> Hi,
>
> on the 4.7 branch just like on the newer one, I'd like to fix the bug
> by simply never propagating through thunks. There even less pre-IPA
> devirtualization going on and so this should have minimal impact.
>
> Bootstrapped and tested on x86_64. OK for the branch?
OK for both branches.
Honza
>
> Thanks,
>
> Martin
>
>
> 2014-04-01 Martin Jambor <mjam...@suse.cz>
>
> PR ipa/60640
> * ipa-cp.c (propagate_constants_accross_call): Do not propagate
> accross thunks.
>
> testsuite/
> * g++.dg/ipa/pr60640-1.C: New test.
> * g++.dg/ipa/pr60640-2.C: Likewise.
> * g++.dg/ipa/pr60640-3.C: Likewise.
>
> diff --git a/gcc/ipa-cp.c b/gcc/ipa-cp.c
> index 454283a..ddf6605 100644
> --- a/gcc/ipa-cp.c
> +++ b/gcc/ipa-cp.c
> @@ -1063,21 +1063,21 @@ propagate_constants_accross_call (struct cgraph_edge
> *cs)
> args_count = ipa_get_cs_argument_count (args);
> parms_count = ipa_get_param_count (callee_info);
>
> - /* If this call goes through a thunk we must not propagate to the first
> (0th)
> - parameter. However, we might need to uncover a thunk from below a
> series
> - of aliases first. */
> + /* If this call goes through a thunk we should not propagate because we
> + cannot redirect edges to thunks. However, we might need to uncover a
> + thunk from below a series of aliases first. */
> alias_or_thunk = cs->callee;
> while (alias_or_thunk->alias)
> alias_or_thunk = cgraph_alias_aliased_node (alias_or_thunk);
> if (alias_or_thunk->thunk.thunk_p)
> {
> - ret |= set_lattice_contains_variable (ipa_get_lattice (callee_info,
> 0));
> - i = 1;
> + for (i = 0; i < parms_count; i++)
> + ret |= set_lattice_contains_variable (ipa_get_lattice (callee_info, i));
> +
> + return ret;
> }
> - else
> - i = 0;
>
> - for (; (i < args_count) && (i < parms_count); i++)
> + for (i = 0; (i < args_count) && (i < parms_count); i++)
> {
> struct ipa_jump_func *jump_func = ipa_get_ith_jump_func (args, i);
> struct ipcp_lattice *dest_lat = ipa_get_lattice (callee_info, i);
> diff --git a/gcc/testsuite/g++.dg/ipa/pr60640-1.C
> b/gcc/testsuite/g++.dg/ipa/pr60640-1.C
> new file mode 100644
> index 0000000..7a0b918
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/ipa/pr60640-1.C
> @@ -0,0 +1,50 @@
> +// { dg-do compile }
> +// { dg-options "-O3" }
> +
> +class ASN1Object
> +{
> +public:
> + virtual ~ASN1Object ();
> +};
> +class A
> +{
> + virtual unsigned m_fn1 () const;
> +};
> +class B
> +{
> +public:
> + ASN1Object Element;
> + virtual unsigned m_fn1 (bool) const;
> +};
> +template <class BASE> class C : public BASE
> +{
> +};
> +
> +class D : ASN1Object, public B
> +{
> +};
> +class G : public D
> +{
> + unsigned m_fn1 (bool) const {}
> +};
> +class F : A
> +{
> +public:
> + F (A);
> + unsigned m_fn1 () const
> + {
> + int a;
> + a = m_fn2 ().m_fn1 (0);
> + return a;
> + }
> + const B &m_fn2 () const { return m_groupParameters; }
> + C<G> m_groupParameters;
> +};
> +template <class D> void BenchMarkKeyAgreement (int *, int *, int)
> +{
> + A f;
> + D d (f);
> +}
> +
> +void BenchmarkAll2 () { BenchMarkKeyAgreement<F>(0, 0, 0); }
> +
> diff --git a/gcc/testsuite/g++.dg/ipa/pr60640-2.C
> b/gcc/testsuite/g++.dg/ipa/pr60640-2.C
> new file mode 100644
> index 0000000..c6e614c
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/ipa/pr60640-2.C
> @@ -0,0 +1,15 @@
> +// { dg-do compile }
> +// { dg-options "-O3" }
> +
> +struct B { virtual unsigned f () const; };
> +struct C { virtual void f (); };
> +struct F { virtual unsigned f (bool) const; ~F (); };
> +struct J : C, F {};
> +struct G : J { unsigned f (bool) const { return 0; } };
> +struct H : B
> +{
> + H (int);
> + unsigned f () const { return ((const F &) h).f (0); }
> + G h;
> +};
> +H h (0);
> diff --git a/gcc/testsuite/g++.dg/ipa/pr60640-3.C
> b/gcc/testsuite/g++.dg/ipa/pr60640-3.C
> new file mode 100644
> index 0000000..21b1f58
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/ipa/pr60640-3.C
> @@ -0,0 +1,81 @@
> +// { dg-do run }
> +// { dg-options "-O3" }
> +
> +struct Distraction
> +{
> + char fc[8];
> + virtual Distraction * return_self ()
> + { return this; }
> +};
> +
> +namespace {
> +
> +struct A;
> +static A * __attribute__ ((noinline, noclone)) get_an_A ();
> +
> +static int go;
> +
> +struct A
> +{
> + int fi;
> +
> + A () : fi(777) {}
> + A (int pi) : fi (pi) {}
> + virtual A * foo (int p) = 0;
> +};
> +
> +struct B;
> +static B * __attribute__ ((noinline, noclone)) get_a_B ();
> +
> +struct B : public Distraction, A
> +{
> + B () : Distraction(), A() { }
> + B (int pi) : Distraction (), A (pi) {}
> + virtual B * foo (int p)
> + {
> + int o = fi;
> + for (int i = 0; i < p; i++)
> + o += i + i * i;
> + go = o;
> +
> + return get_a_B ();
> + }
> +};
> +
> +
> +struct B gb1 (1111), gb2 (2);
> +static B * __attribute__ ((noinline, noclone))
> +get_a_B ()
> +{
> + return &gb1;
> +}
> +
> +static A * __attribute__ ((noinline, noclone))
> +get_an_A ()
> +{
> + return &gb2;
> +}
> +
> +}
> +
> +static int __attribute__ ((noinline, noclone))
> +get_a_number ()
> +{
> + return 5;
> +}
> +
> +extern "C" void abort (void);
> +
> +int main (int argc, char *argv[])
> +{
> + for (int i = 0; i < get_a_number (); i++)
> + {
> + struct A *p = get_an_A ();
> + struct A *r = p->foo (4);
> + if (r->fi != 1111)
> + abort ();
> + if (go != 22)
> + abort ();
> + }
> + return 0;
> +}
