Since in this case we're setting it based on the state at record start
time, not when a register is loaded, UseMemory would not be called, so
this could potentially wipe out texture memory that was valid.
This should ensure that when playing with loop enabled, the first frame is
in the same state each time. There is potentially still issues when the
start frame is set to something other than zero, but I'm not sure how we
could work around this without capturing the entire state on each frame.
Fundamentally, all this does is enforce the invariant that we always
translate effective addresses based on the current BAT registers and
page table before we do anything else with them.
This change can be logically divided into three parts. The first part is
creating a table to represent the current BAT state, and keeping it up to
date (PowerPC::IBATUpdated, PowerPC::DBATUpdated, etc.). This does
nothing by itself, but it's necessary for the other parts.
The second part (mostly in MMU.cpp) is simply removing all the hardcoded
checks for specific untranslated addresses, and consistently translating
addresses using the current BAT configuration. Very straightforward, but a
lot of code changes because we hardcoded assumptions all over the place.
The third part (mostly in Memmap.cpp) is making the fastmem arena reflect
the current BAT configuration. We do this by redoing the mapping (calling
memmap()) based on the BAT table whenever it changes.
One additional minor change is that translation can fail in two ways:
either the segment is a direct store segment, or page table lookup failed.
The difference doesn't usually matter, but the difference affects cache
instructions, like dcbz.
Fix Frame Advance and FifoPlayer pause/unpause/stop.
CPU::EnableStepping is not atomic but is called from multiple threads
which races and leaves the system in a random state; also instruction
stepping was unstable, m_StepEvent had an almost random value because
of the dual purpose it served which could cause races where CPU::Run
would SingleStep when it was supposed to be sleeping.
FifoPlayer never FinishStateMove()d which was causing it to deadlock.
Rather than partially reimplementing CPU::Run, just use CPUCoreBase
and then call CPU::Run(). More DRY and less likely to have weird bugs
specific to the player (i.e the previous freezing on pause/stop).
Refactor PowerPC::state into CPU since it manages the state of the
CPU Thread which is controlled by CPU, not PowerPC. This simplifies
the architecture somewhat and eliminates races that can be caused by
calling PowerPC state functions directly instead of using CPU's
(because they bypassed the EnableStepping lock).
Reading uninitalized memory is non-deterministic. We used to only
clear the memory when using EmulatedBS2_GC or FifoPlayer, but we
now do it during Memory::Init instead so it always gets done.
Texture updates have been moved into TextureCache, while
TMEM updates where moved into bpmem. Code for handling
efb2ram updates was added to TextureCache.
There was a bug for preloaded RGBA8 textures, it only copied
half the texture. The TODO was wrong too.
The PowerPC CPU has bits in MSR (DR and IR) which control whether
addresses are translated. We should respect these instead of mixing
physical addresses and translated addresses into the same address space.
This is mostly mass-renaming calls to memory accesses APIs from places
which expect address translation to use a different version from those
which do not expect address translation.
This does very little on its own, but it's the first step to a correct BAT
implementation.
This isn't technically the correct place to have the downcount variable, but it is similar to what PPSSPP does to gain a bit of extra speed on ARM.
We access this variable quite a bit, with each exit in a block it is subtracted from.
On ARM this required four instructions to load and store the value, while now it only requires two.
This gives an average of 1FPS gain to most games.
Examples:
Crazy Taxi: 54FPS -> 55FPS
Luigi's Mansion: 20FPS -> 21FPS
Wind Waker(Save Screen): 27FPS -> 28FPS
This seems to average a 6mhz to 16mhz CPU core emulation improvement in the few games I've tested.
