On Wed, 24 Feb 2021, Jakub Jelinek wrote:
> On Wed, Feb 24, 2021 at 01:32:02PM +0100, Richard Biener wrote:
> > Small comment about the patch below, which otherwise is OK:
> >
> > I think that !INTEGRAL_TYPE_P (TREE_TYPE (innerop)) is a sufficient
> > condition here.
>
> Unfortunately as shown during the bootstrap, that patch contained a fatal
> thinko,
> > > + default:
> > > + break;
>
> for default: we need return;
>
> Here is a version of the patch that passed bootstrap/regtest on x86_64-linux
> and i686-linux, ok for trunk?
OK.
Thanks,
Richard.
> 2021-02-24 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/80635
> * tree-vrp.c (vrp_simplify_cond_using_ranges): Also handle
> VIEW_CONVERT_EXPR if modes are the same, innerop is integral and
> has mode precision.
>
> * g++.dg/warn/pr80635-1.C: New test.
> * g++.dg/warn/pr80635-2.C: New test.
>
> --- gcc/tree-vrp.c.jj 2021-02-24 12:56:58.573939572 +0100
> +++ gcc/tree-vrp.c 2021-02-24 13:05:22.675326780 +0100
> @@ -4390,11 +4390,22 @@ vrp_simplify_cond_using_ranges (vr_value
> gimple *def_stmt = SSA_NAME_DEF_STMT (op0);
> tree innerop;
>
> - if (!is_gimple_assign (def_stmt)
> - || !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt)))
> + if (!is_gimple_assign (def_stmt))
> return;
>
> - innerop = gimple_assign_rhs1 (def_stmt);
> + switch (gimple_assign_rhs_code (def_stmt))
> + {
> + CASE_CONVERT:
> + innerop = gimple_assign_rhs1 (def_stmt);
> + break;
> + case VIEW_CONVERT_EXPR:
> + innerop = TREE_OPERAND (gimple_assign_rhs1 (def_stmt), 0);
> + if (!INTEGRAL_TYPE_P (TREE_TYPE (innerop)))
> + return;
> + break;
> + default:
> + return;
> + }
>
> if (TREE_CODE (innerop) == SSA_NAME
> && !POINTER_TYPE_P (TREE_TYPE (innerop))
> --- gcc/testsuite/g++.dg/warn/pr80635-1.C.jj 2021-02-24 12:24:15.176834532
> +0100
> +++ gcc/testsuite/g++.dg/warn/pr80635-1.C 2021-02-24 12:24:15.176834532
> +0100
> @@ -0,0 +1,46 @@
> +// PR tree-optimization/80635
> +// { dg-do compile { target c++11 } }
> +// { dg-options "-O2 -Wmaybe-uninitialized" }
> +
> +using size_t = decltype (sizeof (1));
> +inline void *operator new (size_t, void *p) { return p; }
> +template<typename T>
> +struct optional
> +{
> + optional () : m_dummy (), live (false) {}
> + void emplace () { new (&m_item) T (); live = true; }
> + ~optional () { if (live) m_item.~T (); }
> +
> + union
> + {
> + struct {} m_dummy;
> + T m_item;
> + };
> + bool live;
> +};
> +
> +extern int get ();
> +extern void set (int);
> +
> +struct A
> +{
> + A () : m (get ()) {}
> + ~A () { set (m); } // { dg-bogus "may be used uninitialized in this
> function" }
> +
> + int m;
> +};
> +
> +struct B
> +{
> + B ();
> + ~B ();
> +};
> +
> +void func ()
> +{
> + optional<A> maybe_a;
> + optional<B> maybe_b;
> +
> + maybe_a.emplace ();
> + maybe_b.emplace ();
> +}
> --- gcc/testsuite/g++.dg/warn/pr80635-2.C.jj 2021-02-24 12:24:15.176834532
> +0100
> +++ gcc/testsuite/g++.dg/warn/pr80635-2.C 2021-02-24 12:24:15.176834532
> +0100
> @@ -0,0 +1,31 @@
> +// PR tree-optimization/80635
> +// { dg-do compile { target c++17 } }
> +// { dg-options "-O2 -Wmaybe-uninitialized" }
> +
> +#include <optional>
> +
> +extern int get ();
> +extern void set (int);
> +
> +struct A
> +{
> + A () : m (get ()) {}
> + ~A () { set (m); } // { dg-bogus "may be used uninitialized in this
> function" }
> +
> + int m;
> +};
> +
> +struct B
> +{
> + B ();
> + ~B ();
> +};
> +
> +void func ()
> +{
> + std::optional<A> maybe_a;
> + std::optional<B> maybe_b;
> +
> + maybe_a.emplace ();
> + maybe_b.emplace ();
> +}
>
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)
