This allows us to emit the handlers directly in a more efficient manner.
At the same time it allows for an easy fix to emit PIC code, which is
necessary for libretro. This also enables more platform specific
optimizations and variations, perhaps even run-time multiplatform
support.
This removes libco and all the usages of it (+pthreads).
Rewired all dynarecs and interpreter to return after every frame so that
libretro can process events. This required to make dynarec re-entrant.
Dynarecs were updated to check for new frame on every update (IRQ, cycle
exhaustion, I/O write, etc). The performance impact of doing so should
be minimal (and definitely outweight the libco gains). While at it,
fixed small issues to get a bit more perf: arm dynarec was not idling
correctly, mips was using stack when not needed, etc.
Tested on PSP (mips), OGA (armv7), Linux (x86 and interpreter). Not
tested on Android though.
Affects at least SM Adv 4 on PSP, which doesn't load at all.
I think the MIPS pipeline does not like invalidating the Icache and
using it immediately after (seems to read an old value sometimes?).
Rewired it to not do that and instead jump to the handler directly.
Turns out most of that file ends up in JIT section, which is RWX and not
a very nice way to run code really (security issues aside).
This also makes possible to build that file with -ggdb otherwise it
complains about stuff.
This causes crashes in PSP quite often in many games. Other CPUs might
(depending on the processor state) silently return zero or some
undefined value.
The fix is borrowed from ReGBA's codebase
I think this does not make a difference at all in the code, since PC is
treated in a special way anyway (reloaded with an immediate when read
and treated as an indirect branch when written). However for the sake of
completeness I'm undoing what I did. (The comma fix stays :P)
Turns out there were a couple of very interesting and hard to track
bugs. A missing comma made the reg list too short, leaving the 31th
element at the mercy of the linker ordering algorithm, which seems to
work in some cases depending on the compiler version.
Also the cache flush code seemed not to work on my machine (OGA),
not sure why it wored in the past :/
David Guillen Fandos
Autechre
jdgleaver