https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65236
Jan Hubicka <hubicka at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2015-02-27
CC| |hubicka at gcc dot gnu.org
Ever confirmed|0 |1
--- Comment #4 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
One bug with thunks I am aware of is demonstrated by the following testcase:
struct A {
A() {ptr=&b;}
A(const A &a) {ptr = &b;}
void test() { if (ptr != &b) __builtin_abort ();}
int b;
int *ptr;
};
A test1(A a)
{
a.test();
return a;
}
A test2(A a)
{
a.test();
return a;
}
__attribute__ ((noinline))
void
test_me (A (*t)(A))
{
struct A a, b=t(a);
b.test ();
}
int
main()
{
test_me (test1);
test_me (test2);
return 0;
}
we turn test2 into a thunk but after inlining the thunk we end up with
producing extrra copy of return value A.
