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Diffstat (limited to 'contrib/syslinux-4.02/lzo/src/lzo1x_c.ch')
| -rw-r--r-- | contrib/syslinux-4.02/lzo/src/lzo1x_c.ch | 351 |
1 files changed, 351 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/lzo/src/lzo1x_c.ch b/contrib/syslinux-4.02/lzo/src/lzo1x_c.ch new file mode 100644 index 0000000..08d615e --- /dev/null +++ b/contrib/syslinux-4.02/lzo/src/lzo1x_c.ch @@ -0,0 +1,351 @@ +/* lzo1x_c.ch -- implementation of the LZO1[XY]-1 compression algorithm + + This file is part of the LZO real-time data compression library. + + Copyright (C) 2008 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 2007 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 2006 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 2005 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 2004 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 2003 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 2002 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 2001 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 2000 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 1999 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 1998 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 1997 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 1996 Markus Franz Xaver Johannes Oberhumer + All Rights Reserved. + + The LZO library is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License as + published by the Free Software Foundation; either version 2 of + the License, or (at your option) any later version. + + The LZO library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with the LZO library; see the file COPYING. + If not, write to the Free Software Foundation, Inc., + 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + + Markus F.X.J. Oberhumer + <markus@oberhumer.com> + http://www.oberhumer.com/opensource/lzo/ + */ + + + +/*********************************************************************** +// compress a block of data. +************************************************************************/ + +static __lzo_noinline lzo_uint +do_compress ( const lzo_bytep in , lzo_uint in_len, + lzo_bytep out, lzo_uintp out_len, + lzo_voidp wrkmem ) +{ + register const lzo_bytep ip; + lzo_bytep op; + const lzo_bytep const in_end = in + in_len; + const lzo_bytep const ip_end = in + in_len - M2_MAX_LEN - 5; + const lzo_bytep ii; + lzo_dict_p const dict = (lzo_dict_p) wrkmem; + + op = out; + ip = in; + ii = ip; + + ip += 4; + for (;;) + { + register const lzo_bytep m_pos; + lzo_uint m_off; + lzo_uint m_len; + lzo_uint dindex; + + DINDEX1(dindex,ip); + GINDEX(m_pos,m_off,dict,dindex,in); + if (LZO_CHECK_MPOS_NON_DET(m_pos,m_off,in,ip,M4_MAX_OFFSET)) + goto literal; +#if 1 + if (m_off <= M2_MAX_OFFSET || m_pos[3] == ip[3]) + goto try_match; + DINDEX2(dindex,ip); +#endif + GINDEX(m_pos,m_off,dict,dindex,in); + if (LZO_CHECK_MPOS_NON_DET(m_pos,m_off,in,ip,M4_MAX_OFFSET)) + goto literal; + if (m_off <= M2_MAX_OFFSET || m_pos[3] == ip[3]) + goto try_match; + goto literal; + + +try_match: +#if 1 && defined(LZO_UNALIGNED_OK_2) + if (* (const lzo_ushortp) m_pos != * (const lzo_ushortp) ip) +#else + if (m_pos[0] != ip[0] || m_pos[1] != ip[1]) +#endif + { + } + else + { + if __lzo_likely(m_pos[2] == ip[2]) + { +#if 0 + if (m_off <= M2_MAX_OFFSET) + goto match; + if (lit <= 3) + goto match; + if (lit == 3) /* better compression, but slower */ + { + assert(op - 2 > out); op[-2] |= LZO_BYTE(3); + *op++ = *ii++; *op++ = *ii++; *op++ = *ii++; + goto code_match; + } + if (m_pos[3] == ip[3]) +#endif + goto match; + } + else + { + /* still need a better way for finding M1 matches */ +#if 0 + /* a M1 match */ +#if 0 + if (m_off <= M1_MAX_OFFSET && lit > 0 && lit <= 3) +#else + if (m_off <= M1_MAX_OFFSET && lit == 3) +#endif + { + register lzo_uint t; + + t = lit; + assert(op - 2 > out); op[-2] |= LZO_BYTE(t); + do *op++ = *ii++; while (--t > 0); + assert(ii == ip); + m_off -= 1; + *op++ = LZO_BYTE(M1_MARKER | ((m_off & 3) << 2)); + *op++ = LZO_BYTE(m_off >> 2); + ip += 2; + goto match_done; + } +#endif + } + } + + + /* a literal */ +literal: + UPDATE_I(dict,0,dindex,ip,in); + ++ip; + if __lzo_unlikely(ip >= ip_end) + break; + continue; + + + /* a match */ +match: + UPDATE_I(dict,0,dindex,ip,in); + /* store current literal run */ + if (pd(ip,ii) > 0) + { + register lzo_uint t = pd(ip,ii); + + if (t <= 3) + { + assert(op - 2 > out); + op[-2] |= LZO_BYTE(t); + } + else if (t <= 18) + *op++ = LZO_BYTE(t - 3); + else + { + register lzo_uint tt = t - 18; + + *op++ = 0; + while (tt > 255) + { + tt -= 255; + *op++ = 0; + } + assert(tt > 0); + *op++ = LZO_BYTE(tt); + } + do *op++ = *ii++; while (--t > 0); + } + + /* code the match */ + assert(ii == ip); + 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++ +#ifdef LZO1Y + || m_pos[ 9] != *ip++ || m_pos[10] != *ip++ || m_pos[11] != *ip++ + || m_pos[12] != *ip++ || m_pos[13] != *ip++ || m_pos[14] != *ip++ +#endif + ) + { + --ip; + m_len = pd(ip, ii); + assert(m_len >= 3); assert(m_len <= M2_MAX_LEN); + + if (m_off <= M2_MAX_OFFSET) + { + m_off -= 1; +#if defined(LZO1X) + *op++ = LZO_BYTE(((m_len - 1) << 5) | ((m_off & 7) << 2)); + *op++ = LZO_BYTE(m_off >> 3); +#elif defined(LZO1Y) + *op++ = LZO_BYTE(((m_len + 1) << 4) | ((m_off & 3) << 2)); + *op++ = LZO_BYTE(m_off >> 2); +#endif + } + else if (m_off <= M3_MAX_OFFSET) + { + m_off -= 1; + *op++ = LZO_BYTE(M3_MARKER | (m_len - 2)); + goto m3_m4_offset; + } + else +#if defined(LZO1X) + { + m_off -= 0x4000; + assert(m_off > 0); assert(m_off <= 0x7fff); + *op++ = LZO_BYTE(M4_MARKER | + ((m_off & 0x4000) >> 11) | (m_len - 2)); + goto m3_m4_offset; + } +#elif defined(LZO1Y) + goto m4_match; +#endif + } + else + { + { + const lzo_bytep end = in_end; + const lzo_bytep m = m_pos + M2_MAX_LEN + 1; + while (ip < end && *m == *ip) + m++, ip++; + m_len = pd(ip, ii); + } + assert(m_len > M2_MAX_LEN); + + if (m_off <= M3_MAX_OFFSET) + { + m_off -= 1; + if (m_len <= 33) + *op++ = LZO_BYTE(M3_MARKER | (m_len - 2)); + else + { + m_len -= 33; + *op++ = M3_MARKER | 0; + goto m3_m4_len; + } + } + else + { +#if defined(LZO1Y) +m4_match: +#endif + m_off -= 0x4000; + assert(m_off > 0); assert(m_off <= 0x7fff); + if (m_len <= M4_MAX_LEN) + *op++ = LZO_BYTE(M4_MARKER | + ((m_off & 0x4000) >> 11) | (m_len - 2)); + else + { + m_len -= M4_MAX_LEN; + *op++ = LZO_BYTE(M4_MARKER | ((m_off & 0x4000) >> 11)); +m3_m4_len: + while (m_len > 255) + { + m_len -= 255; + *op++ = 0; + } + assert(m_len > 0); + *op++ = LZO_BYTE(m_len); + } + } + +m3_m4_offset: + *op++ = LZO_BYTE((m_off & 63) << 2); + *op++ = LZO_BYTE(m_off >> 6); + } + +#if 0 +match_done: +#endif + ii = ip; + if __lzo_unlikely(ip >= ip_end) + break; + } + + *out_len = pd(op, out); + return pd(in_end,ii); +} + + +/*********************************************************************** +// public entry point +************************************************************************/ + +LZO_PUBLIC(int) +DO_COMPRESS ( const lzo_bytep in , lzo_uint in_len, + lzo_bytep out, lzo_uintp out_len, + lzo_voidp wrkmem ) +{ + lzo_bytep op = out; + lzo_uint t; + + if __lzo_unlikely(in_len <= M2_MAX_LEN + 5) + t = in_len; + else + { + t = do_compress(in,in_len,op,out_len,wrkmem); + op += *out_len; + } + + if (t > 0) + { + const lzo_bytep ii = in + in_len - t; + + if (op == out && t <= 238) + *op++ = LZO_BYTE(17 + t); + else if (t <= 3) + op[-2] |= LZO_BYTE(t); + else if (t <= 18) + *op++ = LZO_BYTE(t - 3); + else + { + lzo_uint tt = t - 18; + + *op++ = 0; + while (tt > 255) + { + tt -= 255; + *op++ = 0; + } + assert(tt > 0); + *op++ = LZO_BYTE(tt); + } + do *op++ = *ii++; while (--t > 0); + } + + *op++ = M4_MARKER | 1; + *op++ = 0; + *op++ = 0; + + *out_len = pd(op, out); + return LZO_E_OK; +} + + +/* +vi:ts=4:et +*/ + |