Re: [B2-devel] New SheepShaver troubles continued...

[Gwenole B. <gb...@di...>]

Hi,

> I had to modify the generated Makefile and replace -O2 with -O1 
> everywhere.

I am only aware of two types of miscompilation with gcc on x86:
1) Don't use -mcpu=pentiumpro, at least with -march=i586 with gcc 
3.3.2. You would get a hang during boot
2) gcc 3.2.2 miscompiles some SSE code, but I workarounded that in the 
sources.

> However when I removed -O2 altogether, SheepShaver did not compile at 
> all.

Have you tried to only lower -O2 to -O1 in DYNGEN_OP_FLAGS? What about 
adding -fno-strict-aliasing and keeping -O2? In the latter case, there 
could indeed be a bug in the code.

> ../kpx_cpu/src/cpu/ppc/ppc-dyngen-ops.cpp -o obj/ppc-dyngen-ops.o

*-ops.cpp files have to be compiled with optimizations. Otherwise you 
will end up with poorer performance.

Do you really have a stock FSF gcc 3.3.2? Have you tried to upgrade to 
3.3.3? At some point, I wanted to exercise a testcase for my hang 
problem with gcc 3.3.2, but getting a crash would be better. ;-)

> I haven't measured how much faster is the newest version, but it still
> suffers from some strange 'stops'.

I have noticed that on AMD64 with gcc 3.3.2 too when experimenting with 
the asm based locking code. I will probably try other alternatives. In 
Unix/sysdeps.h, could you try to disable HAVE_TEST_AND_SET for i386 and 
rebuild at least main_unix.cpp and video_x.cpp?

> There is also problem with configuration interface. In video modes tab
> there is one checkbox that is not described (the 6th one). Selecting
> only 'Windowed 800x600' result in termination of application and
> message:
> SheepShaver.ok: video_x.cpp:1166: bool VideoInit(): Assertion `cur_mode
> != -1' failed.

OK, I will have a look.

Thanks,
Gwenole.