Fix handling of instable types in TNEW/TDUP load forwarding.

Analyzed by Sergey Kaplun. #994

1 files changed, 2 insertions, 1 deletions

diff --git a/src/lj_opt_mem.c b/src/lj_opt_mem.c
index 5b1ad898..9d83ea4a 100644
--- a/src/lj_opt_mem.c
+++ b/src/lj_opt_mem.c
@@ -197,7 +197,8 @@ static TRef fwd_ahload(jit_State *J, IRRef xref)
         if (key->o == IR_KSLOT) key = IR(key->op1);
         lj_ir_kvalue(J->L, &keyv, key);
         tv = lj_tab_get(J->L, ir_ktab(IR(ir->op1)), &keyv);
-        lua_assert(itype2irt(tv) == irt_type(fins->t));
+        if (itype2irt(tv) != irt_type(fins->t))
+          return 0;  /* Type instability in loop-carried dependency. */
         if (irt_isnum(fins->t))
           return lj_ir_knum_u64(J, tv->u64);
         else if (LJ_DUALNUM && irt_isint(fins->t))