From 0d9984b299ece57b5fec22d5d45d55d8f3f6554e Mon Sep 17 00:00:00 2001
From: Sintendo <3380580+Sintendo@users.noreply.github.com>
Date: Thu, 10 Oct 2024 22:16:25 +0200
Subject: [PATCH] JitArm64_SystemRegisters: Optimize mtspr

No need to materialize the immediate if it is zero, we can just use WZR.

Before:
mov    w27, #0x0                 ; =0
str    w27, [x29, #0x1178]

After:
str    wzr, [x29, #0x1178]
---
 Source/Core/Core/PowerPC/JitArm64/JitArm64_SystemRegisters.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Source/Core/Core/PowerPC/JitArm64/JitArm64_SystemRegisters.cpp b/Source/Core/Core/PowerPC/JitArm64/JitArm64_SystemRegisters.cpp
index 87f652d6d4..8ffa1b84aa 100644
--- a/Source/Core/Core/PowerPC/JitArm64/JitArm64_SystemRegisters.cpp
+++ b/Source/Core/Core/PowerPC/JitArm64/JitArm64_SystemRegisters.cpp
@@ -477,7 +477,7 @@ void JitArm64::mtspr(UGeckoInstruction inst)
   }
 
   // OK, this is easy.
-  ARM64Reg RD = gpr.R(inst.RD);
+  ARM64Reg RD = gpr.IsImm(inst.RD, 0) ? ARM64Reg::WZR : gpr.R(inst.RD);
   STR(IndexType::Unsigned, RD, PPC_REG, PPCSTATE_OFF_SPR(iIndex));
 }