From c7aa4d8b6d8a9aa7a2c3be4e796d6b1e9f535460 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Mon, 16 May 2022 21:00:25 -0400
Subject: [PATCH] Fix state transitions.

Confirmed that the 68000 mk 2 now appears correctly to perform a reset.
---
 .../Implementation/68000Mk2Implementation.hpp      | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/Processors/68000Mk2/Implementation/68000Mk2Implementation.hpp b/Processors/68000Mk2/Implementation/68000Mk2Implementation.hpp
index 2ca04edfb..7641d38f0 100644
--- a/Processors/68000Mk2/Implementation/68000Mk2Implementation.hpp
+++ b/Processors/68000Mk2/Implementation/68000Mk2Implementation.hpp
@@ -27,9 +27,12 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
 	// Subtracts `n` half-cycles from `time_remaining_`; if permit_overrun is false, also ConsiderExit()
 #define Spend(n)		time_remaining_ -= (n); if constexpr (!permit_overrun) ConsiderExit()
 
-	// Performs ConsiderExit() only if permit_overrun is true
+	// Performs ConsiderExit() only if permit_overrun is true.
 #define CheckOverrun()	if constexpr (permit_overrun) ConsiderExit()
 
+	// Sets `x` as the next state, and exits now if all remaining time has been extended and permit_overrun is true.
+#define MoveToState(x)	state_ = x; if (permit_overrun && time_remaining_ <= HalfCycles(0)) return
+
 	//
 	// So basic structure is, in general:
 	//
@@ -40,9 +43,8 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
 	//		Spend(10);
 	//		do_a_third_thing();
 	//		Spend(30);
-	//		CheckOverrun();
 	//
-	//		state_ = next_action;
+	//		MoveToState(next_action);
 	//		break;
 	//
 	// Additional notes:
@@ -171,11 +173,11 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
 			IdleBus(1);			// n
 			Prefetch();			// np
 
-			state_ = State::Dispatch;
-			CheckOverrun();
+			MoveToState(State::Dispatch);
 		break;
 
-		default: assert(false);
+		default:
+			assert(false);
 	}}
 
 #undef CheckOverrun