Difference between revisions of "Function code size"
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// Must immediately follow MyProc in the source! | // Must immediately follow MyProc in the source! | ||
− | // Uses the implementation detail that the linker will lay them out in the same order. | + | // 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). |
procedure MyProcEnd; | procedure MyProcEnd; | ||
begin | begin |
Latest revision as of 09:45, 17 September 2023
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 (which is not guaranteed by any linker, so this may not work).
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):
label MyAsmProcEnd;
procedure MyAsmProc; assembler;
asm
// ...
MyAsmProcEnd:
end;
begin
writeln('MyAsmProc code size: ', pointer(@MyAsmProcEnd) - pointer(@MyAsmProc), ' b');
end.
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.