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 <markus@oberhumer.com>

1 files changed, 194 insertions, 141 deletions

diff --git a/lib/lzo/lzo1x_compress.c b/lib/lzo/lzo1x_compress.c
index a6040990a62e..236eb21167b5 100644
--- a/lib/lzo/lzo1x_compress.c
+++ b/lib/lzo/lzo1x_compress.c
@@ -1,194 +1,243 @@
 /*
- *  LZO1X Compressor from MiniLZO
+ *  LZO1X Compressor from LZO
  *
- *  Copyright (C) 1996-2005 Markus F.X.J. Oberhumer <markus@oberhumer.com>
+ *  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 kernel use by:
+ *  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/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;
-
-match:
-		dict[dindex] = ip;
-		if (ip != ii) {
-			size_t t = ip - ii;
+		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;
 
+		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;
+					while (unlikely(tt > 255)) {
+						tt -= 255;
+						*op++ = 0;
+					}
+					*op++ = tt;
 				}
-				*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);
 			}
-			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;
+		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:
 
-			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;
+		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));
-				goto m3_m4_offset;
-			} else {
-				m_off -= 0x4000;
-
-				*op++ = (M4_MARKER | ((m_off & 0x4000) >> 11)
-						| (m_len - 2));
-				goto m3_m4_offset;
+			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 {
-			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_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 & 0x4000) >> 11));
-m3_m4_len:
-					while (m_len > 255) {
-						m_len -= 255;
-						*op++ = 0;
-					}
-
-					*op++ = (m_len);
+			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);
 			}
-m3_m4_offset:
-			*op++ = ((m_off & 63) << 2);
+			*op++ = (m_off << 2);
 			*op++ = (m_off >> 6);
 		}
-
-		ii = ip;
-		if (unlikely(ip >= ip_end))
-			break;
+		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);
@@ -198,16 +247,21 @@ int lzo1x_1_compress(const unsigned char *in, size_t in_len, unsigned char *out,
 			*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);
 	}
@@ -223,4 +277,3 @@ EXPORT_SYMBOL_GPL(lzo1x_1_compress);
 
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("LZO1X-1 Compressor");
-