http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59883
Bug ID: 59883
Summary: Missed C++ front-end devirtualizations
Product: gcc
Version: 4.9.0
Status: UNCONFIRMED
Severity: enhancement
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: hubicka at gcc dot gnu.org
I believe the following testcase:
struct A
{
virtual int foo (void) {return foo();}
};
struct B {
struct A a;
};
struct A a[7];
int test(void)
{
return a[3].foo();
}
int test2(struct B *b)
{
return b->a.foo();
}
ought to get devirtualized by C++ FE based on the fact that the object is
contained within an structure or array. (this is related to PR46507)
In the following testcase:
namespace {
struct A
{
virtual int foo (void) {return 42;}
};
}
int test(void)
{
struct A a, *b=&a;
return b->foo();
}
We can now probably use ipa-devirt's type inheritance graph to work out right
away that A is a final class.
And finally:
struct A
{
virtual int foo (void) {return foo();}
};
IMO allows devirtualization of self recursive functions
