[PATCH] Fix wrong-code with IPA PTA

[Richard Biener]

This fixes a missing constraint for by-reference DECL_RESULT in
nonlocal_p mode.

Bootstrapped and tested on x86_64-unknown-linux-gnu, applied.

Richard.

2015-12-10  Richard Biener  <rguent...@suse.de>

        * tree-ssa-structalias.c (create_function_info_for): Add missing
        constraint from nonlocal for DECL_RESULT.

Index: gcc/tree-ssa-structalias.c
===================================================================
--- gcc/tree-ssa-structalias.c  (revision 231494)
+++ gcc/tree-ssa-structalias.c  (working copy)
@@ -5631,6 +5630,11 @@ create_function_info_for (tree decl, con
       if (DECL_RESULT (decl))
        insert_vi_for_tree (DECL_RESULT (decl), resultvi);
 
+      if (nonlocal_p
+         && DECL_RESULT (decl)
+         && DECL_BY_REFERENCE (DECL_RESULT (decl)))
+       make_constraint_from (resultvi, nonlocal_id);
+
       gcc_assert (prev_vi->offset < resultvi->offset);
       prev_vi->next = resultvi->id;
       prev_vi = resultvi;