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, 166 insertions, 184 deletions

diff --git a/lib/lzo/lzo1x_decompress_safe.c b/lib/lzo/lzo1x_decompress_safe.c
index f2fd0985022..569985d522d 100644
--- a/lib/lzo/lzo1x_decompress_safe.c
+++ b/lib/lzo/lzo1x_decompress_safe.c
@@ -1,12 +1,12 @@
 /*
- *  LZO1X Decompressor from MiniLZO
+ *  LZO1X Decompressor 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>
  */
@@ -15,225 +15,207 @@
 #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;
-	}
-
-	while ((ip < ip_end)) {
-		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) {
-					do {
-						*op++ = *ip++;
-					} while (--t > 0);
-				}
-			} else {
-				do {
-					*op++ = *ip++;
-				} while (--t > 0);
-			}
 		}
+		goto copy_literal_run;
+	}
 
-first_literal_run:
+	for (;;) {
 		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) {
+		if (t < 16) {
+			if (likely(state == 0)) {
+				if (unlikely(t == 0)) {
+					while (unlikely(*ip == 0)) {
 						t += 255;
 						ip++;
-						if (HAVE_IP(1, ip_end, ip))
-							goto input_overrun;
+						NEED_IP(1);
 					}
-					t += 31 + *ip++;
+					t += 15 + *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++;
+				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);
 				}
-				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;
+				TEST_LB(m_pos);
+				NEED_OP(2);
+				op[0] = m_pos[0];
+				op[1] = m_pos[1];
+				op += 2;
+				goto match_next;
+			} else {
+				next = t & 3;
+				m_pos = op - (1 + M2_MAX_OFFSET);
+				m_pos -= t >> 2;
+				m_pos -= *ip++ << 2;
+				t = 3;
 			}
-
-			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);
+		} 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 {
-					COPY4(op, m_pos);
-					op += 4;
-					m_pos += 4;
-					t -= 4;
-				} while (t >= 4);
-				if (t > 0)
-					do {
-						*op++ = *m_pos++;
-					} while (--t > 0);
+					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 {
-copy_match:
-				*op++ = *m_pos++;
-				*op++ = *m_pos++;
+				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;