[Bug tree-optimization/36218] [4.2/4.3/4.4 regression] VRP causes stack overflow while building libgcj

["aph at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>]

------- Comment #14 from aph at gcc dot gnu dot org  2008-07-30 09:23 -------
This patch limits recursion in tree-vrp.

Index: tree-vrp.c
===================================================================
--- tree-vrp.c  (revision 136670)
+++ tree-vrp.c  (working copy)
@@ -4049,6 +4049,8 @@
    the predicate operands, an assert location node is added to the
    list of assertions for the corresponding operands.  */

+static size_t depth;
+
 static bool
 find_conditional_asserts (basic_block bb, tree last)
 {
@@ -4062,6 +4064,10 @@
   need_assert = false;
   bsi = bsi_for_stmt (last);

+  depth++;
+  if (depth > 500)
+    goto ret;
+
   /* Look for uses of the operands in each of the sub-graphs
      rooted at BB.  We need to check each of the outgoing edges
      separately, so that we know what kind of ASSERT_EXPR to
@@ -4121,6 +4127,8 @@
   FOR_EACH_SSA_TREE_OPERAND (op, last, iter, SSA_OP_USE)
     SET_BIT (found_in_subgraph, SSA_NAME_VERSION (op));

+ ret:
+  depth--;
   return need_assert;
 }



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36218