delphi asm code win32 vs win64

Question

My project in Delphi 10.1 has some assembly functions like this:

  function MyFunc: Word;
  asm
    PUSH   0
    FNSTCW [ESP].Word
    POP    EAX
  end;

I need compile project in win64, but some lines like POP EAX has E2116 Invalid combination of opcode and operands Error.

Answer 1

Rather than translating the assembly to x64, you should use the Get8087CW() function in the System unit instead. It should work fine for both platforms (Win32/Win64):

function MyFunc: Word;
begin
  Result := Get8087CW;
end;

In order to translate any other assembly code (which you didn't provide here) from x86 to x64, I suggest you to learn x64 assembling programming.