https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83032
--- Comment #2 from Antony Polukhin <antoshkka at gmail dot com> ---
> I don't think that's one of the cases where the C++ standard allows elision
Yes, you're right (currently I try to convince C++ standard pepole that
allowing it could be benefical).
But C does not forbit such optimization. Following code could benefit from it:
typedef struct big_ { char data[1024];} big;
struct ts {big a; big b; };
struct ts foo();
big testing1() {
return foo().b;
}
> So it could only work if the region was at the extremity of the stack and the
> stack grows in the right direction?
Yes, right. But in the above example it could save you from memcpy.
