ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/liblzf/lzf_c.c
(Generate patch)

Comparing liblzf/lzf_c.c (file contents):
Revision 1.7 by root, Tue Aug 3 15:37:48 2004 UTC vs.
Revision 1.18 by root, Tue Nov 13 08:17:38 2007 UTC

1/* 1/*
2 * Copyright (c) 2000-2003 Marc Alexander Lehmann <pcg@goof.com> 2 * Copyright (c) 2000-2007 Marc Alexander Lehmann <schmorp@schmorp.de>
3 * 3 *
4 * Redistribution and use in source and binary forms, with or without modifica- 4 * Redistribution and use in source and binary forms, with or without modifica-
5 * tion, are permitted provided that the following conditions are met: 5 * tion, are permitted provided that the following conditions are met:
6 * 6 *
7 * 1. Redistributions of source code must retain the above copyright notice, 7 * 1. Redistributions of source code must retain the above copyright notice,
8 * this list of conditions and the following disclaimer. 8 * this list of conditions and the following disclaimer.
9 * 9 *
10 * 2. Redistributions in binary form must reproduce the above copyright 10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the 11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution. 12 * documentation and/or other materials provided with the distribution.
13 *
14 * 3. The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 * 13 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
18 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER- 15 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
19 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 16 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
20 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE- 17 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
24 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH- 21 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
25 * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 22 * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
26 * OF THE POSSIBILITY OF SUCH DAMAGE. 23 * OF THE POSSIBILITY OF SUCH DAMAGE.
27 * 24 *
28 * Alternatively, the contents of this file may be used under the terms of 25 * Alternatively, the contents of this file may be used under the terms of
29 * the GNU General Public License version 2 (the "GPL"), in which case the 26 * the GNU General Public License ("GPL") version 2 or any later version,
30 * provisions of the GPL are applicable instead of the above. If you wish to 27 * in which case the provisions of the GPL are applicable instead of
31 * allow the use of your version of this file only under the terms of the 28 * the above. If you wish to allow the use of your version of this file
32 * GPL and not to allow others to use your version of this file under the 29 * only under the terms of the GPL and not to allow others to use your
33 * BSD license, indicate your decision by deleting the provisions above and 30 * version of this file under the BSD license, indicate your decision
34 * replace them with the notice and other provisions required by the GPL. If 31 * by deleting the provisions above and replace them with the notice
35 * you do not delete the provisions above, a recipient may use your version 32 * and other provisions required by the GPL. If you do not delete the
33 * provisions above, a recipient may use your version of this file under
36 * of this file under either the BSD or the GPL. 34 * either the BSD or the GPL.
37 */ 35 */
38 36
39#include "lzfP.h" 37#include "lzfP.h"
40 38
41#define HSIZE (1 << (HLOG)) 39#define HSIZE (1 << (HLOG))
44 * don't play with this unless you benchmark! 42 * don't play with this unless you benchmark!
45 * decompression is not dependent on the hash function 43 * decompression is not dependent on the hash function
46 * the hashing function might seem strange, just believe me 44 * the hashing function might seem strange, just believe me
47 * it works ;) 45 * it works ;)
48 */ 46 */
47#ifndef FRST
49#define FRST(p) (((p[0]) << 8) + p[1]) 48# define FRST(p) (((p[0]) << 8) | p[1])
50#define NEXT(v,p) (((v) << 8) + p[2]) 49# define NEXT(v,p) (((v) << 8) | p[2])
51#define IDX(h) ((((h ^ (h << 5)) >> (3*8 - HLOG)) - h*5) & (HSIZE - 1)) 50# define IDX(h) ((((h ^ (h << 5)) >> (3*8 - HLOG)) - h*5) & (HSIZE - 1))
51/*# define IDX(h) ((ip[0] * 121 ^ ip[1] * 33 ^ ip[2] * 1) & (HSIZE-1))*/
52#endif
52/* 53/*
53 * IDX works because it is very similar to a multiplicative hash, e.g. 54 * IDX works because it is very similar to a multiplicative hash, e.g.
54 * ((h * 57321 >> (3*8 - HLOG)) & (HSIZE - 1)) 55 * ((h * 57321 >> (3*8 - HLOG)) & (HSIZE - 1))
55 * the latter is also quite fast on newer CPUs, and sligthly better 56 * the latter is also quite fast on newer CPUs, and compresses similarly.
56 * 57 *
57 * the next one is also quite good, albeit slow ;) 58 * the next one is also quite good, albeit slow ;)
58 * (int)(cos(h & 0xffffff) * 1e6) 59 * (int)(cos(h & 0xffffff) * 1e6)
59 */ 60 */
60 61
65# define IDX(h) ((h) & (HSIZE - 1)) 66# define IDX(h) ((h) & (HSIZE - 1))
66#endif 67#endif
67 68
68#define MAX_LIT (1 << 5) 69#define MAX_LIT (1 << 5)
69#define MAX_OFF (1 << 13) 70#define MAX_OFF (1 << 13)
70#define MAX_REF ((1 << 8) + (1 << 3)) 71#define MAX_REF ((1 << 8) + (1 << 3))
72
73#if (__i386 || __amd64) && __GNUC__ >= 3
74# define lzf_movsb(dst, src, len) \
75 asm ("rep movsb" \
76 : "=D" (dst), "=S" (src), "=c" (len) \
77 : "0" (dst), "1" (src), "2" (len));
78#endif
79
80#if __GNUC__ >= 3
81# define expect(expr,value) __builtin_expect ((expr),(value))
82# define inline inline
83#else
84# define expect(expr,value) (expr)
85# define inline static
86#endif
87
88#define expect_false(expr) expect ((expr) != 0, 0)
89#define expect_true(expr) expect ((expr) != 0, 1)
71 90
72/* 91/*
73 * compressed format 92 * compressed format
74 * 93 *
75 * 000LLLLL <L+1> ; literal 94 * 000LLLLL <L+1> ; literal
76 * LLLOOOOO oooooooo ; backref L 95 * LLLooooo oooooooo ; backref L
77 * 111OOOOO LLLLLLLL oooooooo ; backref L+7 96 * 111ooooo LLLLLLLL oooooooo ; backref L+7
78 * 97 *
79 */ 98 */
80 99
81unsigned int 100unsigned int
82lzf_compress (const void *const in_data, unsigned int in_len, 101lzf_compress (const void *const in_data, unsigned int in_len,
83 void *out_data, unsigned int out_len 102 void *out_data, unsigned int out_len
84#if LZF_STATE_ARG 103#if LZF_STATE_ARG
85 , LZF_STATE *htab 104 , LZF_STATE htab
86#endif 105#endif
87 ) 106 )
88{ 107{
89#if !LZF_STATE_ARG 108#if !LZF_STATE_ARG
90 LZF_STATE htab; 109 LZF_STATE htab;
99 unsigned int hval = FRST (ip); 118 unsigned int hval = FRST (ip);
100 unsigned long off; 119 unsigned long off;
101 int lit = 0; 120 int lit = 0;
102 121
103#if INIT_HTAB 122#if INIT_HTAB
104# if USE_MEMCPY
105 memset (htab, 0, sizeof (htab)); 123 memset (htab, 0, sizeof (htab));
106# else 124# if 0
107 for (hslot = htab; hslot < htab + HSIZE; hslot++) 125 for (hslot = htab; hslot < htab + HSIZE; hslot++)
108 *hslot++ = ip; 126 *hslot++ = ip;
109# endif 127# endif
110#endif 128#endif
111 129
112 for (;;) 130 for (;;)
113 { 131 {
114 if (ip < in_end - 2) 132 if (expect_true (ip < in_end - 2))
115 { 133 {
116 hval = NEXT (hval, ip); 134 hval = NEXT (hval, ip);
117 hslot = htab + IDX (hval); 135 hslot = htab + IDX (hval);
118 ref = *hslot; *hslot = ip; 136 ref = *hslot; *hslot = ip;
119 137
137 /* match found at *ref++ */ 155 /* match found at *ref++ */
138 unsigned int len = 2; 156 unsigned int len = 2;
139 unsigned int maxlen = in_end - ip - len; 157 unsigned int maxlen = in_end - ip - len;
140 maxlen = maxlen > MAX_REF ? MAX_REF : maxlen; 158 maxlen = maxlen > MAX_REF ? MAX_REF : maxlen;
141 159
142 do
143 len++;
144 while (len < maxlen && ref[len] == ip[len]);
145
146 if (op + lit + 1 + 3 >= out_end) 160 if (expect_false (op + lit + 1 + 3 >= out_end))
147 return 0; 161 return 0;
148 162
149 if (lit) 163 if (lit)
150 { 164 {
151 *op++ = lit - 1; 165 *op++ = lit - 1;
153 do 167 do
154 *op++ = ip[lit]; 168 *op++ = ip[lit];
155 while (++lit); 169 while (++lit);
156 } 170 }
157 171
172 for (;;)
173 {
174 if (expect_true (ip < in_end - 2 - 8 && maxlen > 8))
175 {
176 len++; if (ref [len] != ip [len]) break;
177 len++; if (ref [len] != ip [len]) break;
178 len++; if (ref [len] != ip [len]) break;
179 len++; if (ref [len] != ip [len]) break;
180 len++; if (ref [len] != ip [len]) break;
181 len++; if (ref [len] != ip [len]) break;
182 len++; if (ref [len] != ip [len]) break;
183 len++; if (ref [len] != ip [len]) break;
184 }
185
186 do
187 len++;
188 while (len < maxlen && ref[len] == ip[len]);
189
190 break;
191 }
192
158 len -= 2; 193 len -= 2;
159 ip++; 194 ip++;
160 195
161 if (len < 7) 196 if (len < 7)
162 { 197 {
168 *op++ = len - 7; 203 *op++ = len - 7;
169 } 204 }
170 205
171 *op++ = off; 206 *op++ = off;
172 207
173#if ULTRA_FAST 208#if ULTRA_FAST || VERY_FAST
174 ip += len; 209 ip += len;
210#if VERY_FAST && !ULTRA_FAST
211 --ip;
212#endif
175 hval = FRST (ip); 213 hval = FRST (ip);
214
176 hval = NEXT (hval, ip); 215 hval = NEXT (hval, ip);
177 htab[IDX (hval)] = ip; 216 htab[IDX (hval)] = ip;
178 ip++; 217 ip++;
218
219#if VERY_FAST && !ULTRA_FAST
220 hval = NEXT (hval, ip);
221 htab[IDX (hval)] = ip;
222 ip++;
223#endif
179#else 224#else
180 do 225 do
181 { 226 {
182 hval = NEXT (hval, ip); 227 hval = NEXT (hval, ip);
183 htab[IDX (hval)] = ip; 228 htab[IDX (hval)] = ip;
186 while (len--); 231 while (len--);
187#endif 232#endif
188 continue; 233 continue;
189 } 234 }
190 } 235 }
191 else if (ip == in_end) 236 else if (expect_false (ip == in_end))
192 break; 237 break;
193 238
194 /* one more literal byte we must copy */ 239 /* one more literal byte we must copy */
195 lit++; 240 lit++;
196 ip++; 241 ip++;
197 242
198 if (lit == MAX_LIT) 243 if (expect_false (lit == MAX_LIT))
199 { 244 {
200 if (op + 1 + MAX_LIT >= out_end) 245 if (op + 1 + MAX_LIT >= out_end)
201 return 0; 246 return 0;
202 247
203 *op++ = MAX_LIT - 1; 248 *op++ = MAX_LIT - 1;
204#if USE_MEMCPY 249
205 memcpy (op, ip - MAX_LIT, MAX_LIT); 250#ifdef lzf_movsb
206 op += MAX_LIT; 251 ip -= lit;
207 lit = 0; 252 lzf_movsb (op, ip, lit);
208#else 253#else
209 lit = -lit; 254 lit = -lit;
210 do 255 do
211 *op++ = ip[lit]; 256 *op++ = ip[lit];
212 while (++lit); 257 while (++lit);
218 { 263 {
219 if (op + lit + 1 >= out_end) 264 if (op + lit + 1 >= out_end)
220 return 0; 265 return 0;
221 266
222 *op++ = lit - 1; 267 *op++ = lit - 1;
268#ifdef lzf_movsb
269 ip -= lit;
270 lzf_movsb (op, ip, lit);
271#else
223 lit = -lit; 272 lit = -lit;
224 do 273 do
225 *op++ = ip[lit]; 274 *op++ = ip[lit];
226 while (++lit); 275 while (++lit);
276#endif
227 } 277 }
228 278
229 return op - (u8 *) out_data; 279 return op - (u8 *) out_data;
230} 280}
281

Diff Legend

Removed lines
+ Added lines
< Changed lines
> Changed lines