MeCore owns a second MIPSState in the ME's address space, held in reset
until released (SetReset). It runs on the interpreter, a slice behind the
main CPU: CoreTiming runs it for the cycles the main CPU has just used, in
Advance and ForceCheck. Its own PRId (COP0 22) and mfic/mtic flag; MMIO
counts as kernel mode on it, and a syscall stops it with an error rather
than reaching HLE. The interpreter's block stepping reads delay slots
through the stepping CPU's memory, and cache instructions log at verbose
level, as ME code flushes its caches in a loop.
Created at boot only for homebrew (PBP with MG category or no SFO, ELF;
the VSH counts, as vshmain.prx loads as an ELF), when "Enable ME
emulation for homebrew" is on: a global checkbox in developer settings,
off by default and not translated yet, or --me-core. Saved in its own
section after MMIO (SaveStart v5), with its own memory; loading a state
creates or removes the ME to match.
The boot page now starts with a reset stub that sends the ME on to
0xBFC00040, where homebrew puts its code (from the firmware's reset code,
read on a PSP-1000).
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
The COP0 register file was a static array in the interpreter, shared by
anything that ran kernel code and lost on a savestate load. It's now part of
MIPSState and saved with it (MIPSState section version 5).
eret returns to EPC, or to ErrorEPC with Status.ERL set, as MIPS32 defines
it; that isn't checked against a PSP yet. It and halt carry a new ENDS_BLOCK
flag: the IR frontend ends the block after them and exits to whatever PC the
interpreter left, and the interpreter's IR-matching block timing stops there
too. TestCPUEret runs it on the interpreter, IR interpreter and JIT.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
The JIT backends' calls out of generated code (the MIPS and IR interpreter
fallbacks, and the bad address report) now take the state the backend was
built for instead of reading currentMIPS. Likewise the interpreter's tick
check, the IR dispatcher's Advance, and a couple of debugger helpers.
MIPSState::InitRegisters() no longer sets currentMIPS; the boot paths set it.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
All ~82 MIPSInt::Int_* functions (Interpreter.cpp/.h,
InterpreterVFPU.cpp/.h) now take an explicit MIPSState *mips instead
of reaching for the global currentMIPS internally, along with their
file-local helpers (DelayBranchTo, SkipLikely, ApplySwizzleS/T,
ApplyPrefixD/ST, RetainInvalidSwizzleST, EatPrefixes). MIPSInterpretFunc,
Interpret(), ExecInstruction()/InterpreterDispatch.cpp (regenerated),
and RunUntilFast() all thread mips through accordingly.
Deliberately left on currentMIPS for now: MIPSVFPUUtils.cpp's
ReadVector/WriteVector/ReadMatrix/WriteMatrix/VFPURewritePrefix -
these are shared with every JIT backend's compile-time VFPU code, so
parameterizing them would balloon this into a JIT-wide refactor. This
is a partial refactor; that's the next boundary to push on.
Several JIT backends (x86 Jit.cpp, ARM/ArmJit.cpp, ARM64/Arm64Jit.cpp,
x86/X64IRJit.cpp, RiscV/RiscVJit.cpp, LoongArch64/LoongArch64Jit.cpp,
ARM64/Arm64IRJit.cpp) bake the raw interpreter function pointer
directly into JIT-generated machine code as their "fall back to the
interpreter for this one op" mechanism, with only a single argument
register set up for the call. Rather than hand-editing register
allocation across four architectures that can't be build-tested here,
added MIPSInterpretTrampoline(MIPSOpcode op) - a 1-arg wrapper around
MIPSInterpret(currentMIPS, op) - and pointed all 7 such call sites at
it instead, leaving that codegen untouched. Two other call sites
(JitLogMiss, JitBranchLog) were plain C++ calls and just got the
extra argument directly.
Verified (Windows x64): PPSSPPWindows/PPSSPPHeadless/UnitTest all
build clean, 49/49 unit tests pass. `test.py -g --graphics=software`:
interpreter 312/314 (cpu/fpu/fpu is the pre-existing, unrelated
interpreter-vs-JIT denormal difference; gpu/rendertarget/copy passes
standalone, so was cross-test state bleed in the batch run, not a
regression), default JIT 314/314, jit-ir 313/314 (gpu/vertices/morph
is an expected difference from the vertex decoder taking a different
mode with this core change, not a bug).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019SKhm9wKEQzRUsx9mTrrtQ
MIPSTables.cpp has walked a tree of tables on every single interpreted
instruction since forever, with a standing TODO asking for exactly this:
"generate smart dispatcher functions from above tables instead of this
slow method." GenerateInterpreterDispatch() does that - it walks the
same tables MIPSGetInstruction() walks at runtime, but resolves the
walk into a nested switch tree once, at generation time, with each
leaf calling straight into the existing MIPSInt::Int_* handlers and
returning that instruction's fixed cycle count. Anything not covered
(invalid opcodes, and the handful of instructions with no interpreter
implemented at all, e.g. tge/tlt/teq) falls back to the existing
MIPSInterpret()/MIPSGetInstructionCycleEstimate() slow path, so the
result is total over all 32-bit inputs, same as the table-walking path.
Wired up via a new headless --generate-interpreter-dispatch flag,
which prints the generated Core/MIPS/InterpreterDispatch.cpp source to
stdout and exits.
Also widens CmdLine.cpp's --help column formatting, which silently
truncated any option name longer than 24 characters - the new option's
name was the first to hit it.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019SKhm9wKEQzRUsx9mTrrtQ
Opens up for having multiple JIT implementations available at runtime,
which could be use for experimenting with new JIT compiler types or for
unit testing one JIT on another architecture.
Very few of the newly virtual calls are on any sort of critical path so
hopefully there will not be a performance loss.
Also auto-saves hashmap additions and reapplies the hashmap on function
rename so that if you rename a function that exists in several copies
they will all be labelled.
Note that actual function replacement is not activated yet.
