re PR tree-optimization/56984 (ICE in tree_vrp.c)

	PR tree-optimization/56984
	* tree-vrp.c (register_edge_assert_for_2): For (x >> M) < N
	and (x >> M) >= N don't register any assertion if N << M is the
	minimum value.

	* gcc.c-torture/compile/pr56984.c: New test.

From-SVN: r198051

gcc/ChangeLog

+2013-04-18  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/56984
+	* tree-vrp.c (register_edge_assert_for_2): For (x >> M) < N
+	and (x >> M) >= N don't register any assertion if N << M is the
+	minimum value.
+
 2013-04-18  Steven Bosscher  <steven@gcc.gnu.org>
 
 	* lower-subreg.c (resolve_simple_move): If called self-recursive,

gcc/testsuite/ChangeLog

 2013-04-18  Jakub Jelinek  <jakub@redhat.com>
 
+	PR tree-optimization/56984
+	* gcc.c-torture/compile/pr56984.c: New test.
+
 	PR rtl-optimization/56992
 	* gcc.dg/pr56992.c: New test.
 

gcc/testsuite/gcc.c-torture/compile/pr56984.c

+/* PR tree-optimization/56984 */
+
+int
+foo (int x)
+{
+  if ((x >> 31) < -1)
+    x++;
+  return x;
+}

gcc/tree-vrp.c

@@ -4895,7 +4895,13 @@ register_edge_assert_for_2 (tree name, edge e, gimple_stmt_iterator bsi,
 	      new_comp_code = comp_code == EQ_EXPR ? LE_EXPR : GT_EXPR;
 	    }
 	  else if (comp_code == LT_EXPR || comp_code == GE_EXPR)
-	    new_val = val2;
+	    {
+	      double_int minval
+		= double_int::min_value (prec, TYPE_UNSIGNED (TREE_TYPE (val)));
+	      new_val = val2;
+	      if (minval == tree_to_double_int (new_val))
+		new_val = NULL_TREE;
+	    }
 	  else
 	    {
 	      double_int maxval