1 files changed, 12 insertions, 0 deletions

diff --git a/parse-events.c b/parse-events.c
index 58ffe51..32c13ac 100644
--- a/parse-events.c
+++ b/parse-events.c
@@ -2030,6 +2030,18 @@ static int arg_num_eval(struct print_arg *arg, long long *val)
                                 break;
                         *val = left - right;
                         break;
+                case '+':
+                        if (arg->op.left->type == PRINT_NULL)
+                                left = 0;
+                        else
+                                ret = arg_num_eval(arg->op.left, &left);
+                        if (!ret)
+                                break;
+                        ret = arg_num_eval(arg->op.right, &right);
+                        if (!ret)
+                                break;
+                        *val = left + right;
+                        break;
                 default:
                         do_warning("unknown op '%s'", arg->op.op);
                         ret = 0;