I've made so many changes I don't dare continue until I check the current stuff in. /test/testatomic.c performs absolutely basic tests to show that the function work as expected. Need a second test to do more detailed tests. /include/SDL_atomic.h provides declarations for all included functions. /src/atomic/linux/SDL_atomic.c provided all the functions. On a generic built the 64 bit functions work, but they are emulated. On a build for -march=pentium and above the 64 bit functions use native instructions /src/atomic/dummy/SDL_atomic.c emulates all the operations using SDL_mutex.h. /src/atomic/win32/SDL_atomic.c is a copy of dummy /src/atomic/macosx/SDL_atomic.s is a copy of dummy These versions of SDL_atomic.c provide a frame work for building the library with a mixture of native and emulated functions. This allows the whole library to be provided on all platforms. (I hope.) I hope this fits with the SDL philosophy of either providing a common subset or emulating when the platform is missing a feature. I have not added dummy, macosx, or win32 to the build. They are there as place holders for future work. I have modified congifure.in to compile sources in /src/atomic/linux. (The SDL configure.in file is an amazing piece of work and I hope I didn't mess it up. :-)

# Makefile to build the SDL library

INCLUDE = -I./include
CFLAGS  = -g -O2 $(INCLUDE)
AR	= ar
RANLIB	= ranlib

CONFIG_H = include/SDL_config.h
TARGET  = libSDL.a
SOURCES = \
	src/*.c \
	src/audio/*.c \
	src/cdrom/*.c \
	src/cpuinfo/*.c \
	src/events/*.c \
	src/file/*.c \
	src/joystick/*.c \
	src/haptic/*.c \
	src/stdlib/*.c \
	src/thread/*.c \
	src/timer/*.c \
	src/video/*.c \
	src/power/*.c \
	src/audio/dummy/*.c \
	src/video/dummy/*.c \
	src/joystick/dummy/*.c \
	src/haptic/dummy/*.c \
	src/cdrom/dummy/*.c \
	src/thread/generic/*.c \
	src/timer/dummy/*.c \
	src/loadso/dummy/*.c \

OBJECTS = $(shell echo $(SOURCES) | sed -e 's,\.c,\.o,g')

all: $(TARGET)

$(TARGET): $(CONFIG_H) $(OBJECTS)
	$(AR) crv $@ $^
	$(RANLIB) $@

$(CONFIG_H):
	cp $(CONFIG_H).default $(CONFIG_H)

clean:
	rm -f $(TARGET) $(OBJECTS)