From df70077e6b27608bfdc9812fa0d2bec6c1a4247b Mon Sep 17 00:00:00 2001
From: Sintendo <bram.speeckaert@gmail.com>
Date: Tue, 5 Jan 2021 18:52:24 +0100
Subject: [PATCH] JitArm64: subfx - Special case a == b

---
 Source/Core/Core/PowerPC/JitArm64/JitArm64_Integer.cpp | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/Source/Core/Core/PowerPC/JitArm64/JitArm64_Integer.cpp b/Source/Core/Core/PowerPC/JitArm64/JitArm64_Integer.cpp
index 645ffc4af5..33e8f47450 100644
--- a/Source/Core/Core/PowerPC/JitArm64/JitArm64_Integer.cpp
+++ b/Source/Core/Core/PowerPC/JitArm64/JitArm64_Integer.cpp
@@ -856,7 +856,13 @@ void JitArm64::subfx(UGeckoInstruction inst)
 
   int a = inst.RA, b = inst.RB, d = inst.RD;
 
-  if (gpr.IsImm(a) && gpr.IsImm(b))
+  if (a == b)
+  {
+    gpr.SetImmediate(d, 0);
+    if (inst.Rc)
+      ComputeRC0(gpr.GetImm(d));
+  }
+  else if (gpr.IsImm(a) && gpr.IsImm(b))
   {
     u32 i = gpr.GetImm(a), j = gpr.GetImm(b);
     gpr.SetImmediate(d, j - i);