CPU: Expand register file to include hi/lo/pc/npc

src/core/cpu_types.h

@@ -50,6 +50,13 @@ enum class Reg : u8
   sp,
   fp,
   ra,
+
+  // not accessible to instructions
+  hi,
+  lo,
+  pc,
+  npc,
+
   count
 };
 
@@ -219,7 +226,7 @@ struct Registers
 {
   union
   {
-    u32 r[32];
+    u32 r[static_cast<u8>(Reg::count)];
 
     struct
     {
@@ -255,13 +262,14 @@ struct Registers
       u32 sp;   // r29
       u32 fp;   // r30
       u32 ra;   // r31
-    };
-  };
 
+      // not accessible to instructions
       u32 hi;
       u32 lo;
       u32 pc;  // at execution time: the address of the next instruction to execute (already fetched)
       u32 npc; // at execution time: the address of the next instruction to fetch
+    };
+  };
 };
 
 enum class Cop0Reg : u8