https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63459
Bug ID: 63459
Summary: operator new and returns_nonnull
Product: gcc
Version: 5.0
Status: UNCONFIRMED
Severity: enhancement
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: hubicka at gcc dot gnu.org
compinling:
struct A {
virtual int foo(){return 1;}
};
struct B {
virtual int bar(){return 4;}
};
struct C:B,A {
virtual int foo(){return 2;}
};
static void
test (struct A *a)
{
if (a->foo() != 2)
__builtin_abort ();
}
int
m()
{
struct A *a = new C;
test (a);
return 0;
}
Leads to:
int m() ()
{
struct A * a;
void * _4;
struct A * iftmp.0_6;
<bb 2>:
_4 = operator new (16);
C::C (_4);
if (_4 != 0B)
goto <bb 3>;
else
goto <bb 4>;
<bb 3>:
iftmp.0_6 = &MEM[(struct C *)_4].D.2251;
<bb 4>:
# a_1 = PHI <iftmp.0_6(3), 0B(2)>
test (a_1);
return 0;
}
in release_ssa dump. It would be nice to use the fact that the default
operator new throw exception instead of returning NULL in out of memory case.
Can optimizer make assumption that THIS parameter to a method call is always
not NULL?
