUN_LENGTH)
	run_length = MAX_ZERO_RUN_LENGTH;
	} else {
	t = ((dv * 0x1824429d) >> (32 - D_BITS)) & D_MASK;
	m_pos = in + dict[t];
	dict[t] = (lzo_dict_t) (ip - in);
	if (unlikely(dv != get_unaligned_le32(m_pos)))
	goto literal;
	}

	ii -= ti;
	ti = 0;
	t = ip - ii;
	if (t != 0) {
	if (t <= 3) {
	op[*state_offset] \|= t;
	COPY4(op, ii);
	op += t;
	} else if (t <= 16) {
	*op++ = (t - 3);
	COPY8(op, ii);
	COPY8(op + 8, ii + 8);
	op += t;
	} else {
	if (t <= 18) {
	*op++ = (t - 3);
	} else {
	size_t tt = t - 18;
	*op++ = 0;
	while (unlikely(tt > 255)) {
	tt -= 255;
	*op++ = 0;
	}
	*op++ = tt;
	}
	do {
	COPY8(op, ii);
	COPY8(op + 8, ii + 8);
	op += 16;
	ii += 16;
	t -= 16;
	} while (t >= 16);
	if (t > 0) do {
	op++ = ii++;
	} while (--t > 0);
	}
	}

	if (unlikely(run_length)) {
	ip += run_length;
	run_length -= MIN_ZERO_RUN_LENGTH;
	put_unaligned_le32((run_length << 21) \| 0xfffc18
	\| (run_length & 0x7), op);
	op += 4;
	run_length = 0;
	*state_offset = -3;
	goto finished_writing_instruction;
	}

	m_len = 4;
	{
	#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && defined(LZO_USE_CTZ64)
	u64 v;
	v = get_unaligned((const u64 *) (ip + m_len)) ^
	get_unaligned((const u64 *) (m_pos + m_len));
	if (unlikely(v == 0)) {
	do {
	m_len += 8;
	v = get_unaligned((const u64 *) (ip + m_len)) ^
	get_unaligned((const u64 *) (m_pos + m_len));
	if (unlikely(ip + m_len >= ip_end))
	goto m_len_done;
	} while (v == 0);
	}
	# if defined(__LITTLE_ENDIAN)
	m_len += (unsigned) __builtin_ctzll(v) / 8;
	# elif defined(__BIG_ENDIAN)
	m_len += (unsigned) __builtin_clzll(v) / 8;
	# else
	# error "missing endian definition"
	# endif
	#elif defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && defined(LZO_USE_CTZ32)
	u32 v;
	v = get_unaligned((const u32 *) (ip + m_len)) ^
	get_unaligned((const u32 *) (m_pos + m_len));
	if (unlikely(v == 0)) {
	do {
	m_len += 4;
	v = get_unaligned((const u32 *) (ip + m_len)) ^
	get_unaligned((const u32 *) (m_pos + m_len));
	if (v != 0)
	break;
	m_len += 4;
	v = get_unaligned((const u32 *) (ip + m_len)) ^
	get_unaligned((const u32 *) (m_pos + m_len));
	if (unlikely(ip + m_len >= ip_end))
	goto m_len_done;
	} while (v == 0);
	}
	# if defined(__LITTLE_ENDIAN)
	m_len += (unsigned) __builtin_ctz(v) / 8;
	# elif defined(__BIG_ENDIAN)
	m_len += (unsigned) __builtin_clz(v) / 8;
	# else
	# error "missing endian definition"
	# endif
	#else
	if (unlikely(ip[m_len] == m_pos[m_len])) {
	do {
	m_len += 1;
	if (ip[m_len] != m_pos[m_len])
	break;
	m_len += 1;
	if (ip[m_len] != m_pos[m_len])
	break;
	m_len += 1;
	if (ip[m_len] != m_pos[m_len])
	break;
	m_len += 1;
	if (ip[m_len] != m_pos[m_len])
	break;
	m_len += 1;
	if (ip[m_len] != m_pos[m_len])
	break;
	m_len += 1;
	if (ip[m_len] != m_pos[m_len])
	break;
	m_len += 1;
	if (ip[m_len] != m_pos[m_len])
	break;
	m_len += 1;
	if (unlikely(ip + m_len >= ip_end))
	goto m_len_done;
	} while (ip[m_len] == m_pos[m_len]);
	}
	#endif
	}
	m_len_done:

	m_off = ip - m_pos;
	ip += m_len;
	if (m_len <= M2_MAX_LEN && m_off <= M2_MAX_OFFSET) {
	m_off -= 1;
	*op++ = (((m_len - 1) << 5) \| ((m_off & 7) << 2));
	*op++ = (m_off >> 3);
	} else if (m_off <= M3_MAX_OFFSET) {
	m_off -= 1;
	if (m_len <= M3_MAX_LEN)
	*op++ = (M3_MARKER \| (m_len - 2));
	else {
	m_len -= M3_MAX_LEN;
	*op++ = M3_MARKER \| 0;
	while (unlikely(m_len > 255)) {
	m_len -= 255;
	*op++ = 0;
	}
	*op++ = (m_len);
	}
	*op++ = (m_off << 2);
	*op++ = (m_off >> 6);
	} else {
	m_off -= 0x4000;
	if (m_len <= M4_MAX_LEN)
	*op++ = (M4_MARKER \| ((m_off >> 11) & 8)
	\| (m_len - 2));
	else {
	if (unlikely(((m_off & 0x403f) == 0x403f)
	&& (m_len >= 261)
	&& (m_len <= 264))
	&& likely(bitstream_version)) {
	// Under lzo-rle, block copies
	// for 261 <= length <= 264 and
	// (distance & 0x80f3) == 0x80f3
	// can result in ambiguous
	// output. Adjust length
	// to 260 to prevent ambiguity.
	ip -= m_len - 260;
	m_len = 260;
	}
	m_len -= M4_MAX_LEN;
	*op++ = (M4_MARKER \| ((m_off >> 11) & 8));
	while (unlikely(m_len > 255)) {
	m_len -= 255;
	*op++ = 0;
	}
	*op++ = (m_len);
	}
	*op++ = (m_off << 2);
	*op++ = (m_off >> 6);
	}
	*state_offset = -2;
	finished_writing_instruction:
	ii = ip;
	goto next;
	}
	*out_len = op - out;
	return in_end - (ii - ti);
	}

	static int lzogeneric1x_1_compress(const unsigned char *in, size_t in_len,
	unsigned char out, size_t out_len,
	void *wrkmem, const unsigned char bitstream_version)
	{
	const unsigned char *ip = in;
	unsigned char *op = out;
	unsigned char *data_start;
	size_t l = in_len;
	size_t t = 0;
	signed char state_offset = -2;
	unsigned int m4_max_offset;

	// LZO v0 will never write 17 as first byte (except for zero-length
	// input), so this is used to version the bitstream
	if (bitstream_version > 0) {
	*op++ = 17;
	*op++ = bitstream_version;
	m4_max_offset = M4_MAX_OFFSET_V1;
	} else {
	m4_max_offset = M4_MAX_OFFSET_V0;
	}

	data_start = op;

	while (l > 20) {
	size_t ll = min_t(size_t, l, m4_max_offset + 1);
	uintptr_t ll_end = (uintptr_t) ip + ll;
	if ((ll_end + ((t + ll) >> 5)) <= ll_end)
	break;
	BUILD_BUG_ON(D_SIZE * sizeof(lzo_dict_t) > LZO1X_1_MEM_COMPRESS);
	memset(wrkmem, 0, D_SIZE * sizeof(lzo_dict_t));
	t = lzo1x_1_do_compress(ip, ll, op, out_len, t, wrkmem,
	&state_offset, bitstream_version);
	ip += ll;
	op += *out_len;
	l -= ll;
	}
	t += l;

	if (t > 0) {
	const unsigned char *ii = in + in_len - t;

	if (op == data_start && t <= 238) {
	*op++ = (17 + t);
	} else if (t <= 3) {
	op[state_offset] \|= t;
	} else if (t <= 18) {
	*op++ = (t - 3);
	} else {
	size_t tt = t - 18;
	*op++ = 0;
	while (tt > 255) {
	tt -= 255;
	*op++ = 0;
	}
	*op++ = tt;
	}
	if (t >= 16) do {
	COPY8(op, ii);
	COPY8(op + 8, ii + 8);
	op += 16;
	ii += 16;
	t -= 16;
	} while (t >= 16);
	if (t > 0) do {
	op++ = ii++;
	} while (--t > 0);
	}

	*op++ = M4_MARKER \| 1;
	*op++ = 0;
	*op++ = 0;

	*out_len = op - out;
	return LZO_E_OK;
	}

	int lzo1x_1_compress(const unsigned char *in, size_t in_len,
	unsigned char out, size_t out_len,
	void *wrkmem)
	{
	return lzogeneric1x_1_compress(in, in_len, out, out_len, wrkmem, 0);
	}

	int lzorle1x_1_compress(const unsigned char *in, size_t in_len,
	unsigned char out, size_t out_len,
	void *wrkmem)
	{
	return lzogeneric1x_1_compress(in, in_len, out, out_len,
	wrkmem, LZO_VERSION);
	}

	EXPORT_SYMBOL_GPL(lzo1x_1_compress);
	EXPORT_SYMBOL_GPL(lzorle1x_1_compress);

	MODULE_LICENSE("GPL");
	MODULE_DESCRIPTION("LZO1X-1 Compressor");