From 6c599960d15888baa717956faaae83170188800d Mon Sep 17 00:00:00 2001
From: Mike Pall <mike>
Date: Sat, 9 Sep 2023 17:36:40 +0200
Subject: [PATCH] ARM64: Improve integer IR_MUL code generation.

Thanks to Peter Cawley. #1070
---
 src/lj_asm_arm64.h | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/lj_asm_arm64.h b/src/lj_asm_arm64.h
index d2cb7823..d9866e9d 100644
--- a/src/lj_asm_arm64.h
+++ b/src/lj_asm_arm64.h
@@ -1391,8 +1391,7 @@ static void asm_intmul(ASMState *as, IRIns *ir)
   if (irt_isguard(ir->t)) {  /* IR_MULOV */
     asm_guardcc(as, CC_NE);
     emit_dm(as, A64I_MOVw, dest, dest);  /* Zero-extend. */
-    emit_nm(as, A64I_CMPw | A64F_SH(A64SH_ASR, 31), RID_TMP, dest);
-    emit_dn(as, A64I_ASRx | A64F_IMMR(32), RID_TMP, dest);
+    emit_nm(as, A64I_CMPx | A64F_EX(A64EX_SXTW), dest, dest);
     emit_dnm(as, A64I_SMULL, dest, right, left);
   } else {
     emit_dnm(as, irt_is64(ir->t) ? A64I_MULx : A64I_MULw, dest, left, right);