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 <ja...@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
>
>
--
Richard Biener <rguent...@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
