Preparation for following commits.
This commit intentionally doesn't touch paired stores,
since paired stores are supposed to flush to zero.
(Consistent with Jit64.)
This simplifies some of the following commits. It does require
an extra register, but hey, we have 32 of them.
Something I think would be nice to add to the register cache
in the future is the ability to keep both the single and double
version of a guest register in two different host registers
when that is useful. That way, the extra register we write to
here can be read by a later instruction, saving us from
having to perform the same conversion again.
When the interpreter writes to a discarded register, its type
must be changed so that it is no longer considered discarded.
Fixes a 62ce1c7 regression.
We normally check for division by zero to know if we should set the
destination register to zero with a XOR. However, when the divisor and
destination registers are the same the explicit zeroing can be omitted.
In addition, some of the surrounding branching can be simplified as
well.
Before:
45 85 FF test r15d,r15d
75 05 jne normal_path
45 33 FF xor r15d,r15d
EB 0C jmp done
normal_path:
B8 5A 00 00 00 mov eax,5Ah
99 cdq
41 F7 FF idiv eax,r15d
44 8B F8 mov r15d,eax
done:
After:
45 85 FF test r15d,r15d
74 0C je done
B8 5A 00 00 00 mov eax,5Ah
99 cdq
41 F7 FF idiv eax,r15d
44 8B F8 mov r15d,eax
done:
Division by a power of two can be slightly improved when the
destination and dividend registers are the same.
Before:
8B C6 mov eax,esi
85 C0 test eax,eax
8D 70 03 lea esi,[rax+3]
0F 49 F0 cmovns esi,eax
C1 FE 02 sar esi,2
After:
85 F6 test esi,esi
8D 46 03 lea eax,[rsi+3]
0F 48 F0 cmovs esi,eax
C1 FE 02 sar esi,2
Repeated erase() + iteration on a std::multimap is extremely slow.
Slow enough that it causes a 7 second long stutter during some
transitions in F-Zero X (a N64 VC game that triggers many, many icache
invalidations).
And slow enough that JitBaseBlockCache::DestroyBlock shows up on a
flame graph as taking >50% of total CPU time on the CPU-GPU thread:
https://i.imgur.com/vvqiFL6.png
This commit optimises those block link queries by replacing the
std::multimap (which is typically implemented with red-black trees)
with hash tables.
Master: https://i.imgur.com/vvqiFL6.png / 7s stutters
(starting from 5.0-2021 and with branch following disabled)
This commit: https://i.imgur.com/hAO74fy.png / ~0.7s stutters, which
is pretty close to 5.0 stable. (5.0-2021 introduced the performance
regression and it is especially noticeable when branch following
is disabled, which is the case for all N64 VC games since 5.0-8377.)
Oversight from #9545, which moved the "new game has been loaded" logic
to a separate OnNewTitleLoad function that has to be called explicitly
*after* a title has loaded.
Coupled with the commit that makes Dolphin not clobber 0x1800-0x3000
when using MIOS, this fixes Wind Waker and other MIOS-patched games
when they are launched from the System Menu.
MIOS puts patch data in low MEM1 (0x1800-0x3000) for its own use.
Overwriting data in this range can cause the IPL to crash when
launching games that get patched by MIOS.
See https://bugs.dolphin-emu.org/issues/11952 for more info.
Not applying the Gecko HLE patches means that Gecko codes will not work
under MIOS, but this is better than the alternative of having specific
games crash.
This particular range is kind of bizarre, and would only interpret
interleave mode 2 as a valid mode, while rejecting interleave mode 1 and
the extension byte mode.
As far as I know, based off the information on Wiibrew, we should be
considering all three values within this range as valid.
This adds a function to get the emulated or real Bluetooth device for
an active emulation instance. This lets us deduplicate all the
`ios->GetDeviceByName("/dev/usb/oh1/57e/305")` calls that are currently
scattered in the codebase and ensures Bluetooth passthrough is being
handled correctly.
This also fixes the broken check in WiimoteCommon::UpdateSource.
There was a confusion between "emulated Bluetooth" (as opposed to
"real Bluetooth" aka Bluetooth passthrough) and "emulated Wiimote".
Specifically, 'Scooby-Doo! Mystery Mayhem', 'Scooby-Doo! Unmasked', 'Ed, Edd n Eddy: The Mis-Edventures', and the Wii version of 'Happy Feet'.
The JIT cache causes problems with emulated icache invalidation in these games, resulting in areas failing to load.
This avoids some warnings, which were originally fixed by ignoring loads with a value of zero (see 636bedb207784db2d58b9986464f6a863677b59e / #3242).
Note that FifoCI will report some changes, but only on the first frame; these seem to be timing related as they don't happen if a different write is used to replace skipped ones.
They appear to relate to perf queries, and combining them with truely unknown commands would probably hide useful information. Furthermore, 0x20 is issued by every title, so without this every title would be recorded as using an unknown command, which is very unhelpful.
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.
This changes FileSystemProxy::Open to return a file descriptor wrapper
that will ensure the FD is closed when it goes out of scope.
By using such a wrapper we make it more difficult to forget to close
file descriptors.
This fixes a leak in ReadBootContent. I should have added such a class
from the beginning... In practice, I don't think this would have caused
any obvious issue because ReadBootContent is only called after an IOS
relaunch -- which clears all FDs -- and most titles do not get close
to the FD limit.
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.
