diff options
Diffstat (limited to 'gcc/ipa.c')
| -rw-r--r-- | gcc/ipa.c | 110 |
1 files changed, 101 insertions, 9 deletions
@@ -27,6 +27,7 @@ along with GCC; see the file COPYING3. If not see #include "timevar.h" #include "gimple.h" #include "ggc.h" +#include "flags.h" /* Fill array order with all nodes with output flag set in the reverse topological order. */ @@ -194,6 +195,19 @@ varpool_can_remove_if_no_refs (struct varpool_node *node) && (DECL_COMDAT (node->decl) || !node->externally_visible)); } +/* Return true when function can be marked local. */ + +static bool +cgraph_local_node_p (struct cgraph_node *node) +{ + return (cgraph_only_called_directly_p (node) + && node->analyzed + && !DECL_EXTERNAL (node->decl) + && !node->local.externally_visible + && !node->reachable_from_other_partition + && !node->in_other_partition); +} + /* Perform reachability analysis and reclaim all unreachable nodes. If BEFORE_INLINING_P is true this function is called before inlining decisions has been made. If BEFORE_INLINING_P is false this function also @@ -408,18 +422,31 @@ cgraph_remove_unreachable_nodes (bool before_inlining_p, FILE *file) } node->aux = NULL; } + if (file) - fprintf (file, "\nReclaiming variables:"); + fprintf (file, "\n"); + + /* We must release unused extern inlines or sanity checking will fail. Rest of transformations + are undesirable at -O0 since we do not want to remove anything. */ + if (!optimize) + return changed; + + if (file) + fprintf (file, "Reclaiming variables:"); for (vnode = varpool_nodes; vnode; vnode = vnext) { vnext = vnode->next; if (!vnode->needed) { - if (file) - fprintf (file, " %s", varpool_node_name (vnode)); - varpool_remove_node (vnode); + if (file) + fprintf (file, " %s", varpool_node_name (vnode)); + varpool_remove_node (vnode); + changed = true; } } + + /* Now update address_taken flags and try to promote functions to be local. */ + if (file) fprintf (file, "\nClearing address taken flags:"); for (node = cgraph_nodes; node; node = node->next) @@ -431,12 +458,22 @@ cgraph_remove_unreachable_nodes (bool before_inlining_p, FILE *file) bool found = false; for (i = 0; ipa_ref_list_refering_iterate (&node->ref_list, i, ref) && !found; i++) - found = true; + { + gcc_assert (ref->use == IPA_REF_ADDR); + found = true; + } if (!found) { if (file) fprintf (file, " %s", cgraph_node_name (node)); node->address_taken = false; + changed = true; + if (cgraph_local_node_p (node)) + { + node->local.local = true; + if (file) + fprintf (file, " (local)"); + } } } @@ -451,6 +488,64 @@ cgraph_remove_unreachable_nodes (bool before_inlining_p, FILE *file) return changed; } +/* Discover variables that have no longer address taken or that are read only + and update their flags. + + FIXME: This can not be done in between gimplify and omp_expand since + readonly flag plays role on what is shared and what is not. Currently we do + this transformation as part of ipa-reference pass, but it would make sense + to do it before early optimizations. */ + +void +ipa_discover_readonly_nonaddressable_vars (void) +{ + struct varpool_node *vnode; + if (dump_file) + fprintf (dump_file, "Clearing variable flags:"); + for (vnode = varpool_nodes; vnode; vnode = vnode->next) + if (vnode->finalized && varpool_all_refs_explicit_p (vnode) + && (TREE_ADDRESSABLE (vnode->decl) || !TREE_READONLY (vnode->decl))) + { + bool written = false; + bool address_taken = false; + int i; + struct ipa_ref *ref; + for (i = 0; ipa_ref_list_refering_iterate (&vnode->ref_list, i, ref) + && (!written || !address_taken); i++) + switch (ref->use) + { + case IPA_REF_ADDR: + address_taken = true; + break; + case IPA_REF_LOAD: + break; + case IPA_REF_STORE: + written = true; + break; + } + if (TREE_ADDRESSABLE (vnode->decl) && !address_taken) + { + if (dump_file) + fprintf (dump_file, " %s (addressable)", varpool_node_name (vnode)); + TREE_ADDRESSABLE (vnode->decl) = 0; + } + if (!TREE_READONLY (vnode->decl) && !address_taken && !written + /* Making variable in explicit section readonly can cause section + type conflict. + See e.g. gcc.c-torture/compile/pr23237.c */ + && DECL_SECTION_NAME (vnode->decl) == NULL) + { + if (dump_file) + fprintf (dump_file, " %s (read-only)", varpool_node_name (vnode)); + TREE_READONLY (vnode->decl) = 1; + } + } + if (dump_file) + fprintf (dump_file, "\n"); +} + +/* Return true when function NODE should be considered externally visible. */ + static bool cgraph_externally_visible_p (struct cgraph_node *node, bool whole_program) { @@ -569,10 +664,7 @@ function_and_variable_visibility (bool whole_program) segfault though. */ dissolve_same_comdat_group_list (node); } - node->local.local = (cgraph_only_called_directly_p (node) - && node->analyzed - && !DECL_EXTERNAL (node->decl) - && !node->local.externally_visible); + node->local.local = cgraph_local_node_p (node); } for (vnode = varpool_nodes; vnode; vnode = vnode->next) { |