add function for checked mrb_int addition

1 files changed, 1 insertions, 3 deletions

diff --git a/src/numeric.c b/src/numeric.c
index 56835edbf..8ea71ada6 100644
--- a/src/numeric.c
+++ b/src/numeric.c
@@ -1109,9 +1109,7 @@ mrb_fixnum_plus(mrb_state *mrb, mrb_value x, mrb_value y)
 
     if (a == 0) return y;
     b = mrb_fixnum(y);
-    c = a + b;
-    if (((a < 0) ^ (b < 0)) == 0 && (a < 0) != (c < 0)) {
-      /* integer overflow */
+    if (mrb_int_add_overflow(a, b, &c)) {
       return mrb_float_value(mrb, (mrb_float)a + (mrb_float)b);
     }
     return mrb_fixnum_value(c);