Commit Graph
13 Commits
Author SHA1 Message Date
Henrik RydgårdandClaude Fable 5.1 b16cd9a734 VFPU: vsgn of a denormal is zero
In the interpreter, the IR interpreter, every backend's FSign and the x86
JIT's own vsgn. Recorded in cpu/vfpu/specials.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
2026-09-22 14:10:22 -06:00
Henrik RydgårdandClaude Fable 5.1 2c801b8a31 VFPU: vsrt1-4 order NaN, denormals and signed zero like the hardware
The same ordering as vmin/vmax (sign and magnitude, denormals compare as
zero), and on a tie vsrt1/2 keep the lower lane of each pair, vsrt3/4 the
upper one. Recorded in cpu/vfpu/specials.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
2026-09-22 14:10:22 -06:00
Henrik RydgårdandClaude Fable 5.1 ed6d13e15f VFPU: bit-exact vh2f and vf2h
vf2h truncates the mantissa (no rounding), gives a signed zero below 2^-14
and a signed inf from 65536 up, and keeps the low ten mantissa bits of a
NaN, so one with those clear becomes inf. vh2f flushes a subnormal half to
a signed zero and keeps inf/NaN mantissa bits unshifted. The x86 JIT's own
vh2f gets the subnormal flush; the other backends go through the
interpreter. Recorded in cpu/vfpu/specials.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
2026-09-22 14:10:22 -06:00
Henrik RydgårdandClaude Fable 5.1 783892ed25 VFPU: Writing an RNG state register keeps 0x3F8 in the top bits
mtvc to RCX0-7 keeps the low 20 bits of the value and forces the top
twelve to 0x3F8 (cpu/vfpu/vrnd), which is also the form vrnds and vrndi
leave them in. We masked with 0x3FFFFFFF. The generator itself matches
hardware for every seed and state in that test.

Interpreter, IR and the arm64 JIT. The x86 and ARM32 JITs don't mask
control register writes at all and are left as they were.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
2026-09-22 12:49:06 -06:00
Henrik RydgårdandClaude Fable 5.1 0af831b5d8 VFPU: An invalid swizzle on the one-lane ops zeroes the result lane
vrcp, vrsq, vsin, vcos, vexp2, vlog2, vsqrt, vasin, vnrcp, vnsin, vrexp2
and vdiv apply the S prefix to their last lane only, taking it from prefix
position 0. When that names a lane other than x, we fed the op an
infinity, which happens to give the right answer for vrcp and vexp2 and
the wrong one for the rest. Hardware writes the lane as zero regardless
of the op (cpu/vfpu/prefix_sat, where vlog2 and vsqrt give zero too),
which is also what RetainInvalidSwizzleST already does for the other ops.

Covers the IR path as well, which hands these cases to the interpreter.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
2026-09-22 11:32:42 -06:00
Henrik RydgårdandClaude Opus 5 675ad0acd6 Interpreter: assorted fixes found while reviewing Core/MIPS
WriteMMIO_U32 was missing the return after the kernel-mode check, so a
user-mode write raised the exception and then went through anyway. The
other five MMIO accessors already return here; this one lost it when the
GPIO/syscon branches were added.

Int_Vrot scanned all four entries of dregs, but GetVectorRegs only fills
the first n - so a vrot with vs == 0 (S000) matched a lane that isn't
there and took the cosine from it. The IR backend gets this right via
IsOverlapSafe, so the two disagreed.

The breakpoint checks in MIPSInterpret and RunUntilDowncountZeroWithChecks
read instr->flags without checking for null, which MIPSGetInstruction
returns for the eight primary opcodes (and many subops) that don't decode.
With a memcheck or register breakpoint active, landing on one of those
crashed instead of raising ILLEGAL.

Also: GetVectorOverlap decoded the second vector with size1 (no callers
today), and RegisterFunction left most of its AnalyzedFunction
uninitialized, including the size that ends up in knownfuncs.ini.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-19 10:02:46 -06:00
Henrik Rydgård 3a1162475b Interpreter: Return 0 on all types of bad memory reads - probably best for IgnoreBadMemoryAccess
But ideally I want to get rid of this at some point.
2026-08-28 14:32:42 +02:00
Henrik RydgårdandClaude Opus 5 991d43a713 Interpreter: reject misaligned lv.q/sv.q instead of carrying them out
These two raised the memory exception and then went ahead and did the access
anyway, unlike every other load/store here. A quadword access that isn't
16-byte aligned isn't valid, so there's nothing to carry out - and on 64-bit,
where GetPointerUnchecked is base + address with no masking, an address that
failed the validity check meant dereferencing whatever that landed on.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SfY7iFJEjmRXf1XGrTs4MF
2026-08-27 19:18:30 +02:00
Henrik RydgårdandClaude Opus 5 53f616faa3 Interpreter: vrot cleared the wrong lane's D prefix saturation
vrot clears the D prefix for the cosine lane, since the prefix doesn't apply
there, but shifted the saturation mask by cosineLane rather than cosineLane * 2.
That field is two bits per element - ApplyPrefixD reads it as (data >> (i * 2))
& 3, and every other site in the file shifts accordingly - so for lanes 1 and up
it cleared the wrong lane's saturation and left the cosine lane's in place. The
mask field next to it is one bit per element and was already right.

Only reachable through the interpreter, but that includes the JITs, which fall
back here for any prefixed vrot.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SfY7iFJEjmRXf1XGrTs4MF
2026-08-27 19:01:23 +02:00
Henrik RydgårdandClaude Opus 5 484898385f Interpreter: don't spin forever on a memory access that's set to be ignored
The alignment checks added in d8edeb7649 return out of the instruction handler
without advancing PC, so with IgnoreBadMemAccess - which is the default, and
which makes Core_MemoryException log and return - the run loop comes straight
back to the same instruction and never gets past it. cpu/crash/crash_read_u32
under -i logged the same SIGSEGV 585096 times in 30 seconds before being killed;
the JIT runs it to completion.

Continue instead, the way Memory::Read_U32 did before those checks existed and
the way the JIT's safe-memory path still does: loads produce zero, stores are
dropped, PC advances. When the exception is set to break rather than ignore,
Core_Break has already stopped the core by the time we get here, so nothing
changes for that case.

lv.q/sv.q are left alone - they already fall through and do the access.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SfY7iFJEjmRXf1XGrTs4MF
2026-08-27 16:43:43 +02:00
Henrik Rydgård c9c886d78f Plumb a MIPS context into ReadVector etc. 2026-08-12 14:02:19 +02:00
Henrik RydgårdandClaude Sonnet 5 ffad0acea1 Plumb an explicit MIPSState *mips through the interpreter's Int_* handlers
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
2026-08-12 14:02:19 +02:00
Henrik RydgårdandClaude Sonnet 5 d718bda178 Rename MIPSInt/MIPSIntVFPU to Interpreter/InterpreterVFPU
Just a file rename (plus updating all build configs and includes) to
give the interpreter source files clearer names. No functional change.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019SKhm9wKEQzRUsx9mTrrtQ
2026-08-12 10:04:40 +02:00