Since the merge of b24b79e, we've gotten reports that the
following games are broken on JitArm64:
* Sonic Heroes
* The SpongeBob SquarePants Movie
* Astérix & Obélix XXL
* The Incredibles: Rise of the Underminer
Disabling the register cache avoids the issue, so the cause
of the bug might not actually have anything to do with the
newly implemented instructions. Nevertheless, I don't want
to ship a beta with this problem present, so I would like to
disable these instructions for the time being.
When making 92d1d60, I checked whether the ~0x1f masking in dcbx
actually was necessary. I came to the conclusion that it wasn't,
so I removed it. However, I hadn't checked the second half of
InvalidateICache closely enough - the masking is actually needed.
This commit re-adds the masking, but this time in C++ code instead
of in jitted code in order to save icache. Though I suppose the
difference doesn't matter all that much, since this is in farcode
and all...
Hopefully fixes https://bugs.dolphin-emu.org/issues/12612.
This implements the behavior described in
https://bugs.dolphin-emu.org/issues/12565.
Thank you to eigenform, delroth, phire, marcan, segher, and Extrems
for all helping in one way or another with the efforts to reverse
engineer this behavior, and to Rylie for reporting the issue.
Write_U16_Swap leaves the upper 32 bits alone. Reimplementing this
correctly in the JIT would require more than one instruction,
so let's just call Write_U16_Swap instead, like Jit64 does.
One of the following commits will add emulation of a quirk
that only happens when writing to memory which is mapped as
write-through or cache-inhibited, so let's keep track of
which memory is mapped in this way.
It was believed that this only mattered when the rounding mode was
set to round to infinity, which games generally don't do, but it
can also affect the sign of the output when the inputs are all zero.
So it turns out you have to pass XMM0 as the clobber register
to HandleNaNs, because HandleNaNs uses BLENDVPD and BLENDVPD
implicitly uses XMM0, and nobody noticed when I broke this in
2c38d64 because nobody plays the one game that needs accurate NaNs.
This reverts commit 66b992cfe4.
A new (additional) correctness issue was revealed in the old
AArch64 code when applying it on top of modern JitArm64:
LSR was being used when LSRV was intended. This commit uses LSRV.
This implementation is pretty efficient in my opinion. And "As
long as we aren't falling back to interpreter we're winning a lot"
applies to basically every instruction to some degree anyway.
The dcbz instruction needs to lock W30 so that the slowmem code will
push and pop it when calling into C++. Also, the slowmem code expects
that the address is present in W0, so replace the use of W0 as a scratch
register in the fastmem code with the now locked W30.
We currently have a bug when calling Arm64GPRCache::Flush with
FlushMode::MaintainState, zero free host registers, and at least
one guest register containing an immediate. We end up grabbing
a temporary register from the register cache in order to be
able to write the immediate to memory, but grabbing a temporary
register when there are zero free registers causes the least
recently used register to be flushed in a way which does not
maintain the state of the register cache.
To get around this, require callers to pass in a temporary
register in the GPR MaintainState case. In other cases,
passing in a temporary register is not required but can help
avoid spilling a register (if the caller already had a
temporary register at hand anyway, which in particular will
be the case in my upcoming memcheck pull request).
