The following patch fixes a latent issue in IPA PTA with LTO where
it doesn't properly honor partition boundaries.
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied.
Richard.
2015-12-10 Richard Biener <rguent...@suse.de>
* tree-ssa-structalias.c (struct variable_info): Add
is_ipa_escape_point flag.
(new_var_info): Initialize to false.
(find_func_aliases): Generate escape constraints for stores
properly in IPA mode.
(ipa_pta_execute): Compute is_ipa_escape_point for globals.
Index: gcc/tree-ssa-structalias.c
===================================================================
--- gcc/tree-ssa-structalias.c (revision 231498)
+++ gcc/tree-ssa-structalias.c (working copy)
@@ -160,6 +160,8 @@
The is_global_var bit which marks escape points is overly conservative
in IPA mode. Split it to is_escape_point and is_global_var - only
externally visible globals are escape points in IPA mode.
+ There is now is_ipa_escape_point but this is only used in a few
+ selected places.
The way we introduce DECL_PT_UID to avoid fixing up all points-to
sets in the translation unit when we copy a DECL during inlining
@@ -265,6 +267,9 @@ struct variable_info
/* True if this represents a global variable. */
unsigned int is_global_var : 1;
+ /* True if this represents a module escape point for IPA analysis. */
+ unsigned int is_ipa_escape_point : 1;
+
/* True if this represents a IPA function info. */
unsigned int is_fn_info : 1;
@@ -374,6 +379,7 @@ new_var_info (tree t, const char *name,
ret->is_restrict_var = false;
ret->ruid = 0;
ret->is_global_var = (t == NULL_TREE);
+ ret->is_ipa_escape_point = false;
ret->is_fn_info = false;
if (t && DECL_P (t))
ret->is_global_var = (is_global_var (t)
@@ -4779,11 +4785,13 @@ find_func_aliases (struct function *fn,
}
/* If there is a store to a global variable the rhs escapes. */
if ((lhsop = get_base_address (lhsop)) != NULL_TREE
- && DECL_P (lhsop)
- && is_global_var (lhsop)
- && (!in_ipa_mode
- || DECL_EXTERNAL (lhsop) || TREE_PUBLIC (lhsop)))
- make_escape_constraint (rhsop);
+ && DECL_P (lhsop))
+ {
+ varinfo_t vi = get_vi_for_tree (lhsop);
+ if ((! in_ipa_mode && vi->is_global_var)
+ || vi->is_ipa_escape_point)
+ make_escape_constraint (rhsop);
+ }
}
/* Handle escapes through return. */
else if (gimple_code (t) == GIMPLE_RETURN
@@ -4794,8 +4802,7 @@ find_func_aliases (struct function *fn,
if (!in_ipa_mode
|| !(fi = get_vi_for_tree (fn->decl)))
make_escape_constraint (gimple_return_retval (return_stmt));
- else if (in_ipa_mode
- && fi != NULL)
+ else if (in_ipa_mode)
{
struct constraint_expr lhs ;
struct constraint_expr *rhsp;
@@ -7498,7 +7505,15 @@ ipa_pta_execute (void)
if (var->alias && var->analyzed)
continue;
- get_vi_for_tree (var->decl);
+ varinfo_t vi = get_vi_for_tree (var->decl);
+
+ /* For the purpose of IPA PTA unit-local globals are not
+ escape points. */
+ bool nonlocal_p = (var->used_from_other_partition
+ || var->externally_visible
+ || var->force_output);
+ if (nonlocal_p)
+ vi->is_ipa_escape_point = true;
}
if (dump_file
