PowerPC: Use broader mask for checking loadstore exceptions

We will need to check for EXCEPTION_ALIGNMENT in addition to
EXCEPTION_DSI. Let's also throw in EXCEPTION_FAKE_MEMCHECK_HIT
while we're at it so we can skip doing fake DSI exceptions for that.

Reordering the exceptions enum is done for the sake of saving one
instruction on AArch64 when checking for loadstore exceptions.
(Bitwise operations can encode immediates containing a run of ones
of an arbitrary length, rotated by an arbitrary amount of bits,
and in order to make use of this all loadstore exceptions should
have adjacent bit positions.)

Source/Core/Core/PowerPC/CachedInterpreter/CachedInterpreter.cpp

@@ -170,9 +170,9 @@ static bool CheckFPU(u32 data)
   return false;
 }
 
-static bool CheckDSI(u32 data)
+static bool CheckLoadStore(u32 data)
 {
-  if (PowerPC::ppcState.Exceptions & EXCEPTION_DSI)
+  if (PowerPC::ppcState.Exceptions & ANY_LOADSTORE_EXCEPTION)
   {
     PowerPC::CheckExceptions();
     PowerPC::ppcState.downcount -= data;
@@ -287,7 +287,7 @@ void CachedInterpreter::Jit(u32 address)
         m_code.emplace_back(WritePC, op.address);
       m_code.emplace_back(PPCTables::GetInterpreterOp(op.inst), op.inst);
       if (memcheck)
-        m_code.emplace_back(CheckDSI, js.downcountAmount);
+        m_code.emplace_back(CheckLoadStore, js.downcountAmount);
       if (idle_loop)
         m_code.emplace_back(CheckIdle, js.blockStart);
       if (endblock)

Source/Core/Core/PowerPC/Gekko.h

@@ -900,14 +900,15 @@ enum
   EXCEPTION_DECREMENTER = 0x00000001,
   EXCEPTION_SYSCALL = 0x00000002,
   EXCEPTION_EXTERNAL_INT = 0x00000004,
-  EXCEPTION_DSI = 0x00000008,
-  EXCEPTION_ISI = 0x00000010,
+  EXCEPTION_ISI = 0x00000008,
+  EXCEPTION_DSI = 0x00000010,
   EXCEPTION_ALIGNMENT = 0x00000020,
-  EXCEPTION_FPU_UNAVAILABLE = 0x00000040,
-  EXCEPTION_PROGRAM = 0x00000080,
-  EXCEPTION_PERFORMANCE_MONITOR = 0x00000100,
+  EXCEPTION_FAKE_MEMCHECK_HIT = 0x00000040,
+  EXCEPTION_FPU_UNAVAILABLE = 0x00000080,
+  EXCEPTION_PROGRAM = 0x00000100,
+  EXCEPTION_PERFORMANCE_MONITOR = 0x00000200,
 
-  EXCEPTION_FAKE_MEMCHECK_HIT = 0x00000200,
+  ANY_LOADSTORE_EXCEPTION = EXCEPTION_DSI | EXCEPTION_ALIGNMENT | EXCEPTION_FAKE_MEMCHECK_HIT,
 };
 
 constexpr s32 SignExt16(s16 x)

Source/Core/Core/PowerPC/Interpreter/Interpreter.cpp

@@ -188,7 +188,7 @@ int Interpreter::SingleStepInner()
     else if (MSR.FP)
     {
       m_op_table[m_prev_inst.OPCD](m_prev_inst);
-      if (PowerPC::ppcState.Exceptions & EXCEPTION_DSI)
+      if (PowerPC::ppcState.Exceptions & ANY_LOADSTORE_EXCEPTION)
       {
         CheckExceptions();
       }
@@ -204,7 +204,7 @@ int Interpreter::SingleStepInner()
       else
       {
         m_op_table[m_prev_inst.OPCD](m_prev_inst);
-        if (PowerPC::ppcState.Exceptions & EXCEPTION_DSI)
+        if (PowerPC::ppcState.Exceptions & ANY_LOADSTORE_EXCEPTION)
         {
           CheckExceptions();
         }