The JITs used to find a block by overwriting its first instruction with an "emuhack" holding
the offset into the code space, and replacement functions installed their own emuhack the same
way. Anything that read code (savestates, the debugger, memory dumps, cheats, the function
hasher, games reading their own code) had to translate them back.
Blocks now live in a block shadow: one u32 per guest instruction, indexed by the PC masked with
BLOCK_SHADOW_MASK (1GB on 64-bit, folding the kernel and uncached mirrors; 256MB on 32-bit, iOS
and Switch, where address space is short), with the low bits cleared so a misaligned PC can't
read across two entries. Only the ranges under memory views are committed, so a bad PC still
faults in the dispatcher, and the shadow is reserved before the memory map so it can't land in
a gap of the 4GB window. Entries hold full 32-bit offsets, lifting the 16MB limit. The
dispatchers on every backend, and the IR interpreter's loop, look blocks up there.
A hooked instruction without a compiled block gets the JIT's hook value in its entry: the offset
of the dispatcher's compile path (1 for the interpreters, the IR arena keeping that offset
empty), so dispatching there compiles a block, and the frontends substitute the hook. Compiling
replaces the entry with the block's, and destroying the block puts the hook value back. The hook
value is rewritten when the JIT changes or regenerates its dispatcher.
Hooks live in a map keyed by the masked address, and are dropped when the game overwrites the
hooked instruction, or when an icache invalidation finds the function's hash (immediates masked,
as when matching it) changed. Those checks run when queued invalidations are processed, since
cheats and the debugger queue them before writing. Installing and removing hooks invalidates
deferred, as it happens in HLE calls that can run inside a block. The cache instruction goes
through MIPSState, so it drops changed hooks too.
With clean memory, the save/clear/restore around savestates, memory reads and dumps goes away,
as do the source-range invalidations in the memcpy replacements, sceDmac and the cheats.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
ApplyHostRoundingMode and RestoreHostRoundingMode only had SSE2 and ARM64
branches, so everywhere else the guest's rounding mode was silently
ignored and ceil and floor rounded to nearest. Fall back to fesetround,
which covers riscv64 and loongarch64 and whatever comes next.
That clears both rounding mismatches in cpu/fpu/fpu on those two. What's
left there is flush-to-zero, which neither ISA has any control for, so
the test still fails - a denormal result survives where the PSP would
have flushed it.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Every JIT backend puts the host FPU into the mode fcr31 asks for (bits 0-1 and
24) before running emulated code, and takes it back out before calling any host
code. The plain interpreter did none of that, so all its float math rounded to
nearest with denormals intact no matter what the game had set - cpu/fpu/fpu
fails under -i and passes under the JIT on exactly this.
Move the helpers the IR interpreter already had for this out of IRInterpreter
and into MIPS.cpp as ApplyHostRoundingMode/RestoreHostRoundingMode, and use them
around the interpreter's run loop and single step, restoring around syscalls and
replacement functions, which are host code. ctc1 re-applies immediately, since
the interpreter has no block boundary to defer it to.
round.w.s changes with it: it was floorf(x + 0.5f), which is half-away-from-zero
rather than the half-to-even every JIT produces, and the add would now pick up
the guest's rounding mode on top of that. round_ieee_754 is both correct and
mode-independent, and is what cvt.w.s already used for the same rounding.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SfY7iFJEjmRXf1XGrTs4MF
* Rename LogType to Log
* Explicitly use the Log:: enum when logging. Allows for autocomplete when editing.
* Mac/ARM64 buildfix
* Do the same with the hle result log macros
* Rename the log names to mixed case while at it.
* iOS buildfix
* Qt buildfix attempt, ARM32 buildfix
Previously, invalidating icache could happen while running, which might
cause the CPU to return into outer space. This runs such invalidations
after letting the CPU exit.
It was easy to trigger this with the debugger: step using the GE debugger,
add a CPU memory breakpoint, then resume from the GE debugger.
However, cheats and the like could cause similar issues.
If stepping, we may get into a delay slot within interpreted code, and
then try to run (i.e. Step Out), which won't clear the delay slot
properly.
This can cause weird behavior when interp is used again later, in addition
to immediate wrong branching behavior.
Buildfixing
Move some file util files
Buildfix
Move KeyMap.cpp/h to Core where they belong better.
libretro buildfix attempt
Move ini_file
More buildfixes
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.
