parallel-ps2/tests

What the tests under tests/ cover

Run everything with sh tests/run-all.sh. Six of the suites score the emulator against console captures and want a checkout to compare against:

PS2AUTOTESTS=/path/to/ps2autotests   ee, fpu, iop, mmi, vif, vu
PS1TESTS=/path/to/ps1-tests          iop, for the GTE and MDEC oracles

    git clone https://github.com/unknownbrackets/ps2autotests
    git clone https://github.com/JaCzekanski/ps1-tests

Without them those suites skip rather than fail, so the script is still worth running with neither set.

SANITIZER=undefined sh tests/run-all.sh builds under UBSan, and everything that links emulator code is clean under it. Two suites ignore the variable on purpose: faultstress and spsc are concurrency tests and build with -fsanitize=thread unconditionally, since that is what they are for. fpaudit honours it but drops it for jit_stage, which emits and runs machine code of its own that ASan's shadow mapping does not survive.

Do a clean build between sanitizers with different define sets rather than reusing objects.

The two kinds of harness

Most ops are scored twice, and the pair is deliberate.

A transcribing harness copies the semantics out of the emulator and scores the copy against the capture. It is cheap, has no link dependencies, and catches a wrong answer.

A real-code harness links the emulator's own translation unit and calls the ops through their real entry points. It catches what a transcription cannot: drift between the copy and the code, undefined behaviour under a sanitizer, and mistakes in the parts a transcription quietly reimplements correctly.

Keeping both is what found the DIV_S bug -- hwfpu.c scored 36 of 36 on a block where hwrealfpu.cpp scored 27, and only one of them could be right. Where the two disagree, that disagreement is the finding.

Coverage

Suite	Harness	Cases	Through
mmi	hwreal.cpp	2690 across 101 ops	MMI.cpp
mmi	hwelem.c, hwpmfhl.c, hwsa.c	1933	transcription
mmi	hwscore.c	428, not printed as a count	transcription
ee	hwrealee.cpp	944 across 56 ops	R5900OpcodeImpl.cpp
ee	hwalu, hwload, hwstore, hwmuldiv, hwbranch	1186	transcription
ee	hwspr.cpp	448	SPR.cpp
ee	hwperf.c	85	transcription
ee	hwcpcond.cpp	6	COP0.cpp
ee	hwgslabel.cpp	4	Gif_Unit.cpp
fpu	hwrealfpu.cpp	939 across 25 ops	FPU.cpp
fpu	hwfpu.c, hwfcr.c, hwbranch.c	595	ps2float.c + transcription
iop	hwrealiop.cpp	563 across 33 ops	R3000AOpcodeTables.cpp
iop	hwalu, hwlsu, hwmuldiv, hwbranch	722	transcription
iop	hwgtefuzz.cpp	1100	IopGte.cpp
vu	hwrealvu.cpp	479 across 28 ops	VUops.cpp, VU0.cpp
vu	hwclip, hwrandom, hwint, hwefu, hwfdiv, hwctc2	295	transcription
vif	hwunpack.cpp	42 formats + 16 write modes + 4 layout	Vif_Unpack.cpp
emitter	hwas.cpp	9213	c89ops.h vs GNU as

What is deliberately not scored

Each of these was looked at and left, for a reason worth knowing before looking again.

Needs the emulator running, not a function of inputs. The kernel/ tree (24 captures: threads, semaphores, event flags), dma/dmac/tagintr, dma/vif/basic and mskpath3, memory/ee/default, and the IOP libc captures, which run real IRX code rather than anything this tree implements. dma/dmac/tagintr got as far as a written scorer: driving the tag chain needs the real hwDmacSrcChain, and linking Hw.cpp for it pulls in sixty more symbols for four cases.

Needs instruction sequencing. ee/branchdelay, ee/lsudelay, iop/branchdelay, iop/hilodelay, iop/lsudelay, vu/lower/fdivdelay. These report what an instruction inside a delay slot observes. The EE branchdelay properties were verified by reading instead, which is how the IOP JALR bug was found.

Would be circular. dma/spr/normal -- its two claims are SADR masking to 0x3FF0 and MADR dropping bit 31, both in Dmac.cpp's write path. Reaching that path needs the hardware register file; restating the masks in a test would compare two constants transcribed by hand, and pass whatever the emulator did.

No oracle in the capture. cpu/cop and gpu/gp0-e1 in ps1-tests print pass/fail summaries rather than values, so there is nothing to score against.

Implemented but deferred. The PS1 MDEC status register: the oracle exists in tests/iop/hwmdec.cpp and scores 0 of 1289, wired as a report rather than a gate. Making it pass means restructuring rl2blk to expose block-level state, which is a real change rather than a test.

Not reachable by any harness here. The arm64 EE recompiler decodes with nested switches rather than tables -- about 190 case labels -- so the dispatch audit in tests/ee/tabaudit.c and tests/iop/tabaudit.c cannot reach it. A misplaced case there is the same class of bug as a swapped table entry and nothing would catch it.

Known gaps inside passing suites

A clean score measures what the capture asks, not what the instruction does. These are the places where those differ, found by mutating the emulator and seeing what still passed:

• CLIP (vu): the fourteen cases pin the comparison but not the six-bit shift that accumulates the flag across calls, and no operand has a denormal w. Two thirds of the op is unexercised.
• VIF column masking: the stmod scenarios use a mask that selects row and data only, so the MaskCol arm never runs.
• SLTIU and the immediate split (ee, iop): no line in either capture uses a negative or high-bit immediate, so sign- and zero-extension are indistinguishable. Both suites now carry cases derived from the MIPS definition instead, marked as such.
• TQWC == 0 (spr): no interleave case leaves it zero on its own.
• VU EFU accuracy (vu): scored as floors, not targets, and the floors depend on vu0ExtraOverflow, which defaults off. hwefu.c hardcodes the clamp and so models the other configuration; that is why its EATAN score differs from hwrealvu's.

The traps this tree has hit

Recorded because each cost real time and each looks like an emulator bug first.

Silent under-coverage is the recurring one: a block whose name or operand shape stops matching the capture contributes nothing and reports success. Three blocks were absent that way -- mult and multu in the EE harness, pcpyh and prevh in the MMI one -- and none was found by a failing test. The harnesses now compare what they parsed against the number of lines each block has, and a mismatch is a failure.

The others, in short: named constants missing from a table drop lines without failing; the variable shifts print value-first, not source-first, which has caught four separate harnesses; and several captures seed a register differently from their neighbours, so a value that looks like a result may be a source or a leftover.