From 281f426d602596f855d8fea787ad7a514365244d Mon Sep 17 00:00:00 2001
From: Mike Pall <mike>
Date: Mon, 6 Dec 2010 00:38:21 +0100
Subject: [PATCH] Add minimal set of fold rules for KINT64.

---
 src/lj_opt_fold.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/src/lj_opt_fold.c b/src/lj_opt_fold.c
index 6df1a08a..8ccfc6bd 100644
--- a/src/lj_opt_fold.c
+++ b/src/lj_opt_fold.c
@@ -661,6 +661,25 @@ LJFOLDF(simplify_intsub_k)
   return RETRYFOLD;
 }
 
+LJFOLD(ADD any KINT64)
+LJFOLDF(simplify_intadd_k64)
+{
+  if (ir_kint64(fright)->u64 == 0)  /* i + 0 ==> i */
+    return LEFTFOLD;
+  return NEXTFOLD;
+}
+
+LJFOLD(SUB any KINT64)
+LJFOLDF(simplify_intsub_k64)
+{
+  uint64_t k = ir_kint64(fright)->u64;
+  if (k == 0)  /* i - 0 ==> i */
+    return LEFTFOLD;
+  fins->o = IR_ADD;  /* i - k ==> i + (-k) */
+  fins->op2 = (IRRef1)lj_ir_kint64(J, -k);  /* Overflow for -2^63 ok. */
+  return RETRYFOLD;
+}
+
 LJFOLD(SUB any any)
 LJFOLD(SUBOV any any)
 LJFOLDF(simplify_intsub)