SPDX standardizes how source code conveys its copyright and licensing
information. See https://spdx.github.io/spdx-spec/1-rationale/ . SPDX
tags are adopted in many large projects, including things like the Linux
kernel.
According to the C standard, an offsetof expression must evaluate to an
address constant, otherwise it's undefined behavior.
Fixes https://bugs.dolphin-emu.org/issues/12409
See also https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95942
There are still improper uses of offsetof (mostly in JitArm64) but
fixing that will take more effort since there's a PPCSTATE_OFF wrapper
macro that is sometimes used with non-array members and sometimes used
with arrays and variable indices... Let's keep that for another PR.
An unfortunately large single commit that deglobalizes the DSP code.
(which I'm very sorry about).
This would have otherwise been extremely difficult to separate due to
extensive use of the globals in very coupling ways that would result in
more scaffolding to work around than is worth it.
Aside from the video code, I believe only the DSP code is the hairiest
to deal with in terms of globals, so I guess it's best to get this dealt
with right off the bat.
A summary of what this commit does:
- Turns the DSPInterpreter into its own class
This is the most involved portion of this change.
The bulk of the changes are turning non-member functions into member
functions that would be situated into the Interpreter class.
- Eliminates all usages to globals within DSPCore.
This generally involves turning a lot of non-member functions into
member functions that are either situated within SDSP or DSPCore.
- Discards DSPDebugInterface (it wasn't hooked up to anything,
and for the sake of eliminating global state, I'd rather get rid of
it than think up ways for this class to be integrated with
everything else.
- Readjusts the DSP JIT to handle calling out to member functions.
In most cases, this just means wrapping respective member function
calles into thunk functions.
Surprisingly, this doesn't even make use of the introduced System class.
It was possible all along to do this without it. We can house everything
within the DSPLLE class, which is quite nice =)
The intent here is to generate a more compact instruction if a 32-bit
immediate can be zero-extended to the desired 64-bit immediate.
Nowadays the emitter is smart enough to do this for us, so this logic is
redundant.
There's no need to load the 64-bit immediate into a temporary register.
x64 will sign-extend 32-bit immediates to 64 bits, giving us the exact
value we need in this case.
48 C7 C0 00 00 FF FF mov rax,0FFFFFFFFFFFF0000h
48 21 C2 and rdx,rax
48 81 E2 00 00 FF FF and rdx,0FFFFFFFFFFFF0000h
- LEA is a bit silly when the source and the destination are the same. A
simple ADD or SHL will do in those cases.
66 8D 04 45 00 00 00 00 lea ax,[rax*2]
66 03 C0 add ax,ax
48 8D 04 00 lea rax,[rax+rax]
48 03 C0 add rax,rax
66 8D 14 D5 00 00 00 00 lea dx,[rdx*8]
66 C1 E2 03 shl dx,3
- When scaling by 2, consider summing the register with itself instead.
The former always needs a 32-bit displacement, so the sum is more
compact.
66 8D 14 45 00 00 00 00 lea dx,[rax*2]
66 8D 14 00 lea dx,[rax+rax]
Identical, except that this used a temporary register as scratch instead
of RCX. round_long_acc now no longer needs scratch, so we can
deduplicate the logic.
Given we now use a base class for the interface, we can make all member
functions, types and constants that aren't directly related to
instructions private.
This function was duplicated across all the opcode tables: the main info
tables, the interpreter tables, and the x86-64 JIT tables. However, we
can just make the type of the std::array parameter a template type and
get rid of this duplication.
This adds a base class that is used to replace the concrete instance of
the x64 JIT pointer within DSPCore. This fully removes the direct use
(read: non-ifdefed) usage of x86-64-specifics within the main DSP code.
Said base can also be used for creating JITs for other architectures,
such as AArch64, etc.
This is one of the last things that needed to be done in order to
finally separate the x86-64-specific code from the rest of the common
DSP code. This splits the tables up similar to how it's currently done
for the PowerPC CPU tables.
Now, the tables are split up and within their own relevant source files,
so the main table within the common DSP code acts as the "info" table
that provides specifics about a particular instruction, while the other
tables contain the actual instruction.
With this out of the way, all that's left is to make a general base for
the emitters and we can then replace the x64 JIT pointer in DSPCore with
it, getting all x64 out of the common code once and for all.
While shuffling all the code around, the removal of the DSPEmitter
includes in some places uncovered indirect inclusions, so this also
fixes those as well.
By making the jitted function a private static function of DSPEmitter,
we can allow access to data members within the context of the function
without making them public overall.
This finally makes all data members for the x64 DSP emitter private.
While the code is namespaced out properly, the files weren't separated
into their own directory. This moves the files so that introducing a general
interface is easier in the future for supporting other architectures.
Given none of these are used outside of the DSPEmitter class (nor does
it really make sense to allow them to be used outside of the class),
these should all be made private.
Makes it more self-documenting which stack is being loaded or stored to,
as C, D, and magic numbers are extremely vague. It also enforces a
strongly-typed API instead of accepting arbitrary integral values.
It also adds the two other missing stack register names -- loop address
and loop counter.
