The following is a compilation of Delphi, added to the Lazarus project error

[myisjwj]

The following is a compilation of Delphi, added to the Lazarus project only 32-bit cpu available, 64-bit error

Code: Pascal  [Select][+][-]

1. function StdWndProc(Window: HWND; Message: UINT; WParam: WPARAM; LParam: WPARAM): LRESULT; stdcall;
2. {$IF Defined(CPUX86)}
3. { In    ECX = Address of method pointer }
4. { Out   EAX = Result }
5. asm
6.         XOR     EAX,EAX
7.         PUSH    EAX
8.         PUSH    LParam
9.         PUSH    WParam
10.         PUSH    Message
11.         MOV     EDX,ESP
12.         MOV     EAX,[ECX].Longint[4]
13.         CALL    [ECX].Pointer
14.         ADD     ESP,12
15.         POP     EAX
16. end;
17. {$ELSEIF Defined(CPUX64)}
18. { In    R11 = Address of method pointer }
19. { Out   RAX = Result }
20. var
21.   Msg: TMessage;
22. asm
23.         .PARAMS 2 //Error: Not a directive or local symbol .PARAMS; Error: Unrecognized opcode .PARAMS;Assembler syntax error
24.         MOV     Msg.Msg,Message
25.         MOV     Msg.WParam,WParam
26.         MOV     Msg.LParam,LParam
27.         MOV     Msg.Result,0 //Error: Invalid reference syntax
28.         LEA     RDX,Msg //Unknown identifier "RDX"
29.         MOV     RCX,[R11].TMethod.Data//Unknown identifier "RCX";Error: Assembler syntax error in operand;Error: Unknown identifier "R11";Error: Assembler syntax error in operand;Error: Unknown identifier ".TMethod";Error: Assembler syntax error in operand;Error: Unknown identifier "DATA"
30.         CALL    [R11].TMethod.Code //Error: Assembler syntax error in operand; Error: Unknown identifier "R11"; Error: Assembler syntax error in operand; Error: Unknown identifier ".TMethod"; Error: Assembler syntax error in operand; Error: Unknown identifier "CODE"
31.         MOV     RAX,Msg.Result//Error: Unknown identifier "RAX"
32. end;
33.  
34. {$ENDIF CPUX64}

How to rewrite the 64-bit assembly

[Fibonacci]

{$asmmode intel}

[myisjwj]

Thank you very much Fibonacci
Added {$asmmode intel} other lines do not report errors. But the first line
.PARAMS 2
Still report an error
Error: Not a directive or local symbol .PARAMS

[Thaddy]

That is mitigated by the closing [register..register] in FPC, but it is indeed an incompatibility. Name the registers used (predates delphi)
It solves the same problem.
(then again, why? because the compiler does a better job here - not always -.
Pointless use of assembler.)

[marcov]

The win64 stackframe has rules about the shadow store, allocating stack space for register parameters (if not leaf?). https://www.ired.team/miscellaneous-reversing-forensics/windows-kernel-internals/windows-x64-calling-convention-stack-frame

There already is a bugreport for some of the many missing x64 pseudo directives. https://gitlab.com/freepascal.org/fpc/source/-/issues/31012

[Thaddy]

So declaring a local field of size 32 bytes together with nostackframe will do that?
Something along the lines:

Code: Pascal  [Select][+][-]

1. type
2.   TstackallocMem = packed array[0..31] of byte;
3.  
4. procedure testme(a,b:integer);assembler;nostackframe;
5. var
6.    tm:TstackallocMem;// 32 packed bytes on top of stack? this can be seen by compiling with -al in the s file
7. asm
8. .....
9. end;

Not tested, but something along that line should work. But again, this is a silly use of assembler given what the compiler already generates in -O3 or higher and using pure Pascal. Almost identical....It is just setting up the function call, why bother doing that in assembler?
It is certainly not "faster"...Speed by assembler to setup just a function call is a misconception.
Or is there some other reason, where it really does matter? Such cases exist, but not here:You have to show us a better use-case.
And using pure Pascal has the advantage that it is really FPU agnostic.
That said, Marcov is much better versed in all kind of asm trickery with a background in image manipulation.
But don't use assembler just to set up a function call!, that is, well, clueless and pointless. It really is...

[marcov]

It might in Delphi, since it introduced those options.