From 3bdc6498c4c012a8fbf9cfa2756a5b07f56f1540 Mon Sep 17 00:00:00 2001
From: Mike Pall <mike>
Date: Thu, 15 Aug 2024 00:07:34 +0200
Subject: [PATCH] Limit CSE for IR_CARG to fix loop optimizations.

Thanks to Peter Cawley. #1244
---
 src/lj_opt_fold.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/lj_opt_fold.c b/src/lj_opt_fold.c
index b437d672..98ec28c6 100644
--- a/src/lj_opt_fold.c
+++ b/src/lj_opt_fold.c
@@ -2171,6 +2171,17 @@ LJFOLD(CNEW any any)
 LJFOLD(XSNEW any any)
 LJFOLDX(lj_ir_emit)
 
+/* -- Miscellaneous ------------------------------------------------------- */
+
+LJFOLD(CARG any any)
+LJFOLDF(cse_carg)
+{
+  TRef tr = lj_opt_cse(J);
+  if (tref_ref(tr) < J->chain[IR_LOOP])  /* CSE across loop? */
+    return EMITFOLD;  /* Raw emit. Assumes fins is left intact by CSE. */
+  return tr;
+}
+
 /* ------------------------------------------------------------------------ */
 
 /* Every entry in the generated hash table is a 32 bit pattern: