Imported Upstream version 1.3.9
[debian/gzip] / lib / match.c
diff --git a/lib/match.c b/lib/match.c
new file mode 100644 (file)
index 0000000..66cb1ca
--- /dev/null
@@ -0,0 +1,772 @@
+/* match.s -- optional optimized asm version of longest match in deflate.c
+
+   Copyright (C) 2002, 2006 Free Software Foundation, Inc.
+   Copyright (C) 1992-1993 Jean-loup Gailly
+
+   This program 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, or (at your option)
+   any later version.
+
+   This program 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 this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/*
+ * 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.c,v 1.1 2006/11/20 08:40:34 eggert 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   */