From 3aaf05290aeed9682334510fa38886338b64ad73 Mon Sep 17 00:00:00 2001 From: Jan Hubicka Date: Wed, 21 May 2014 08:16:03 +0200 Subject: [PATCH] re PR tree-optimization/60899 (undef reference generated with -fdevirtualize-speculatively) PR tree-optimization/60899 * gimple-fold.c (can_refer_decl_in_current_unit_p): Cleanup; assume all static symbols will have definition wile parsing and check the do have definition later in compilation; check that variable referring symbol will be output before concluding that reference is safe; be conservative for referring local statics; be more precise about when comdat is output in other partition. g++.dg/ipa/devirt-11.C: Update template. From-SVN: r210676 --- gcc/ChangeLog | 10 ++++++ gcc/gimple-fold.c | 54 +++++++++++----------------- gcc/testsuite/ChangeLog | 5 +++ gcc/testsuite/g++.dg/ipa/devirt-11.C | 7 ++-- 4 files changed, 39 insertions(+), 37 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 104c87d0ccb..fe3e7ec8feb 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,13 @@ +2014-05-20 Jan Hubicka + + PR tree-optimization/60899 + * gimple-fold.c (can_refer_decl_in_current_unit_p): Cleanup; + assume all static symbols will have definition wile parsing and + check the do have definition later in compilation; check that + variable referring symbol will be output before concluding that + reference is safe; be conservative for referring local statics; + be more precise about when comdat is output in other partition. + 2014-05-20 Jan Hubicka PR bootstrap/60984 diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c index 1c2eed5dd1f..44bb0e2b187 100644 --- a/gcc/gimple-fold.c +++ b/gcc/gimple-fold.c @@ -94,8 +94,12 @@ can_refer_decl_in_current_unit_p (tree decl, tree from_decl) /* Static objects can be referred only if they was not optimized out yet. */ if (!TREE_PUBLIC (decl) && !DECL_EXTERNAL (decl)) { + /* Before we start optimizing unreachable code we can be sure all + static objects are defined. */ + if (cgraph_function_flags_ready) + return true; snode = symtab_get_node (decl); - if (!snode) + if (!snode || !snode->definition) return false; node = dyn_cast (snode); return !node || !node->global.inlined_to; @@ -103,10 +107,12 @@ can_refer_decl_in_current_unit_p (tree decl, tree from_decl) /* We will later output the initializer, so we can refer to it. So we are concerned only when DECL comes from initializer of - external var. */ + external var or var that has been optimized out. */ if (!from_decl || TREE_CODE (from_decl) != VAR_DECL - || !DECL_EXTERNAL (from_decl) + || (!DECL_EXTERNAL (from_decl) + && (vnode = varpool_get_node (from_decl)) != NULL + && vnode->definition) || (flag_ltrans && symtab_get_node (from_decl)->in_other_partition)) return true; @@ -123,9 +129,9 @@ can_refer_decl_in_current_unit_p (tree decl, tree from_decl) reference imply need to include function body in the curren tunit. */ if (TREE_PUBLIC (decl) && !DECL_COMDAT (decl)) return true; - /* We are not at ltrans stage; so don't worry about WHOPR. - Also when still gimplifying all referred comdat functions will be - produced. + /* We have COMDAT. We are going to check if we still have definition + or if the definition is going to be output in other partition. + Bypass this when gimplifying; all needed functions will be produced. As observed in PR20991 for already optimized out comdat virtual functions it may be tempting to not necessarily give up because the copy will be @@ -134,35 +140,17 @@ can_refer_decl_in_current_unit_p (tree decl, tree from_decl) units where they are used and when the other unit was compiled with LTO it is possible that vtable was kept public while the function itself was privatized. */ - if (!flag_ltrans && (!DECL_COMDAT (decl) || !cgraph_function_flags_ready)) + if (!cgraph_function_flags_ready) return true; - /* OK we are seeing either COMDAT or static variable. In this case we must - check that the definition is still around so we can refer it. */ - if (TREE_CODE (decl) == FUNCTION_DECL) - { - node = cgraph_get_node (decl); - /* Check that we still have function body and that we didn't took - the decision to eliminate offline copy of the function yet. - The second is important when devirtualization happens during final - compilation stage when making a new reference no longer makes callee - to be compiled. */ - if (!node || !node->definition || node->global.inlined_to) - { - gcc_checking_assert (!TREE_ASM_WRITTEN (decl)); - return false; - } - } - else if (TREE_CODE (decl) == VAR_DECL) - { - vnode = varpool_get_node (decl); - if (!vnode || !vnode->definition) - { - gcc_checking_assert (!TREE_ASM_WRITTEN (decl)); - return false; - } - } - return true; + snode = symtab_get_node (decl); + if (!snode + || ((!snode->definition || DECL_EXTERNAL (decl)) + && (!snode->in_other_partition + || (!snode->forced_by_abi && !snode->force_output)))) + return false; + node = dyn_cast (snode); + return !node || !node->global.inlined_to; } /* CVAL is value taken from DECL_INITIAL of variable. Try to transform it into diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 142c9fa08a1..117c65f7701 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2014-05-20 Jan Hubicka + + PR tree-optimization/60899 + g++.dg/ipa/devirt-11.C: Update template. + 2014-05-20 Edward Smith-Rowland <3dw4rd@verizon.net> PR C++/61038 diff --git a/gcc/testsuite/g++.dg/ipa/devirt-11.C b/gcc/testsuite/g++.dg/ipa/devirt-11.C index d30d56cff24..3246e214f14 100644 --- a/gcc/testsuite/g++.dg/ipa/devirt-11.C +++ b/gcc/testsuite/g++.dg/ipa/devirt-11.C @@ -42,8 +42,7 @@ bar () baz (); c + d; } -/* While inlining function called once we should devirtualize a new call to fn2 - and two to fn3. While doing so the new symbol for fn2 needs to be - introduced. */ -/* { dg-final { scan-ipa-dump-times "Discovered a virtual call to a known target" 3 "inline" } } */ +/* While inlining function called once we should devirtualize a new call to fn3. + Because fn2 is already removed, we should not devirtualize. */ +/* { dg-final { scan-ipa-dump-times "Discovered a virtual call to a known target" 1 "inline" } } */ /* { dg-final { cleanup-ipa-dump "inline" } } */