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Comparing liblzf/lzf_c.c (file contents):
Revision 1.12 by root, Tue Jun 19 21:25:01 2007 UTC vs.
Revision 1.21 by root, Tue Nov 13 08:38:56 2007 UTC

1/* 1/*
2 * Copyright (c) 2000-2005 Marc Alexander Lehmann <schmorp@schmorp.de> 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))
… …
48 */ 46 */
49#ifndef FRST 47#ifndef FRST
50# define FRST(p) (((p[0]) << 8) | p[1]) 48# define FRST(p) (((p[0]) << 8) | p[1])
51# define NEXT(v,p) (((v) << 8) | p[2]) 49# define NEXT(v,p) (((v) << 8) | p[2])
52# 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))
53//# define IDX(h) ((ip[0] * 121 ^ ip[1] * 33 ^ ip[2] * 1) & (HSIZE-1)) 51/*# define IDX(h) ((ip[0] * 121 ^ ip[1] * 33 ^ ip[2] * 1) & (HSIZE-1))*/
54#endif 52#endif
55/* 53/*
56 * 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.
57 * ((h * 57321 >> (3*8 - HLOG)) & (HSIZE - 1)) 55 * ((h * 57321 >> (3*8 - HLOG)) & (HSIZE - 1))
58 * the latter is also quite fast on newer CPUs, and compresses similarly. 56 * the latter is also quite fast on newer CPUs, and compresses similarly.
… …
69#endif 67#endif
70 68
71#define MAX_LIT (1 << 5) 69#define MAX_LIT (1 << 5)
72#define MAX_OFF (1 << 13) 70#define MAX_OFF (1 << 13)
73#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)
74 90
75/* 91/*
76 * compressed format 92 * compressed format
77 * 93 *
78 * 000LLLLL <L+1> ; literal 94 * 000LLLLL <L+1> ; literal
… …
102 unsigned int hval = FRST (ip); 118 unsigned int hval = FRST (ip);
103 unsigned long off; 119 unsigned long off;
104 int lit = 0; 120 int lit = 0;
105 121
106#if INIT_HTAB 122#if INIT_HTAB
107# if USE_MEMCPY
108 memset (htab, 0, sizeof (htab)); 123 memset (htab, 0, sizeof (htab));
109# else 124# if 0
110 for (hslot = htab; hslot < htab + HSIZE; hslot++) 125 for (hslot = htab; hslot < htab + HSIZE; hslot++)
111 *hslot++ = ip; 126 *hslot++ = ip;
112# endif 127# endif
113#endif 128#endif
114 129
115 for (;;) 130 for (;;)
116 { 131 {
117 if (ip < in_end - 2) 132 if (expect_true (ip < in_end - 2))
118 { 133 {
119 hval = NEXT (hval, ip); 134 hval = NEXT (hval, ip);
120 hslot = htab + IDX (hval); 135 hslot = htab + IDX (hval);
121 ref = *hslot; *hslot = ip; 136 ref = *hslot; *hslot = ip;
122 137
… …
140 /* match found at *ref++ */ 155 /* match found at *ref++ */
141 unsigned int len = 2; 156 unsigned int len = 2;
142 unsigned int maxlen = in_end - ip - len; 157 unsigned int maxlen = in_end - ip - len;
143 maxlen = maxlen > MAX_REF ? MAX_REF : maxlen; 158 maxlen = maxlen > MAX_REF ? MAX_REF : maxlen;
144 159
145 if (op + lit + 1 + 3 >= out_end) 160 if (expect_false (op + lit + 1 + 3 >= out_end))
146 return 0; 161 return 0;
147 162
148 do 163 if (expect_false (lit))
149 len++;
150 while (len < maxlen && ref[len] == ip[len]);
151
152 if (lit)
153 { 164 {
154 *op++ = lit - 1; 165 *op++ = lit - 1;
155 lit = -lit; 166 lit = -lit;
156 do 167 do
157 *op++ = ip[lit]; 168 *op++ = ip[lit];
158 while (++lit); 169 while (expect_false (++lit));
170 }
171
172 for (;;)
173 {
174 if (expect_true (maxlen > 16))
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 len++; if (ref [len] != ip [len]) break;
185 len++; if (ref [len] != ip [len]) break;
186 len++; if (ref [len] != ip [len]) break;
187 len++; if (ref [len] != ip [len]) break;
188 len++; if (ref [len] != ip [len]) break;
189 len++; if (ref [len] != ip [len]) break;
190 len++; if (ref [len] != ip [len]) break;
191 len++; if (ref [len] != ip [len]) break;
192 }
193
194 do
195 len++;
196 while (len < maxlen && ref[len] == ip[len]);
197
198 break;
159 } 199 }
160 200
161 len -= 2; 201 len -= 2;
162 ip++; 202 ip++;
163 203
… …
199 while (len--); 239 while (len--);
200#endif 240#endif
201 continue; 241 continue;
202 } 242 }
203 } 243 }
204 else if (ip == in_end) 244 else if (expect_false (ip == in_end))
205 break; 245 break;
206 246
207 /* one more literal byte we must copy */ 247 /* one more literal byte we must copy */
208 lit++; 248 lit++;
209 ip++; 249 ip++;
210 250
211 if (lit == MAX_LIT) 251 if (expect_false (lit == MAX_LIT))
212 { 252 {
213 if (op + 1 + MAX_LIT >= out_end) 253 if (op + 1 + MAX_LIT >= out_end)
214 return 0; 254 return 0;
215 255
216 *op++ = MAX_LIT - 1; 256 *op++ = MAX_LIT - 1;
217#if USE_MEMCPY 257
218 memcpy (op, ip - MAX_LIT, MAX_LIT); 258#ifdef lzf_movsb
219 op += MAX_LIT; 259 ip -= MAX_LIT;
220 lit = 0; 260 lzf_movsb (op, ip, lit);
221#else 261#else
222 lit = -lit; 262 lit = -lit;
223 do 263 do
224 *op++ = ip[lit]; 264 *op++ = ip[lit];
225 while (++lit); 265 while (++lit);
… …
231 { 271 {
232 if (op + lit + 1 >= out_end) 272 if (op + lit + 1 >= out_end)
233 return 0; 273 return 0;
234 274
235 *op++ = lit - 1; 275 *op++ = lit - 1;
276#ifdef lzf_movsb
277 ip -= lit;
278 lzf_movsb (op, ip, lit);
279#else
236 lit = -lit; 280 lit = -lit;
237 do 281 do
238 *op++ = ip[lit]; 282 *op++ = ip[lit];
239 while (++lit); 283 while (++lit);
284#endif
240 } 285 }
241 286
242 return op - (u8 *) out_data; 287 return op - (u8 *) out_data;
243} 288}
289

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