From 6a47370219ced8dc63a5c81b20159924d1c1f885 Mon Sep 17 00:00:00 2001
From: Wunkolo <Wunkolo@gmail.com>
Date: Wed, 25 Mar 2026 21:48:37 -0700
Subject: [PATCH] [a64] Fix `ATOMIC_EXCHANGE` `swp` operand order

`swp` is weird and actually writes the first operand into the
memory address into the third operand,
_and puts the old value into the second operand_.
---
 src/xenia/cpu/backend/a64/a64_seq_memory.cc | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/xenia/cpu/backend/a64/a64_seq_memory.cc b/src/xenia/cpu/backend/a64/a64_seq_memory.cc
index e5424bd99..bf7600363 100644
--- a/src/xenia/cpu/backend/a64/a64_seq_memory.cc
+++ b/src/xenia/cpu/backend/a64/a64_seq_memory.cc
@@ -909,7 +909,7 @@ struct ATOMIC_EXCHANGE_I8
     }
 
     if (e.IsFeatureEnabled(kA64EmitLSE)) {
-      e.swpalb(i.dest, e.w0, ptr(e.x4));
+      e.swpalb(e.w0, i.dest, ptr(e.x4));
       return;
     }
 
@@ -938,7 +938,7 @@ struct ATOMIC_EXCHANGE_I16
     }
 
     if (e.IsFeatureEnabled(kA64EmitLSE)) {
-      e.swpalh(i.dest, e.w0, ptr(e.x4));
+      e.swpalh(e.w0, i.dest, ptr(e.x4));
       return;
     }
 
@@ -968,7 +968,7 @@ struct ATOMIC_EXCHANGE_I32
     }
 
     if (e.IsFeatureEnabled(kA64EmitLSE)) {
-      e.swpal(i.dest, e.w0, ptr(e.x4));
+      e.swpal(e.w0, i.dest, ptr(e.x4));
       return;
     }