-OoDEADSTORE takes on too much, chapter Ⅳ.

I just found that compiling my application with and without -OoDEADSTORE and diffing -al assembler outputs yields exclusively -OoDEADSTORE bugs, maybe because I dislike to write the code that would be affected by -OoDEADSTORE in the first place...

This code compiled with -O4 -OoDEADSTORE drops chosen := -10. Funny thing is that doing something at all in then makes the bug disappear, not to speak of negating if condition and moving break into then.

{$mode objfpc}
function ChooseMinus10: SizeInt;
var
	chosen: SizeInt;
begin
	chosen := -10;
	repeat
		if random(1) = 0 then else break;
		exit(chosen);
	until false;
	result := -20;
end;

begin
	writeln('Must be -10: ', ChooseMinus10);
end.

Possible output:

Must be -10: 857404