{---------------------------------------------------------------------------
(c) Copyright	 Aleksandrov O.E., 1999

   Molecular Physics department, USTU, Ekaterinsburg, K-2, 620002, RUSSIA
   phone 75-47-15
   E-mail: aleks@dpt.ustu.ru

(c) Copyright Александров О.Е., 1999

   620002, Екатеринбург, К-2, УГТУ, Кафедра молекулярной физики
   тел. 75-47-15
   E-mail: aleks@dpt.ustu.ru
----------------------------------------------------------------------------}
{$O+,F+,N-,S-,Q-}
{ Delphi 3 compatible }
{$IfDef VER70} {$Define Seg16} {$EndIf}
Unit xStrings;

INTERFACE

{$IfDef Seg16}
procedure Exchange(var var1,var2; size:word);
function Equal(const p1,p2; size:word):boolean;
function FindDifference(const p1,p2; size:word):word;
{БЫСТРОЕ заполнение участка памяти шаблоном}
procedure FillMemByPattern(var Memory;  Size:word;
			   const Pattern; PatternSize:word);
procedure FillMemByByte(var Memory;  Size:word; b:Byte);
procedure FillMemByWord(var Memory;  Size:word; w:Word);
{$Else IfDef Seg16}
procedure Exchange(var var1,var2; size:cardinal); register;
function Equal(const p1,p2; size:cardinal):boolean;
function FindDifference(const p1,p2; size:cardinal):cardinal;
{БЫСТРОЕ заполнение участка памяти шаблоном}
procedure FillMemByPattern(var Memory;  Size:cardinal;
			   const Pattern; PatternSize:cardinal);
procedure FillMemByByte(var Memory;  Size:cardinal; b:Byte);
procedure FillMemByWord(var Memory;  Size:cardinal; w:Word);
{$EndIf Def Seg16}

procedure myMove(var src,dst; size:word);
procedure xxMove;
procedure MoveStr(src:string; var dst:string);
procedure MoveDiff(var src,dst; size:word);

function BytesSum(var area; size:word):longint;

function AscizLength(var beg):word;
function AscizLenLim(var beg; uplimit:word):word;

function NthStr(var fstr; num:word):string;

function CopyToStr(str:Pointer; n:Byte):string;
function Asciz2String(str:PChar):string;

procedure FillByteArray(var ByteArray:array of byte;  b:Byte);
procedure FillWordArray(var WordArray:array of word;  w:word);

IMPLEMENTATION

procedure FillByteArray(var ByteArray:array of byte;  b:Byte);
begin
  FillMemByByte(ByteArray,  Succ(High(ByteArray)), b);
end;

procedure FillWordArray(var WordArray:array of word;  w:word);
begin
  FillMemByWord(WordArray,  Succ(High(WordArray)), w);
end;

procedure FillMemByByte;
assembler;
{$IfNDef Delphi}
asm
  mov cx,Size; jcxz @End
  les di,Memory; mov al,b
  cld
  shr cx,1; jnc @FillW
   stosb
  jcxz @End
  @FillW:
  mov ah,al
  rep stosw
  @End:
end;
{$Else IfNDef Delphi}
asm
  {mov ecx,Size;} jcxz @Skip
  push edi
  mov edi,Memory;
  mov al,b
  shr cx,1; jnc @FillW
   stosb
  jcxz @End
  @FillW:
   mov ah,al
   stosw
  jcxz @End
  @FillDW:
   mov ah,al; mov dx,ax; shl eax,16; mov ax,dx
   rep stosd
  @End:
  pop edi
  @Skip:
end;
{$EndIf NDef Delphi}

procedure FillMemByWord;
assembler;
{$IfNDef Delphi}
asm
  mov cx,Size; jcxz @End
  les di,Memory; mov ax,w
  cld
  rep stosw
  @End:
end;
{$Else IfNDef Delphi}
asm
  {mov ecx,Size;} jcxz @Skip
  push edi
  mov edi,Memory;
  mov ax,w;
  shr cx,1; jnc @FillDW
   stosw
  jcxz @End
  @FillDW:
   mov dx,ax; shl eax,16; mov ax,dx
   rep stosd
  @End:
  pop edi
  @Skip:
end;
{$EndIf NDef Delphi}

procedure FillMemByPattern;
assembler;
{$IfNDef Delphi}
asm
  push ds
  mov ax,Size
  mov dx,PatternSize;
  mov cx,dx
  cmp ax,cx; jae @Cont
    mov cx,ax
  @Cont:
  jcxz @Done
  les di,Memory;  mov bx,di
  lds si,Pattern
  cld
  {копирование 1 Pattern в Memory}
  shr cx,1
  jnc @FillWords
    movsb; jcxz @Skip
  @FillWords:
    rep movsw
  @Skip:
  {копирование остального}
  mov cx,ax; sub cx,dx; jbe @Done
    mov si,bx; mov dx,es; mov ds,dx
    shr cx,1
    jnc @AFillWords
      movsb; jcxz @ASkip
    @AFillWords:
      rep movsw
    @ASkip:
  @Done:
  pop ds
end;
(*asm
  push ds
  les di,Memory; mov ax,Size;
  lds bx,Pattern; mov dx,PatternSize;
  cld
  @Loop:
    sub ax,dx; jc @EndLoop
    call @SubMove
  jmp @Loop
  { begin -- локальная подпрограмма --}
      @SubMove:
	mov si,bx;
	mov cx,dx; shr cx,1
	jnc @FillWords
	  movsb
	@FillWords:
	  rep movsw
      retn
  { end -- локальная подпрограмма --}
  @EndLoop:
    add ax,dx; mov dx,ax; call @SubMove
    pop ds
end;*)
{$Else IfNDef Delphi}
asm
  push ebx; push esi; push edi
  mov edi,Memory;  mov eax,Size;
  mov esi,Pattern; mov edx,PatternSize;
  mov ecx,edx
  cmp eax,ecx; jae @Cont
    mov ecx,eax
  @Cont:
  jecxz @Done
  mov ebx,edi
  {копирование 1 Pattern в Memory}
  shr cx,1
  jnc @FillWords
    movsb; jcxz @Skip
  @FillWords:
    rep movsw
  @Skip:
  {копирование остального}
  mov ecx,eax; sub ecx,edx; jbe @Done
    mov esi,ebx
    shr cx,1
    jnc @AFillWords
      movsb; jcxz @ASkip
    @AFillWords:
      rep movsw
    @ASkip:
  @Done:
  pop edi; pop esi; pop ebx
end;
(*asm
  push ebx; push esi; push edi
  mov edi,Memory;
  mov eax,Size;
  mov ebx,Pattern;
  mov edx,PatternSize;
  @Loop:
    sub eax,edx; jc @EndLoop
    call @SubMove
  jmp @Loop
  { begin -- локальная подпрограмма --}
      @SubMove:
	mov esi,ebx;
	mov ecx,edx; shr ecx,1
	jnc @FillWords
	  movsb
	@FillWords:
	  rep movsw
      retn
  { end -- локальная подпрограмма --}
  @EndLoop:
    add eax,edx; mov edx,eax; call @SubMove
  pop edi; pop esi; pop ebx
end;*)
{$EndIf NDef Delphi}

{-----------------------------------------------------------------------------}
{  Exchange - обменивает местами две области памяти }
procedure Exchange;
  assembler;
{$IfDef Seg16}
  asm
    cld                        { ;exchange goes upward}
    mov     dx,ds              { ;save DS}
    lds     si,var1            { ;get first address}
    les     di,var2            { ;get second address}
    mov     cx,size            { ;get number of bytes to exchange}
    shr     cx,1               { ;get word count (low bit -> carry)}
    jnc     @ExchangeWords     { ;if no odd byte, enter loop}
      mov     al,es:[di]         { ;read odd byte from var2}
      movsb                      { ;move a byte from var1 to var2}
      mov     [si-1],al          { ;write var2 byte to var1}
    @ExchangeWords:
    jcxz    @Finis             { ;done if only one byte to exchange}
    mov     bx,-2              { ;BX is a handy place to keep -2}
    @ExchangeWordsLoop:
       mov     ax,es:[di]         { ;read a word from var2}
       movsw                      { ;do a move from var1 to var2}
       mov     [bx][si],ax        { ;write var2 word to var1}
    loop @ExchangeWordsLoop    { ;repeat "count div 2" times}
    @Finis:
    mov     ds,dx              { ;get back Turbo's DS}
  end;
{$Else IfDef Seg16}
  asm
    push ebx; push esi; push edi
    mov     esi,var1            { ;get first address}
    mov     edi,var2            { ;get second address}
//    mov     cx,size            { ;get number of bytes to exchange }
    shr     ecx,1               { ;get word count (low bit -> carry)}
    jnc     @ExchangeWord     { ;if no odd byte, enter loop}
      mov     al,[edi]         { ;read odd byte from var2}
      movsb                      { ;move a byte from var1 to var2}
      mov     [esi-1],al          { ;write var2 byte to var1}
    @ExchangeWord:
    shr     ecx,1               { ;get Dword count (low bit -> carry)}
    jnc     @ExchangeDWords     { ;if no odd word, enter loop}
      mov     ax,[edi]         { ;read odd byte from var2}
      movsw                      { ;move a byte from var1 to var2}
      mov     [esi-2],ax          { ;write var2 word to var1}
    @ExchangeDWords:
    jecxz    @Finis            { ;done if less than one dword to exchange}
    mov     ebx,-4              { ;BX is a handy place to keep -4}
    @ExchangeDWordsLoop:
       mov     eax,[edi]         { ;read a word from var2}
       movsd                      { ;do a move from var1 to var2}
       mov     [ebx][esi],eax        { ;write var2 dword to var1}
    loop @ExchangeDWordsLoop    { ;repeat "count div 2" times}
    @Finis:
    pop edi; pop esi; pop ebx
  end;
{$EndIf Def Seg16}


procedure xxMove;
{ DX:SI -> source; ES:DI -> dest; CX:=count of bytes }
assembler;
{$IfDef Seg16}
  asm
    jcxz @End
    cmp Test8086,2
    mov ax,ds; mov ds,dx; cld
    jae @cpu386

    cmp si,di
    jae @Forward
      std
      dec cx; add si,cx; add di,cx; inc cx; movsb
    @Forward:
      shr cx,1  { CX:=CX div 2;  CF:=CX mod 2 }
      jnc @MWrds
	movsb
      @MWrds: rep movsw
    jmp @Exit

@cpu386:
    cmp si,di
    jae @Forward3
      std
      dec cx; add si,cx; add di,cx; inc cx
      shr cx,1  { CX:=CX div 2;  CF:=CX mod 2 }
      jnc @NoByte3
	movsb
      @NoByte3:
	dec si; dec di
	shr cx,1; jnc @NoWord3
	  movsw
	@NoWord3:
	  sub si,2; sub di,2
	jmp @MDW3
    @Forward3:
      shr cx,1  { CX:=CX div 2;  CF:=CX mod 2 }
      jnc @MW3
	movsb
      @MW3: shr cx,1; jnc @MDW3
	movsw
      @MDW3: jcxz @SkipMDW3
	db $F3, $66, $A5 {rep movsd}
      @SkipMDW3:

    @Exit:
    cld
    mov ds,ax
    @End:
  end;
{$Else IfDef Seg16}
{ ESI -> source; EDI -> dest; ECX:=count of bytes }
  asm
    jcxz @Skip
    cmp esi,edi
    jae @Forward3
      std
      dec ecx; add esi,ecx; add edi,ecx; inc ecx
      shr cx,1  { CX:=CX div 2;  CF:=CX mod 2 }
      jnc @NoByte3
	movsb
      @NoByte3:
	dec esi; dec edi
	shr ecx,1; jnc @NoWord3
	  movsw
	@NoWord3:
	  sub esi,2; sub edi,2
	jmp @MDW3
    @Forward3:
      cld
      shr ecx,1  { CX:=CX div 2;  CF:=CX mod 2 }
      jnc @MW3
	movsb
      @MW3: shr ecx,1; jnc @MDW3
	movsw
      @MDW3: jecxz @SkipMDW3
	rep movsd
      @SkipMDW3:

   @Skip:
  end;
{$EndIf Def Seg16}

procedure myMove;
assembler;
{$IfDef Seg16}
  asm
    mov cx,size; les si,src; mov dx,es; les di,dst;
    push cs
    call near(xxMove)
  end;
{$Else Seg16}
  asm
    push ebx; push esi; push edi
    xor ecx,ecx; mov cx,size;
    mov esi,src; mov edi,dst;
    call xxMove
    cld
    pop edi; pop esi; pop ebx
  end;
{$EndIf Def Seg16}

procedure MoveStr;
assembler;
{$IfDef Seg16}
  asm
    les si,src; mov cl,es:[si]; xor ch,ch; inc cx; mov dx,es;
    les di,dst
    push cs
    call near(xxMove)
  end;
{$Else Seg16}
  asm
    push ebx; push esi; push edi
    mov esi,src; mov cl,[esi]; xor ch,ch; inc cx; mov edi,dst
    call xxMove
    cld
    pop edi; pop esi; pop ebx
  end;
{$EndIf Def Seg16}

procedure MoveDiff;
  assembler;
{$IfDef Seg16}
  asm
    mov dx,ds { Сохранение DS }
    mov cx,size;
    lds si,src
    les di,dst
    cld
    shr cx,1  { CX:=CX div 2 }
    jnc @NoM
      movsb
    @NoM: rep movsw
    mov ds,dx { Восстановление DS }
  end;
{$Else Seg16}
  asm
    push ebx; push esi; push edi
    xor ecx,ecx;
    mov cx,size;
    mov esi,src
    mov edi,dst
    cld
    shr ecx,1  { CX:=CX div 2 }
    jnc @NoMB
      movsb
    @NoMB:
    shr ecx,1  { CX:=CX div 2 }
    jnc @NoMW
      movsw
    @NoMW: rep movsd
    pop edi; pop esi; pop ebx
  end;
{$EndIf Def Seg16}

function BytesSum(var area; size:word):longint;
  assembler;
{$IfDef Seg16}
  asm
    xor ax,ax; xor dx,dx
    mov cx,size; jcxz @End
    mov di,ds; lds si,area; xor bx,bx
    cld
    @loop:
      lodsb; add bx,ax; adc dx,0
    loop @loop
    mov ax,bx
    mov ds,di
    @End:
  end;
{$Else Seg16}
  asm
    xor eax,eax
    xor ecx,ecx;
    mov cx,size; jecxz @End
    push ebx; push esi
    mov esi,area; xor ebx,ebx
    cld
    @loop:
      lodsb; add ebx,eax
    loop @loop
    mov eax,ebx
    pop esi; pop ebx
    @End:
  end;
{$EndIf Def Seg16}

{$IfDef Seg16}
function Equal(const p1,p2; size:word):boolean;
 { Check the equivalence of two memory areas
    P1 -> first area;
    P2 -> second area;
    SIZE:= size of areas to compare;

    Return: TRUE - if equal, FALSE - if not equal.
 }
  assembler;
  asm
    mov dx,ds { Сохранение DS }
    mov cx,size;
    jcxz @OK
    les di,p1; lds si,p2
    xor al,al
    cld
    shr cx,1  { CX:=CX div 2; CF:=CX mod 2 }
    jnc @CmpWords
      cmpsb; jne @END
    @CmpWords: jcxz @OK
      repe cmpsw
    jne @END
      @OK:
      mov al,TRUE { AL:=TRUE }
    @End:
    mov ds,dx { Восстановление DS }
  end;
{$Else Seg16}
function Equal(const p1,p2; size:cardinal):boolean;
 { Check the equivalence of two memory areas
    P1 -> first area;
    P2 -> second area;
    SIZE:= size of areas to compare;

    Return: TRUE - if equal, FALSE - if not equal.
 }
  assembler;
  asm
    push ebx; push esi; push edi
    mov ecx,size
    jecxz @OK
    mov edi,p1
    mov esi,p2
    xor eax,eax
    shr cx,1  { CX:=CX div 2; CF:=CX mod 2 }
    jnc @CmpWords
      cmpsb; jne @END
    @CmpWords:
    shr cx,1  { CX:=CX div 2; CF:=CX mod 2 }
    jnc @CmpDWords
      cmpsw; jne @END
    @CmpDWords: jecxz @OK
      repe cmpsd
    jne @END
    @OK:
      mov eax,TRUE { AL:=TRUE }
    @End:
    pop edi; pop esi; pop ebx
  end;
{$EndIf Def Seg16}

{$IfDef Seg16}
function FindDifference(const p1,p2; size:word):word;
  assembler;
  asm
    mov dx,ds { Сохранение DS }
    mov cx,size; les di,p1; lds si,p2
    cld
    mov ax,cx
    repe cmpsb
    je @OK
      sub ax,cx; inc ax
    jmp @End
    @OK:
      xor ax,ax
    @End:
    mov ds,dx { Восстановление DS }
  end;
{$Else Seg16}
function FindDifference(const p1,p2; size:cardinal):cardinal;
  assembler;
  asm
    push ebx; push esi; push edi
    mov ecx,size;
    mov edi,p1
    mov esi,p2
    mov eax,ecx;
    cld
    repe cmpsb
    xchg eax,ecx
    je @END
      xchg eax,ecx; sub eax,ecx; inc eax
    @End:
    pop edi; pop esi; pop ebx
  end;
{$EndIf Def Seg16}

function AscizLen:word; near;
assembler;
{$IfDef Seg16}
    asm
      mov bx,cx
      cld
      xor al,al; repne scasb
      xchg ax,bx; sub ax,cx
      dec ax
    end;
{$Else Seg16}
  asm
    mov ebx,ecx
    cld
    xor al,al; repne scasb
    xchg eax,ebx; sub eax,ecx
    dec eax
  end;
{$EndIf Def Seg16}

function AscizLength;
assembler;
{$IfDef Seg16}
    asm
      les di,beg  { Load addres to ES:[DI] }
      mov cx,$FFFF
      call AscizLen
    end;
{$Else Seg16}
  asm
    push ebx; push edi
    mov edi,beg  { Load addres to EDI }
    mov ecx,$FFFFFFFF
    call AscizLen
    pop edi; pop ebx
  end;
{$EndIf Def Seg16}

function AscizLenLim;
assembler;
{$IfDef Seg16}
    asm
      les di,beg  { Load addres to ES:[DI] }
      mov cx,uplimit
      call AscizLen
    end;
{$Else Seg16}
  asm
    push ebx; push edi
    mov edi,beg  { Load addres to ES:[DI] }
    xor ecx,ecx; mov cx,uplimit
    call AscizLen
    pop edi; pop ebx
  end;
{$EndIf Def Seg16}
{---------------------------------------------------------------------------}

function NthStr(var fstr; num:word):string;
assembler;
{$IfDef Seg16}
asm
  mov cx,num
  cld; les si,fstr; xor ah,ah; jcxz @First
  @Loop:
     SEGES lodsb; add si,ax
  loop @Loop
  @First:
  push es; push si
  les di,@Result; push es; push di
  {$IFOPT P+}
    {$IFOPT G+} push $ff {$ELSE} mov ax,$FF; push ax {$ENDIF}
  {$ENDIF}
  call MoveStr
end;
{$Else Seg16}
asm
  push ebx; push esi; push edi
  xor ecx,ecx; mov cx,num
  cld; mov esi,fstr; xor eax,eax; jecxz @First
  @Loop:
    lodsb; add esi,eax
  loop @Loop
  @First:
  mov edi,@Result
  xor ecx,ecx; mov cl,[esi]
  call xxMove
  pop edi; pop esi; pop ebx
end;
{$EndIf Def Seg16}

function CopyToStr;
assembler;
{$IfDef Seg16}
asm
  cld
  les di,@Result
  mov al,n
  stosb
  xor ah,ah; xchg ax,cx; jcxz @Exit
  mov dx,ds
  lds si,str
  shr cx,1  { CX:=CX div 2 }
  jnc @NoM
    movsb
  @NoM: rep movsw
  mov ds,dx
  @Exit:
end;
{$Else Seg16}
asm
  push ebx; push esi; push edi
  mov esi,str
  mov edi,@Result
  xor ecx,ecx
  mov cl,n
  call xxMove
  cld
  pop edi; pop esi; pop ebx
end;
{$EndIf Def Seg16}

function Asciz2String(str:PChar):string;
assembler;
{$IfDef Seg16}
asm
  les di,str  { Load addres to ES:[DI] }
  mov cx,255
  call AscizLen
  cld
  les di,@Result
  stosb
  xor ah,ah; xchg ax,cx; jcxz @Exit
  mov dx,ds
  lds si,str
  shr cx,1  { CX:=CX div 2 }
  jnc @NoM
    movsb
  @NoM: rep movsw
  mov ds,dx
  @Exit:
end;
{$Else Seg16}
asm
  push ebx; push esi; push edi
  mov esi,str
  mov edi,str  { Load addres to EDI }
  mov ecx,255
  call AscizLen
  mov edi,@Result
  call xxMove
  pop edi; pop esi; pop ebx
end;
{$EndIf Def Seg16}
END.