From 94288d5a9408c11adc515b505aeb5381ea4dfc0f Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Sat, 21 May 2022 19:53:28 -0400
Subject: [PATCH] Excludes DBcc from standard operand fetch.

---
 .../68000ComparativeTests.mm                  | 40 +++++++++----------
 .../Implementation/68000Mk2Implementation.hpp |  6 ++-
 2 files changed, 24 insertions(+), 22 deletions(-)

diff --git a/OSBindings/Mac/Clock SignalTests/68000ComparativeTests.mm b/OSBindings/Mac/Clock SignalTests/68000ComparativeTests.mm
index b794d06af..4fd301f75 100644
--- a/OSBindings/Mac/Clock SignalTests/68000ComparativeTests.mm	
+++ b/OSBindings/Mac/Clock SignalTests/68000ComparativeTests.mm	
@@ -156,30 +156,30 @@ struct TestProcessor: public CPU::MC68000Mk2::BusHandler {
 
 	// To limit tests run to a subset of files and/or of tests, uncomment and fill in below.
 	_fileSet = [NSSet setWithArray:@[
-		@"divu_divs.json",
+//		@"divu_divs.json",
 
 		// Below this line are passing tests.
-		@"abcd_sbcd.json",
-		@"add_sub.json",
-		@"addi_subi_cmpi.json",
-		@"addq_subq.json",
-		@"addx_subx.json",
-		@"bcc.json",
-		@"btst_bchg_bclr_bset.json",
-		@"chk.json",
-		@"cmp.json",
+//		@"abcd_sbcd.json",
+//		@"add_sub.json",
+//		@"addi_subi_cmpi.json",
+//		@"addq_subq.json",
+//		@"addx_subx.json",
+//		@"bcc.json",
+//		@"btst_bchg_bclr_bset.json",
+//		@"chk.json",
+//		@"cmp.json",
 		@"dbcc_scc.json",
-		@"eor_and_or.json",
-		@"eori_andi_ori.json",
-		@"ext.json",
-		@"jsr.json",
-		@"movem.json",
-		@"movep.json",
-		@"nbcd.json",
-		@"ext.json",
-		@"swap.json",
+//		@"eor_and_or.json",
+//		@"eori_andi_ori.json",
+//		@"ext.json",
+//		@"jsr.json",
+//		@"movem.json",
+//		@"movep.json",
+//		@"nbcd.json",
+//		@"ext.json",
+//		@"swap.json",
 	]];		// 19/32 = 59 % done, as far as the tests go.
-//	_testSet = [NSSet setWithArray:@[@"DIVU 80ec"]];
+	_testSet = [NSSet setWithArray:@[@"DBcc 0051"]];
 }
 
 - (void)testAll {
diff --git a/Processors/68000Mk2/Implementation/68000Mk2Implementation.hpp b/Processors/68000Mk2/Implementation/68000Mk2Implementation.hpp
index 89ce10331..b84ca22ca 100644
--- a/Processors/68000Mk2/Implementation/68000Mk2Implementation.hpp
+++ b/Processors/68000Mk2/Implementation/68000Mk2Implementation.hpp
@@ -590,7 +590,7 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
 					}
 				});
 
-				StdCASE(DBcc,	perform_state_ = DBcc);
+				StdCASE(DBcc,	MoveToState(DBcc));
 
 				StdCASE(Bccb,	perform_state_ = Bcc);
 				StdCASE(Bccw,	perform_state_ = Bcc);
@@ -1405,6 +1405,8 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
 		// DBcc
 		//
 		BeginState(DBcc):
+			operand_[0].w = uint32_t(int16_t(prefetch_.w));
+
 			InstructionSet::M68k::perform<
 				InstructionSet::M68k::Model::M68000,
 				ProcessorBase,
@@ -1436,7 +1438,7 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
 			// Yacht lists an extra np here; I'm assuming it's a read from where
 			// the PC would have gone, had the branch been taken. So do that,
 			// but then reset the PC to where it would have been.
-			Prefetch();
+			Prefetch();		// np
 
 			program_counter_.l = instruction_address_.l + 4;
 			Prefetch();		// np