From 9914243d6815cd988d81783bf24a7e23c084ae83 Mon Sep 17 00:00:00 2001
From: "Yukihiro \"Matz\" Matsumoto" <matz@ruby.or.jp>
Date: Fri, 1 Sep 2023 15:29:40 +0900
Subject: [PATCH] vm.c: use direct array access if possible

---
 src/vm.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/vm.c b/src/vm.c
index b9742507d..9340b0c00 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -1556,7 +1556,15 @@ RETRY_TRY_BLOCK:
       switch (mrb_type(va)) {
       case MRB_TT_ARRAY:
         if (!mrb_integer_p(vb)) goto getidx_fallback;
-        regs[a] = mrb_ary_entry(va, mrb_integer(vb));
+        else {
+          mrb_int idx = mrb_integer(vb);
+          if (0 <= idx && idx < RARRAY_LEN(va)) {
+            regs[a] = RARRAY_PTR(va)[idx];
+          }
+          else {
+            regs[a] = mrb_ary_entry(va, idx);
+          }
+        }
         break;
       case MRB_TT_HASH:
         va = mrb_hash_get(mrb, va, vb);