re PR tree-optimization/43879 (-fipa-pta causes various miscompilations)

2010-05-04  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/43879
	* tree-ssa-structalias.c (alias_get_name): Use
	DECL_ASSEMBLER_NAME if available.
	(create_function_info_for): Return the varinfo node.
	(ipa_pta_execute): Associate same-body aliases and extra names
	with their origin nodes varinfo.  Dump DECL_ASSEMBLER_NAME.

	* g++.dg/torture/pr43879-1_0.C: New testcase.
	* g++.dg/torture/pr43879-1_1.C: Likewise.

From-SVN: r159026

gcc/ChangeLog

+2010-05-04  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/43879
+	* tree-ssa-structalias.c (alias_get_name): Use
+	DECL_ASSEMBLER_NAME if available.
+	(create_function_info_for): Return the varinfo node.
+	(ipa_pta_execute): Associate same-body aliases and extra names
+	with their origin nodes varinfo.  Dump DECL_ASSEMBLER_NAME.
+
 2010-05-04  Kaz Kojima  <kkojima@gcc.gnu.org>
 
 	* config/sh/sh.c (sh_small_register_classes_for_mode_p): Remove

gcc/testsuite/ChangeLog

+2010-05-04  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/43879
+	* g++.dg/torture/pr43879-1_0.C: New testcase.
+	* g++.dg/torture/pr43879-1_1.C: Likewise.
+
 2010-05-03  Dodji Seketeli  <dodji@redhat.com>
 
 	PR c++/43953

gcc/testsuite/g++.dg/torture/pr43879-1_0.C

+struct A {
+    int *i;
+    A();
+    ~A();
+};
+
+static int x = 0;
+
+A::A() : i(&x) {}
+A::~A() {}
+

gcc/testsuite/g++.dg/torture/pr43879-1_1.C

+/* { dg-do run } */
+/* { dg-options "-fipa-pta" } */
+/* { dg-additional-sources "pr43879-1_0.C" } */
+
+struct A {
+    int *i;
+    A();
+    ~A();
+};
+
+static inline int
+aa(int *a, int *b)
+{
+  (void)b;
+  return *a;
+}
+
+struct B {
+    B() : i(0) {}
+    int i;
+    B(const A &a) : i(0)
+    {
+      f(*a.i);
+    }
+    void __attribute__((noinline, noclone))
+	f(int j)
+	  {
+	    aa(&i, &j);
+	    i = 1;
+	  }
+};
+
+int
+test()
+{
+  B b1;
+  B b2 = B(A());
+  b1 = B(A());
+  if (b1.i != b2.i) __builtin_abort();
+  return 0;
+}
+
+int
+main()
+{
+  return test();
+}
+

gcc/tree-ssa-structalias.c

@@ -2759,10 +2759,14 @@ lookup_vi_for_tree (tree t)
 static const char *
 alias_get_name (tree decl)
 {
-  const char *res = get_name (decl);
+  const char *res;
   char *temp;
   int num_printed = 0;
 
+  if (DECL_ASSEMBLER_NAME_SET_P (decl))
+    res = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
+  else
+    res= get_name (decl);
   if (res != NULL)
     return res;
 
@@ -4956,7 +4960,7 @@ count_num_arguments (tree decl, bool *is_varargs)
 /* Creation function node for DECL, using NAME, and return the index
    of the variable we've created for the function.  */
 
-static unsigned int
+static varinfo_t
 create_function_info_for (tree decl, const char *name)
 {
   struct function *fn = DECL_STRUCT_FUNCTION (decl);
@@ -5129,7 +5133,7 @@ create_function_info_for (tree decl, const char *name)
       prev_vi = argvi;
     }
 
-  return vi->id;
+  return vi;
 }
 
 
@@ -6565,6 +6569,9 @@ ipa_pta_execute (void)
   /* Build the constraints.  */
   for (node = cgraph_nodes; node; node = node->next)
     {
+      struct cgraph_node *alias;
+      varinfo_t vi;
+
       /* Nodes without a body are not interesting.  Especially do not
          visit clones at this point for now - we get duplicate decls
 	 there for inline clones at least.  */
@@ -6572,13 +6579,26 @@ ipa_pta_execute (void)
 	  || node->clone_of)
 	continue;
 
-      create_function_info_for (node->decl,
-				cgraph_node_name (node));
+      vi = create_function_info_for (node->decl,
+				     alias_get_name (node->decl));
+
+      /* Associate the varinfo node with all aliases.  */
+      for (alias = node->same_body; alias; alias = alias->next)
+	insert_vi_for_tree (alias->decl, vi);
     }
 
   /* Create constraints for global variables and their initializers.  */
   for (var = varpool_nodes; var; var = var->next)
-    get_vi_for_tree (var->decl);
+    {
+      struct varpool_node *alias;
+      varinfo_t vi;
+
+      vi = get_vi_for_tree (var->decl);
+
+      /* Associate the varinfo node with all aliases.  */
+      for (alias = var->extra_name; alias; alias = alias->next)
+	insert_vi_for_tree (alias->decl, vi);
+    }
 
   if (dump_file)
     {
@@ -6601,9 +6621,14 @@ ipa_pta_execute (void)
 	continue;
 
       if (dump_file)
-	fprintf (dump_file,
-		 "Generating constraints for %s\n",
-		 cgraph_node_name (node));
+	{
+	  fprintf (dump_file,
+		   "Generating constraints for %s", cgraph_node_name (node));
+	  if (DECL_ASSEMBLER_NAME_SET_P (node->decl))
+	    fprintf (dump_file, " (%s)",
+		     IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (node->decl)));
+	  fprintf (dump_file, "\n");
+	}
 
       func = DECL_STRUCT_FUNCTION (node->decl);
       old_func_decl = current_function_decl;