diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index 8d18e19d6e4..1efb907ae5e 100644
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -3247,6 +3247,42 @@ register_edge_assert_for_2 (tree name, edge e,
 	    }
 	}
     }
+
+  /* For things like (T)a CMP (T)b register asserts for a CMP b if possible.  */
+  if (TREE_CODE_CLASS (comp_code) == tcc_comparison
+      && TREE_CODE (val) == SSA_NAME
+      && (INTEGRAL_TYPE_P (TREE_TYPE (val))
+	  || POINTER_TYPE_P (TREE_TYPE (val))))
+    {
+      gassign *def1 = dyn_cast <gassign *> (SSA_NAME_DEF_STMT (name));
+      gassign *def2 = dyn_cast <gassign *> (SSA_NAME_DEF_STMT (val));
+      if (def1 && def2
+	  && CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def1))
+	  && CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def2))
+	  && types_compatible_p (TREE_TYPE (gimple_assign_rhs1 (def1)),
+				 TREE_TYPE (gimple_assign_rhs1 (def2)))
+	  && (TYPE_PRECISION (TREE_TYPE (gimple_assign_rhs1 (def1)))
+	      <= TYPE_PRECISION (TREE_TYPE (val)))
+	  && (comp_code == EQ_EXPR
+	      || comp_code == NE_EXPR
+	      || (TYPE_SIGN (TREE_TYPE (val))
+		  == TYPE_SIGN (TREE_TYPE (gimple_assign_rhs1 (def1))))
+	      || (TYPE_UNSIGNED (TREE_TYPE (gimple_assign_rhs1 (def1)))
+		  && (TYPE_PRECISION (TREE_TYPE (gimple_assign_rhs1 (def1)))
+		      < TYPE_PRECISION (TREE_TYPE (val))))))
+	{
+	  tree op0 = gimple_assign_rhs1 (def1);
+	  tree op1 = gimple_assign_rhs1 (def2);
+	  enum tree_code alt_comp_code = comp_code;
+	  if (TREE_CODE (op0) != SSA_NAME)
+	    {
+	      alt_comp_code = swap_tree_comparison (alt_comp_code);
+	      std::swap (op0, op1);
+	    }
+	  if (TREE_CODE (op0) == SSA_NAME)
+	    add_assert_info (asserts, op0, op0, alt_comp_code, op1);
+	}
+    }
 }
 
 /* OP is an operand of a truth value expression which is known to have