* match.s -- optional optimized asm version of longest match in deflate.c* Copyright (C) 1992-1993 Jean-loup Gailly** Adapted for X68000 by NIIMI Satoshi <a01309@cfi.waseda.ac.jp>* Adapted for the Amiga by Carsten Steger <stegerc@informatik.tu-muenchen.de>* using the code in match.S.* The major change in this code consists of removing all unaligned* word accesses, because they cause 68000-based machines to crash.* For maximum speed, UNALIGNED_OK can be defined.* The program will then only run on 68020-based machines, though.Cur_Match       reg     d0      ; Must be in d0!Best_Len        reg     d1Loop_Counter    reg     d2Scan_Start      reg     d3Scan_End        reg     d4Limit           reg     d5Chain_Length    reg     d6Scan_Test       reg     d7Scan            reg     a0Match           reg     a1Prev_Address    reg     a2Scan_Ini        reg     a3Match_Ini       reg     a4MAX_MATCH       equ     258MIN_MATCH       equ     3WSIZE           equ     32768MAX_DIST        equ     WSIZE-MAX_MATCH-MIN_MATCH-1        .xref   _max_chain_length        .xref   _prev_length        .xref   _prev        .xref   _window        .xref   _strstart        .xref   _good_match        .xref   _match_start        .xref   _nice_match        .xdef   _match_init        .xdef   _longest_match        .text        .even_match_init:        rts_longest_match:        move.l  4(sp),Cur_Match.ifdef  UNALIGNED_OK        movem.l d2-d6/a2-a4,-(sp).else        movem.l d2-d7/a2-a4,-(sp).endif        move.l  _max_chain_length,Chain_Length        move.l  _prev_length,Best_Len        lea     _prev,Prev_Address        lea     _window+MIN_MATCH,Match_Ini        move.l  _strstart,Limit        move.l  Match_Ini,Scan_Ini        add.l   Limit,Scan_Ini        subi.w  #MAX_DIST,Limit        bhi.b   limit_ok        moveq   #0,Limitlimit_ok:        cmp.l   _good_match,Best_Len        bcs.b   length_ok        lsr.l   #2,Chain_Lengthlength_ok:        subq.l  #1,Chain_Length.ifdef  UNALIGNED_OK        move.w  -MIN_MATCH(Scan_Ini),Scan_Start        move.w  -MIN_MATCH-1(Scan_Ini,Best_Len.w),Scan_End.else        move.b  -MIN_MATCH(Scan_Ini),Scan_Start        lsl.w   #8,Scan_Start        move.b  -MIN_MATCH+1(Scan_Ini),Scan_Start        move.b  -MIN_MATCH-1(Scan_Ini,Best_Len.w),Scan_End        lsl.w   #8,Scan_End        move.b  -MIN_MATCH(Scan_Ini,Best_Len.w),Scan_End.endif        bra.b   do_scanlong_loop:.ifdef  UNALIGNED_OK        move.w  -MIN_MATCH-1(Scan_Ini,Best_Len.w),Scan_End.else        move.b  -MIN_MATCH-1(Scan_Ini,Best_Len.w),Scan_End        lsl.w   #8,Scan_End        move.b  -MIN_MATCH(Scan_Ini,Best_Len.w),Scan_End.endifshort_loop:        lsl.w   #1,Cur_Match        move.w  0(Prev_Address,Cur_Match.l),Cur_Match        cmp.w   Limit,Cur_Match        dbls    Chain_Length,do_scan        bra.b   returndo_scan:        move.l  Match_Ini,Match        add.l   Cur_Match,Match.ifdef  UNALIGNED_OK        cmp.w   -MIN_MATCH-1(Match,Best_Len.w),Scan_End        bne.b   short_loop        cmp.w   -MIN_MATCH(Match),Scan_Start        bne.b   short_loop.else        move.b  -MIN_MATCH-1(Match,Best_Len.w),Scan_Test        lsl.w   #8,Scan_Test        move.b  -MIN_MATCH(Match,Best_Len.w),Scan_Test        cmp.w   Scan_Test,Scan_End        bne.b   short_loop        move.b  -MIN_MATCH(Match),Scan_Test        lsl.w   #8,Scan_Test        move.b  -MIN_MATCH+1(Match),Scan_Test        cmp.w   Scan_Test,Scan_Start        bne.b   short_loop.endif        move.w  #(MAX_MATCH-MIN_MATCH),Loop_Counter        move.l  Scan_Ini,Scanscan_loop:        cmpm.b  (Match)+,(Scan)+        dbne    Loop_Counter,scan_loop        sub.l   Scan_Ini,Scan        addq.l  #(MIN_MATCH-1),Scan        cmp.l   Best_Len,Scan        bls.b   short_loop        move.l  Scan,Best_Len        move.l  Cur_Match,_match_start        cmp.l   _nice_match,Best_Len        bcs.b   long_loopreturn:        move.l  Best_Len,d0.ifdef  UNALIGNED_OK        movem.l (sp)+,d2-d6/a2-a4.else        movem.l (sp)+,d2-d7/a2-a4.endif        rts        end