From dab3dcaafb7626bc5a659124b57cb7af2296f422 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Fri, 20 Oct 2023 21:36:50 -0400
Subject: [PATCH] Fix LODS: REP is not REPE.

---
 .../Implementation/PerformImplementation.hpp    | 17 ++++++++++++++---
 OSBindings/Mac/Clock SignalTests/8088Tests.mm   |  2 +-
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/InstructionSets/x86/Implementation/PerformImplementation.hpp b/InstructionSets/x86/Implementation/PerformImplementation.hpp
index 9d71babe2..1160b2aaf 100644
--- a/InstructionSets/x86/Implementation/PerformImplementation.hpp
+++ b/InstructionSets/x86/Implementation/PerformImplementation.hpp
@@ -1360,7 +1360,7 @@ bool repetition_over(const InstructionT &instruction, AddressT &eCX) {
 }
 
 template <typename AddressT, typename InstructionT, typename FlowControllerT>
-void repeat(const InstructionT &instruction, Status &status, AddressT &eCX, FlowControllerT &flow_controller) {
+void repeat_ene(const InstructionT &instruction, Status &status, AddressT &eCX, FlowControllerT &flow_controller) {
 	if(
 		instruction.repetition() == Repetition::None ||		// No repetition => stop.
 		!(--eCX) ||											// [e]cx is zero after being decremented => stop.
@@ -1372,6 +1372,17 @@ void repeat(const InstructionT &instruction, Status &status, AddressT &eCX, Flow
 	flow_controller.repeat_last();
 }
 
+template <typename AddressT, typename InstructionT, typename FlowControllerT>
+void repeat(const InstructionT &instruction, AddressT &eCX, FlowControllerT &flow_controller) {
+	if(
+		instruction.repetition() == Repetition::None ||		// No repetition => stop.
+		!(--eCX)											// [e]cx is zero after being decremented => stop.
+	) {
+		return;
+	}
+	flow_controller.repeat_last();
+}
+
 template <typename IntT, typename AddressT, typename InstructionT, typename MemoryT, typename FlowControllerT>
 void cmps(const InstructionT &instruction, AddressT &eCX, AddressT &eSI, AddressT &eDI, MemoryT &memory, Status &status, FlowControllerT &flow_controller) {
 	if(repetition_over<AddressT>(instruction, eCX)) {
@@ -1388,7 +1399,7 @@ void cmps(const InstructionT &instruction, AddressT &eCX, AddressT &eSI, Address
 
 	Primitive::sub<false, false>(lhs, rhs, status);
 
-	repeat<AddressT>(instruction, status, eCX, flow_controller);
+	repeat_ene<AddressT>(instruction, status, eCX, flow_controller);
 }
 
 template <typename IntT, typename AddressT, typename InstructionT, typename MemoryT, typename FlowControllerT>
@@ -1403,7 +1414,7 @@ void lods(const InstructionT &instruction, AddressT &eCX, AddressT &eSI, IntT &e
 	eAX = memory.template access<IntT>(source_segment, eSI);
 	eSI += status.direction<AddressT>() * sizeof(IntT);
 
-	repeat<AddressT>(instruction, status, eCX, flow_controller);
+	repeat<AddressT>(instruction, eCX, flow_controller);
 }
 
 
diff --git a/OSBindings/Mac/Clock SignalTests/8088Tests.mm b/OSBindings/Mac/Clock SignalTests/8088Tests.mm
index 629e99a1e..b4086eff4 100644
--- a/OSBindings/Mac/Clock SignalTests/8088Tests.mm	
+++ b/OSBindings/Mac/Clock SignalTests/8088Tests.mm	
@@ -404,7 +404,7 @@ struct FailedExecution {
 		// TODO: MOVS, SCAS, STOS
 */
 		// CMPS
-//		@"A6.json.gz",	@"A7.json.gz",
+		@"A6.json.gz",	@"A7.json.gz",
 
 		// LODS
 		@"AC.json.gz",	@"AD.json.gz",