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>
RiscVRegCache::FlushBeforeCall claimed the caller-saved X and F registers
"match between X0 and F0". They don't: X0-X4 are zero/ra/sp/gp/tp and are
never allocated, but F0-F4 (ft0-ft4) are caller-saved and are in the FPR
allocation order. A block that spilled into them and then called out (for
vsin or vcos, say) had the callee destroy registers the cache still
thought were live and dirty. LoongArch and arm64 get this right.
The LoongArch signed div-by-zero sequence applied its ADDI_D(-1) after
the jump target, so it ran on both paths: a negative numerator ended up
with a quotient of 0 instead of 1, and a non-negative one borrowed into
the remainder in the high half, giving hi = num - 1. Insert the -1 into
the low word rather than subtracting, and branch around the other case.
FCvtScaledWS loaded 0x7FFFFFFF into SCRATCHF1 and then immediately
overwrote it with the multiplier, while the FSELs picked SCRATCHF2 - a
register the function never writes. A NAN input produced whatever was
left there.
Also:
- RISC-V had no SyscallUnresolved case, falling through to INVALIDOP,
which is a live assert in release builds. Added it, matching arm64.
- applyRoundingMode_ fed fcr31 straight to FSRM, which only takes three
bits - the flags at 2-6 could turn a mode of 0 into 4. Mask with 3
first, as MIPS.cpp and LoongArch64Asm.cpp do.
- OverwriteExit lacked arm64's assert that the exit fits the 8-byte hole,
which matters more here since QuickJ is 4, 8 or 12 bytes.
- Both backends allocated the FMin/FMax temp GPR inside the conditional
NAN path, where a spill store would only run on one side while the
regcache assumed it always ran. Hoisted above the branch.
Both backends build now, and pspautotests and the unit tests pass under
qemu on each - but nothing in the suite reaches the paths above, so the
two worth checking were checked by running the emitted sequences
directly. The div-by-zero one is wrong for all eight numerators tried and
right for all eight after. The rounding one turns a guest mode of 0 into
RMM whenever fcr31 has its inexact flag set, so 0.5 converts to 1 rather
than 0. The rest are still by inspection: they need register pressure, an
unresolved import, or a debug build to reach.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
* 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
