Commit Graph

9 Commits

Author SHA1 Message Date
Sylpheed RE agent
c696657613 re: the trailing data table is a per-phase TIMELINE of scheduled routines
Decodes the table found at the end of every phase region.  Layout:

    int  N
    N x [ int offset ; float t ; int kind ]      -- 8-byte typed records,
                                                    tag 0x19 int, 0x1A float

1 + 3N matches the record count in every phase measured (Stage 02: 76/40/55
records for N = 25/13/18).

Checks, all independent of each other:
  schedule entries disc-wide                675
  0x1A float records disc-wide              675   (counted by a different route)
  offsets landing on the instruction stream 675/675 = 100.0%
  control, random 4-aligned offsets                  33.3%

The floats are seconds -- 0, 0.5, 1, 4, 5, 30, 50, 60, 90, 120, 150, 170, 180, 210,
240, 270, 300, 330, 360, 420, 570, 1020, 1080, 1140, 1170 -- and the targets are small
one-shot coroutines that set arguments, call one built-in and end_coroutine.  kind is
0 (556) or 5 (119) and is not identified.

Runtime cross-check, recorded as consistency rather than confirmation: the closed
REMAINING OB work measured Stage 02's squadron arrivals at t = 0, 120 and 210 s over
n=5 emulator runs, and all three appear in phase 1's static schedule, with 120 and 210
each appearing TWICE.  These are round numbers and phase 1 has ~22 distinct times over
0-1170, so presence alone is not unlikely; the doubling is the sharper detail and was
not predicted in advance.

New artefacts data/isl-stage02-schedule.txt and data/isl-schedule-all.txt with a
committed generator (isl_report.py schedule).  calls, phase-ends, conditions and
phase-guards all regenerate byte-identical.

Not settled and said so: kind is unread; the consumer is unread, so the decode rests
on the structural checks above; whether the clock is per-phase or per-mission is an
inference from the layout; and this is NOT what starts the unreachable code -- 0 of
the 675 targets are unreached run-starts, so that ~15% gap stands.
2026-08-27 07:07:35 +00:00
Sylpheed RE agent
6cbfe0524f re: the sufficient side -- each phase exit now names the condition that FIRES it
Dominance said a phase cannot end unless X.  A port also needs "once X holds, it
must end", and that is a must-reach set: nodes from which END_PHASE is unavoidable,
as a least fixpoint where n qualifies when it has successors and ALL of them qualify.

The conservatism is deliberate and is the honest answer: a loop never enters the set,
because a poll loop reaches its exit only if the polled predicate eventually becomes
true, which is a liveness property rather than a graph one.

A dominating condition is a TRIGGER when the successor it takes on being satisfied
lies in that set.  Over all 28 stages: 732 dominating conditions, 234 triggers
(31.97%).  isl_report.py phase-guards now tags every line precond / TRIGGER.

The split lands where it should.  Stage 02's phase-1 objective exit is six
preconditions -- player alive, TCN004 destroyed, t <= 210, ADT102/ADT107/ADT113
destroyed -- and exactly ONE trigger: hp_pct_test(ADN101, 0) != 1.  Destroying ADN101
is what fires the phase.  That is a sentence a port can implement.

Per-exit distribution over 172 reachable exits: 89 have exactly one trigger, 42 have
none, 41 have several.  The 42 with none are not a failure -- they are the exits no
branch fires; Stage 02's 0x006260 ends on read_freg(0) < 1200, a timeout, and time
passing is not a property of the graph, so declining to call it a trigger is correct.

Recorded as a heuristic rather than a rule: "the first trigger is the point of no
return" holds for 33 of the 41 multi-trigger exits, with 8 counterexamples where a
precondition appears after a trigger.  The likely cause is that the listing is
ordered by file offset, which is not execution order -- coroutines and jumps let a
lower offset run later.  Not asserted.

calls, phase-ends and conditions all regenerate byte-identical; the two phase-guards
artefacts change only by gaining the tags.
2026-08-27 06:34:39 +00:00
Sylpheed RE agent
2876449965 re: phase-guards for all 28 stages, and a 6/6 cross-check from an unrelated method
isl_report.py now accepts a directory, so the dominance analysis runs over the whole
disc: data/isl-phase-guards-all.txt, 177 phase exits, of which only 5 (2.8%) are
reachable from no static entry.  CFG reach ranges 69.5% (S26) to 95.8% (S25), median
about 4 dominating conditions per exit.

The lopsided number in the per-stage table was the six TUTORIAL stages, S18-S23, each
with exactly ONE exit and exactly ONE dominating condition.  That could have been a
degenerate result, so I looked: it is the same condition in all six,

    END_PHASE  <-  builtin104() != 1

and isl-builtins.md reached built-in 104 from call-site USAGE alone -- "S18-S23 only,
followed by wait_s 39/39, preceded by end_coroutine 37/39, a textbook poll loop".
Usage said 104 is the tutorial's polled test; dominance says it is the tutorial's
clear condition.  Two unrelated methods, six for six.

Stage 16 -- the corpus outlier whose script may be compiled C++ -- resolves as well:
read_freg(0) < 600, player_gauge0_test, player_gauge1_test, and two builtin141 calls
differing in a single argument (0 vs -4000), which is the shape of a position or zone
test.  builtin141 is unread, so it is not named.

Stage 02's separate artefact regenerates byte-identical.

Also added: an RLIMIT_AS cap in isl_report's entry point.  The dominator pass
OOM-killed a run earlier on this 15 GB box; a bad input should now fail the process
rather than the machine.

Still not settled and stated in the doc: dominance gives necessary, not sufficient,
conditions; the 5 unreachable exits need the trigger queue at phase+272; builtin104,
builtin141 and builtin7 all appear in clear conditions and are unread.
2026-08-27 06:19:44 +00:00
Sylpheed RE agent
983c5d112c re: the per-phase clear conditions, by dominance over the ISL CFG
Closes the backlog's "which condition guards each END_PHASE".  With the CFG from the
previous commit this is a graph query, not new machinery.

The obvious query is WRONG for this language, and I implemented it first: "one
successor reaches END_PHASE and the other does not" finds 1/62/1 guards across Stage
02's three phases, and the 1s are both the same read_freg(0) < 1200 timeout -- every
objective test missed.  The cause is the dominant idiom: a POLL LOOP's loop-back
branch also reaches the exit, one iteration later, so neither successor discriminates.
The asymmetric 1/62/1 is what exposed it; a uniform number would have read as
plausible.

Dominance has no such blind spot: a condition dominates an exit when every path from
an entry passes through it, so it is NECESSARY for the phase to end that way, and a
poll loop's test dominates its own exit by construction.  Iterative dominators
converge in 3 passes over 15670/18739 instructions (83.6%).

Result for Stage 02 -- every exit in all three phases is dominated by
unit_hp_pct(TCN001, Character_Player_Test) != 0, the player's ship being alive, which
falls out rather than being assumed.  Beyond that, phase 1's objective exit requires
hp_pct_test on ADT102, ADT107 and ADT113; phase 3's requires ADT301 and ADT302;
read_freg(0) gates at 210 / 300 and times out at 1200; random(3) and random(5)
dominate only the exits that pick one of several closing lines.

Two of the 15 exits are reachable from NO static entry, both FORCE_END_PHASE.  That
agrees with the independently measured 389 unreachable routines: they are started from
the trigger queue at phase+272, by data rather than code.

Practical note recorded: the first dominator run was OOM-killed -- 6743 nodes each
holding a Python set of up to 6743 elements.  Integer bitmasks run in seconds.

Not settled, and said so: dominance gives necessary, not sufficient, conditions; only
Stage 02's artefact is committed; one listed condition is still an unresolved
<unknown>; read_freg's units are inferred from the gate values, not read.

calls, phase-ends and conditions all regenerate byte-identical.
2026-08-27 06:12:41 +00:00
Sylpheed RE agent
29eda81ede re: recover ISL conditions by CFG dataflow instead of a linear walk
The linear walk's 10% unknown was a floor imposed by the method: a block entered only
by a branch has a well-defined state, just not one a straight-line pass can see.
tools/re-capture/isl_cfg.py replaces it with a worklist fixpoint that joins each
block's state over its ACTUAL predecessors -- a value survives only if every
predecessor agrees.

Over all 28 stages:
  instructions reached by the CFG          85.0%
  condition sites, unknown LHS             756 (10.00%) -> 402 (5.32%)
  of those, never reached at all           389
  joined away (predecessors disagree)       13
  both resolve but DISAGREE                161   <- linear walk was wrong here

Those 161 are on top of the 889 the previous jmp fix caught.

Two zero-results on the way, both my own bug, both caught because the number looked
wrong rather than because a test failed:

  * The first CFG run reached only 36% of instructions and made things WORSE (35%
    unknown).  Cause: the phase bases reach almost nothing.  Most routines are
    COROUTINES the engine starts from its trigger queue, with no static predecessor,
    so every start_coroutine target has to be seeded as an entry.
  * That seeding then found ZERO entries in a file with 216 start_coroutine calls,
    because the target is staged in TWO steps -- special[0] = imm, then
    local[0] = special[0] -- and I matched only the direct-immediate form.

Reachability went 36% -> 64% -> 85% as each was fixed.

The 389 still unreached are an honest limit rather than a gap: nothing in the bytecode
starts them; they are entered from the trigger queue at phase+272, by data rather than
code, so no purely static analysis reaches them.

isl_report.py conditions now uses isl_cfg; calls and phase-ends regenerate
byte-identical.  Stage 02 unknowns drop from 71 to 25.
2026-08-27 06:02:37 +00:00
Sylpheed RE agent
f32def9a05 re: resolve every ISL condition's comparand -- the clear conditions are readable
The deque ops are an EXPRESSION STACK: push the left operand, evaluate the right
(a built-in call, whose result lands in special[0]), pop the comparand back into
special[1], compare.  Tracking that through the linear decode is enough to recover
what each site tests.

Evidence the model is right, not just plausible:
  push vs pop across all 28 stages          1877 vs 1877
  files that underflow or end unbalanced    0 of 28
  Stage 02 pop.i sites followed by cmp.i    319 / 319
  ops immediately before a pop.i            call x313, cmp.a x6

isl.conditions() recovers 7563 condition sites disc-wide with 0.0% left as an
unresolved special[N]; 83.2% have a built-in call as the LHS and 99.7% compare
against a plain number.  Most-tested: hp_pct_test 1955, unit_state 1257,
unit_relation 796, dist_lt 450, unit_alive 413.

They read as conditions now:
  if unit_alive(TCN105) != 1
  if hp_pct_test(ADT308, 0) != 1
  if dist_lt(ADT308, TCN000, 15000) != 1      (world unit = 1 m, so 15 km)
  if unit_state(ADT308) == 1

data/isl-stage02-conditions.txt was a stale artefact with NO generator -- the thing
isl_report.py's docstring complained about.  It has one now (isl_report.py
conditions).  The calls and phase-ends artefacts both regenerate byte-identical, so
the change is additive.

Recorded rather than glossed: 15 of Stage 02's 965 sites (1.6%) attribute the LHS to
end_coroutine, which returns no value -- the tracker sets special[0] on EVERY call,
so those show a stale value and are wrong, not imprecise.  The fix is to set it only
for built-ins that write [phase+164], which the vtable work makes checkable.
2026-08-27 05:28:50 +00:00
Sylpheed RE agent
228680edf0 re: the ISL stream is flat -- refute the "needs coroutine entry points" blocker
Two files (isl_report.py's docstring and structures/isl-builtins.md) recorded the
same blocker on a faithful per-phase condition listing: that it needs the coroutine
entry points from start_coroutine's operand.  Measured against isl.call_sites(),
which enumerates by scanning the encoding rather than by decoding and so is an
independent denominator:

  linear + jumps, stopping at ret (what the tool did)   133 / 2846 =   4.7%
  linear + jumps, continuing past ret                  2275 / 2846 =  79.9%
  ... + following start_coroutine (the recorded fix)   2355 / 2846 =  82.7%
  plain linear decode, no control flow at all          2846 / 2846 = 100.0%

Following the coroutine entries buys 2.8 points.  Disc-wide, a plain linear decode
from the first phase base reaches 25705/25705 call sites over all 28 stages, and
28/28 decode clean to code_end with no desync.

The real bug was isl.dis ending on `if op == 20: break`.  Op 20 is `ret`, but this
is a coroutine VM -- the thread suspends and resumes at the FOLLOWING instruction,
so code continues past it.  dis() now takes stop_at_ret (default True, preserving
the old output: data/isl-stage02.txt regenerates byte-identical) and
isl.linear_offsets() is the correct walk.

By-product, kept with its control: start_coroutine's target is staged slot 0 --
73/83 phase-1 sites land on a valid instruction, against a 38.7% chance rate for an
arbitrary 4-aligned offset.

New artefact data/isl-stage02-phase-ends.txt with a committed generator
(isl_report.py phase-ends).  It shows END_PHASE's call site is the WRONG place to
read a clear condition: all 12 Stage-02 sites sit in one stereotyped outro.  Not
settled, and stated as such: op10/op13/op14/op21/op23 are unread handlers, so the
condition in the poll loop upstream cannot be named yet.
2026-08-27 05:00:49 +00:00
Sylpheed RE agent
009bca880e re: an ISL symbol operand is a (tag, index) pair — and two more names withdrawn
Verified rather than adopted: a subagent proposed that every even operand
slot is a type tag. Measured, the strong form is false and a precise form is
true.

TRUE: a SYMBOL operand is two words, a tag holding the constant 1 followed
by the index. Slot 0 is the integer 1 in 19899/19899 calls whose slot 4 is a
unit; slot 8 is tag-shaped in 100% of calls for every built-in taking a
second unit; slot 16 is 1 in 152/152 for built-in 128, the only one taking a
third. The 24 built-ins whose slot 0 is NOT the constant are exactly those
taking no symbol there. This explains the unit slots 4/12/20 rather than
replacing them.

FALSE as stated: slot 8 is a bare double for built-ins 4, 20, 24, 26, 28,
29, 90, 106 and 127, and built-in 75 carries five bare indices at 0/4/8/12/16
with no tags at all. Each built-in has a fixed signature and is 100%
self-consistent; none of the 34 with >=20 sites mixes the two.

Symbol table 1 has three types -- 1 routes (1362), 6 messages (2247), 7
effects (81) -- and its operand slots are type-pure, measured the same way.
Resolving them makes listings say what the script means:
`request_script_message(MSG_VOICE_D_257, ...)`, a fourth independent
confirmation of that name. Slots 24@4, 46@12 and 114@4 resolve 100% but MIX
types 6 and 1, so they are left unresolved rather than guessed.

Two more names withdrawn, neither replaced:
* 88 `camera_at` -- ZERO call sites in all 28 stages; never testable.
* 90 `camera_at_route` -- 8 sites, all Stage 02 phase 3, first operand is
  symtab-1 type 7 `eff_n0071`, an EFFECT name, in 8/8, with a per-missile
  Route_ADT301..308_p3M at slot 20. Not aimed at a camera.

Left unnamed on purpose: replacing a guessed name with another guess is how
the three names corrected earlier today went wrong.

Also flagged: 115 `named_event`'s only symbol operand is an eff_* name in
84/84 sites, so that name is suspect too. Not renamed pending a handler read.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PMRJjbxLqZtsb5Vb7KunPE
2026-08-25 22:51:07 +00:00
Sylpheed RE agent
1ba5d0a4a3 re: three ISL built-in names were wrong, including the most-used one
All re-read twice — the handler, and the thing it calls — because each had
been named from its shape rather than its effect.

* id 11 `yield` -> `end_coroutine`. 0x82272624 is li r11,1 ; li r3,3 ;
  stw r11,164(r31), and the dispatcher's r3==3 arm erases the thread from
  the active list and returns it to the free list. It destroys the thread.
  2945 sites game-wide, 372 in Stage 02 — the most-used built-in there was.
* id 5 `await_label` -> `kill_coroutine(label)`. sub_82273B08 kills the
  thread parked at the target pc, or itself if the target is its own pc.
  It waits for nothing.
* id 100 `push_trigger` -> `reset_phase_threads`. It clears the trigger
  container and then frees every thread whose pc differs from the caller's
  — the opposite of pushing a trigger. Corroborated by usage: its 12 Stage
  02 sites all sit in the phase terminator, next to timer_stop,
  clear_flag(-1) and MARK_LAST_PHASE.

One name recovered from the game's own text: opcode 992 prints
"RequestScriptMessage %s" at 0x820A5700, so id 64 is request_script_message
(2683 sites).

Return codes documented properly: 1 = restart the coroutine from its entry
(previously not recorded at all), 3 = terminate. And the blocking set was
wrong in two places — it is 102, 120, 137, 142, 143. Id 97 does NOT block;
its handler ends `b 0x822724F8`, so it always returns 0.

Unit-operand resolution settled from DATA over all 28 stages rather than by
reading 147 handlers: a slot qualifies only if every value is a valid
symtab-2 index, it takes >=15 distinct values, AND its maximum reaches most
of the table — that last clause is what discriminates, since every small
integer is trivially "in range". 31 built-ins at slot 4, 8 at slot 12, one
at slot 20. It also refutes set_flag's slot 0, whose maximum overruns the
table, and the resolver now declines rather than inventing a name.

New and unexplained: symtab-2 holds two types, 2 and 8, and built-ins 95 and
128 take type 8 at slot 12 in 100% of their sites.

A downstream inference is withdrawn with it: the note reading the live
trigger counter attributed it to "the script arming watches as it goes" via
built-in 100. The measurement stands; the attribution does not.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PMRJjbxLqZtsb5Vb7KunPE
2026-08-25 22:09:05 +00:00