Findfirst/Findnext in Assembler

[neolithos]

Aus Classes.pas

Delphi-Quellcode:

procedure BinToHex(Buffer, Text: PChar; BufSize: Integer); assembler;
const
  Convert: array[0..15] of Char = '0123456789ABCDEF';
var
  I: Integer;
begin
  for I := 0 to BufSize - 1 do
  begin
    Text[0] := Convert[Byte(Buffer[I]) shr 4];
    Text[1] := Convert[Byte(Buffer[I]) and $F];
    Inc(Text, 2);
  end;
end;
{asm
        PUSH    ESI
        PUSH    EDI
        MOV     ESI,EAX
        MOV     EDI,EDX
        MOV     EDX,0
        JMP     @@1
@@0:    DB      '0123456789ABCDEF'
@@1:    LODSB
        MOV     DL,AL
        AND     DL,0FH
        MOV     AH,@@0.Byte[EDX]
        MOV     DL,AL
        SHR     DL,4
        MOV     AL,@@0.Byte[EDX]
        STOSW
        DEC     ECX
        JNE     @@1
        POP     EDI
        POP     ESI
end;}

function HexToBin(Text, Buffer: PChar; BufSize: Integer): Integer; assembler;
const
  Convert: array['0'..'f'] of SmallInt =
    ( 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,-1,-1,-1,-1,-1,-1,
     -1,10,11,12,13,14,15,-1,-1,-1,-1,-1,-1,-1,-1,-1,
     -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
     -1,10,11,12,13,14,15);
var
  I: Integer;
begin
  I := BufSize;
  while I > 0 do
  begin
    if not (Text[0] in ['0'..'f']) or not (Text[1] in ['0'..'f']) then Break;
    Buffer[0] := Char((Convert[Text[0]] shl 4) + Convert[Text[1]]);
    Inc(Buffer);
    Inc(Text, 2);
    Dec(I);
  end;
  Result := BufSize - I;
end;

{asm
        PUSH    ESI
        PUSH    EDI
        PUSH    EBX
        MOV     ESI,EAX
        MOV     EDI,EDX
        MOV     EBX,EDX
        MOV     EDX,0
        JMP     @@1
@@0:    DB       0, 1, 2, 3, 4, 5, 6, 7, 8, 9,-1,-1,-1,-1,-1,-1
        DB      -1,10,11,12,13,14,15,-1,-1,-1,-1,-1,-1,-1,-1,-1
        DB      -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
        DB      -1,10,11,12,13,14,15
@@1:    LODSW
        CMP     AL,'0'
        JB      @@2
        CMP     AL,'f'
        JA      @@2
        MOV     DL,AL
        MOV     AL,@@0.Byte[EDX-'0']
        CMP     AL,-1
        JE      @@2
        SHL     AL,4
        CMP     AH,'0'
        JB      @@2
        CMP     AH,'f'
        JA      @@2
        MOV     DL,AH
        MOV     AH,@@0.Byte[EDX-'0']
        CMP     AH,-1
        JE      @@2
        OR      AL,AH
        STOSB
        DEC     ECX
        JNE     @@1
@@2:    MOV     EAX,EDI
        SUB     EAX,EBX
        POP     EBX
        POP     EDI
        POP     ESI
end;}