https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97435
Bug ID: 97435
Summary: Lifetime of temporaries not correctly extending when
optiimzation are enabled
Product: gcc
Version: 10.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: chris at chrissavoie dot com
Target Milestone: ---
Godbolt example: https://godbolt.org/z/fssed1
The following code:
struct A {
__attribute__((noinline))
A(int i) : data(i) {}
A& operator+=(int i) { data += i; return *this; }
int data;
};
int main() {
A const& b = A(5) += 5;
A c(6);
return b.data + c.data; // 16 expected
}
Will return 16 when compiled without optimizations, 11 when compiled with
optimizations (-O1 or greater) and 6 with noinline disabled and optimizations
on.
Browsing versions on godbolt it looks like the inline version of the bug
appeared between versions 4.9.3 and 5.1. The noinline version appeared between
versions 4.6.4 and 4.7.3.
