unit Tools;

interface
uses
  Sysutils;

type
{$IFDEF VER120}
  dword = longword;
{$ELSE}
  dword = longint;
{$ENDIF}

function LRot16(X: word; c: integer): word; assembler;
function RRot16(X: word; c: integer): word; assembler;
function LRot32(X: dword; c: integer): dword; assembler;
function RRot32(X: dword; c: integer): dword; assembler;
procedure XorBlock(I1, I2, O1: PByteArray; Len: integer);
procedure IncBlock(P: PByteArray; Len: integer);

implementation

function LRot16(X: word; c: integer): word; assembler;
asm
  mov ecx,&c
  mov ax,&X
  rol ax,cl
  mov &Result,ax
end;

function RRot16(X: word; c: integer): word; assembler;
asm
  mov ecx,&c
  mov ax,&X
  ror ax,cl
  mov &Result,ax
end;

function LRot32(X: dword; c: integer): dword; register; assembler;
asm
  mov ecx, edx
  rol eax, cl
end;

function RRot32(X: dword; c: integer): dword; register; assembler;
asm
  mov ecx, edx
  ror eax, cl
end;

procedure XorBlock(I1, I2, O1: PByteArray; Len: integer);
var
  i: integer;
begin
  for i := 0 to Len - 1 do
    O1[i] := I1[i] xor I2[i];
end;

procedure IncBlock(P: PByteArray; Len: integer);
begin
  Inc(P[Len - 1]);
  if (P[Len - 1] = 0) and (Len > 1) then
    IncBlock(P, Len - 1);
end;

end.