Delphi 64 bits asm compiling error

The following functions do not compile with the 64 bits Delphi XE2 compiler. (The errors all relate to the fld instructions.)

[dcc64 Error] Project1.dpr(12): E2116 Invalid combination of opcode and operands 
[dcc64 Error] Project1.dpr(13): E2116 Invalid combination of opcode and operands
[dcc64 Error] Project1.dpr(20): E2116 Invalid combination of opcode and operands

Line 12 & 13:

fld Y
fld X

Line 20:

fld X

Unfortunately I have no assembly skills and I am using this third party code which I need to port to 64 bits. Can you help me in making it work on both 32 bits and 64 bits?

function PartArcTan(Y, X: Extended): Extended;
asm
  fld Y              // st(0) = Y
  fld X              // st(0) = X
  fpatan             // st(0) = ArcTan(Y, X)
  fwait
end;

function ArcSin(X: Extended): Extended; // -1 <= X <= 1
asm
  fld X               // st(0) = X
  fld st(0)           // st(1) = X
  fmul st(0), st(0)   // st(0) = Sqr(X)
  fld1                // st(0) = 1
  fsubrp st(1), st(0) // st(0) = 1 - Sqr(X)
  fsqrt               // st(0) = Sqrt(1 - Sqr(X))
  fpatan              // st(0) = ArcTan(X, Sqrt(1 - X*X))
  fwait
end;