diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d79f5befb28..da514e8a935 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2012-03-12  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/52533
+	* tree-vrp.c (register_edge_assert_for_2): Use double_int
+	type for mask, only handle shifts by non-zero in-range
+	shift count, for LE_EXPR and GT_EXPR if new_val is
+	maximum, don't add the assertion.
+
 2012-02-12  Kirill Yukhin  <kirill.yukhin@intel.com>
 
 	* doc/invoke.texi: Document -mrtm option.
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index d12b3356993..4721de45ce1 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2012-03-12  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/52533
+	* gcc.c-torture/compile/pr52533.c: New test.
+
 2012-03-12  Kirill Yukhin  <kirill.yukhin@intel.com>
 
 	* gcc.target/i386/rtm-xabort-1.c: New.
diff --git a/gcc/testsuite/gcc.c-torture/compile/pr52533.c b/gcc/testsuite/gcc.c-torture/compile/pr52533.c
new file mode 100644
index 00000000000..82753cd73d6
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr52533.c
@@ -0,0 +1,19 @@
+/* PR tree-optimization/52533 */
+
+int
+foo (unsigned char x)
+{
+  if (x <= 9)
+    return '0' + x;
+  else if (x <= 15)
+    return 'a' + (x - 10);
+  else
+    return 0;
+}
+
+void
+bar (unsigned char x, unsigned char *y)
+{
+  y[0] = foo ((unsigned char) (x >> 4));
+  y[1] = foo ((unsigned char) (x & 0x0f));
+}
diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index d3922db038a..febe33f93c0 100644
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -4470,7 +4470,8 @@ register_edge_assert_for_2 (tree name, edge e, gimple_stmt_iterator bsi,
       gimple def_stmt = SSA_NAME_DEF_STMT (name);
       tree name2 = NULL_TREE, cst2 = NULL_TREE;
       tree val2 = NULL_TREE;
-      unsigned HOST_WIDE_INT mask[2] = { 0, 0 };
+      double_int mask = double_int_zero;
+      unsigned int prec = TYPE_PRECISION (TREE_TYPE (val));
 
       /* Extract CST2 from the right shift.  */
       if (is_gimple_assign (def_stmt)
@@ -4480,23 +4481,13 @@ register_edge_assert_for_2 (tree name, edge e, gimple_stmt_iterator bsi,
 	  cst2 = gimple_assign_rhs2 (def_stmt);
 	  if (TREE_CODE (name2) == SSA_NAME
 	      && host_integerp (cst2, 1)
-	      && (unsigned HOST_WIDE_INT) tree_low_cst (cst2, 1)
-		 < 2 * HOST_BITS_PER_WIDE_INT
 	      && INTEGRAL_TYPE_P (TREE_TYPE (name2))
+	      && IN_RANGE (tree_low_cst (cst2, 1), 1, prec - 1)
+	      && prec <= 2 * HOST_BITS_PER_WIDE_INT
 	      && live_on_edge (e, name2)
 	      && !has_single_use (name2))
 	    {
-	      if ((unsigned HOST_WIDE_INT) tree_low_cst (cst2, 1)
-		  < HOST_BITS_PER_WIDE_INT)
-		mask[0] = ((unsigned HOST_WIDE_INT) 1
-			   << tree_low_cst (cst2, 1)) - 1;
-	      else
-		{
-		  mask[1] = ((unsigned HOST_WIDE_INT) 1
-			     << (tree_low_cst (cst2, 1)
-				 - HOST_BITS_PER_WIDE_INT)) - 1;
-		  mask[0] = -1;
-		}
+	      mask = double_int_mask (tree_low_cst (cst2, 1));
 	      val2 = fold_binary (LSHIFT_EXPR, TREE_TYPE (val), val, cst2);
 	    }
 	}
@@ -4515,37 +4506,40 @@ register_edge_assert_for_2 (tree name, edge e, gimple_stmt_iterator bsi,
 	    {
 	      if (!TYPE_UNSIGNED (TREE_TYPE (val)))
 		{
-		  unsigned int prec = TYPE_PRECISION (TREE_TYPE (val));
 		  tree type = build_nonstandard_integer_type (prec, 1);
 		  tmp = build1 (NOP_EXPR, type, name2);
 		  val2 = fold_convert (type, val2);
 		}
 	      tmp = fold_build2 (MINUS_EXPR, TREE_TYPE (tmp), tmp, val2);
-	      new_val = build_int_cst_wide (TREE_TYPE (tmp), mask[0], mask[1]);
+	      new_val = double_int_to_tree (TREE_TYPE (tmp), mask);
 	      new_comp_code = comp_code == EQ_EXPR ? LE_EXPR : GT_EXPR;
 	    }
 	  else if (comp_code == LT_EXPR || comp_code == GE_EXPR)
 	    new_val = val2;
 	  else
 	    {
-	      new_val = build_int_cst_wide (TREE_TYPE (val2),
-					    mask[0], mask[1]);
-	      new_val = fold_binary (BIT_IOR_EXPR, TREE_TYPE (val2),
-				     val2, new_val);
+	      mask = double_int_ior (tree_to_double_int (val2), mask);
+	      if (double_int_minus_one_p (double_int_sext (mask, prec)))
+		new_val = NULL_TREE;
+	      else
+		new_val = double_int_to_tree (TREE_TYPE (val2), mask);
 	    }
 
-	  if (dump_file)
+	  if (new_val)
 	    {
-	      fprintf (dump_file, "Adding assert for ");
-	      print_generic_expr (dump_file, name2, 0);
-	      fprintf (dump_file, " from ");
-	      print_generic_expr (dump_file, tmp, 0);
-	      fprintf (dump_file, "\n");
-	    }
+	      if (dump_file)
+		{
+		  fprintf (dump_file, "Adding assert for ");
+		  print_generic_expr (dump_file, name2, 0);
+		  fprintf (dump_file, " from ");
+		  print_generic_expr (dump_file, tmp, 0);
+		  fprintf (dump_file, "\n");
+		}
 
-	  register_new_assert_for (name2, tmp, new_comp_code, new_val,
-				   NULL, e, bsi);
-	  retval = true;
+	      register_new_assert_for (name2, tmp, new_comp_code, new_val,
+				       NULL, e, bsi);
+	      retval = true;
+	    }
 	}
     }