| Message ID | 20161212191759.GE3541@tucnak.redhat.com |
|---|---|
| State | New |
| Headers | show |
On Mon, 12 Dec 2016, Jakub Jelinek wrote: > Hi! > > The local pure const pass notices the static ctor is looping const, > so sets TREE_READONLY and DECL_LOOPING_CONST_OR_PURE_P and does not > clear DECL_STATIC_CONSTRUCTOR bit because it is looping. > Then the ipa pure const pass notices the static ctor is non-looping const, > clears DECL_LOOPING_CONST_OR_PURE_P and DECL_STATIC_CONSTRUCTOR bit, > but because it has been TREE_READONLY already, it doesn't set > TODO_remove_functions from the pass and ipa-comdat pass assumes that > unreachable cgraph nodes have been pruned. > > Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for > trunk? Ok. Richard. > 2016-12-12 Jakub Jelinek <jakub@redhat.com> > > PR ipa/77905 > * ipa-pure-const.c (cdtor_p): Return true for > DECL_STATIC_{CON,DE}STRUCTOR even when it is > DECL_LOOPING_CONST_OR_PURE_P. > > * g++.dg/ipa/pr77905.C: New test. > > --- gcc/ipa-pure-const.c.jj 2016-09-02 19:09:33.000000000 +0200 > +++ gcc/ipa-pure-const.c 2016-12-12 11:51:24.808518093 +0100 > @@ -1195,7 +1195,8 @@ static bool > cdtor_p (cgraph_node *n, void *) > { > if (DECL_STATIC_CONSTRUCTOR (n->decl) || DECL_STATIC_DESTRUCTOR (n->decl)) > - return !TREE_READONLY (n->decl) && !DECL_PURE_P (n->decl); > + return ((!TREE_READONLY (n->decl) && !DECL_PURE_P (n->decl)) > + || DECL_LOOPING_CONST_OR_PURE_P (n->decl)); > return false; > } > > --- gcc/testsuite/g++.dg/ipa/pr77905.C.jj 2016-12-12 11:53:42.645770248 +0100 > +++ gcc/testsuite/g++.dg/ipa/pr77905.C 2016-12-12 11:53:35.000000000 +0100 > @@ -0,0 +1,21 @@ > +// PR ipa/77905 > +// { dg-do compile } > +// { dg-options "-O2" } > + > +struct A { > + A(int); > +}; > +struct B : A { > + B(); > +} A; > +struct C : virtual A { > + C(int); > +}; > +A::A(int x) { > + if (x) > + A(0); > +} > + > +B::B() : A(1) {} > + > +C::C(int) : A(1) {} > > Jakub > >
--- gcc/ipa-pure-const.c.jj 2016-09-02 19:09:33.000000000 +0200 +++ gcc/ipa-pure-const.c 2016-12-12 11:51:24.808518093 +0100 @@ -1195,7 +1195,8 @@ static bool cdtor_p (cgraph_node *n, void *) { if (DECL_STATIC_CONSTRUCTOR (n->decl) || DECL_STATIC_DESTRUCTOR (n->decl)) - return !TREE_READONLY (n->decl) && !DECL_PURE_P (n->decl); + return ((!TREE_READONLY (n->decl) && !DECL_PURE_P (n->decl)) + || DECL_LOOPING_CONST_OR_PURE_P (n->decl)); return false; } --- gcc/testsuite/g++.dg/ipa/pr77905.C.jj 2016-12-12 11:53:42.645770248 +0100 +++ gcc/testsuite/g++.dg/ipa/pr77905.C 2016-12-12 11:53:35.000000000 +0100 @@ -0,0 +1,21 @@ +// PR ipa/77905 +// { dg-do compile } +// { dg-options "-O2" } + +struct A { + A(int); +}; +struct B : A { + B(); +} A; +struct C : virtual A { + C(int); +}; +A::A(int x) { + if (x) + A(0); +} + +B::B() : A(1) {} + +C::C(int) : A(1) {}
Hi! The local pure const pass notices the static ctor is looping const, so sets TREE_READONLY and DECL_LOOPING_CONST_OR_PURE_P and does not clear DECL_STATIC_CONSTRUCTOR bit because it is looping. Then the ipa pure const pass notices the static ctor is non-looping const, clears DECL_LOOPING_CONST_OR_PURE_P and DECL_STATIC_CONSTRUCTOR bit, but because it has been TREE_READONLY already, it doesn't set TODO_remove_functions from the pass and ipa-comdat pass assumes that unreachable cgraph nodes have been pruned. Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? 2016-12-12 Jakub Jelinek <jakub@redhat.com> PR ipa/77905 * ipa-pure-const.c (cdtor_p): Return true for DECL_STATIC_{CON,DE}STRUCTOR even when it is DECL_LOOPING_CONST_OR_PURE_P. * g++.dg/ipa/pr77905.C: New test. Jakub