The swaps are confusing and don't accomplish much.
It was originally written like this:
u32 pte = bswap(*(u32*)&base_mem[pteg_addr]);
then bswap was changed to Common::swap32, and then the array access
was replaced with Memory::Read_U32, leading to the useless swaps.
While 6xx_pem.pdf §7.6.1.1 mentions that the number of trailing
zeros in HTABORG must be equal to the number of trailing ones
in the mask (i.e. HTABORG must be properly aligned), this is actually
not a hard requirement. Real hardware will just OR the base address
anyway. Ignoring SDR changes would lead to incorrect emulation.
Logging a warning instead of dropping the SDR update silently is a
saner behaviour.
JitArm64::DoJit contains a check where it prints a warning and tries
to pause emulation if instructed to compile code at address 0. I'm
assuming this was done in order to provide a nicer error behavior
in cases where PC was accidentally set to null. Unfortunately, it
has started causing us problems recently, as 688bd61 writes and runs
some code at address 0 to simulate the PPC being held in reset.
What makes this worse is that calling Core::SetState from the CPU
thread is actually not allowed and will cause a deadlock instead of
the intended behavior. I don't believe there is anything on a real
console that would stop you from executing code at address 0 (as
long as the MMU has been set up to allow it), and Jit64::DoJit
doesn't contain any check like this, so let's remove the check.
This commit adds a new "discarded" state for registers.
Discarding a register is like flushing it, but without
actually writing its value back to memory. We can discard
a register only when it is guaranteed that no instruction
will read from the register before it is next written to.
Discarding reduces the register pressure a little, and can
also let us skip a few flushes on interpreter fallbacks.
The output of instructions like fabsx and ps_sel is store-safe
if and only if the relevant inputs are. The old code was always
marking the output as store-safe if the output was a single,
and never otherwise.
Also, the old code was treating the output of psq_l/psq_lu as
store-safe, which seems incorrect (if dequantization is disabled).
If we know at compile time that the PPC carry flag definitely
has a certain value, we can bake that value into the emitted code
and skip having to read from PPCState.
When a save state is loaded, the IOS device serving bluetooth
is cast as BluetoothEmuDevice. If, however, a real Wiimote
with BT passthrough is used, this caused the game to crash.
Now the proper device class is used.
At a first glance it may look like a part of the code I added to
srawx in efeda3b has a bug when a == s. The code actually happens
to work correctly, but in the interest of making the code easier
to reason about, I'd like to change the way it's implemented. This
change should improve the pipelining a little in the a == s case too.
21c152f added a small hack to DVDInterface to keep WBFS and CISO
files working with Nintendo's "Error #001" anti-piracy check.
Unfortunately I don't think it's possible to support WBFS and
CISO without any kind of hack or heuristic, but what we can do
is replace the 21c152f hack (which applies regardless of file
format) with a hack that only is active when using WBFS or CISO.
This change is similar to 2a5a399, but the disc size is
calculated in a different way.
