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)