From a91b55f5ca6828f5a15fbb6a673c7b2da3ff6647 Mon Sep 17 00:00:00 2001
From: "Yukihiro \"Matz\" Matsumoto" <matz@ruby.or.jp>
Date: Sat, 26 Mar 2022 11:11:00 +0900
Subject: [PATCH] codegen.c: allow constant folding for multiply with zero.

---
 mrbgems/mruby-compiler/core/codegen.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mrbgems/mruby-compiler/core/codegen.c b/mrbgems/mruby-compiler/core/codegen.c
index 1a4f6b213..258aee8ae 100644
--- a/mrbgems/mruby-compiler/core/codegen.c
+++ b/mrbgems/mruby-compiler/core/codegen.c
@@ -844,13 +844,14 @@ gen_muldiv(codegen_scope *s, uint8_t op, uint16_t dst)
       goto normal;
     }
     struct mrb_insn_data data0 = mrb_decode_insn(mrb_prev_pc(s, data.addr));
-    if (!get_int_operand(s, &data0, &n0) || n == 0) {
+    if (!get_int_operand(s, &data0, &n0)) {
       goto normal;
     }
     if (op == OP_MUL) {
       if (mrb_int_mul_overflow(n0, n, &n)) goto normal;
     }
     else { /* OP_DIV */
+      if (n == 0) goto normal;
       if (n0 == MRB_INT_MIN && n == -1) goto normal;
       n = mrb_div_int(s->mrb, n0, n);
     }