tdup-as-keys.patch

diff --git a/src/lj_opt_mem.c b/src/lj_opt_mem.c
index e04a622..0cc420e 100644
--- a/src/lj_opt_mem.c
+++ b/src/lj_opt_mem.c
@@ -135,6 +135,31 @@ static TRef fwd_ahload(jit_State *J, IRRef xref)
   IRRef lim = xref;  /* Search limit. */
   IRRef ref;
 
+  /* Key is a newly allocated table. Walk the chain of stores up to the
+  ** key allocation itself and see it is ever potentially used to create
+  ** a reference (by checking if it aliases any of the keys). If it does
+  ** not we can drop the load.
+  */
+  if (xr->o == IR_HREF &&
+      (IR(xr->op2)->o == IR_TNEW || IR(xr->op2)->o == IR_TDUP)) {
+    int found = 0;
+    IRRef tab = xr->op2;
+    ref = J->chain[fins->o+IRDELTA_L2S];
+    while (ref > tab) {
+      IRIns *store = IR(ref);
+      IRIns *refb = IR(store->op1);
+      if ((refb->o == IR_HREF || refb->o == IR_NEWREF) &&
+          aa_table(J, tab, refb->op2) != ALIAS_NO) {
+        found = 1;
+        break;
+      }
+      ref = store->prev;
+    }
+    if (!found) {
+      return TREF_NIL;
+    }
+  }
+
   /* Search for conflicting stores. */
   ref = J->chain[fins->o+IRDELTA_L2S];
   while (ref > xref) {