lib/lzo: Update LZO compression to current upstream version

This commit updates the kernel LZO code to the current upsteam version
which features a significant speed improvement - benchmarking the Calgary
and Silesia test corpora typically shows a doubled performance in
both compression and decompression on modern i386/x86_64/powerpc machines.

Signed-off-by: Markus F.X.J. Oberhumer <[e-mail]>

include/linux/lzo.h

···
  *  LZO Public Kernel Interface
  *  A mini subset of the LZO real-time data compression library
  *
- *  Copyright (C) 1996-2005 Markus F.X.J. Oberhumer <[e-mail]>
+ *  Copyright (C) 1996-2012 Markus F.X.J. Oberhumer <[e-mail]>
  *
  *  The full LZO package can be found at:
  *  http://www.oberhumer.com/opensource/lzo/
  *
- *  Changed for kernel use by:
+ *  Changed for Linux kernel use by:
  *  Nitin Gupta <[e-mail]>
  *  Richard Purdie <[e-mail]>
  */
 
-#define LZO1X_MEM_COMPRESS	(16384 * sizeof(unsigned char *))
-#define LZO1X_1_MEM_COMPRESS	LZO1X_MEM_COMPRESS
+#define LZO1X_1_MEM_COMPRESS	(8192 * sizeof(unsigned short))
+#define LZO1X_MEM_COMPRESS	LZO1X_1_MEM_COMPRESS
 
 #define lzo1x_worst_compress(x) ((x) + ((x) / 16) + 64 + 3)
 
-/* This requires 'workmem' of size LZO1X_1_MEM_COMPRESS */
+/* This requires 'wrkmem' of size LZO1X_1_MEM_COMPRESS */
 int lzo1x_1_compress(const unsigned char *src, size_t src_len,
-			unsigned char *dst, size_t *dst_len, void *wrkmem);
+		     unsigned char *dst, size_t *dst_len, void *wrkmem);
 
 /* safe decompression with overrun testing */
 int lzo1x_decompress_safe(const unsigned char *src, size_t src_len,
-			unsigned char *dst, size_t *dst_len);
+			  unsigned char *dst, size_t *dst_len);
 
 /*
  * Return values (< 0 = Error)
···
 #define LZO_E_EOF_NOT_FOUND		(-7)
 #define LZO_E_INPUT_NOT_CONSUMED	(-8)
 #define LZO_E_NOT_YET_IMPLEMENTED	(-9)
+#define LZO_E_INVALID_ARGUMENT		(-10)
 
 #endif

lib/lzo/lzo1x_compress.c

···
 /*
- *  LZO1X Compressor from MiniLZO
+ *  LZO1X Compressor from LZO
  *
- *  Copyright (C) 1996-2005 Markus F.X.J. Oberhumer <[e-mail]>
+ *  Copyright (C) 1996-2012 Markus F.X.J. Oberhumer <[e-mail]>
  *
  *  The full LZO package can be found at:
  *  http://www.oberhumer.com/opensource/lzo/
  *
- *  Changed for kernel use by:
+ *  Changed for Linux kernel use by:
  *  Nitin Gupta <[e-mail]>
  *  Richard Purdie <[e-mail]>
  */
 
 #include <linux/module.h>
 #include <linux/kernel.h>
-#include <linux/lzo.h>
 #include <asm/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, void *wrkmem)
+lzo1x_1_do_compress(const unsigned char *in, size_t in_len,
+		    unsigned char *out, size_t *out_len,
+		    size_t ti, void *wrkmem)
 {
+	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 - M2_MAX_LEN - 5;
-	const unsigned char ** const dict = wrkmem;
-	const unsigned char *ip = in, *ii = ip;
-	const unsigned char *end, *m, *m_pos;
-	size_t m_off, m_len, dindex;
-	unsigned char *op = out;
+	const unsigned char * const ip_end = in + in_len - 20;
+	const unsigned char *ii;
+	lzo_dict_t * const dict = (lzo_dict_t *) wrkmem;
 
-	ip += 4;
+	op = out;
+	ip = in;
+	ii = ip;
+	ip += ti < 4 ? 4 - ti : 0;
 
 	for (;;) {
-		dindex = ((size_t)(0x21 * DX3(ip, 5, 5, 6)) >> 5) & D_MASK;
-		m_pos = dict[dindex];
-
-		if (m_pos < in)
-			goto literal;
-
-		if (ip == m_pos || ((size_t)(ip - m_pos) > M4_MAX_OFFSET))
-			goto literal;
-
-		m_off = ip - m_pos;
-		if (m_off <= M2_MAX_OFFSET || m_pos[3] == ip[3])
-			goto try_match;
-
-		dindex = (dindex & (D_MASK & 0x7ff)) ^ (D_HIGH | 0x1f);
-		m_pos = dict[dindex];
-
-		if (m_pos < in)
-			goto literal;
-
-		if (ip == m_pos || ((size_t)(ip - m_pos) > M4_MAX_OFFSET))
-			goto literal;
-
-		m_off = ip - m_pos;
-		if (m_off <= M2_MAX_OFFSET || m_pos[3] == ip[3])
-			goto try_match;
-
-		goto literal;
-
-try_match:
-		if (get_unaligned((const unsigned short *)m_pos)
-				== get_unaligned((const unsigned short *)ip)) {
-			if (likely(m_pos[2] == ip[2]))
-					goto match;
-		}
-
+		const unsigned char *m_pos;
+		size_t t, m_len, m_off;
+		u32 dv;
 literal:
-		dict[dindex] = ip;
-		++ip;
+		ip += 1 + ((ip - ii) >> 5);
+next:
 		if (unlikely(ip >= ip_end))
 			break;
-		continue;
+		dv = get_unaligned_le32(ip);
+		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;
 
-match:
-		dict[dindex] = ip;
-		if (ip != ii) {
-			size_t t = ip - ii;
-
+		ii -= ti;
+		ti = 0;
+		t = ip - ii;
+		if (t != 0) {
 			if (t <= 3) {
 				op[-2] |= t;
-			} else if (t <= 18) {
+				COPY4(op, ii);
+				op += t;
+			} else if (t <= 16) {
 				*op++ = (t - 3);
+				COPY8(op, ii);
+				COPY8(op + 8, ii + 8);
+				op += t;
 			} else {
-				size_t tt = t - 18;
-
-				*op++ = 0;
-				while (tt > 255) {
-					tt -= 255;
+				if (t <= 18) {
+					*op++ = (t - 3);
+				} else {
+					size_t tt = t - 18;
 					*op++ = 0;
-				}
-				*op++ = tt;
-			}
-			do {
-				*op++ = *ii++;
-			} while (--t > 0);
-		}
-
-		ip += 3;
-		if (m_pos[3] != *ip++ || m_pos[4] != *ip++
-				|| m_pos[5] != *ip++ || m_pos[6] != *ip++
-				|| m_pos[7] != *ip++ || m_pos[8] != *ip++) {
-			--ip;
-			m_len = ip - ii;
-
-			if (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;
-				*op++ = (M3_MARKER | (m_len - 2));
-				goto m3_m4_offset;
-			} else {
-				m_off -= 0x4000;
-
-				*op++ = (M4_MARKER | ((m_off & 0x4000) >> 11)
-						| (m_len - 2));
-				goto m3_m4_offset;
-			}
-		} else {
-			end = in_end;
-			m = m_pos + M2_MAX_LEN + 1;
-
-			while (ip < end && *m == *ip) {
-				m++;
-				ip++;
-			}
-			m_len = ip - ii;
-
-			if (m_off <= M3_MAX_OFFSET) {
-				m_off -= 1;
-				if (m_len <= 33) {
-					*op++ = (M3_MARKER | (m_len - 2));
-				} else {
-					m_len -= 33;
-					*op++ = M3_MARKER | 0;
-					goto m3_m4_len;
-				}
-			} else {
-				m_off -= 0x4000;
-				if (m_len <= M4_MAX_LEN) {
-					*op++ = (M4_MARKER
-						| ((m_off & 0x4000) >> 11)
-						| (m_len - 2));
-				} else {
-					m_len -= M4_MAX_LEN;
-					*op++ = (M4_MARKER
-						| ((m_off & 0x4000) >> 11));
-m3_m4_len:
-					while (m_len > 255) {
-						m_len -= 255;
+					while (unlikely(tt > 255)) {
+						tt -= 255;
 						*op++ = 0;
 					}
-
-					*op++ = (m_len);
+					*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);
 			}
-m3_m4_offset:
-			*op++ = ((m_off & 63) << 2);
-			*op++ = (m_off >> 6);
 		}
 
-		ii = ip;
-		if (unlikely(ip >= ip_end))
-			break;
-	}
+		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;
+		ii = ip;
+		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 {
+				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);
+		}
+		goto next;
+	}
 	*out_len = op - out;
-	return in_end - ii;
+	return in_end - (ii - ti);
 }
 
-int lzo1x_1_compress(const unsigned char *in, size_t in_len, unsigned char *out,
-			size_t *out_len, void *wrkmem)
+int lzo1x_1_compress(const unsigned char *in, size_t in_len,
+		     unsigned char *out, size_t *out_len,
+		     void *wrkmem)
 {
-	const unsigned char *ii;
+	const unsigned char *ip = in;
 	unsigned char *op = out;
-	size_t t;
+	size_t l = in_len;
+	size_t t = 0;
 
-	if (unlikely(in_len <= M2_MAX_LEN + 5)) {
-		t = in_len;
-	} else {
-		t = _lzo1x_1_do_compress(in, in_len, op, out_len, wrkmem);
+	while (l > 20) {
+		size_t ll = l <= (M4_MAX_OFFSET + 1) ? 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);
+		ip += ll;
 		op += *out_len;
+		l  -= ll;
 	}
+	t += l;
 
 	if (t > 0) {
-		ii = in + in_len - t;
+		const unsigned char *ii = in + in_len - t;
 
 		if (op == out && t <= 238) {
 			*op++ = (17 + t);
···
 			*op++ = (t - 3);
 		} else {
 			size_t tt = t - 18;
-
 			*op++ = 0;
 			while (tt > 255) {
 				tt -= 255;
 				*op++ = 0;
 			}
-
 			*op++ = tt;
 		}
-		do {
+		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);
 	}
···
 
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("LZO1X-1 Compressor");
-

lib/lzo/lzo1x_decompress_safe.c

···
 /*
- *  LZO1X Decompressor from MiniLZO
+ *  LZO1X Decompressor from LZO
  *
- *  Copyright (C) 1996-2005 Markus F.X.J. Oberhumer <[e-mail]>
+ *  Copyright (C) 1996-2012 Markus F.X.J. Oberhumer <[e-mail]>
  *
  *  The full LZO package can be found at:
  *  http://www.oberhumer.com/opensource/lzo/
  *
- *  Changed for kernel use by:
+ *  Changed for Linux kernel use by:
  *  Nitin Gupta <[e-mail]>
  *  Richard Purdie <[e-mail]>
  */
···
 #include <linux/module.h>
 #include <linux/kernel.h>
 #endif
-
 #include <asm/unaligned.h>
 #include <linux/lzo.h>
 #include "lzodefs.h"
 
-#define HAVE_IP(x, ip_end, ip) ((size_t)(ip_end - ip) < (x))
-#define HAVE_OP(x, op_end, op) ((size_t)(op_end - op) < (x))
-#define HAVE_LB(m_pos, out, op) (m_pos < out || m_pos >= op)
-
-#define COPY4(dst, src)	\
-		put_unaligned(get_unaligned((const u32 *)(src)), (u32 *)(dst))
+#define HAVE_IP(x)      ((size_t)(ip_end - ip) >= (size_t)(x))
+#define HAVE_OP(x)      ((size_t)(op_end - op) >= (size_t)(x))
+#define NEED_IP(x)      if (!HAVE_IP(x)) goto input_overrun
+#define NEED_OP(x)      if (!HAVE_OP(x)) goto output_overrun
+#define TEST_LB(m_pos)  if ((m_pos) < out) goto lookbehind_overrun
 
 int lzo1x_decompress_safe(const unsigned char *in, size_t in_len,
-			unsigned char *out, size_t *out_len)
+			  unsigned char *out, size_t *out_len)
 {
+	unsigned char *op;
+	const unsigned char *ip;
+	size_t t, next;
+	size_t state = 0;
+	const unsigned char *m_pos;
 	const unsigned char * const ip_end = in + in_len;
 	unsigned char * const op_end = out + *out_len;
-	const unsigned char *ip = in, *m_pos;
-	unsigned char *op = out;
-	size_t t;
 
-	*out_len = 0;
+	op = out;
+	ip = in;
 
+	if (unlikely(in_len < 3))
+		goto input_overrun;
 	if (*ip > 17) {
 		t = *ip++ - 17;
-		if (t < 4)
+		if (t < 4) {
+			next = t;
 			goto match_next;
-		if (HAVE_OP(t, op_end, op))
-			goto output_overrun;
-		if (HAVE_IP(t + 1, ip_end, ip))
-			goto input_overrun;
-		do {
-			*op++ = *ip++;
-		} while (--t > 0);
-		goto first_literal_run;
+		}
+		goto copy_literal_run;
 	}
 
-	while ((ip < ip_end)) {
+	for (;;) {
 		t = *ip++;
-		if (t >= 16)
-			goto match;
-		if (t == 0) {
-			if (HAVE_IP(1, ip_end, ip))
-				goto input_overrun;
-			while (*ip == 0) {
-				t += 255;
-				ip++;
-				if (HAVE_IP(1, ip_end, ip))
-					goto input_overrun;
-			}
-			t += 15 + *ip++;
-		}
-		if (HAVE_OP(t + 3, op_end, op))
-			goto output_overrun;
-		if (HAVE_IP(t + 4, ip_end, ip))
-			goto input_overrun;
-
-		COPY4(op, ip);
-		op += 4;
-		ip += 4;
-		if (--t > 0) {
-			if (t >= 4) {
-				do {
-					COPY4(op, ip);
-					op += 4;
-					ip += 4;
-					t -= 4;
-				} while (t >= 4);
-				if (t > 0) {
+		if (t < 16) {
+			if (likely(state == 0)) {
+				if (unlikely(t == 0)) {
+					while (unlikely(*ip == 0)) {
+						t += 255;
+						ip++;
+						NEED_IP(1);
+					}
+					t += 15 + *ip++;
+				}
+				t += 3;
+copy_literal_run:
+#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
+				if (likely(HAVE_IP(t + 15) && HAVE_OP(t + 15))) {
+					const unsigned char *ie = ip + t;
+					unsigned char *oe = op + t;
+					do {
+						COPY8(op, ip);
+						op += 8;
+						ip += 8;
+						COPY8(op, ip);
+						op += 8;
+						ip += 8;
+					} while (ip < ie);
+					ip = ie;
+					op = oe;
+				} else
+#endif
+				{
+					NEED_OP(t);
+					NEED_IP(t + 3);
 					do {
 						*op++ = *ip++;
 					} while (--t > 0);
 				}
-			} else {
-				do {
-					*op++ = *ip++;
-				} while (--t > 0);
-			}
-		}
-
-first_literal_run:
-		t = *ip++;
-		if (t >= 16)
-			goto match;
-		m_pos = op - (1 + M2_MAX_OFFSET);
-		m_pos -= t >> 2;
-		m_pos -= *ip++ << 2;
-
-		if (HAVE_LB(m_pos, out, op))
-			goto lookbehind_overrun;
-
-		if (HAVE_OP(3, op_end, op))
-			goto output_overrun;
-		*op++ = *m_pos++;
-		*op++ = *m_pos++;
-		*op++ = *m_pos;
-
-		goto match_done;
-
-		do {
-match:
-			if (t >= 64) {
-				m_pos = op - 1;
-				m_pos -= (t >> 2) & 7;
-				m_pos -= *ip++ << 3;
-				t = (t >> 5) - 1;
-				if (HAVE_LB(m_pos, out, op))
-					goto lookbehind_overrun;
-				if (HAVE_OP(t + 3 - 1, op_end, op))
-					goto output_overrun;
-				goto copy_match;
-			} else if (t >= 32) {
-				t &= 31;
-				if (t == 0) {
-					if (HAVE_IP(1, ip_end, ip))
-						goto input_overrun;
-					while (*ip == 0) {
-						t += 255;
-						ip++;
-						if (HAVE_IP(1, ip_end, ip))
-							goto input_overrun;
-					}
-					t += 31 + *ip++;
-				}
-				m_pos = op - 1;
-				m_pos -= get_unaligned_le16(ip) >> 2;
-				ip += 2;
-			} else if (t >= 16) {
-				m_pos = op;
-				m_pos -= (t & 8) << 11;
-
-				t &= 7;
-				if (t == 0) {
-					if (HAVE_IP(1, ip_end, ip))
-						goto input_overrun;
-					while (*ip == 0) {
-						t += 255;
-						ip++;
-						if (HAVE_IP(1, ip_end, ip))
-							goto input_overrun;
-					}
-					t += 7 + *ip++;
-				}
-				m_pos -= get_unaligned_le16(ip) >> 2;
-				ip += 2;
-				if (m_pos == op)
-					goto eof_found;
-				m_pos -= 0x4000;
-			} else {
+				state = 4;
+				continue;
+			} else if (state != 4) {
+				next = t & 3;
 				m_pos = op - 1;
 				m_pos -= t >> 2;
 				m_pos -= *ip++ << 2;
-
-				if (HAVE_LB(m_pos, out, op))
-					goto lookbehind_overrun;
-				if (HAVE_OP(2, op_end, op))
-					goto output_overrun;
-
-				*op++ = *m_pos++;
-				*op++ = *m_pos;
-				goto match_done;
-			}
-
-			if (HAVE_LB(m_pos, out, op))
-				goto lookbehind_overrun;
-			if (HAVE_OP(t + 3 - 1, op_end, op))
-				goto output_overrun;
-
-			if (t >= 2 * 4 - (3 - 1) && (op - m_pos) >= 4) {
-				COPY4(op, m_pos);
-				op += 4;
-				m_pos += 4;
-				t -= 4 - (3 - 1);
-				do {
-					COPY4(op, m_pos);
-					op += 4;
-					m_pos += 4;
-					t -= 4;
-				} while (t >= 4);
-				if (t > 0)
-					do {
-						*op++ = *m_pos++;
-					} while (--t > 0);
+				TEST_LB(m_pos);
+				NEED_OP(2);
+				op[0] = m_pos[0];
+				op[1] = m_pos[1];
+				op += 2;
+				goto match_next;
 			} else {
-copy_match:
-				*op++ = *m_pos++;
-				*op++ = *m_pos++;
+				next = t & 3;
+				m_pos = op - (1 + M2_MAX_OFFSET);
+				m_pos -= t >> 2;
+				m_pos -= *ip++ << 2;
+				t = 3;
+			}
+		} else if (t >= 64) {
+			next = t & 3;
+			m_pos = op - 1;
+			m_pos -= (t >> 2) & 7;
+			m_pos -= *ip++ << 3;
+			t = (t >> 5) - 1 + (3 - 1);
+		} else if (t >= 32) {
+			t = (t & 31) + (3 - 1);
+			if (unlikely(t == 2)) {
+				while (unlikely(*ip == 0)) {
+					t += 255;
+					ip++;
+					NEED_IP(1);
+				}
+				t += 31 + *ip++;
+				NEED_IP(2);
+			}
+			m_pos = op - 1;
+			next = get_unaligned_le16(ip);
+			ip += 2;
+			m_pos -= next >> 2;
+			next &= 3;
+		} else {
+			m_pos = op;
+			m_pos -= (t & 8) << 11;
+			t = (t & 7) + (3 - 1);
+			if (unlikely(t == 2)) {
+				while (unlikely(*ip == 0)) {
+					t += 255;
+					ip++;
+					NEED_IP(1);
+				}
+				t += 7 + *ip++;
+				NEED_IP(2);
+			}
+			next = get_unaligned_le16(ip);
+			ip += 2;
+			m_pos -= next >> 2;
+			next &= 3;
+			if (m_pos == op)
+				goto eof_found;
+			m_pos -= 0x4000;
+		}
+		TEST_LB(m_pos);
+#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
+		if (op - m_pos >= 8) {
+			unsigned char *oe = op + t;
+			if (likely(HAVE_OP(t + 15))) {
+				do {
+					COPY8(op, m_pos);
+					op += 8;
+					m_pos += 8;
+					COPY8(op, m_pos);
+					op += 8;
+					m_pos += 8;
+				} while (op < oe);
+				op = oe;
+				if (HAVE_IP(6)) {
+					state = next;
+					COPY4(op, ip);
+					op += next;
+					ip += next;
+					continue;
+				}
+			} else {
+				NEED_OP(t);
 				do {
 					*op++ = *m_pos++;
-				} while (--t > 0);
+				} while (op < oe);
 			}
-match_done:
-			t = ip[-2] & 3;
-			if (t == 0)
-				break;
+		} else
+#endif
+		{
+			unsigned char *oe = op + t;
+			NEED_OP(t);
+			op[0] = m_pos[0];
+			op[1] = m_pos[1];
+			op += 2;
+			m_pos += 2;
+			do {
+				*op++ = *m_pos++;
+			} while (op < oe);
+		}
 match_next:
-			if (HAVE_OP(t, op_end, op))
-				goto output_overrun;
-			if (HAVE_IP(t + 1, ip_end, ip))
-				goto input_overrun;
-
-			*op++ = *ip++;
-			if (t > 1) {
+		state = next;
+		t = next;
+#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
+		if (likely(HAVE_IP(6) && HAVE_OP(4))) {
+			COPY4(op, ip);
+			op += t;
+			ip += t;
+		} else
+#endif
+		{
+			NEED_IP(t + 3);
+			NEED_OP(t);
+			while (t > 0) {
 				*op++ = *ip++;
-				if (t > 2)
-					*op++ = *ip++;
+				t--;
 			}
-
-			t = *ip++;
-		} while (ip < ip_end);
+		}
 	}
-
-	*out_len = op - out;
-	return LZO_E_EOF_NOT_FOUND;
 
 eof_found:
 	*out_len = op - out;
-	return (ip == ip_end ? LZO_E_OK :
-		(ip < ip_end ? LZO_E_INPUT_NOT_CONSUMED : LZO_E_INPUT_OVERRUN));
+	return (t != 3       ? LZO_E_ERROR :
+		ip == ip_end ? LZO_E_OK :
+		ip <  ip_end ? LZO_E_INPUT_NOT_CONSUMED : LZO_E_INPUT_OVERRUN);
+
 input_overrun:
 	*out_len = op - out;
 	return LZO_E_INPUT_OVERRUN;

lib/lzo/lzodefs.h

···
 /*
  *  lzodefs.h -- architecture, OS and compiler specific defines
  *
- *  Copyright (C) 1996-2005 Markus F.X.J. Oberhumer <[e-mail]>
+ *  Copyright (C) 1996-2012 Markus F.X.J. Oberhumer <[e-mail]>
  *
  *  The full LZO package can be found at:
  *  http://www.oberhumer.com/opensource/lzo/
  *
- *  Changed for kernel use by:
+ *  Changed for Linux kernel use by:
  *  Nitin Gupta <[e-mail]>
  *  Richard Purdie <[e-mail]>
  */
 
-#define LZO_VERSION		0x2020
-#define LZO_VERSION_STRING	"2.02"
-#define LZO_VERSION_DATE	"Oct 17 2005"
+
+#define COPY4(dst, src)	\
+		put_unaligned(get_unaligned((const u32 *)(src)), (u32 *)(dst))
+#if defined(__x86_64__)
+#define COPY8(dst, src)	\
+		put_unaligned(get_unaligned((const u64 *)(src)), (u64 *)(dst))
+#else
+#define COPY8(dst, src)	\
+		COPY4(dst, src); COPY4((dst) + 4, (src) + 4)
+#endif
+
+#if defined(__BIG_ENDIAN) && defined(__LITTLE_ENDIAN)
+#error "conflicting endian definitions"
+#elif defined(__x86_64__)
+#define LZO_USE_CTZ64	1
+#define LZO_USE_CTZ32	1
+#elif defined(__i386__) || defined(__powerpc__)
+#define LZO_USE_CTZ32	1
+#elif defined(__arm__) && (__LINUX_ARM_ARCH__ >= 5)
+#define LZO_USE_CTZ32	1
+#endif
 
 #define M1_MAX_OFFSET	0x0400
 #define M2_MAX_OFFSET	0x0800
···
 #define M3_MARKER	32
 #define M4_MARKER	16
 
-#define D_BITS		14
-#define D_MASK		((1u << D_BITS) - 1)
+#define lzo_dict_t      unsigned short
+#define D_BITS		13
+#define D_SIZE		(1u << D_BITS)
+#define D_MASK		(D_SIZE - 1)
 #define D_HIGH		((D_MASK >> 1) + 1)
-
-#define DX2(p, s1, s2)	(((((size_t)((p)[2]) << (s2)) ^ (p)[1]) \
-							<< (s1)) ^ (p)[0])
-#define DX3(p, s1, s2, s3)	((DX2((p)+1, s2, s3) << (s1)) ^ (p)[0])