re PR tree-optimization/47615 (ICE: too deep recursion in…

re PR tree-optimization/47615 (ICE: too deep recursion in phi_translate/phi_translate_1 with -ftree-pre -fno-tree-fre -fno-tree-sra)

2011-02-07  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/47615
	* tree-ssa-sccvn.h (run_scc_vn): Take a vn-walk mode argument.
	* tree-ssa-sccvn.c (default_vn_walk_kind): New global.
	(run_scc_vn): Initialize it.
	(visit_reference_op_load): Use it.
	* tree-ssa-pre.c (execute_pre): Use VN_WALK if in PRE.

	* g++.dg/opt/pr47615.C: New testcase.

From-SVN: r169888

gcc/ChangeLog

+2011-02-07  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/47615
+	* tree-ssa-sccvn.h (run_scc_vn): Take a vn-walk mode argument.
+	* tree-ssa-sccvn.c (default_vn_walk_kind): New global.
+	(run_scc_vn): Initialize it.
+	(visit_reference_op_load): Use it.
+	* tree-ssa-pre.c (execute_pre): Use VN_WALK if in PRE.
+
 2011-02-07  Ulrich Weigand  <Ulrich.Weigand@de.ibm.com>
 
 	* config/spu/spu.c (spu_init_libfuncs): Install SImode and

gcc/testsuite/ChangeLog

 2011-02-07  Richard Guenther  <rguenther@suse.de>
 
+	PR tree-optimization/47615
+	* g++.dg/opt/pr47615.C: New testcase.
+
+2011-02-07  Richard Guenther  <rguenther@suse.de>
+
 	PR tree-optimization/47621
 	* gcc.dg/torture/pr47621.c: New testcase.
 

gcc/tree-ssa-pre.c

@@ -4853,7 +4853,7 @@ execute_pre (bool do_fre)
   if (!do_fre)
     loop_optimizer_init (LOOPS_NORMAL);
 
-  if (!run_scc_vn ())
+  if (!run_scc_vn (do_fre ? VN_WALKREWRITE : VN_WALK))
     {
       if (!do_fre)
 	loop_optimizer_finalize ();

gcc/tree-ssa-sccvn.c

@@ -1244,6 +1244,7 @@ vn_reference_lookup_1 (vn_reference_t vr, vn_reference_t *vnresult)
 
 static tree *last_vuse_ptr;
 static vn_lookup_kind vn_walk_kind;
+static vn_lookup_kind default_vn_walk_kind;
 
 /* Callback for walk_non_aliased_vuses.  Adjusts the vn_reference_t VR_
    with the current VUSE and performs the expression lookup.  */
@@ -2261,14 +2262,15 @@ visit_reference_op_load (tree lhs, tree op, gimple stmt)
 
   last_vuse = gimple_vuse (stmt);
   last_vuse_ptr = &last_vuse;
-  result = vn_reference_lookup (op, gimple_vuse (stmt), VN_WALKREWRITE, NULL);
+  result = vn_reference_lookup (op, gimple_vuse (stmt),
+				default_vn_walk_kind, NULL);
   last_vuse_ptr = NULL;
 
   /* If we have a VCE, try looking up its operand as it might be stored in
      a different type.  */
   if (!result && TREE_CODE (op) == VIEW_CONVERT_EXPR)
     result = vn_reference_lookup (TREE_OPERAND (op, 0), gimple_vuse (stmt),
-    				  VN_WALKREWRITE, NULL);
+    				  default_vn_walk_kind, NULL);
 
   /* We handle type-punning through unions by value-numbering based
      on offset and size of the access.  Be prepared to handle a
@@ -3463,15 +3465,18 @@ set_hashtable_value_ids (void)
 }
 
 /* Do SCCVN.  Returns true if it finished, false if we bailed out
-   due to resource constraints.  */
+   due to resource constraints.  DEFAULT_VN_WALK_KIND_ specifies
+   how we use the alias oracle walking during the VN process.  */
 
 bool
-run_scc_vn (void)
+run_scc_vn (vn_lookup_kind default_vn_walk_kind_)
 {
   size_t i;
   tree param;
   bool changed = true;
 
+  default_vn_walk_kind = default_vn_walk_kind_;
+
   init_scc_vn ();
   current_info = valid_info;
 

gcc/tree-ssa-sccvn.h

@@ -165,11 +165,13 @@ typedef struct vn_ssa_aux
   unsigned needs_insertion : 1;
 } *vn_ssa_aux_t;
 
+typedef enum { VN_NOWALK, VN_WALK, VN_WALKREWRITE } vn_lookup_kind;
+
 /* Return the value numbering info for an SSA_NAME.  */
 extern vn_ssa_aux_t VN_INFO (tree);
 extern vn_ssa_aux_t VN_INFO_GET (tree);
 tree vn_get_expr_for (tree);
-bool run_scc_vn (void);
+bool run_scc_vn (vn_lookup_kind);
 void free_scc_vn (void);
 tree vn_nary_op_lookup (tree, vn_nary_op_t *);
 tree vn_nary_op_lookup_stmt (gimple, vn_nary_op_t *);
@@ -187,7 +189,6 @@ void copy_reference_ops_from_ref (tree, VEC(vn_reference_op_s, heap) **);
 void copy_reference_ops_from_call (gimple, VEC(vn_reference_op_s, heap) **);
 bool ao_ref_init_from_vn_reference (ao_ref *, alias_set_type, tree,
 				    VEC (vn_reference_op_s, heap) *);
-typedef enum { VN_NOWALK, VN_WALK, VN_WALKREWRITE } vn_lookup_kind;
 tree vn_reference_lookup_pieces (tree, alias_set_type, tree,
 				 VEC (vn_reference_op_s, heap) *,
 				 vn_reference_t *, vn_lookup_kind);