+++ /dev/null
-/* 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>
- */
-
-/* $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
- error: this asm version is for 386 or 680x0 only
-#endif /* mc68000 || mc68020 */
-#endif /* i386 || _I386 */
projects / debian / gzip / blobdiff