tree-ssa-structalias.c (do_ds_constraint): Stores in global variables add them to ESCAPED.

2009-06-16  Richard Guenther  <rguenther@suse.de>

	* tree-ssa-structalias.c (do_ds_constraint): Stores in global
	variables add them to ESCAPED.
	(find_func_aliases): Do not make all indirectly stored values
	escaped.

	* gcc.dg/tree-ssa/pta-escape-1.c: New testcase.
	* gcc.dg/tree-ssa/pta-escape-2.c: Likewise.
	* gcc.dg/tree-ssa/pta-escape-3.c: Likewise.
	* gcc.dg/tree-ssa/ssa-fre-27.c: Likewise.

From-SVN: r148525

gcc/ChangeLog

+2009-06-16  Richard Guenther  <rguenther@suse.de>
+
+	* tree-ssa-structalias.c (do_ds_constraint): Stores in global
+	variables add them to ESCAPED.
+	(find_func_aliases): Do not make all indirectly stored values
+	escaped.
+
 2009-06-16  Rafael Avila de Espindola  <espindola@google.com>
 
 	* config/i386/winnt.c (i386_pe_encode_section_info): Update call to

gcc/testsuite/ChangeLog

+2009-06-16  Richard Guenther  <rguenther@suse.de>
+
+	* gcc.dg/tree-ssa/pta-escape-1.c: New testcase.
+	* gcc.dg/tree-ssa/pta-escape-2.c: Likewise.
+	* gcc.dg/tree-ssa/pta-escape-3.c: Likewise.
+	* gcc.dg/tree-ssa/ssa-fre-27.c: Likewise.
+
 2009-06-16  Martin Jambor  <mjambor@suse.cz>
 
 	* testsuite/gcc.c-torture/compile/pr40432.c: New file.

gcc/testsuite/gcc.dg/tree-ssa/pta-escape-1.c

+/* { dg-do run } */
+/* { dg-options "-O -fdump-tree-alias-details" } */
+
+int *i;
+void __attribute__((noinline))
+foo (void)
+{
+  *i = 1;
+}
+int __attribute__((noinline))
+bar(int local_p)
+{
+  int x = 0;
+  int *j;
+  int **p;
+  if (local_p)
+    p = &j;
+  else
+    p = &i;
+  *p = &x;  /* This makes x escape.  */
+  foo ();
+  return x;
+}
+extern void abort (void);
+int main()
+{
+  int k = 2;
+  i = &k;
+  if (bar (1) != 0 || k != 1)
+    abort ();
+  if (bar (0) != 1)
+    abort ();
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump "ESCAPED, points-to vars: { x }" "alias" } } */
+/* { dg-final { cleanup-tree-dump "alias" } } */

gcc/testsuite/gcc.dg/tree-ssa/pta-escape-2.c

+/* { dg-do run } */
+/* { dg-options "-O -fdump-tree-alias-details" } */
+
+int *i;
+void __attribute__((noinline))
+foo (void)
+{
+  *i = 1;
+}
+int __attribute__((noinline))
+bar(int local_p, int **q)
+{
+  int x = 0;
+  int *j;
+  int **p;
+  if (local_p)
+    p = &j;
+  else
+    p = q;
+  *p = &x;  /* This makes x escape.  */
+  foo ();
+  return x;
+}
+extern void abort (void);
+int main()
+{
+  int k = 2;
+  int **q = &i;
+  i = &k;
+  if (bar (1, q) != 0 || k != 1)
+    abort ();
+  if (bar (0, q) != 1)
+    abort ();
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump "ESCAPED, points-to vars: { x }" "alias" } } */
+/* { dg-final { cleanup-tree-dump "alias" } } */

gcc/testsuite/gcc.dg/tree-ssa/pta-escape-3.c

+/* { dg-do run } */
+/* { dg-options "-O -fdump-tree-alias-details" } */
+
+int *i;
+void __attribute__((noinline))
+foo (void)
+{
+  *i = 1;
+}
+int **__attribute__((noinline,const))
+foobar (void)
+{
+  return &i;
+}
+int __attribute__((noinline))
+bar(int local_p)
+{
+  int x = 0;
+  int *j;
+  int **p;
+  if (local_p)
+    p = &j;
+  else
+    p = foobar();
+  *p = &x;  /* This makes x escape.  */
+  foo ();
+  return x;
+}
+extern void abort (void);
+int main()
+{
+  int k = 2;
+  i = &k;
+  if (bar (1) != 0 || k != 1)
+    abort ();
+  if (bar (0) != 1)
+    abort ();
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump "ESCAPED, points-to vars: { x }" "alias" } } */
+/* { dg-final { cleanup-tree-dump "alias" } } */

gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-27.c

+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-fre-details" } */
+
+int *q;
+void __attribute__((noinline))
+bar (void)
+{
+  *q = 1;
+}
+int foo(int which_p)
+{
+  int x = 0;
+  int *i,*j;
+  int **p;
+  if (which_p)
+    p = &i;
+  else
+    p = &j;
+  *p = &x;
+  bar ();
+  return x;
+}
+
+/* { dg-final { scan-tree-dump "Replaced x with 0" "fre" } } */
+/* { dg-final { cleanup-tree-dump "fre" } } */

gcc/tree-ssa-structalias.c

@@ -1664,6 +1664,19 @@ do_ds_constraint (constraint_t c, bitmap delta)
       unsigned int t;
       HOST_WIDE_INT fieldoffset = v->offset + loff;
 
+      /* If v is a NONLOCAL then this is an escape point.  */
+      if (j == nonlocal_id)
+	{
+	  t = find (escaped_id);
+	  if (add_graph_edge (graph, t, rhs)
+	      && bitmap_ior_into (get_varinfo (t)->solution, sol)
+	      && !TEST_BIT (changed, t))
+	    {
+	      SET_BIT (changed, t);
+	      changed_count++;
+	    }
+	}
+
       if (v->is_special_var)
 	continue;
 
@@ -1680,18 +1693,24 @@ do_ds_constraint (constraint_t c, bitmap delta)
 	  if (v->may_have_pointers)
 	    {
 	      t = find (v->id);
-	      if (add_graph_edge (graph, t, rhs))
+	      if (add_graph_edge (graph, t, rhs)
+		  && bitmap_ior_into (get_varinfo (t)->solution, sol)
+		  && !TEST_BIT (changed, t))
 		{
-		  if (bitmap_ior_into (get_varinfo (t)->solution, sol))
-		    {
-		      if (t == rhs)
-			sol = get_varinfo (rhs)->solution;
-		      if (!TEST_BIT (changed, t))
-			{
-			  SET_BIT (changed, t);
-			  changed_count++;
-			}
-		    }
+		  SET_BIT (changed, t);
+		  changed_count++;
+		}
+	    }
+	  /* If v is a global variable then this is an escape point.  */
+	  if (is_global_var (v->decl))
+	    {
+	      t = find (escaped_id);
+	      if (add_graph_edge (graph, t, rhs)
+		  && bitmap_ior_into (get_varinfo (t)->solution, sol)
+		  && !TEST_BIT (changed, t))
+		{
+		  SET_BIT (changed, t);
+		  changed_count++;
 		}
 	    }
 
@@ -3734,31 +3753,15 @@ find_func_aliases (gimple origt)
 		process_constraint (new_constraint (*c, *c2));
 	    }
 	}
+      /* 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))
+	make_escape_constraint (rhsop);
     }
 
   stmt_escape_type = is_escape_site (t);
-  if (stmt_escape_type == ESCAPE_STORED_IN_GLOBAL)
-    {
-      gcc_assert (is_gimple_assign (t));
-      if (gimple_assign_rhs_code (t) == ADDR_EXPR)
-	{
-	  tree rhs = gimple_assign_rhs1 (t);
-	  tree base = get_base_address (TREE_OPERAND (rhs, 0));
-	  if (base
-	      && (!DECL_P (base)
-		  || !is_global_var (base)))
-	    make_escape_constraint (rhs);
-	}
-      else if (get_gimple_rhs_class (gimple_assign_rhs_code (t))
-	       == GIMPLE_SINGLE_RHS)
-	{
-	  if (could_have_pointers (gimple_assign_rhs1 (t)))
-	    make_escape_constraint (gimple_assign_rhs1 (t));
-	}
-      else
-	gcc_unreachable ();
-    }
-  else if (stmt_escape_type == ESCAPE_BAD_CAST)
+  if (stmt_escape_type == ESCAPE_BAD_CAST)
     {
       gcc_assert (is_gimple_assign (t));
       gcc_assert (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (t))