From 361b42be9ca20c9a5ec7be20640377486722df72 Mon Sep 17 00:00:00 2001
From: Sergio Martin <eienburuu@gmail.com>
Date: Sun, 14 Jan 2024 13:51:21 +0100
Subject: [PATCH] More optimizations

---
 source/core/Nes_Core.h  | 140 ++++++++++++++++++++++++++++++++++++++--
 source/core/Nes_Cpu.cpp |   4 +-
 2 files changed, 135 insertions(+), 9 deletions(-)

diff --git a/source/core/Nes_Core.h b/source/core/Nes_Core.h
index 9409a49..e8ef183 100644
--- a/source/core/Nes_Core.h
+++ b/source/core/Nes_Core.h
@@ -1,16 +1,15 @@
+#pragma once
 
 // Internal NES emulator
 
 // Nes_Emu 0.7.0
 
-#ifndef NES_CORE_H
-#define NES_CORE_H
 
 #include "blargg_common.h"
 #include "Nes_Apu.h"
 #include "Nes_Cpu.h"
 #include "Nes_Ppu.h"
-class Nes_Mapper;
+#include "Nes_Mapper.h"
 class Nes_Cart;
 class Nes_State;
 
@@ -32,8 +31,8 @@ public:
 	
 	void irq_changed();
 	void event_changed();
-	
-public: private: friend class Nes_Emu;
+	 
+public: private: friend class Nes_Emu; 
 	
 	struct impl_t
 	{
@@ -113,4 +112,133 @@ private:
 
 int mem_differs( void const* p, int cmp, unsigned long s );
 
-#endif
+inline int Nes_Core::cpu_read( nes_addr_t addr, nes_time_t time )
+{
+	//LOG_FREQ( "cpu_read", 16, addr >> 12 );
+	
+	{
+		int result = cpu::low_mem [addr & 0x7FF];
+		if ( !(addr & 0xE000) )
+			return result;
+	}
+	
+	{
+		int result = *cpu::get_code( addr );
+		if ( addr > 0x7FFF )
+			return result;
+	}
+	
+	time += cpu_time_offset;
+	if ( addr < 0x4000 )
+		return ppu.read( addr, time );
+	
+	clock_ = time;
+	if ( data_reader_mapped [addr >> page_bits] )
+	{
+		int result = mapper->read( time, addr );
+		if ( result >= 0 )
+			return result;
+	}
+	
+	if ( addr < 0x6000 )
+		return read_io( addr );
+	
+	if ( addr < sram_readable )
+		return impl->sram [addr & (impl_t::sram_size - 1)];
+	
+	if ( addr < lrom_readable )
+		return *cpu::get_code( addr );
+	
+	return addr >> 8; // simulate open bus
+}
+
+inline int Nes_Core::cpu_read_ppu( nes_addr_t addr, nes_time_t time )
+{
+	//LOG_FREQ( "cpu_read_ppu", 16, addr >> 12 );
+	
+	// Read of status register (0x2002) is heavily optimized since many games
+	// poll it hundreds of times per frame.
+	nes_time_t next = ppu_2002_time;
+	int result = ppu.r2002;
+	if ( addr == 0x2002 )
+	{
+		ppu.second_write = false;
+		if ( time >= next )
+			result = ppu.read_2002( time + cpu_time_offset );
+	}
+	else
+	{
+		result = cpu::low_mem [addr & 0x7FF];
+		if ( addr >= 0x2000 )
+			result = cpu_read( addr, time );
+	}
+	
+	return result;
+}
+
+inline void Nes_Core::cpu_write_2007( int data )
+{
+	// ppu.write_2007() is inlined
+	if ( ppu.write_2007( data ) & Nes_Ppu::vaddr_clock_mask )
+		mapper->a12_clocked();
+}
+
+inline void Nes_Core::cpu_write( nes_addr_t addr, int data, nes_time_t time )
+{
+	//LOG_FREQ( "cpu_write", 16, addr >> 12 );
+	
+	if ( !(addr & 0xE000) )
+	{
+		cpu::low_mem [addr & 0x7FF] = data;
+		return;
+	}
+	
+	time += cpu_time_offset;
+	if ( addr < 0x4000 )
+	{
+		if ( (addr & 7) == 7 )
+			cpu_write_2007( data );
+		else
+			ppu.write( time, addr, data );
+		return;
+	}
+	
+	clock_ = time;
+	if ( data_writer_mapped [addr >> page_bits] && mapper->write_intercepted( time, addr, data ) )
+		return;
+	
+	if ( addr < 0x6000 )
+	{
+		write_io( addr, data );
+		return;
+	}
+	
+	if ( addr < sram_writable )
+	{
+		impl->sram [addr & (impl_t::sram_size - 1)] = data;
+		return;
+	}
+	
+	if ( addr > 0x7FFF )
+	{
+		mapper->write( clock_, addr, data );
+		return;
+	}
+}
+
+#define NES_CPU_READ_PPU( cpu, addr, time ) \
+	STATIC_CAST(Nes_Core&,*cpu).cpu_read_ppu( addr, time )
+
+#define NES_CPU_READ( cpu, addr, time ) \
+	STATIC_CAST(Nes_Core&,*cpu).cpu_read( addr, time )
+
+#define NES_CPU_WRITEX( cpu, addr, data, time ){\
+	STATIC_CAST(Nes_Core&,*cpu).cpu_write( addr, data, time );\
+}
+
+#define NES_CPU_WRITE( cpu, addr, data, time ){\
+	if ( addr < 0x800 ) cpu->low_mem [addr] = data;\
+	else if ( addr == 0x2007 ) STATIC_CAST(Nes_Core&,*cpu).cpu_write_2007( data );\
+	else STATIC_CAST(Nes_Core&,*cpu).cpu_write( addr, data, time );\
+}
+
diff --git a/source/core/Nes_Cpu.cpp b/source/core/Nes_Cpu.cpp
index 4149d37..185b2d9 100644
--- a/source/core/Nes_Cpu.cpp
+++ b/source/core/Nes_Cpu.cpp
@@ -2,13 +2,11 @@
 // Nes_Emu 0.7.0. http://www.slack.net/~ant/nes-emu/
 
 #include "Nes_Cpu.h"
-
 #include <string.h>
 #include <limits.h>
 #include "blargg_endian.h"
 #include <stdio.h>
-
-#include "nes_cpu_io.h"
+#include <Nes_Core.h>
 
 /* Copyright (C) 2003-2006 Shay Green. This module is free software; you
 can redistribute it and/or modify it under the terms of the GNU Lesser