Function code size: what changed

Revision 0 to 1. Removed lines have a minus sign; added lines have a plus sign.

Title: Function code size

New		Line
1	+	Advice from programmer [Rika](https://gitlab.com/runewalsh).
2	+
3	+	Pascal function binary size can be measured (to within the procedure entry alignment... usually 16 bytes) with:
4	+
5	+	``` pascal
6	+	procedure MyProc;
7	+	begin
8	+	// ...
9	+	end;
10	+
11	+	// Must immediately follow MyProc in the source!
12	+	// Uses the implementation detail that the linker will lay them out in the same order (which is not guaranteed by any linker, so this may not work).
13	+	procedure MyProcEnd;
14	+	begin
15	+	end;
16	+
17	+	begin
18	+	writeln('MyProc code size: ', pointer(@MyProcEnd) - pointer(@MyProc), ' b');
19	+	end.
20	+	```
21	+
22	+	For assembler routines, either do the same but make MyProcEnd assembler too (still not sure if it works, I use the method below... but it definitely doesn’t work when mixing Pascal and assembler procedures). Or do the following (finer and more future-compatible way that sadly does not compile with Pascal routines):
23	+
24	+	``` pascal
25	+	label MyAsmProcEnd;
26	+
27	+	procedure MyAsmProc; assembler;
28	+	asm
29	+	// ...
30	+	MyAsmProcEnd:
31	+	end;
32	+
33	+	begin
34	+	writeln('MyAsmProc code size: ', pointer(@MyAsmProcEnd) - pointer(@MyAsmProc), ' b');
35	+	end.
36	+	```
37	+
38	+	This method misses the epilogue size, but the epilogue is negligible (1-digit) and constant; and if you have X bytes, after adding 17 more bytes of instructions you will have exactly X + 17.
39	+
40	+	---
41	+	From the Free Pascal wiki, page "Function code size", as it stood on 2023-09-17 after a change by Jonas, out of the wiki's dump of 2024-05-26. Copyright stays with the author who wrote it, according to the old wiki's [[Licensing]] page. If you have concerns about this material, [message the admin](/wiki-contact).

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