function FirstCharInBuffer(const C: Char; const Buffer,BufLen,StartPos: Integer): Integer;
asm
  //eax <-- C
  //edx <-- Buffer
  //ecx <-- BufLen

  //Comment out for speed. In this unit, it is impossible! But if you copy and
  //paste this function to other place, it is safe not comment out following 2
  //blocks

  //Buffer is NULL ?
  //test edx,edx
  //je @@Exit

  //BufLen <= 0 ?
  //cmp ecx,0
  //jle @@Exit

 //BufLen <= StartPos ?
  cmp ecx,StartPos
  jle @@Exit

  //if (BufLen <= StartPos) then
  //begin // over bounds
  //  Result := -1;
   // Exit;
 // end;

  //save register
  push edi

  mov edi,edx
  add edi,StartPos
  sub ecx,StartPos

@@Compare:
  //repne scasb, optimize for speed, 2001.11.6
  cmp al,[edi]
  je @@Found
  inc edi
  dec ecx
  test ecx,ecx
  jz @@NotFound
  jmp @@Compare

@@Found:
  mov eax,edi
  sub eax,edx

  //restore register
  pop edi
  jmp @@OK

@@NotFound:
  //restore register
  pop edi

@@Exit:
  xor eax,eax
  dec eax

@@OK:
end;

function FirstCharInBuffer(const C: Char; const Buffer,BufLen,StartPos: Integer): Integer;
var
  P: PChar;
  Remain: Integer;
  Mpos:PChar;
  edi,ecx:Integer;
  CurrentLen: Integer;    
  CurrentByte: Byte;
  BufAsByte: Array of Byte absolute Buffer;
begin
   CurrentLen := StartPos;
   if (BufLen <= 0) or (BufLen <= StartPos) then
   begin // over bounds
    Result := -1;
    Exit;
   end;
   edi := Buffer;
   edi := edi+StartPos;
   ecx := BufLen-StartPos;
   while edi <= BufLen do
    CurrentByte := BufAsByte[edi];
  begin
      if(CurrentByte = edi)then
      begin
          inc(edi);
      end;
  end;
   Result := -1;
   Exit;
end;

function FirstCharInBuffer(const C: Char; const Buffer; BufLen, StartPos: Integer): Integer;