mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-16 16:54:20 +08:00
8b975bd3f9
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>
280 lines
6.1 KiB
C
280 lines
6.1 KiB
C
/*
|
|
* 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 <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,
|
|
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 - 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;
|
|
size_t t, m_len, m_off;
|
|
u32 dv;
|
|
literal:
|
|
ip += 1 + ((ip - ii) >> 5);
|
|
next:
|
|
if (unlikely(ip >= ip_end))
|
|
break;
|
|
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;
|
|
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);
|
|
}
|
|
}
|
|
|
|
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 - ti);
|
|
}
|
|
|
|
int lzo1x_1_compress(const unsigned char *in, size_t in_len,
|
|
unsigned char *out, size_t *out_len,
|
|
void *wrkmem)
|
|
{
|
|
const unsigned char *ip = in;
|
|
unsigned char *op = out;
|
|
size_t l = in_len;
|
|
size_t t = 0;
|
|
|
|
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) {
|
|
const unsigned char *ii = in + in_len - t;
|
|
|
|
if (op == out && t <= 238) {
|
|
*op++ = (17 + t);
|
|
} else if (t <= 3) {
|
|
op[-2] |= 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;
|
|
}
|
|
EXPORT_SYMBOL_GPL(lzo1x_1_compress);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_DESCRIPTION("LZO1X-1 Compressor");
|