File: match.c

package info (click to toggle)
gzip 1.3.5-15
  • links: PTS
  • area: main
  • in suites: etch-m68k
  • size: 1,484 kB
  • ctags: 1,056
  • sloc: ansic: 7,066; sh: 869; asm: 179; makefile: 136; perl: 11
file content (758 lines) | stat: -rw-r--r-- 21,990 bytes parent folder | download | duplicates (3)
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
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
/* match.s -- optional optimized asm version of longest match in deflate.c
 * Copyright (C) 2002 Free Software Foundation, Inc.
 * Copyright (C) 1992-1993 Jean-loup Gailly
 * This is free software; you can redistribute it and/or modify it under the
 * terms of the GNU General Public License, see the file COPYING.
 *
 * The 68020 version has been written by Francesco Potorti` <pot@cnuce.cnr.it>
 * with adaptations by Carsten Steger <stegerc@informatik.tu-muenchen.de>,
 * Andreas Schwab <schwab@lamothe.informatik.uni-dortmund.de> and
 * Kristoffer Eriksson <ske@pkmab.se>
 *
 * The ia64 version has been written by Sverre Jarp (HP Labs) 2001-2002.
 * Unwind directives and some reformatting for better readability added by
 * David Mosberger-Tang <davidm@hpl.hp.com>.
 */

/* $Id: match.S,v 0.14 1993/06/11 18:33:24 jloup Exp $ */

/* Preprocess with -DNO_UNDERLINE if your C compiler does not prefix
 * external symbols with an underline character '_'.
 */
#ifdef NO_UNDERLINE
#  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

#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 gzip.h, then change its value below.
 * This version assumes static allocation of the arrays (-DDYN_ALLOC not used).
 */

	.file   "match.S"

#define MAX_MATCH	258
#define MAX_MATCH2	$128 /* MAX_MATCH/2-1 */
#define MIN_MATCH	3
#define    WSIZE	$32768
#define MAX_DIST	WSIZE - MAX_MATCH - MIN_MATCH - 1

	.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
 */

_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 	_max_chain_length,%ebp /* chain_length = max_chain_length */
	mov 	_strstart,%edi
	mov 	%edi,%edx
	sub	MAX_DIST,%edx          /* limit = strstart-MAX_DIST */
	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 	-3(%ebx,%edi),%ax      /* ax = scan[best_len-1..best_len] */
        movw 	-2(%edi),%cx           /* cx = scan[0..1] */
	cmp	_good_match,%ebx       /* do we have a good match already? */
        jb      do_scan
	shr 	$2,%ebp                /* chain_length >>= 2 */
        jmp     do_scan

        .align  4
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
        movw    _prev(%esi,%esi),%si    /* cur_match = prev[cur_match] */
                                        /* top word of esi is still 0 */
        cmp     %edx,%esi		/* cur_match <= limit ? */
        jbe     the_end
        dec     %ebp                    /* --chain_length */
        jz      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

        lea     _window+2(%esi),%esi    /* si = match */
        mov     %edi,%eax               /* ax = scan+2 */
        mov 	MAX_MATCH2,%ecx         /* scan for at most MAX_MATCH bytes */
        rep;    cmpsw                   /* loop until mismatch */
        je      maxmatch                /* match of length MAX_MATCH? */
mismatch:
        movb    -2(%edi),%cl        /* mismatch on first or second byte? */
        subb    -2(%esi),%cl        /* cl = 0 if first bytes equal */
        xchg    %edi,%eax           /* edi = scan+2, eax = end of scan */
        sub     %edi,%eax           /* eax = len */
	sub	%eax,%esi           /* esi = cur_match + 2 + offset(window) */
	sub	$2+_window,%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 */
        cmp     _nice_match,%eax        /* len >= nice_match ? */
        jl      long_loop
the_end:
        mov     %ebx,%eax               /* result = eax = best_len */
	pop     %ebx
        pop     %esi
        pop     %edi
        pop     %ebp
        ret
maxmatch:
        cmpsb
        jmp     mismatch

#else

/* ======================== 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)

#define MAX_MATCH 	258
#define MIN_MATCH	3
#define WSIZE		32768
#define MAX_DIST 	(WSIZE - MAX_MATCH - MIN_MATCH - 1)

	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
	cmpl	invert_maybe(_nice_match,Best_Len)
	blos	L__long_loop
L__return:
	moveml	postinc(Stack_Pointer),imm(popreg)
	rts

#else

# if defined (__ia64__)

/* ======================== ia64 version ================================= */

/*
 * 'longest_match.S' (assembly program for gzip for the IA-64 architecture)
 *
 * Optimised for McKinley, but with Merced-compatibility, such as MIB+MIB, used wherever
 * possible.
 *
 * Copyright: Sverre Jarp (HP Labs) 2001-2002
 *
 * See deflate.c for c-version
 * Version 2 - Optimize the outer loop
 */

#include <endian.h>

#if __BYTE_ORDER == ____BIG_ENDIAN
#define  first  shl
#define  second shr.u
#define  count  czx1.l
#else
#define  first  shr.u
#define  second shl
#define  count  czx1.r
#endif

// 24 rotating register (r32 - r55)

#define s_vmatch0		r32
#define s_vmatch1		r33
#define s_vmatbst		r34
#define s_vmatbst1		r35
#define s_amatblen		r36

#define s_tm1			r56
#define s_tm2			r57
#define s_tm3			r58
#define s_tm4			r59
#define s_tm5			r60
#define	s_tm6			r61
#define s_tm7			r62
#define s_tm8			r63

#define s_vlen			r31
#define s_vstrstart		r30
#define s_vchainlen		r29
#define s_awinbest		r28
#define s_vcurmatch		r27
#define s_vlimit		r26
#define s_vscanend		r25
#define s_vscanend1		r24
#define s_anicematch		r23
#define	s_vscan0		r22
#define s_vscan1		r21

#define s_aprev			r20
#define s_awindow		r19
#define s_amatchstart		r18
#define s_ascan			r17
#define s_amatch		r16
#define s_wmask			r15
#define s_ascanend		r14

#define s_vspec_cmatch		r11		// next iteration
#define s_lcsave		r10
#define s_prsave		r9
#define s_vbestlen		r8		// return register

#define s_vscan3		r3
#define s_vmatch3		r2

#define p_no			p2
#define p_yes			p3
#define p_shf			p4		//
#define p_bn2			p5		// Use in loop (indicating bestlen != 2)

#define p_nbs			p9		// not new best_len
#define p_nnc			p10		// not nice_length
#define p_ll			p11
#define p_end			p12

#define MAX_MATCH		258
#define MIN_MATCH		  4
#define WSIZE		      32768
#define MAX_DIST		WSIZE - MAX_MATCH - MIN_MATCH - 1

#define	R_INPUT			1
#define R_LOCAL			31
#define	R_OUTPUT		0
#define R_ROTATING		24
#define MLAT			3
#define SHLAT			2

#define	mova			mov
#define movi0			mov
#define cgtu			cmp.gt.unc
#define cgeu			cmp.ge.unc
#define cneu			cmp.ne.unc

	.global longest_match
	.proc longest_match
	.align 32
longest_match:
// --  Cycle: 0
	.prologue
{.mmi
	 alloc r2=ar.pfs,R_INPUT,R_LOCAL,R_OUTPUT,R_ROTATING
	.rotr scan[MLAT+2], match[MLAT+2], shscan0[SHLAT+1], \
	      shscan1[SHLAT+1], shmatch0[SHLAT+1], shmatch1[SHLAT+1]
	.rotp lc[MLAT+SHLAT+2]
	mova s_vspec_cmatch=in0 // cur_match from input register
	add s_tm1=@gprel(strstart),gp // a(a(strstart))
}{.mmi
	add s_tm3=@gprel(prev_length),gp // a(a(prev_length))
	add s_tm5=@ltoff(window),gp // a(a(window))
	add s_tm6=@ltoff(prev),gp // a(a(prev))
	;;
}{.mmb	//  Cycle: 1
	ld4 s_vstrstart=[s_tm1] // strstart
	ld4 s_vbestlen=[s_tm3] // best_len = prev_length
	brp.loop.imp .cmploop,.cmploop+48
}{.mli
	add s_tm2=@gprel(max_chain_length),gp // a(a(max_chain_length))
	movl s_wmask=WSIZE-1
	;;
}{.mmi	//  Cycle: 2
	ld8 s_aprev=[s_tm6] // a(prev)
	ld8 s_awindow=[s_tm5] // a(window)
	.save pr, s_prsave
	movi0 s_prsave=pr // save predicates
}{.mmi
	add s_tm4=@gprel(good_match),gp // a(a(good_match))
	add s_tm7=@ltoff(nice_match),gp // a(a(nice_match))
	add s_tm8=@ltoff(match_start),gp // a(match_start)
	;;
}{.mmi	//  Cycle: 3
	ld8 s_anicematch=[s_tm7] // a(nice_match)
	ld8 s_amatchstart=[s_tm8] // a(match_start)
	.save ar.lc, s_lcsave
	movi0 s_lcsave=ar.lc // save loop count register
}{.mmi
	.body
	add s_tm1=-(MAX_MATCH + MIN_MATCH),s_wmask // maxdist
	cmp.eq p_ll,p0=r0,r0 // parallel compare initialized as 'true'
	mova s_vcurmatch=s_vspec_cmatch
	;;
}{.mmi	//  Cycle: 4
	ld4 s_vchainlen=[s_tm2] // chain_length=max_chain_length
	ld4 s_tm4=[s_tm4] // v(good_match)
	add s_ascan=s_awindow,s_vstrstart // scan=window + strstart
}{.mmi
	sub s_vlimit=s_vstrstart, s_tm1 // limit=strstart - MAX_DIST
	add s_amatch=s_awindow,s_vspec_cmatch // match=window + cur_match
	and s_vspec_cmatch =s_vspec_cmatch,s_wmask
	;;
}{.mmi	//  Cycle: 5
	add s_amatblen=s_amatch,s_vbestlen //
	cneu p_bn2,p0=2,s_vbestlen // set if bestlen != 2
	add s_ascanend=s_ascan,s_vbestlen // compute a(scan) + best_len
}{.mmi
	ld1 s_vscan0=[s_ascan],1 // NB: s_ascan++
	ld1 s_vmatch0=[s_amatch],1
	cgtu p0,p_no=s_vlimit,r0 // is result positive ?
	;;
}{.mmi	//  Cycle: 6
	ld1.nt1 s_vscan1=[s_ascan],2 // NB: s_ascan+3 in total
	ld1.nt1 s_vmatch1=[s_amatch],2
	add s_awinbest=s_awindow,s_vbestlen //
	;;
}{.mmi	//  Cycle: 7
	ld1.nt1 s_vscanend=[s_ascanend],-1 // scan_end=scan[best_len]
	ld1.nt1 s_vmatbst=[s_amatblen],-1
(p_no)	mova s_vlimit=r0
	;;
}{.mmi	//  Cycle: 8
(p_bn2)	ld1.nt1 s_vscanend1=[s_ascanend],1 // scan_end1=scan[best_len-1]
(p_bn2)	ld1.nt1 s_vmatbst1=[s_amatblen]
	shladd s_vspec_cmatch =s_vspec_cmatch,1,s_aprev
}{.mmi
	cgeu p_shf,p0=s_vbestlen,s_tm4 // is (prev_length >= good_match) ?
	;;
}{.mmi	//  Cycle: 9
	ld1.nt1 s_vscan3=[s_ascan]
	ld2.nt1 s_vspec_cmatch=[s_vspec_cmatch]
	mova	s_vlen=3
}{.mmi
(p_shf)	shr.u s_vchainlen=s_vchainlen,2 // (cur_len) >> 2
	;;
}{.mmi	//  Cycle: 10
	ld1.nt1 s_vmatch3=[s_amatch]
	// p_ll switched on as soon as we get a mismatch:
	cmp.eq.and p_ll,p0=s_vmatch0,s_vscan0
	cmp.eq.and p_ll,p0=s_vmatbst,s_vscanend
}{.mib
	cmp.eq.and p_ll,p0=s_vmatch1,s_vscan1
(p_bn2)	cmp.eq.and p_ll,p0=s_vmatbst1,s_vscanend1
(p_ll)	br.cond.dpnt.many .test_more
	;;
}

.next_iter:
{.mmi	// Cycle 0
	add s_amatch=s_awindow,s_vspec_cmatch  	// match=window + cur_match
	mov s_vcurmatch=s_vspec_cmatch		// current value
	add s_vchainlen=-1,s_vchainlen 		// --chain_length
}{.mib
	cmp.le.unc p_end,p0=s_vspec_cmatch,s_vlimit
	and s_vspec_cmatch=s_vspec_cmatch,s_wmask
(p_end)	br.cond.dptk.many .terminate
	;;
}{.mmi	// Cycle 1
	ld1 s_vmatch0=[s_amatch],1		// load match[0]
	// compute prev[cur_match]:
	shladd s_vspec_cmatch=s_vspec_cmatch,1,s_aprev
	cmp.eq.unc p_end,p0=s_vchainlen,r0
} {.mib
	nop.m 0
	add s_amatblen=s_awinbest,s_vcurmatch	// match=window + cur_match
(p_end)	br.cond.dptk.many .terminate
	;;
}{.mmi	// Cycle 2 (short)
	ld2.nt1 s_vspec_cmatch=[s_vspec_cmatch]		// get next cur_match
	;;
}{.mmi	// Cycle 3 (short)
	ld1.nt1 s_vmatbst=[s_amatblen],-1	// load match[best_len]
	cmp.ne.unc p_ll,p0=r0,r0     // parallel compare initialized as 'false'
	;;
}{.mmi	// Cycle 4 (short)
	// load match[1] - - note: match += 3 (in total):
	ld1.nt1 s_vmatch1=[s_amatch],2
	;;
	// Cycle 5  (short)
(p_bn2)	ld1.nt1 s_vmatbst1=[s_amatblen]		// load match[best_len-1]
}{.mib	// Here we (MOST LIKELY) pay a L2-fetch stall
	// p_ll switched on as soon as we get a mismatch:
	cmp.ne.or p_ll,p0=s_vmatch0,s_vscan0
	cmp.ne.or p_ll,p0=s_vmatbst,s_vscanend
(p_ll)	br.cond.dptk.many .next_iter
	;;
}{.mmi	// Cycle 6
	ld1.nt1 s_vmatch3=[s_amatch]
	mova s_vlen=3
	nop.i 0
}{.mib
	cmp.ne.or p_ll,p0=s_vmatch1,s_vscan1
(p_bn2)	cmp.ne.or p_ll,p0=s_vmatbst1,s_vscanend1
(p_ll)	br.cond.dptk.many .next_iter
	;;
}

// We have passed the first hurdle - Are there additional matches ???

.test_more:
{.mmi	// Cycle 0
	and s_tm3=7,s_ascan			// get byte offset
	and s_tm4=7,s_amatch			// get byte offset
	movi0 ar.ec=MLAT+SHLAT+2		// NB: One trip more than usual
}{.mib
	cmp.ne.unc p_no,p0=s_vscan3,s_vmatch3	// does not next one differ?
(p_no)  br.cond.dptk.many .only3
	;;
}{.mmi	// Cycle 1
	and s_tm1=-8,s_ascan	// get aligned address
	shladd s_tm3=s_tm3,3,r0
	movi0 ar.lc=31		// 32 times around the loop (8B at a time)
}{.mib
	and s_tm2=-8,s_amatch			// get aligned address
	shladd s_tm4=s_tm4,3,r0
	nop.b 0
	;;
}{.mmi	// Cycle 2
	ld8.nt1 scan[1]=[s_tm1],8			// load first chunk
	sub s_tm5=64,s_tm3				// 64 - amount
	movi0 pr.rot=1<<16
}{.mmi
	ld8.nt1 match[1]=[s_tm2],8	// load first chunk
	sub s_tm6=64,s_tm4		// 64 - amount
	add s_vlen=-8,s_vlen		// will be updated at least once
	;;
}
	.align 32
.cmploop:
{.mmi	// Cycle 0
(lc[0])			ld8 scan[0]=[s_tm1],8		// next scan chunk
(lc[MLAT+SHLAT+1]) 	add s_vlen=8,s_vlen
(lc[MLAT])		first shscan0[0]=scan[MLAT+1],s_tm3
}{.mib
(lc[MLAT+SHLAT+1]) 	cmp.ne.unc p_no,p0=s_tm7,s_tm8	// break search if !=
(lc[MLAT])		first shmatch0[0]=match[MLAT+1],s_tm4
(p_no)			br.cond.dpnt.many .mismatch
			;;
}{.mii  // Cycle 1
(lc[0])			ld8 match[0]=[s_tm2],8
			// shift left(le) or right(be):
(lc[MLAT])		second shscan1[0]=scan[MLAT],s_tm5
(lc[MLAT])		second shmatch1[0]=match[MLAT],s_tm6
}{.mmb
(lc[MLAT+SHLAT])	or s_tm7=shscan0[SHLAT],shscan1[SHLAT]
(lc[MLAT+SHLAT])	or s_tm8=shmatch0[SHLAT],shmatch1[SHLAT]
			br.ctop.dptk.many .cmploop
			;;
}{.mfi
	mov s_vlen=258
	nop.f 0
}{.mfi
	nop.f 0    // realign
	;;
}
.mismatch:
{.mii	// Cycle 0 (short)
(p_no)	pcmp1.eq s_tm2=s_tm7,s_tm8 	// find first non-matching character
	nop.i 0
	;;
	// Cycle 1 (short)
(p_no)	count s_tm1=s_tm2
	;;
}{.mib	// Cycle 2 (short)
(p_no)	add s_vlen=s_vlen,s_tm1		// effective length
	nop.i 0
	clrrrb
	;;
}

.only3:
{.mib	// Cycle 0 (short)
	cmp.gt.unc p0,p_nbs=s_vlen,s_vbestlen		// (len > best_len) ?
(p_nbs)	br.cond.dpnt.many .next_iter			// if not, re-iternate
	;;
}{.mmi	// Cycle 1 (short)
	ld4 s_tm7=[s_anicematch] 			// nice_match
	st4 [s_amatchstart]= s_vcurmatch
	add s_ascanend=s_ascan,s_vlen			// reset with best_len
	;;
}{.mmi	// Cycle 2 (short)
	mova s_vbestlen=s_vlen
	add s_ascanend=-3,s_ascanend		// remember extra offset
	;;
}{.mmi	// Cycle 3 (short)
	ld1 s_vscanend=[s_ascanend],-1		// scan_end=scan[best_len]
	add s_awinbest=s_awindow,s_vbestlen	// update with new best_len
  	cmp.ne.unc p_bn2,p0=2,s_vbestlen	// set if bestlen != 2
	;;
}{.mib	// Cycle 4 (short)
	// scan_end1=scan[best_len-1] NB: s_ascanend reset:
	ld1.nt1 s_vscanend1=[s_ascanend],1
	cmp.lt.unc p_nnc,p0=s_vlen,s_tm7	// compare with nice_match
(p_nnc)	br.cond.dptk.many .next_iter
	;;
}
.terminate:
{.mii	// Cycle 0/1
	nop.m 0
	movi0 ar.lc=s_lcsave
	movi0 pr=s_prsave,-1
}{.mbb
	nop.m 0
	nop.b 0
	br.ret.sptk.many rp	// ret0 is identical to best_len
	;;
}
	.endp

	.global match_init
	.proc match_init
match_init:
	sub ret0=ret0,ret0
	br.ret.sptk.many rp
	.endp

# else
 error: this asm version is for 386 or 680x0 or ia64 only 
# endif /* __ia64__ */
#endif /* mc68000 || mc68020 */
#endif /* i386 || _I386   */