This adds support for x86-64 dynarec both on Windows and Linux. Since
they have different requirements there's some macro magic in the stubs
file.
This also fixes x86 support in some cases: stack alignment requirements
where violated all over. This allows the usage of clang as a compiler
(which has a tendency to use SSE instructions more often than gcc does).
To support this I also reworked the mmap/VirtualAlloc magic to make sure
JIT arena stays close to .text.
Fixed some other minor issues and removed some unnecessary JIT code here
and there. clang tends to do some (wrong?) assumptions about global
symbols alignment.
This gets rid of the bloated memmap_win32.c in favour of a much simpler
wrapper. This will be needed in the future since the wrapper does not
support MAP_FIXED maps (necessary for some platforms)
This removes one branch and emits the region selection code directly in
the JIT cache. Trading memory for speed (although it's not a big
improvement).
This is a step towards enabling MMAP caches in ARM (due to the 32MB
offset limitation in branches).
Let's see, this should fix issues on platforms that do not support
running the emu at 59.73 FPS. We run the emu at fake 60fps, which means
we produce more audio samples than the original device.
Instead of missing samples (which produce cracks in the audio) we should
be producing some extra samples, which will result in a frame drop every
now and then (like every minute or so, so it's not noticeable).
This introduced a potential race condition between the start of a SWI
and the BIOS handling the exception by returning to system mode. During
this ~10 instruction window, having an IRQ that issues a SWI causes bad
behaviour that results in crashes or other weirdness.
Fixes a couple of games and potentially many weird and obscure bugs here
and there (hard to reproduce sometimes).
This fixes a race condition that happens whenever the ROM cache is flushed but
the RAM one is not, causing any SWI calls (implemented as direct branches) to
jump to random instructions.
The fix could be to flush both caches at the same time (~expensive on
low mem platforms), use indirect jumps (a bit expensive) or emit the SWI
handler below the watermark to ensure it is never flushed. This is cheap
and effective, requires minimal changes.
This is around 8% perf improvement alone.
This also fixes many flag calculation/usage bugs (in corner cases) since
we use the x86 cpu native ALU flags (which are more or less the same as
ARM's). Passes all test ROMs for ALUs and no changes in game compat.
David Guillen Fandos
twinaphex