Delphi Programming/Assembler in Delphi

Since Turbo Pascal 1.0, the use of assembly code within Borland (currently Embarcadero) languages was quite easy.

In Delphi, simply put an assembly block between asm...end; within a code block, or you can declare a whole function procedure as assembler.

Global or local variables can be used normally, but of course they will work as pointers.

Examples:

function StrLen(S: PChar): Cardinal;
begin
  asm
    MOV   EDX, EDI
    MOV   EDI, EAX
    MOV   ECX,0FFFFFFFFh
    XOR   AL, AL
    REPNE SCASB
    MOV   EAX, 0FFFFFFFEh
    SUB   EAX, ECX
    MOV   EDI, EDX
  end;
end;

function StrLen(S: PChar): Cardinal;
asm
  MOV   EDX, EDI
  MOV   EDI, EAX
  MOV   ECX, 0FFFFFFFFh
  XOR   AL, AL
  REPNE SCASB
  MOV   EAX, 0FFFFFFFEh
  SUB   EAX, ECX
  MOV   EDI, EDX
end;