Linux: Enabled LTO for clang (+25-30% performance)

README.md

@@ -31,7 +31,6 @@ Things that ***may or may not*** be added in the future, in no particular order:
 -Support for more UNIF boards and more NES/Famicom input devices  
 -Debugger improvements (APU state display, etc.)  
 -Shaders  
--Improvements to movie file format to support a few things that currently do not work  
 -Libretro support  
 -TAS editor  
 
@@ -50,6 +49,7 @@ To compile and run Mesen under Linux, you will need:
 * SDL2  (package: libsdl2-dev)
 
 The makefile contains some more information at the top.  Running "make" will build the x64 version by default, and then "make run" should start the emulator.  
+LTO is supported under clang, which gives a large performance boost (25-30%+), so turning it on is highly recommended (see makefile for details).  
 
 
 ## LICENSE ##

build.sh

@@ -1,9 +1,13 @@
 #!/bin/sh
+
+#This is a build script used for official releases which does not build the UI
+#Read the makefile and use "make" to build Mesen normally
+
 MESENPLATFORM=x64 make clean
-MESENPLATFORM=x64 make core -j 4
+LTO=true MESENPLATFORM=x64 make core -j 16
 
 MESENPLATFORM=x86 make clean
-MESENPLATFORM=x86 make core -j 4
+LTO=true MESENPLATFORM=x86 make core -j 16
 
 cp ./InteropDLL/obj.x64/libMesenCore.x64.dll ./bin
 cp ./InteropDLL/obj.x86/libMesenCore.x86.dll ./bin

makefile

@@ -2,16 +2,30 @@
 #Both clang & gcc work fine - clang seems to output faster code
 #The only external dependency is SDL2 - everything else is pretty standard.
 #Run "make" to build, "make run" to run
+
+#----------------------
+#Platform Configuration
+#----------------------
 #To specify whether you want to build for x86 or x64:
 #"MESENPLATFORM=x86 make" or "MESENPLATFORM=x64 make"
 #Default is x64
 
+#-----------------------
+# Link Time Optimization
+#-----------------------
+#LTO is supported for clang only
+#LTO gives a 25-30% performance boost, so use it whenever you can
+#Usage: LTO=true make
+
 CPPC=clang++
 GCCOPTIONS=-fPIC -Wall --std=c++14 -O3
 
 CC=clang
 CCOPTIONS=-fPIC -Wall -O3
 
+AR=ar -rcs
+LINKFLAG=
+
 ifeq ($(MESENPLATFORM),x86)
 	MESENPLATFORM=x86
 
@@ -23,6 +37,13 @@ else
 	CCOPTIONS += -m64
 endif
 
+ifeq ($(LTO),true)
+	AR=llvm-ar q
+	CCOPTIONS += -flto
+	GCCOPTIONS += -flto
+	LINKFLAG=-fuse-ld=gold
+endif
+
 OBJFOLDER=obj.$(MESENPLATFORM)
 SHAREDLIB=libMesenCore.$(MESENPLATFORM).dll
 RELEASEFOLDER=bin/$(MESENPLATFORM)/Release
@@ -57,12 +78,12 @@ rungametests:
 
 testhelper: InteropDLL/$(OBJFOLDER)/$(SHAREDLIB)
 	mkdir -p TestHelper/$(OBJFOLDER)
-	ar -rcs TestHelper/$(OBJFOLDER)/libSevenZip.a $(SEVENZIPOBJ)
-	ar -rcs TestHelper/$(OBJFOLDER)/libLua.a $(LUAOBJ)
-	ar -rcs TestHelper/$(OBJFOLDER)/libMesenLinux.a $(LINUXOBJ) $(LIBEVDEVOBJ)
-	ar -rcs TestHelper/$(OBJFOLDER)/libUtilities.a $(UTILOBJ)
-	ar -rcs TestHelper/$(OBJFOLDER)/libCore.a $(COREOBJ)	
-	cd TestHelper/$(OBJFOLDER) && $(CPPC) $(GCCOPTIONS) -Wl,-z,defs -Wno-parentheses -Wno-switch -o testhelper ../*.cpp ../../InteropDLL/ConsoleWrapper.cpp -L ./ -lCore -lMesenLinux -lUtilities -lSevenZip -pthread -lSDL2 -lstdc++fs
+	$(AR) TestHelper/$(OBJFOLDER)/libSevenZip.a $(SEVENZIPOBJ)
+	$(AR) TestHelper/$(OBJFOLDER)/libLua.a $(LUAOBJ)
+	$(AR) TestHelper/$(OBJFOLDER)/libMesenLinux.a $(LINUXOBJ) $(LIBEVDEVOBJ)
+	$(AR) TestHelper/$(OBJFOLDER)/libUtilities.a $(UTILOBJ)
+	$(AR) TestHelper/$(OBJFOLDER)/libCore.a $(COREOBJ)	
+	cd TestHelper/$(OBJFOLDER) && $(CPPC) $(GCCOPTIONS) $(LINKFLAG) -Wl,-z,defs -Wno-parentheses -Wno-switch -o testhelper ../*.cpp ../../InteropDLL/ConsoleWrapper.cpp -L ./ -lCore -lMesenLinux -lUtilities -lSevenZip -pthread -lSDL2 -lstdc++fs
 
 SevenZip/$(OBJFOLDER)/%.o: SevenZip/%.c
 	mkdir -p SevenZip/$(OBJFOLDER) && cd SevenZip/$(OBJFOLDER) && $(CC) $(CCOPTIONS) -c $(patsubst SevenZip/%, ../%, $<)
@@ -87,15 +108,18 @@ Linux/$(OBJFOLDER)/%.o: Linux/libevdev/%.c
 
 InteropDLL/$(OBJFOLDER)/$(SHAREDLIB): $(SEVENZIPOBJ) $(LUAOBJ) $(UTILOBJ) $(COREOBJ) $(LIBEVDEVOBJ) $(LINUXOBJ) InteropDLL/ConsoleWrapper.cpp InteropDLL/DebugWrapper.cpp
 	mkdir -p InteropDLL/$(OBJFOLDER)
-	ar -rcs InteropDLL/$(OBJFOLDER)/libSevenZip.a $(SEVENZIPOBJ)
-	ar -rcs InteropDLL/$(OBJFOLDER)/libLua.a $(LUAOBJ)
-	ar -rcs InteropDLL/$(OBJFOLDER)/libMesenLinux.a $(LINUXOBJ) $(LIBEVDEVOBJ)
-	ar -rcs InteropDLL/$(OBJFOLDER)/libUtilities.a $(UTILOBJ)
-	ar -rcs InteropDLL/$(OBJFOLDER)/libCore.a $(COREOBJ)
-	cd InteropDLL/$(OBJFOLDER) && $(CPPC) $(GCCOPTIONS) -Wl,-z,defs -Wno-parentheses -Wno-switch -shared -o $(SHAREDLIB) ../*.cpp -L . -lMesenLinux -lCore -lUtilities -lLua -lSevenZip -pthread -lSDL2 -lstdc++fs
+	$(AR) InteropDLL/$(OBJFOLDER)/libSevenZip.a $(SEVENZIPOBJ)
+	$(AR) InteropDLL/$(OBJFOLDER)/libLua.a $(LUAOBJ)
+	$(AR) InteropDLL/$(OBJFOLDER)/libMesenLinux.a $(LINUXOBJ) $(LIBEVDEVOBJ)
+	$(AR) InteropDLL/$(OBJFOLDER)/libUtilities.a $(UTILOBJ)
+	$(AR) InteropDLL/$(OBJFOLDER)/libCore.a $(COREOBJ)
+	cd InteropDLL/$(OBJFOLDER) && $(CPPC) $(GCCOPTIONS) $(LINKFLAG) -Wl,-z,defs -Wno-parentheses -Wno-switch -shared -o $(SHAREDLIB) ../*.cpp -L . -lMesenLinux -lCore -lUtilities -lLua -lSevenZip -pthread -lSDL2 -lstdc++fs
+
+debug:
+	MONO_LOG_LEVEL=debug mono $(RELEASEFOLDER)/Mesen.exe
 
 run:
-	MONO_LOG_LEVEL=debug mono $(RELEASEFOLDER)/Mesen.exe
+	mono $(RELEASEFOLDER)/Mesen.exe
 
 clean:
 	rm Lua/$(OBJFOLDER) -r -f