From 93088b355c4dc54160a308e8c35318e91fef6c5c Mon Sep 17 00:00:00 2001
From: Adrian Conlon <98398945+AdrianConlon@users.noreply.github.com>
Date: Sun, 31 Dec 2023 14:58:15 +0000
Subject: [PATCH] M6502: Unify accumulator write page boundary fixup code

---
 M6502/inc/mos6502.h   |  5 +++++
 M6502/src/mos6502.cpp | 15 ++++++---------
 2 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/M6502/inc/mos6502.h b/M6502/inc/mos6502.h
index cec6105..5c8737c 100644
--- a/M6502/inc/mos6502.h
+++ b/M6502/inc/mos6502.h
@@ -190,6 +190,11 @@ namespace EightBit {
 		void sta_AbsoluteY() noexcept;
 		void sta_IndirectIndexedY() noexcept;
 
+		void write_A_with_fixup(const register16_t& address, uint8_t unfixed_page) noexcept {
+			getBytePaged(unfixed_page, address.low);	// Possible fixup for page boundary crossing
+			memoryWrite(address, A());
+		}
+
 		uint8_t x = 0;		// index register X
 		uint8_t y = 0;		// index register Y
 		uint8_t a = 0;		// accumulator
diff --git a/M6502/src/mos6502.cpp b/M6502/src/mos6502.cpp
index b520650..c53947a 100644
--- a/M6502/src/mos6502.cpp
+++ b/M6502/src/mos6502.cpp
@@ -73,14 +73,14 @@ void EightBit::MOS6502::handleINT() noexcept {
 void EightBit::MOS6502::interrupt() noexcept {
 	const bool reset = m_handlingRESET;
 	const bool nmi = m_handlingNMI;
-	const bool irq = m_handlingINT;
-	const bool hardware = nmi || irq || reset;
-	const bool software = !hardware;
 	if (reset) {
 		dummyPush(PC().high);
 		dummyPush(PC().low);
 		dummyPush(P());
 	} else {
+		const bool irq = m_handlingINT;
+		const bool hardware = nmi || irq || reset;
+		const bool software = !hardware;
 		pushWord(PC());
 		push(P() | (software ? BF : 0));
 	}
@@ -748,18 +748,15 @@ void EightBit::MOS6502::sre(const uint8_t value) noexcept {
 
 void EightBit::MOS6502::sta_AbsoluteX() noexcept {
 	const auto [address, page] = Address_AbsoluteX();
-	getBytePaged(page, address.low);
-	memoryWrite(address, A());
+	write_A_with_fixup(address, page);
 }
 
 void EightBit::MOS6502::sta_AbsoluteY() noexcept {
 	const auto [address, page] = Address_AbsoluteY();
-	getBytePaged(page, address.low);
-	memoryWrite(address, A());
+	write_A_with_fixup(address, page);
 }
 
 void EightBit::MOS6502::sta_IndirectIndexedY() noexcept {
 	const auto [address, page] = Address_IndirectIndexedY();
-	getBytePaged(page, address.low);	// Possible fixup for page boundary crossing
-	memoryWrite(address, A());
+	write_A_with_fixup(address, page);
 }