/***************************************************************
 *         aPLib v0.12b  -  the smaller the better :)          *
 *                 WATCOM assembler depacker                   *
 *                                                             *
 *    Copyright (c) 1998 by  ÄúJibzúÄ  All Rights Reserved     *
 ***************************************************************/

#ifndef __APACK_DEPACK
#define __APACK_DEPACK

/* NOTE: if you don't include debug, you may remove the push ebp + pop ebp */

void aP_depack_asm_fast(unsigned char *, unsigned char *);
#pragma aux aP_depack_asm_fast = \
      "push    ebp                    " \
      "cld                            " \
      "mov     dh, 1                  " \
"nexttag:                             " \
      "dec     dh                     " \
      "jnz     stillbitsleftA         " \
      "mov     dl, [esi]              " \
      "inc     esi                    " \
      "mov     dh, 8                  " \
"stillbitsleftA:                      " \
      "add     dl, dl                 " \
      "jc      not_literal            " \
"literal:                             " \
      "movsb                          " \
      "jmp     short nexttag          " \
"not_literal:                         " \
      "dec     dh                     " \
      "jnz     stillbitsleftB         " \
      "mov     dl, [esi]              " \
      "inc     esi                    " \
      "mov     dh, 8                  " \
"stillbitsleftB:                      " \
      "add     dl, dl                 " \
      "jnc     codepair               " \
      "dec     dh                     " \
      "jnz     stillbitsleftC         " \
      "mov     dl, [esi]              " \
      "inc     esi                    " \
      "mov     dh, 8                  " \
"stillbitsleftC:                      " \
      "add     dl, dl                 " \
      "jnc     shortmatch             " \
      "xor     eax, eax               " \
      "dec     dh                     " \
      "jnz     stillbitsleft_eaxA     " \
      "mov     dl, [esi]              " \
      "inc     esi                    " \
      "mov     dh, 8                  " \
"stillbitsleft_eaxA:                  " \
      "add     dl, dl                 " \
      "adc     eax, eax               " \
      "dec     dh                     " \
      "jnz     stillbitsleft_eaxB     " \
      "mov     dl, [esi]              " \
      "inc     esi                    " \
      "mov     dh, 8                  " \
"stillbitsleft_eaxB:                  " \
      "add     dl, dl                 " \
      "adc     eax, eax               " \
      "dec     dh                     " \
      "jnz     stillbitsleft_eaxC     " \
      "mov     dl, [esi]              " \
      "inc     esi                    " \
      "mov     dh, 8                  " \
"stillbitsleft_eaxC:                  " \
      "add     dl, dl                 " \
      "adc     eax, eax               " \
      "dec     dh                     " \
      "jnz     stillbitsleft_eaxD     " \
      "mov     dl, [esi]              " \
      "inc     esi                    " \
      "mov     dh, 8                  " \
"stillbitsleft_eaxD:                  " \
      "add     dl, dl                 " \
      "adc     eax, eax               " \
      "neg     eax                    " \
      "jz      thewrite               " \
      "mov     al, [edi+eax]          " \
"thewrite:                            " \
      "stosb                          " \
      "jmp     short nexttag          " \
"codepair:                            " \
      "jmp     short getgamma_eax     " \
"getgamma_eax_ret:                    " \
      "sub     eax, 2                 " \
      "jnz     normalcodepair         " \
      "call    getgamma               " \
"copydata2:                           " \
      "push    esi                    " \
      "mov     esi, edi               " \
      "sub     esi, ebp               " \
      "rep     movsb                  " \
      "pop     esi                    " \
      "jmp     short nexttag          " \
"normalcodepair:                      " \
      "dec     eax                    " \
      "shl     eax, 8                 " \
      "lodsb                          " \
      "mov     ebx, eax               " \
      "call    getgamma               " \
      "cmp     ebx, 127               " \
      "ja      domatch3               " \
      "add     ecx, 2                 " \
"domatch3:                            " \
      "mov     ebp, ebx               " \
      "push    esi                    " \
      "mov     esi, edi               " \
      "sub     esi, ebx               " \
      "rep     movsb                  " \
      "pop     esi                    " \
      "jmp     short nexttag          " \
"shortmatch:                          " \
      "xor     eax, eax               " \
      "lodsb                          " \
      "xor     ecx, ecx               " \
      "db      0xc0, 0xe8, 0x01       " \
      "jz      donedepacking          " \
      "adc     ecx, 2                 " \
      "mov     ebx, eax               " \
"domatch:                             " \
      "push    esi                    " \
      "mov     esi, edi               " \
      "sub     esi, ebx               " \
      "rep     movsb                  " \
      "pop     esi                    " \
      "jmp     short nexttag          " \
\
\
"getgamma_eax:                        " \
      "mov     eax, 1                 " \
"getgammaloop_eax:                    " \
      "dec     dh                     " \
      "jnz     stillbitsleft_eax      " \
      "mov     dl, [esi]              " \
      "inc     esi                    " \
      "mov     dh, 8                  " \
"stillbitsleft_eax:                   " \
      "add     dl, dl                 " \
      "jnc     getgammabit_eax        " \
      "dec     dh                     " \
      "jnz     stillbitsleft_eax2     " \
      "mov     dl, [esi]              " \
      "inc     esi                    " \
      "mov     dh, 8                  " \
"stillbitsleft_eax2:                  " \
      "add     dl, dl                 " \
      "adc     eax, eax               " \
      "jmp     short getgammaloop_eax " \
"getgammabit_eax:                     " \
      "dec     dh                     " \
      "jnz     stillbitsleft_eax4     " \
      "mov     dl, [esi]              " \
      "inc     esi                    " \
      "mov     dh, 8                  " \
"stillbitsleft_eax4:                  " \
      "add     dl, dl                 " \
      "adc     eax, eax               " \
      "jmp     short getgamma_eax_ret " \
\
\
"getgamma:                            " \
      "mov     ecx, 1                 " \
"getgammaloop:                        " \
      "dec     dh                     " \
      "jnz     stillbitsleft2         " \
      "mov     dl, [esi]              " \
      "inc     esi                    " \
      "mov     dh, 8                  " \
"stillbitsleft2:                      " \
      "add     dl, dl                 " \
      "jnc     getgammabit            " \
      "dec     dh                     " \
      "jnz     stillbitsleft3         " \
      "mov     dl, [esi]              " \
      "inc     esi                    " \
      "mov     dh, 8                  " \
"stillbitsleft3:                      " \
      "add     dl, dl                 " \
      "adc     ecx, ecx               " \
      "jmp     short getgammaloop     " \
"getgammabit:                         " \
      "dec     dh                     " \
      "jnz     stillbitsleft4         " \
      "mov     dl, [esi]              " \
      "inc     esi                    " \
      "mov     dh, 8                  " \
"stillbitsleft4:                      " \
      "add     dl, dl                 " \
      "adc     ecx, ecx               " \
      "ret                            " \
"donedepacking:                       " \
      "pop     ebp                    " \
   parm   [esi] [edi] \
   modify exact [eax ebx ecx edx ebp esi edi];

void aP_depack_asm(unsigned char *, unsigned char *);
#pragma aux aP_depack_asm = \
      "push    ebp                    " \
      "cld                            " \
      "mov     dh, 1                  " \
"nexttag:                             " \
      "call    getbit                 " \
      "jc      not_literal            " \
"literal:                             " \
      "movsb                          " \
      "jmp     short nexttag          " \
"not_literal:                         " \
      "call    getbit                 " \
      "jnc     codepair               " \
      "call    getbit                 " \
      "jnc     shortmatch             " \
      "xor     ecx, ecx               " \
      "call    getgammabit            " \
      "call    getgammabit            " \
      "call    getgammabit            " \
      "call    getgammabit            " \
      "mov     ebx, ecx               " \
      "mov     cl, 1                  " \
      "test    ebx, ebx               " \
      "jnz     domatch                " \
      "xchg    eax, ebx               " \
      "jmp     short domatch_continue " \
"codepair:                            " \
      "call    getgamma               " \
      "dec     ecx                    " \
      "dec     ecx                    " \
      "jnz     normalcodepair         " \
      "mov     ebx, ebp               " \
      "call    getgamma               " \
      "jmp     short domatch          " \
"normalcodepair:                      " \
      "dec     ecx                    " \
      "shl     ecx, 8                 " \
      "lodsb                          " \
      "mov     cl, al                 " \
      "mov     eax, ecx               " \
      "mov     ebp, eax               " \
      "xchg    eax, ebx               " \
      "call    getgamma               " \
      "cmp     ebx, 127               " \
      "ja      domatch                " \
      "inc     ecx                    " \
      "inc     ecx                    " \
      "jmp     short domatch          " \
"shortmatch:                          " \
      "lodsb                          " \
      "xor     ecx, ecx               " \
      "shr     al, 1                  " \
      "jz      donedepacking          " \
      "adc     ecx, 2                 " \
      "cbw                            " \
      "cwde                           " \
      "xchg    eax, ebx               " \
"domatch:                             " \
      "neg     ebx                    " \
"copydata:                            " \
      "mov     al, [edi+ebx]          " \
"domatch_continue:                    " \
      "stosb                          " \
      "loop    copydata               " \
      "jmp     short nexttag          " \
"getbit:                              " \
      "dec     dh                     " \
      "jnz     stillbitsleft          " \
      "lodsb                          " \
      "xchg    eax, edx               " \
      "mov     dh, 8                  " \
"stillbitsleft:                       " \
      "add     dl, dl                 " \
      "ret                            " \
"getgamma:                            " \
      "mov     ecx, 1                 " \
"getgammaloop:                        " \
      "call    getbit                 " \
      "jnc     getgammabit            " \
      "call    getgammabit            " \
      "jmp     short getgammaloop     " \
"getgammabit:                         " \
      "call    getbit                 " \
      "adc     ecx, ecx               " \
      "ret                            " \
"donedepacking:                       " \
      "pop     ebp                    " \
   parm   [esi] [edi] \
   modify exact [eax ebx ecx edx ebp esi edi];

#endif