-
Notifications
You must be signed in to change notification settings - Fork 0
/
match.S
407 lines (355 loc) · 13.8 KB
/
match.S
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
/*
Copyright (c) 1990-2005 Info-ZIP. All rights reserved.
See the accompanying file LICENSE, version 2004-May-22 or later
(the contents of which are also included in zip.h) for terms of use.
If, for some reason, both of these files are missing, the Info-ZIP license
also may be found at: ftp://ftp.info-zip.org/pub/infozip/license.html
*/
/*
* match.s by Jean-loup Gailly. Translated to 32 bit code by Kai Uwe Rommel.
* The 68020 version has been written by Francesco Potorti` <[email protected]>
* with adaptations by Carsten Steger <[email protected]>,
* Andreas Schwab <[email protected]> and
* Kristoffer Eriksson <[email protected]>
*/
/* This file is NOT used in conjunction with zlib. */
#ifndef USE_ZLIB
/* Preprocess with -DNO_UNDERLINE if your C compiler does not prefix
* external symbols with an underline character '_'.
*/
#if defined(NO_UNDERLINE) || defined(__ELF__)
# define _prev prev
# define _window window
# define _match_start match_start
# define _prev_length prev_length
# define _good_match good_match
# define _nice_match nice_match
# define _strstart strstart
# define _max_chain_length max_chain_length
# define _match_init match_init
# define _longest_match longest_match
#endif
#ifdef DYN_ALLOC
error: DYN_ALLOC not yet supported in match.s
#endif
/* Use 16-bytes alignment if your assembler supports it. Warning: gas
* uses a log(x) parameter (.align 4 means 16-bytes alignment). On SVR4
* the parameter is a number of bytes.
*/
#ifndef ALIGNMENT
# define ALIGNMENT 4
#endif
#ifndef WSIZE
# define WSIZE 32768
#endif
#define MIN_MATCH 3
#define MAX_MATCH 258
#define MIN_LOOKAHEAD (MAX_MATCH + MIN_MATCH + 1)
#define MAX_DIST (WSIZE - MIN_LOOKAHEAD)
#if defined(i386) || defined(_I386) || defined(_i386) || defined(__i386)
/* This version is for 386 Unix or OS/2 in 32 bit mode.
* Warning: it uses the AT&T syntax: mov source,dest
* This file is only optional. If you want to force the C version,
* add -DNO_ASM to CFLAGS in Makefile and set OBJA to an empty string.
* If you have reduced WSIZE in (g)zip.h, then make sure this is
* assembled with an equivalent -DWSIZE=<whatever>.
* This version assumes static allocation of the arrays (-DDYN_ALLOC not used).
*/
.file "match.S"
.globl _match_init
.globl _longest_match
.text
_match_init:
ret
/*-----------------------------------------------------------------------
* Set match_start to the longest match starting at the given string and
* return its length. Matches shorter or equal to prev_length are discarded,
* in which case the result is equal to prev_length and match_start is
* garbage.
* IN assertions: cur_match is the head of the hash chain for the current
* string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
*/
.align ALIGNMENT
_longest_match: /* int longest_match(cur_match) */
#define cur_match 20(%esp)
/* return address */ /* esp+16 */
push %ebp /* esp+12 */
push %edi /* esp+8 */
push %esi /* esp+4 */
push %ebx /* esp */
/*
* match equ esi
* scan equ edi
* chain_length equ ebp
* best_len equ ebx
* limit equ edx
*/
mov cur_match,%esi
mov _strstart,%edx
mov _max_chain_length,%ebp /* chain_length = max_chain_length */
mov %edx,%edi
sub $(MAX_DIST),%edx /* limit = strstart-MAX_DIST */
cld /* string ops increment si and di */
jae limit_ok
sub %edx,%edx /* limit = NIL */
limit_ok:
add $2+_window,%edi /* edi = offset(window+strstart+2) */
mov _prev_length,%ebx /* best_len = prev_length */
movw -2(%edi),%cx /* cx = scan[0..1] */
movw -3(%ebx,%edi),%ax /* ax = scan[best_len-1..best_len] */
cmp _good_match,%ebx /* do we have a good match already? */
jb do_scan
shr $2,%ebp /* chain_length >>= 2 */
jmp do_scan
.align ALIGNMENT
long_loop:
/* at this point, edi == scan+2, esi == cur_match */
movw -3(%ebx,%edi),%ax /* ax = scan[best_len-1..best_len] */
movw -2(%edi),%cx /* cx = scan[0..1] */
short_loop:
/*
* at this point, di == scan+2, si == cur_match,
* ax = scan[best_len-1..best_len] and cx = scan[0..1]
*/
and $(WSIZE-1), %esi
dec %ebp /* --chain_length */
movw _prev(,%esi,2),%si /* cur_match = prev[cur_match] */
/* top word of esi is still 0 */
jz the_end
cmp %edx,%esi /* cur_match <= limit ? */
jbe the_end
do_scan:
cmpw _window-1(%ebx,%esi),%ax/* check match at best_len-1 */
jne short_loop
cmpw _window(%esi),%cx /* check min_match_length match */
jne short_loop
add $2+_window,%esi /* si = match */
mov $((MAX_MATCH>>1)-1),%ecx/* scan for at most MAX_MATCH bytes */
mov %edi,%eax /* ax = scan+2 */
repe; cmpsw /* loop until mismatch */
je maxmatch /* match of length MAX_MATCH? */
mismatch:
movb -2(%edi),%cl /* mismatch on first or second byte? */
xchg %edi,%eax /* edi = scan+2, eax = end of scan */
subb -2(%esi),%cl /* cl = 0 if first bytes equal */
sub %edi,%eax /* eax = len */
sub $2+_window,%esi /* esi = cur_match + len */
sub %eax,%esi /* esi = cur_match */
subb $1,%cl /* set carry if cl == 0 (cannot use DEC) */
adc $0,%eax /* eax = carry ? len+1 : len */
cmp %ebx,%eax /* len > best_len ? */
jle long_loop
mov %esi,_match_start /* match_start = cur_match */
mov %eax,%ebx /* ebx = best_len = len */
#ifdef FULL_SEARCH
cmp $(MAX_MATCH),%eax /* len >= MAX_MATCH ? */
#else
cmp _nice_match,%eax /* len >= nice_match ? */
#endif
jl long_loop
the_end:
mov %ebx,%eax /* result = eax = best_len */
pop %ebx
pop %esi
pop %edi
pop %ebp
ret
.align ALIGNMENT
maxmatch:
cmpsb
jmp mismatch
#else /* !(i386 || _I386 || _i386 || __i386) */
/* ======================== 680x0 version ================================= */
#if defined(m68k)||defined(mc68k)||defined(__mc68000__)||defined(__MC68000__)
# ifndef mc68000
# define mc68000
# endif
#endif
#if defined(__mc68020__) || defined(__MC68020__) || defined(sysV68)
# ifndef mc68020
# define mc68020
# endif
#endif
#if defined(mc68020) || defined(mc68000)
#if (defined(mc68020) || defined(NeXT)) && !defined(UNALIGNED_OK)
# define UNALIGNED_OK
#endif
#ifdef sysV68 /* Try Motorola Delta style */
# define GLOBAL(symbol) global symbol
# define TEXT text
# define FILE(filename) file filename
# define invert_maybe(src,dst) dst,src
# define imm(data) &data
# define reg(register) %register
# define addl add.l
# define addql addq.l
# define blos blo.b
# define bhis bhi.b
# define bras bra.b
# define clrl clr.l
# define cmpmb cmpm.b
# define cmpw cmp.w
# define cmpl cmp.l
# define lslw lsl.w
# define lsrl lsr.l
# define movel move.l
# define movew move.w
# define moveb move.b
# define moveml movem.l
# define subl sub.l
# define subw sub.w
# define subql subq.l
# define IndBase(bd,An) (bd,An)
# define IndBaseNdxl(bd,An,Xn) (bd,An,Xn.l)
# define IndBaseNdxw(bd,An,Xn) (bd,An,Xn.w)
# define predec(An) -(An)
# define postinc(An) (An)+
#else /* default style (Sun 3, NeXT, Amiga, Atari) */
# define GLOBAL(symbol) .globl symbol
# define TEXT .text
# define FILE(filename) .even
# define invert_maybe(src,dst) src,dst
# if defined(sun) || defined(mc68k)
# define imm(data) #data
# else
# define imm(data) \#data
# endif
# define reg(register) register
# define blos bcss
# if defined(sun) || defined(mc68k)
# define movel movl
# define movew movw
# define moveb movb
# endif
# define IndBase(bd,An) An@(bd)
# define IndBaseNdxl(bd,An,Xn) An@(bd,Xn:l)
# define IndBaseNdxw(bd,An,Xn) An@(bd,Xn:w)
# define predec(An) An@-
# define postinc(An) An@+
#endif /* styles */
#define Best_Len reg(d0) /* unsigned */
#define Cur_Match reg(d1) /* Ipos */
#define Loop_Counter reg(d2) /* int */
#define Scan_Start reg(d3) /* unsigned short */
#define Scan_End reg(d4) /* unsigned short */
#define Limit reg(d5) /* IPos */
#define Chain_Length reg(d6) /* unsigned */
#define Scan_Test reg(d7)
#define Scan reg(a0) /* *uch */
#define Match reg(a1) /* *uch */
#define Prev_Address reg(a2) /* *Pos */
#define Scan_Ini reg(a3) /* *uch */
#define Match_Ini reg(a4) /* *uch */
#define Stack_Pointer reg(sp)
GLOBAL (_match_init)
GLOBAL (_longest_match)
TEXT
FILE ("match.S")
_match_init:
rts
/*-----------------------------------------------------------------------
* Set match_start to the longest match starting at the given string and
* return its length. Matches shorter or equal to prev_length are discarded,
* in which case the result is equal to prev_length and match_start is
* garbage.
* IN assertions: cur_match is the head of the hash chain for the current
* string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
*/
/* int longest_match (cur_match) */
#ifdef UNALIGNED_OK
# define pushreg 15928 /* d2-d6/a2-a4 */
# define popreg 7292
#else
# define pushreg 16184 /* d2-d7/a2-a4 */
# define popreg 7420
#endif
_longest_match:
movel IndBase(4,Stack_Pointer),Cur_Match
moveml imm(pushreg),predec(Stack_Pointer)
movel _max_chain_length,Chain_Length
movel _prev_length,Best_Len
movel imm(_prev),Prev_Address
movel imm(_window+MIN_MATCH),Match_Ini
movel _strstart,Limit
movel Match_Ini,Scan_Ini
addl Limit,Scan_Ini
subw imm(MAX_DIST),Limit
bhis L__limit_ok
clrl Limit
L__limit_ok:
cmpl invert_maybe(_good_match,Best_Len)
blos L__length_ok
lsrl imm(2),Chain_Length
L__length_ok:
subql imm(1),Chain_Length
#ifdef UNALIGNED_OK
movew IndBase(-MIN_MATCH,Scan_Ini),Scan_Start
movew IndBaseNdxw(-MIN_MATCH-1,Scan_Ini,Best_Len),Scan_End
#else
moveb IndBase(-MIN_MATCH,Scan_Ini),Scan_Start
lslw imm(8),Scan_Start
moveb IndBase(-MIN_MATCH+1,Scan_Ini),Scan_Start
moveb IndBaseNdxw(-MIN_MATCH-1,Scan_Ini,Best_Len),Scan_End
lslw imm(8),Scan_End
moveb IndBaseNdxw(-MIN_MATCH,Scan_Ini,Best_Len),Scan_End
#endif
bras L__do_scan
L__long_loop:
#ifdef UNALIGNED_OK
movew IndBaseNdxw(-MIN_MATCH-1,Scan_Ini,Best_Len),Scan_End
#else
moveb IndBaseNdxw(-MIN_MATCH-1,Scan_Ini,Best_Len),Scan_End
lslw imm(8),Scan_End
moveb IndBaseNdxw(-MIN_MATCH,Scan_Ini,Best_Len),Scan_End
#endif
L__short_loop:
lslw imm(1),Cur_Match
movew IndBaseNdxl(0,Prev_Address,Cur_Match),Cur_Match
cmpw invert_maybe(Limit,Cur_Match)
dbls Chain_Length,L__do_scan
bras L__return
L__do_scan:
movel Match_Ini,Match
addl Cur_Match,Match
#ifdef UNALIGNED_OK
cmpw invert_maybe(IndBaseNdxw(-MIN_MATCH-1,Match,Best_Len),Scan_End)
bne L__short_loop
cmpw invert_maybe(IndBase(-MIN_MATCH,Match),Scan_Start)
bne L__short_loop
#else
moveb IndBaseNdxw(-MIN_MATCH-1,Match,Best_Len),Scan_Test
lslw imm(8),Scan_Test
moveb IndBaseNdxw(-MIN_MATCH,Match,Best_Len),Scan_Test
cmpw invert_maybe(Scan_Test,Scan_End)
bne L__short_loop
moveb IndBase(-MIN_MATCH,Match),Scan_Test
lslw imm(8),Scan_Test
moveb IndBase(-MIN_MATCH+1,Match),Scan_Test
cmpw invert_maybe(Scan_Test,Scan_Start)
bne L__short_loop
#endif
movew imm((MAX_MATCH-MIN_MATCH+1)-1),Loop_Counter
movel Scan_Ini,Scan
L__scan_loop:
cmpmb postinc(Match),postinc(Scan)
dbne Loop_Counter,L__scan_loop
subl Scan_Ini,Scan
addql imm(MIN_MATCH-1),Scan
cmpl invert_maybe(Best_Len,Scan)
bls L__short_loop
movel Scan,Best_Len
movel Cur_Match,_match_start
#ifdef FULL_SEARCH
cmpl invert_maybe(imm(MAX_MATCH),Best_Len)
#else
cmpl invert_maybe(_nice_match,Best_Len)
#endif
blos L__long_loop
L__return:
moveml postinc(Stack_Pointer),imm(popreg)
rts
#else
error: this asm version is for 386 or 680x0 only
#endif /* mc68000 || mc68020 */
#endif /* i386 || _I386 || _i386 || __i386 */
#endif /* !USE_ZLIB */