Passing QWord in 32-bit program

[LemonParty]

Let's say I have a function:

Code: Pascal  [Select][+][-]

1. function F1(A, B: Integer; C: QWord): Integer
2. begin
3.  
4. end;
5.  

In what registers passing C in 32-bit mode?

[Thaddy]

A EAX
B EDX
C ECX
This is explicitly 32 bit Intel only and only for what you describe.

If you did not know that, you should not use it! You will crash your computer.
Usually the compiler is better.
But feel free to wander into the useless world of assembler "optimizations" which was only relevant 25 years ago. Great fun and guaranteed to crash....
Unless highly specialized work is required, stay away from assembler on modern compilers. It is fun but very seldomly faster..
(marcov has some cases where it is faster)

If you did not know the first, you are likely to write slower code when attempting to use assembler.
That is not what you want, is it?

[Nimbus]

Obviously a 64-bit QWord won't fit in a 32-bit register. It will be put on stack instead.

[LemonParty]

Yes. C is passing over stack and located at [ebp+8].

[d2010]

Code: [Select]

Type myQ32word=array[0..16] of integer;end;
Type myQ16word=array[0..32] of word;end;

inside BPW.exe you define function F1(A, B: Integer; C: Q16Word): Integer
inside Lazarus32x  function F1(A, B: Integer; C: Q32Word): Integer
The range 0..16 is corecty? or 16-is too big?
 

Let's say I have a function:

Code: Pascal  [Select][+][-]

1. function F1(A, B: Integer; C: QWord): Integer
2. begin
3.  
4. end;
5.  

In what registers passing C in 32-bit mode?

Inside