From 8304ae33613c197ae377ed246d705f0b2a398e38 Mon Sep 17 00:00:00 2001
From: Sintendo <3380580+Sintendo@users.noreply.github.com>
Date: Thu, 10 Oct 2024 22:13:30 +0200
Subject: [PATCH 1/3] JitArm64_RegCache: Add IsImm helper

Because checking if a register is a specific immediate is a rather
common operation.
---
 Source/Core/Core/PowerPC/JitArm64/JitArm64_RegCache.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Source/Core/Core/PowerPC/JitArm64/JitArm64_RegCache.h b/Source/Core/Core/PowerPC/JitArm64/JitArm64_RegCache.h
index 9ea4e0e3b6..bfc9f32a54 100644
--- a/Source/Core/Core/PowerPC/JitArm64/JitArm64_RegCache.h
+++ b/Source/Core/Core/PowerPC/JitArm64/JitArm64_RegCache.h
@@ -286,6 +286,8 @@ public:
   // Gets the immediate that a register is set to. Only valid for guest GPRs.
   u32 GetImm(size_t preg) const { return GetGuestGPROpArg(preg).GetImm(); }
 
+  bool IsImm(size_t preg, u32 imm) { return IsImm(preg) && GetImm(preg) == imm; }
+
   // Binds a guest GPR to a host register, optionally loading its value.
   //
   // preg: The guest register index.

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 2/3] 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));
 }
 

From a9a779a6b9a9843c456d208575c7749e89a33429 Mon Sep 17 00:00:00 2001
From: Sintendo <3380580+Sintendo@users.noreply.github.com>
Date: Thu, 10 Oct 2024 22:21:31 +0200
Subject: [PATCH 3/3] JitArm64_Integer: Use IsImm helper more

---
 Source/Core/Core/PowerPC/JitArm64/JitArm64_Integer.cpp | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/Source/Core/Core/PowerPC/JitArm64/JitArm64_Integer.cpp b/Source/Core/Core/PowerPC/JitArm64/JitArm64_Integer.cpp
index f3d263379c..63ccff4c47 100644
--- a/Source/Core/Core/PowerPC/JitArm64/JitArm64_Integer.cpp
+++ b/Source/Core/Core/PowerPC/JitArm64/JitArm64_Integer.cpp
@@ -649,7 +649,7 @@ void JitArm64::cmp(UGeckoInstruction inst)
     SXTW(CR, gpr.R(b));
     NEG(CR, CR);
   }
-  else if (gpr.IsImm(a) && gpr.GetImm(a) == 0xFFFFFFFF)
+  else if (gpr.IsImm(a, 0xFFFFFFFF))
   {
     SXTW(CR, gpr.R(b));
     MVN(CR, CR);
@@ -1640,7 +1640,7 @@ void JitArm64::divwx(UGeckoInstruction inst)
     if (inst.Rc)
       ComputeRC0(imm_d);
   }
-  else if (gpr.IsImm(a) && gpr.GetImm(a) == 0)
+  else if (gpr.IsImm(a, 0))
   {
     // Zero divided by anything is always zero
     gpr.SetImmediate(d, 0);
@@ -1829,7 +1829,7 @@ void JitArm64::slwx(UGeckoInstruction inst)
     if (inst.Rc)
       ComputeRC0(gpr.GetImm(a));
   }
-  else if (gpr.IsImm(s) && gpr.GetImm(s) == 0)
+  else if (gpr.IsImm(s, 0))
   {
     gpr.SetImmediate(a, 0);
     if (inst.Rc)
@@ -1934,7 +1934,7 @@ void JitArm64::srawx(UGeckoInstruction inst)
       ComputeRC0(gpr.GetImm(a));
     return;
   }
-  else if (gpr.IsImm(s) && gpr.GetImm(s) == 0)
+  else if (gpr.IsImm(s, 0))
   {
     gpr.SetImmediate(a, 0);
     ComputeCarry(false);