special instructions should come first

src/emulator/main.rs

@@ -58,6 +58,20 @@ fn tick(state: &mut EmulatorState) {
     match instruction {
         0x00 => {} // NOP
 
+        /* Special */
+        0xfb => state.ei = true,  // EI
+        0xf3 => state.ei = false, // DI
+        0x76 => {
+            if state.ei {
+                todo!()
+            } else {
+                // HLT
+                println!("HLT called after DI; exiting.");
+                print_state(state);
+                std::process::exit(0);
+            }
+        }
+
         /* Maths */
         // INR
         0x04 => arithmetic::inr(Register::B, state),
@@ -90,20 +104,6 @@ fn tick(state: &mut EmulatorState) {
         0xc6 => arithmetic::adi(next_byte(), state),                                 // ADI
         0xce => arithmetic::aci(next_byte(), state),                                 // ACI
 
-        /* Special */
-        0xfb => state.ei = true,  // EI
-        0xf3 => state.ei = false, // DI
-        0x76 => {
-            if state.ei {
-                todo!()
-            } else {
-                // HLT
-                println!("HLT called after DI; exiting.");
-                print_state(state);
-                std::process::exit(0);
-            }
-        }
-
         _ => not_implemented(state),
     }