Function code size

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Revision as of 20:06, 6 September 2023 by Alextpp (talk | contribs)
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Advice from programmer Rika.

Pascal function binary size can be measured (to within the procedure entry alignment... usually 16 bytes) with:

procedure MyProc;
begin
  // ...
end;

// Must immediately follow MyProc in the source!
// Uses the implementation detail that the linker will lay them out in the same order.
procedure MyProcEnd; 
begin
end;

begin
  writeln('MyProc code size: ', pointer(@MyProcEnd) - pointer(@MyProc), ' b');
end.

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... and would miss the prologue and epilogue if it did):

label MyAsmProcStart, MyAsmProcEnd;

procedure MyAsmProc; assembler;
asm
MyAsmProcStart:
  ...
MyAsmProcEnd:
end;

begin
  writeln('MyAsmProc code size: ', pointer(@MyAsmProcEnd) - pointer(@MyAsmProcStart), ' b');
end.