CPU/Recompiler: Support three-operand basic operations

e.g. add r1, r2, r3. This eliminates the extra move on ARM.

src/core/cpu_recompiler_code_generator.cpp

@@ -328,9 +328,16 @@ Value CodeGenerator::AddValues(const Value& lhs, const Value& rhs, bool set_flag
     return res;
   }
   else
+  {
+    if (lhs.IsInHostRegister())
+    {
+      EmitAdd(res.host_reg, lhs.host_reg, rhs, set_flags);
+    }
+    else
     {
       EmitCopyValue(res.host_reg, lhs);
-    EmitAdd(res.host_reg, rhs, set_flags);
+      EmitAdd(res.host_reg, res.host_reg, rhs, set_flags);
+    }
     return res;
   }
 }
@@ -368,9 +375,17 @@ Value CodeGenerator::SubValues(const Value& lhs, const Value& rhs, bool set_flag
     return res;
   }
   else
+  {
+    if (lhs.IsInHostRegister())
+    {
+      EmitSub(res.host_reg, lhs.host_reg, rhs, set_flags);
+    }
+    else
     {
       EmitCopyValue(res.host_reg, lhs);
-    EmitSub(res.host_reg, rhs, set_flags);
+      EmitSub(res.host_reg, res.host_reg, rhs, set_flags);
+    }
+
     return res;
   }
 }
@@ -469,9 +484,22 @@ Value CodeGenerator::ShlValues(const Value& lhs, const Value& rhs)
   }
 
   Value res = m_register_cache.AllocateScratch(lhs.size);
+  if (rhs.HasConstantValue(0))
+  {
     EmitCopyValue(res.host_reg, lhs);
-  if (!rhs.HasConstantValue(0))
+  }
-    EmitShl(res.host_reg, res.size, rhs);
+  else
+  {
+    if (lhs.IsInHostRegister())
+    {
+      EmitShl(res.host_reg, lhs.host_reg, res.size, rhs);
+    }
+    else
+    {
+      EmitCopyValue(res.host_reg, lhs);
+      EmitShl(res.host_reg, res.host_reg, res.size, rhs);
+    }
+  }
   return res;
 }
 
@@ -502,9 +530,22 @@ Value CodeGenerator::ShrValues(const Value& lhs, const Value& rhs)
   }
 
   Value res = m_register_cache.AllocateScratch(lhs.size);
+  if (rhs.HasConstantValue(0))
+  {
     EmitCopyValue(res.host_reg, lhs);
-  if (!rhs.HasConstantValue(0))
+  }
-    EmitShr(res.host_reg, res.size, rhs);
+  else
+  {
+    if (lhs.IsInHostRegister())
+    {
+      EmitShr(res.host_reg, lhs.host_reg, res.size, rhs);
+    }
+    else
+    {
+      EmitCopyValue(res.host_reg, lhs);
+      EmitShr(res.host_reg, res.host_reg, res.size, rhs);
+    }
+  }
   return res;
 }
 
@@ -538,9 +579,22 @@ Value CodeGenerator::SarValues(const Value& lhs, const Value& rhs)
   }
 
   Value res = m_register_cache.AllocateScratch(lhs.size);
+  if (rhs.HasConstantValue(0))
+  {
     EmitCopyValue(res.host_reg, lhs);
-  if (!rhs.HasConstantValue(0))
+  }
-    EmitSar(res.host_reg, res.size, rhs);
+  else
+  {
+    if (lhs.IsInHostRegister())
+    {
+      EmitSar(res.host_reg, lhs.host_reg, res.size, rhs);
+    }
+    else
+    {
+      EmitCopyValue(res.host_reg, lhs);
+      EmitSar(res.host_reg, res.host_reg, res.size, rhs);
+    }
+  }
   return res;
 }
 
@@ -582,8 +636,15 @@ Value CodeGenerator::OrValues(const Value& lhs, const Value& rhs)
     return res;
   }
 
+  if (lhs.IsInHostRegister())
+  {
+    EmitOr(res.host_reg, lhs.host_reg, rhs);
+  }
+  else
+  {
     EmitCopyValue(res.host_reg, lhs);
-  EmitOr(res.host_reg, rhs);
+    EmitOr(res.host_reg, res.host_reg, rhs);
+  }
   return res;
 }
 
@@ -617,12 +678,19 @@ Value CodeGenerator::AndValues(const Value& lhs, const Value& rhs)
   Value res = m_register_cache.AllocateScratch(lhs.size);
   if (lhs.HasConstantValue(0) || rhs.HasConstantValue(0))
   {
-    EmitXor(res.host_reg, res);
+    EmitXor(res.host_reg, res.host_reg, res);
     return res;
   }
 
+  if (lhs.IsInHostRegister())
+  {
+    EmitAnd(res.host_reg, lhs.host_reg, rhs);
+  }
+  else
+  {
     EmitCopyValue(res.host_reg, lhs);
-  EmitAnd(res.host_reg, rhs);
+    EmitAnd(res.host_reg, res.host_reg, rhs);
+  }
   return res;
 }
 
@@ -665,8 +733,17 @@ Value CodeGenerator::XorValues(const Value& lhs, const Value& rhs)
     return res;
   }
 
+  if (lhs.IsInHostRegister())
+  {
+    EmitXor(res.host_reg, lhs.host_reg, rhs);
+
+  }
+  else
+  {
     EmitCopyValue(res.host_reg, lhs);
-  EmitXor(res.host_reg, rhs);
+    EmitXor(res.host_reg, res.host_reg, rhs);
+  }
+
   return res;
 }
 
@@ -942,7 +1019,7 @@ bool CodeGenerator::Compile_Shift(const CodeBlockInstruction& cbi)
     // rd <- rt op (rs & 0x1F)
     shamt = m_register_cache.ReadGuestRegister(cbi.instruction.r.rs);
     if constexpr (!SHIFTS_ARE_IMPLICITLY_MASKED)
-      EmitAnd(shamt.host_reg, Value::FromConstantU32(0x1F));
+      EmitAnd(shamt.host_reg, shamt.host_reg, Value::FromConstantU32(0x1F));
   }
 
   Value result;
@@ -1414,10 +1491,7 @@ bool CodeGenerator::Compile_cop0(const CodeBlockInstruction& cbi)
             if (write_mask != UINT32_C(0xFFFFFFFF))
             {
               // need to adjust the mask
-              Value scratch = m_register_cache.AllocateScratch(RegSize_32);
+              value = AndValues(value, Value::FromConstantU32(write_mask));
-              EmitCopyValue(scratch.host_reg, value);
-              EmitAnd(scratch.host_reg, Value::FromConstantU32(write_mask));
-              value = std::move(scratch);
             }
 
             EmitStoreCPUStructField(offset, value);
@@ -1447,11 +1521,10 @@ bool CodeGenerator::Compile_cop0(const CodeBlockInstruction& cbi)
         EmitLoadCPUStructField(sr.host_reg, RegSize_32, offsetof(Core, m_cop0_regs.sr.bits));
         {
           Value new_mode_bits = m_register_cache.AllocateScratch(RegSize_32);
-          EmitCopyValue(new_mode_bits.host_reg, sr);
+          EmitShr(new_mode_bits.host_reg, sr.host_reg, new_mode_bits.size, Value::FromConstantU32(2));
-          EmitShr(new_mode_bits.host_reg, new_mode_bits.size, Value::FromConstantU32(2));
+          EmitAnd(new_mode_bits.host_reg, new_mode_bits.host_reg, Value::FromConstantU32(mode_bits_mask));
-          EmitAnd(new_mode_bits.host_reg, Value::FromConstantU32(mode_bits_mask));
+          EmitAnd(sr.host_reg, sr.host_reg, Value::FromConstantU32(~mode_bits_mask));
-          EmitAnd(sr.host_reg, Value::FromConstantU32(~mode_bits_mask));
+          EmitOr(sr.host_reg, sr.host_reg, new_mode_bits);
-          EmitOr(sr.host_reg, new_mode_bits);
         }
 
         EmitStoreCPUStructField(offsetof(Core, m_cop0_regs.sr.bits), sr);

src/core/cpu_recompiler_code_generator.h

@@ -48,18 +48,18 @@ public:
   void EmitSignExtend(HostReg to_reg, RegSize to_size, HostReg from_reg, RegSize from_size);
   void EmitZeroExtend(HostReg to_reg, RegSize to_size, HostReg from_reg, RegSize from_size);
   void EmitCopyValue(HostReg to_reg, const Value& value);
-  void EmitAdd(HostReg to_reg, const Value& value, bool set_flags);
+  void EmitAdd(HostReg to_reg, HostReg from_reg, const Value& value, bool set_flags);
-  void EmitSub(HostReg to_reg, const Value& value, bool set_flags);
+  void EmitSub(HostReg to_reg, HostReg from_reg, const Value& value, bool set_flags);
   void EmitCmp(HostReg to_reg, const Value& value);
   void EmitMul(HostReg to_reg_hi, HostReg to_reg_lo, const Value& lhs, const Value& rhs, bool signed_multiply);
   void EmitInc(HostReg to_reg, RegSize size);
   void EmitDec(HostReg to_reg, RegSize size);
-  void EmitShl(HostReg to_reg, RegSize size, const Value& amount_value);
+  void EmitShl(HostReg to_reg, HostReg from_reg, RegSize size, const Value& amount_value);
-  void EmitShr(HostReg to_reg, RegSize size, const Value& amount_value);
+  void EmitShr(HostReg to_reg, HostReg from_reg, RegSize size, const Value& amount_value);
-  void EmitSar(HostReg to_reg, RegSize size, const Value& amount_value);
+  void EmitSar(HostReg to_reg, HostReg from_reg, RegSize size, const Value& amount_value);
-  void EmitAnd(HostReg to_reg, const Value& value);
+  void EmitAnd(HostReg to_reg, HostReg from_reg, const Value& value);
-  void EmitOr(HostReg to_reg, const Value& value);
+  void EmitOr(HostReg to_reg, HostReg from_reg, const Value& value);
-  void EmitXor(HostReg to_reg, const Value& value);
+  void EmitXor(HostReg to_reg, HostReg from_reg, const Value& value);
   void EmitTest(HostReg to_reg, const Value& value);
   void EmitNot(HostReg to_reg, RegSize size);
   void EmitSetConditionResult(HostReg to_reg, RegSize to_size, Condition condition);

src/core/cpu_recompiler_code_generator_x64.cpp

@@ -366,7 +366,7 @@ void CodeGenerator::EmitCopyValue(HostReg to_reg, const Value& value)
   }
 }
 
-void CodeGenerator::EmitAdd(HostReg to_reg, const Value& value, bool set_flags)
+void CodeGenerator::EmitAdd(HostReg to_reg, HostReg from_reg, const Value& value, bool set_flags)
 {
   DebugAssert(value.IsConstant() || value.IsInHostRegister());
 
@@ -374,6 +374,9 @@ void CodeGenerator::EmitAdd(HostReg to_reg, const Value& value, bool set_flags)
   {
     case RegSize_8:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg8(to_reg), GetHostReg8(from_reg));
+
       if (value.IsConstant())
         m_emit->add(GetHostReg8(to_reg), SignExtend32(Truncate8(value.constant_value)));
       else
@@ -383,6 +386,9 @@ void CodeGenerator::EmitAdd(HostReg to_reg, const Value& value, bool set_flags)
 
     case RegSize_16:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg16(to_reg), GetHostReg16(from_reg));
+
       if (value.IsConstant())
         m_emit->add(GetHostReg16(to_reg), SignExtend32(Truncate16(value.constant_value)));
       else
@@ -392,6 +398,9 @@ void CodeGenerator::EmitAdd(HostReg to_reg, const Value& value, bool set_flags)
 
     case RegSize_32:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg32(to_reg), GetHostReg32(from_reg));
+
       if (value.IsConstant())
         m_emit->add(GetHostReg32(to_reg), Truncate32(value.constant_value));
       else
@@ -401,6 +410,9 @@ void CodeGenerator::EmitAdd(HostReg to_reg, const Value& value, bool set_flags)
 
     case RegSize_64:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg64(to_reg), GetHostReg64(from_reg));
+
       if (value.IsConstant())
       {
         if (!Xbyak::inner::IsInInt32(value.constant_value))
@@ -423,7 +435,7 @@ void CodeGenerator::EmitAdd(HostReg to_reg, const Value& value, bool set_flags)
   }
 }
 
-void CodeGenerator::EmitSub(HostReg to_reg, const Value& value, bool set_flags)
+void CodeGenerator::EmitSub(HostReg to_reg, HostReg from_reg, const Value& value, bool set_flags)
 {
   DebugAssert(value.IsConstant() || value.IsInHostRegister());
 
@@ -431,6 +443,9 @@ void CodeGenerator::EmitSub(HostReg to_reg, const Value& value, bool set_flags)
   {
     case RegSize_8:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg8(to_reg), GetHostReg8(from_reg));
+
       if (value.IsConstant())
         m_emit->sub(GetHostReg8(to_reg), SignExtend32(Truncate8(value.constant_value)));
       else
@@ -440,6 +455,9 @@ void CodeGenerator::EmitSub(HostReg to_reg, const Value& value, bool set_flags)
 
     case RegSize_16:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg16(to_reg), GetHostReg16(from_reg));
+
       if (value.IsConstant())
         m_emit->sub(GetHostReg16(to_reg), SignExtend32(Truncate16(value.constant_value)));
       else
@@ -449,6 +467,9 @@ void CodeGenerator::EmitSub(HostReg to_reg, const Value& value, bool set_flags)
 
     case RegSize_32:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg32(to_reg), GetHostReg32(from_reg));
+
       if (value.IsConstant())
         m_emit->sub(GetHostReg32(to_reg), Truncate32(value.constant_value));
       else
@@ -458,6 +479,9 @@ void CodeGenerator::EmitSub(HostReg to_reg, const Value& value, bool set_flags)
 
     case RegSize_64:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg64(to_reg), GetHostReg64(from_reg));
+
       if (value.IsConstant())
       {
         if (!Xbyak::inner::IsInInt32(value.constant_value))
@@ -691,7 +715,7 @@ void CodeGenerator::EmitDec(HostReg to_reg, RegSize size)
   }
 }
 
-void CodeGenerator::EmitShl(HostReg to_reg, RegSize size, const Value& amount_value)
+void CodeGenerator::EmitShl(HostReg to_reg, HostReg from_reg, RegSize size, const Value& amount_value)
 {
   DebugAssert(amount_value.IsConstant() || amount_value.IsInHostRegister());
 
@@ -708,6 +732,9 @@ void CodeGenerator::EmitShl(HostReg to_reg, RegSize size, const Value& amount_va
   {
     case RegSize_8:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg8(to_reg), GetHostReg8(from_reg));
+
       if (amount_value.IsConstant())
         m_emit->shl(GetHostReg8(to_reg), Truncate8(amount_value.constant_value));
       else
@@ -717,6 +744,9 @@ void CodeGenerator::EmitShl(HostReg to_reg, RegSize size, const Value& amount_va
 
     case RegSize_16:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg16(to_reg), GetHostReg16(from_reg));
+
       if (amount_value.IsConstant())
         m_emit->shl(GetHostReg16(to_reg), Truncate8(amount_value.constant_value));
       else
@@ -726,6 +756,9 @@ void CodeGenerator::EmitShl(HostReg to_reg, RegSize size, const Value& amount_va
 
     case RegSize_32:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg32(to_reg), GetHostReg32(from_reg));
+
       if (amount_value.IsConstant())
         m_emit->shl(GetHostReg32(to_reg), Truncate32(amount_value.constant_value));
       else
@@ -735,6 +768,9 @@ void CodeGenerator::EmitShl(HostReg to_reg, RegSize size, const Value& amount_va
 
     case RegSize_64:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg64(to_reg), GetHostReg64(from_reg));
+
       if (amount_value.IsConstant())
         m_emit->shl(GetHostReg64(to_reg), Truncate32(amount_value.constant_value));
       else
@@ -747,7 +783,7 @@ void CodeGenerator::EmitShl(HostReg to_reg, RegSize size, const Value& amount_va
     m_emit->pop(m_emit->rcx);
 }
 
-void CodeGenerator::EmitShr(HostReg to_reg, RegSize size, const Value& amount_value)
+void CodeGenerator::EmitShr(HostReg to_reg, HostReg from_reg, RegSize size, const Value& amount_value)
 {
   DebugAssert(amount_value.IsConstant() || amount_value.IsInHostRegister());
 
@@ -764,6 +800,9 @@ void CodeGenerator::EmitShr(HostReg to_reg, RegSize size, const Value& amount_va
   {
     case RegSize_8:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg8(to_reg), GetHostReg8(from_reg));
+
       if (amount_value.IsConstant())
         m_emit->shr(GetHostReg8(to_reg), Truncate8(amount_value.constant_value));
       else
@@ -773,6 +812,9 @@ void CodeGenerator::EmitShr(HostReg to_reg, RegSize size, const Value& amount_va
 
     case RegSize_16:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg16(to_reg), GetHostReg16(from_reg));
+
       if (amount_value.IsConstant())
         m_emit->shr(GetHostReg16(to_reg), Truncate8(amount_value.constant_value));
       else
@@ -782,6 +824,9 @@ void CodeGenerator::EmitShr(HostReg to_reg, RegSize size, const Value& amount_va
 
     case RegSize_32:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg32(to_reg), GetHostReg32(from_reg));
+
       if (amount_value.IsConstant())
         m_emit->shr(GetHostReg32(to_reg), Truncate32(amount_value.constant_value));
       else
@@ -791,6 +836,9 @@ void CodeGenerator::EmitShr(HostReg to_reg, RegSize size, const Value& amount_va
 
     case RegSize_64:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg64(to_reg), GetHostReg64(from_reg));
+
       if (amount_value.IsConstant())
         m_emit->shr(GetHostReg64(to_reg), Truncate32(amount_value.constant_value));
       else
@@ -803,7 +851,7 @@ void CodeGenerator::EmitShr(HostReg to_reg, RegSize size, const Value& amount_va
     m_emit->pop(m_emit->rcx);
 }
 
-void CodeGenerator::EmitSar(HostReg to_reg, RegSize size, const Value& amount_value)
+void CodeGenerator::EmitSar(HostReg to_reg, HostReg from_reg, RegSize size, const Value& amount_value)
 {
   DebugAssert(amount_value.IsConstant() || amount_value.IsInHostRegister());
 
@@ -820,6 +868,9 @@ void CodeGenerator::EmitSar(HostReg to_reg, RegSize size, const Value& amount_va
   {
     case RegSize_8:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg8(to_reg), GetHostReg8(from_reg));
+
       if (amount_value.IsConstant())
         m_emit->sar(GetHostReg8(to_reg), Truncate8(amount_value.constant_value));
       else
@@ -829,6 +880,9 @@ void CodeGenerator::EmitSar(HostReg to_reg, RegSize size, const Value& amount_va
 
     case RegSize_16:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg16(to_reg), GetHostReg16(from_reg));
+
       if (amount_value.IsConstant())
         m_emit->sar(GetHostReg16(to_reg), Truncate8(amount_value.constant_value));
       else
@@ -838,6 +892,9 @@ void CodeGenerator::EmitSar(HostReg to_reg, RegSize size, const Value& amount_va
 
     case RegSize_32:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg32(to_reg), GetHostReg32(from_reg));
+
       if (amount_value.IsConstant())
         m_emit->sar(GetHostReg32(to_reg), Truncate32(amount_value.constant_value));
       else
@@ -847,6 +904,9 @@ void CodeGenerator::EmitSar(HostReg to_reg, RegSize size, const Value& amount_va
 
     case RegSize_64:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg64(to_reg), GetHostReg64(from_reg));
+
       if (amount_value.IsConstant())
         m_emit->sar(GetHostReg64(to_reg), Truncate32(amount_value.constant_value));
       else
@@ -859,13 +919,16 @@ void CodeGenerator::EmitSar(HostReg to_reg, RegSize size, const Value& amount_va
     m_emit->pop(m_emit->rcx);
 }
 
-void CodeGenerator::EmitAnd(HostReg to_reg, const Value& value)
+void CodeGenerator::EmitAnd(HostReg to_reg, HostReg from_reg, const Value& value)
 {
   DebugAssert(value.IsConstant() || value.IsInHostRegister());
   switch (value.size)
   {
     case RegSize_8:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg8(to_reg), GetHostReg8(from_reg));
+
       if (value.IsConstant())
         m_emit->and_(GetHostReg8(to_reg), Truncate32(value.constant_value & UINT32_C(0xFF)));
       else
@@ -875,6 +938,9 @@ void CodeGenerator::EmitAnd(HostReg to_reg, const Value& value)
 
     case RegSize_16:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg16(to_reg), GetHostReg16(from_reg));
+
       if (value.IsConstant())
         m_emit->and_(GetHostReg16(to_reg), Truncate32(value.constant_value & UINT32_C(0xFFFF)));
       else
@@ -884,6 +950,9 @@ void CodeGenerator::EmitAnd(HostReg to_reg, const Value& value)
 
     case RegSize_32:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg32(to_reg), GetHostReg32(from_reg));
+
       if (value.IsConstant())
         m_emit->and_(GetHostReg32(to_reg), Truncate32(value.constant_value));
       else
@@ -893,6 +962,9 @@ void CodeGenerator::EmitAnd(HostReg to_reg, const Value& value)
 
     case RegSize_64:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg64(to_reg), GetHostReg64(from_reg));
+
       if (value.IsConstant())
       {
         if (!Xbyak::inner::IsInInt32(value.constant_value))
@@ -915,13 +987,16 @@ void CodeGenerator::EmitAnd(HostReg to_reg, const Value& value)
   }
 }
 
-void CodeGenerator::EmitOr(HostReg to_reg, const Value& value)
+void CodeGenerator::EmitOr(HostReg to_reg, HostReg from_reg, const Value& value)
 {
   DebugAssert(value.IsConstant() || value.IsInHostRegister());
   switch (value.size)
   {
     case RegSize_8:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg8(to_reg), GetHostReg8(from_reg));
+
       if (value.IsConstant())
         m_emit->or_(GetHostReg8(to_reg), Truncate32(value.constant_value & UINT32_C(0xFF)));
       else
@@ -931,6 +1006,9 @@ void CodeGenerator::EmitOr(HostReg to_reg, const Value& value)
 
     case RegSize_16:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg16(to_reg), GetHostReg16(from_reg));
+
       if (value.IsConstant())
         m_emit->or_(GetHostReg16(to_reg), Truncate32(value.constant_value & UINT32_C(0xFFFF)));
       else
@@ -940,6 +1018,9 @@ void CodeGenerator::EmitOr(HostReg to_reg, const Value& value)
 
     case RegSize_32:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg32(to_reg), GetHostReg32(from_reg));
+
       if (value.IsConstant())
         m_emit->or_(GetHostReg32(to_reg), Truncate32(value.constant_value));
       else
@@ -949,6 +1030,9 @@ void CodeGenerator::EmitOr(HostReg to_reg, const Value& value)
 
     case RegSize_64:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg64(to_reg), GetHostReg64(from_reg));
+
       if (value.IsConstant())
       {
         if (!Xbyak::inner::IsInInt32(value.constant_value))
@@ -971,13 +1055,16 @@ void CodeGenerator::EmitOr(HostReg to_reg, const Value& value)
   }
 }
 
-void CodeGenerator::EmitXor(HostReg to_reg, const Value& value)
+void CodeGenerator::EmitXor(HostReg to_reg, HostReg from_reg, const Value& value)
 {
   DebugAssert(value.IsConstant() || value.IsInHostRegister());
   switch (value.size)
   {
     case RegSize_8:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg8(to_reg), GetHostReg8(from_reg));
+
       if (value.IsConstant())
         m_emit->xor_(GetHostReg8(to_reg), Truncate32(value.constant_value & UINT32_C(0xFF)));
       else
@@ -987,6 +1074,9 @@ void CodeGenerator::EmitXor(HostReg to_reg, const Value& value)
 
     case RegSize_16:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg16(to_reg), GetHostReg16(from_reg));
+
       if (value.IsConstant())
         m_emit->xor_(GetHostReg16(to_reg), Truncate32(value.constant_value & UINT32_C(0xFFFF)));
       else
@@ -996,6 +1086,9 @@ void CodeGenerator::EmitXor(HostReg to_reg, const Value& value)
 
     case RegSize_32:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg32(to_reg), GetHostReg32(from_reg));
+
       if (value.IsConstant())
         m_emit->xor_(GetHostReg32(to_reg), Truncate32(value.constant_value));
       else
@@ -1005,6 +1098,9 @@ void CodeGenerator::EmitXor(HostReg to_reg, const Value& value)
 
     case RegSize_64:
     {
+      if (to_reg != from_reg)
+        m_emit->mov(GetHostReg64(to_reg), GetHostReg64(from_reg));
+
       if (value.IsConstant())
       {
         if (!Xbyak::inner::IsInInt32(value.constant_value))

src/core/cpu_recompiler_register_cache.cpp

@@ -394,7 +394,7 @@ Value RegisterCache::ReadGuestRegister(Reg guest_reg, bool cache /* = true */, b
     if (force_host_register)
     {
       Value temp = AllocateScratch(RegSize_32, forced_host_reg);
-      m_code_generator.EmitXor(temp.host_reg, temp);
+      m_code_generator.EmitXor(temp.host_reg, temp.host_reg, temp);
       return temp;
     }