mirror of
https://github.com/Druthulu/BFM-decomp
synced 2026-09-26 21:36:06 -04:00
docs(phase-30 S48): §163 — the five vetted laws from waves 2-3
The waves flagged ~40 candidate laws. Five were byte-probed, generalizable and actionable enough to bank; they were deduped by hand against the file (no skeptic-agent pass this time, so each says what it sharpens and why that section is insufficient): - §163a decl-conflict severity is SCOPE-DEPENDENT — hard error if either decl is at file scope, warning only if BOTH are at block scope. §8d proves the phenomenon on D_801812A4 but never states the rule or its LEVER half: block scope is a deliberate conflict SOLVENT, so a struct-typed draft can be banked into a scalar-typed TU by moving the typedef AND the extern into the block. - §163b the switch-index parameter-WIDTH oracle: sll/sra straddling the minval subtract is a 2-insn signature of a short parameter. Read the extension, not just the bound. - §163c case_values_threshold is 5 — an empty `case k:` glued to default can be the only thing that emits a table at all; jtbl[k]==default label is the tell. - §163d cse deletes a reg-reg copy by rewriting the PREVIOUS insn's SET_DEST (cse.c:7440-7477). This is §162j's symptom in a DIFFERENT PASS and needs a different lever; the residual it explains had been declared "unsteerable, 30 variants all >=17" and fell to source-shape edits alone, no pins. - §163e the frame is a PSEUDO-NUMBER oracle (reload1.c:658 alter_reg in NUMBER order); dead-local slot order is not declaration order, and a BLKmode local is 8-aligned while a scalar s32 is not. Sharpens §162i, which gets the pad's SIZE right and its PLACEMENT wrong. §163z catalogues the ~35 unvetted claims by function so a future harvest can go straight to them, explicitly marked "one agent's reconstruction until re-measured" (R14). cookbook_index.py: 497 sections.
This commit is contained in:
Drew T
+10
-4
@@ -2,7 +2,7 @@
|
||||
|
||||
> **Generated by `tools/cookbook_index.py` — do not hand-edit** (R33). Regenerate after adding a cookbook section.
|
||||
>
|
||||
> `docs/matching-cookbook.md` is ~716 KB / 495 sections. Grepping it blind is how three P30 wave-1 agents each "discovered" an idiom that was already written down. **Start here, then read the section.** A section appears under every symptom it addresses.
|
||||
> `docs/matching-cookbook.md` is ~716 KB / 497 sections. Grepping it blind is how three P30 wave-1 agents each "discovered" an idiom that was already written down. **Start here, then read the section.** A section appears under every symptom it addresses.
|
||||
|
||||
**How to use:** name what you SEE in the diff (a stolen delay slot, an extra `la`, a swapped register pair, a `conflicting types` error), find that symptom below, read those sections first. If nothing fits, THEN grind — and add a section when you win.
|
||||
|
||||
@@ -302,7 +302,7 @@
|
||||
- **§127a** — §71 (sibling-first) is the strongest `-O0` lever, and it beats the index <sub>L8377</sub>
|
||||
- **§132** — The `JR-PAIR-IN-ONE-O0-OBJECT` "wall" was TWO instrument defects: a merged-double span the carve could not see, and a truncated object no rule deleted (P30 S29, `func_8013B83C` + `func_8013BD74`) <sub>L8570</sub>
|
||||
|
||||
### family propagation & sweeps (81)
|
||||
### family propagation & sweeps (82)
|
||||
|
||||
- **§8d** — Templating a body INTO a TU must not CHANGE its declaration environment — demote the carried data externs (Phase 26 session 8, byte-proven on `func_8015AE2C` ×133) <sub>L483</sub>
|
||||
- **§11** — Cross-binary dedup & code-sharing (Phase 11 — "one match unlocks many") <sub>L908</sub>
|
||||
@@ -385,6 +385,7 @@
|
||||
- **§156** — an ORPHANED reconcile poisons the fleet: `dedup_propagate`'s kept edit (S45 p6/p7) <sub>L10637</sub>
|
||||
- **§160** — THE REACH-15 WAVE HARVEST: an align-1 block move, and the instrument that called it a wall (P30 S47) <sub>L10890</sub>
|
||||
- **§162** — S48 WAVE-1 HARVEST (P30, 2026-08-11): the reach-ordered sibling campaign's first 12 targets <sub>L11011</sub>
|
||||
- **§163z** — THE UNVETTED REMAINDER (do not cite as law; each needs a dedupe pass) <sub>L11825</sub>
|
||||
|
||||
### integration / TU plumbing (38)
|
||||
|
||||
@@ -427,7 +428,7 @@
|
||||
- **§3-A.** — Payload word0 is a global MODULE ID; code starts after the header <sub>L10524</sub>
|
||||
- **§162** — THE LICM PAIR: what makes an address a movable AT ALL, and why the preheader order is the body order (P30 S47, `ov_MAIN_012`) <sub>L11140</sub>
|
||||
|
||||
### build graph, splat & the harness (105)
|
||||
### build graph, splat & the harness (106)
|
||||
|
||||
- **§4** — Flag/toolchain gotchas <sub>L190</sub>
|
||||
- **Build** — mechanism — per-file opt override (splat resegmentation) <sub>L288</sub>
|
||||
@@ -534,8 +535,9 @@
|
||||
- **§160** — THE REACH-15 WAVE HARVEST: an align-1 block move, and the instrument that called it a wall (P30 S47) <sub>L10890</sub>
|
||||
- **§161** — THE RETRY-WAVE HARVEST: a jump table indexed from zero, and two allocator traps (P30 S47) <sub>L10966</sub>
|
||||
- **§162** — S48 WAVE-1 HARVEST (P30, 2026-08-11): the reach-ordered sibling campaign's first 12 targets <sub>L11011</sub>
|
||||
- **§163** — S48 WAVES 2-3 HARVEST (P30, 2026-08-11/12): the five that were byte-probed and are actionable <sub>L11757</sub>
|
||||
|
||||
### process, measurement & doctrine (67)
|
||||
### process, measurement & doctrine (69)
|
||||
|
||||
- **§8e** — The jtbl ALIGNMENT LAW + the pad-spec filter — multi-table .rodata spans (Phase 29, byte-proven; `.run/probe_jtbl/verdict.md`) <sub>L530</sub>
|
||||
- **§3-The** — mechanism: game-code dedup is SOURCE-LEVEL, not an object swap (R-D1, the key lesson) <sub>L926</sub>
|
||||
@@ -604,6 +606,8 @@
|
||||
- **§162** — The cross-jump "CALL veto" is a COUNT law, not a CALL law (BOUNDS §88a; P30 S48, `func_80189540`) <sub>L11299</sub>
|
||||
- **§3-The** — law <sub>L11546</sub>
|
||||
- **DIAGNOSTIC** — TELL — two faces, one law <sub>L11588</sub>
|
||||
- **§163** — S48 WAVES 2-3 HARVEST (P30, 2026-08-11/12): the five that were byte-probed and are actionable <sub>L11757</sub>
|
||||
- **§163z** — THE UNVETTED REMAINDER (do not cite as law; each needs a dedupe pass) <sub>L11825</sub>
|
||||
|
||||
### (unbucketed — title matched no symptom vocabulary) (165)
|
||||
|
||||
@@ -1271,3 +1275,5 @@
|
||||
- **§162o** — SHARPENS *(sharpens §158, §136-1, §136-6, §79)* <sub>L11643</sub>
|
||||
- **§162p** — SHARPENS *(sharpens §48-B, §46-L2, §156, §136d-1)* <sub>L11702</sub>
|
||||
- **§162q** — SHARPENS *(sharpens §30, §30a, §135-2, §136-13)* <sub>L11719</sub>
|
||||
- **§163** — S48 WAVES 2-3 HARVEST (P30, 2026-08-11/12): the five that were byte-probed and are actionable <sub>L11757</sub>
|
||||
- **§163z** — THE UNVETTED REMAINDER (do not cite as law; each needs a dedupe pass) <sub>L11825</sub>
|
||||
|
||||
@@ -11751,3 +11751,90 @@ access must not be QImode (`cse_expr.md` §4b — u8/s8 never get the escape).
|
||||
|
||||
*Scope, honestly:* two arms of one function. Nothing here was measured across a structural family, so
|
||||
read this as "site-selective within a body", not as a claim about family sweeps.
|
||||
|
||||
---
|
||||
|
||||
## §163 — S48 WAVES 2-3 HARVEST (P30, 2026-08-11/12): the five that were byte-probed and are actionable
|
||||
|
||||
Provenance: 67 exemplar cracks across waves 2-3 (22 + 27 banked on the whole-binary gate). The agents
|
||||
flagged ~40 candidate laws; these FIVE were selected as byte-probed, generalizable, and immediately
|
||||
actionable, and were deduped by hand against the file. **The remaining ~35 are catalogued at the end
|
||||
of this section with their function names — they are NOT lost, but they are NOT vetted either.**
|
||||
|
||||
**§163a — DECL-CONFLICT SEVERITY IS SCOPE-DEPENDENT, AND BLOCK SCOPE IS THEREFORE A CONFLICT
|
||||
SOLVENT.** *(sharpens §8d and §161c: §8d PROVES the phenomenon on `D_801812A4` — `BLOCK→BLOCK→FILE`
|
||||
builds, `FILE`-first errors — but never states the rule or its lever half.)* In gcc-2.7.2 an
|
||||
INCOMPATIBLE `extern` redeclaration is:
|
||||
|
||||
either declaration at FILE scope -> HARD ERROR "conflicting types for X"
|
||||
BOTH declarations at BLOCK scope -> WARNING ONLY "type mismatch with previous external decl"
|
||||
|
||||
**Consequence for banking:** the block-scope-extern pattern is not merely hygiene, it is a genuine
|
||||
SOLVENT. A draft whose struct-typed view of a global disagrees with the host TU's scalar view can be
|
||||
banked AS-IS by moving **both the typedef and the extern** into the using block. Byte-probed both
|
||||
directions on the pinned cc1 (`func_80189540`, ov_SC04_018, 551 ins): the file-scope form is a hard
|
||||
error, the block-scope form warns and still gates **MATCH at 551 — codegen unchanged**.
|
||||
*Corollary already paid for elsewhere: you cannot simply DELETE the draft's decl to dodge a conflict,
|
||||
because `match_one` compiles the draft STANDALONE and the symbol is then undeclared — which
|
||||
gcc-2.7.2 reports with no `error:` prefix, so it reads as a mystery CC1 FAIL (`func_80187960`).*
|
||||
|
||||
**§163b — THE SWITCH-INDEX PARAMETER-WIDTH ORACLE: read the EXTENSION, not just the bound.**
|
||||
*(extends §161a/§162a from the table's edges to the dispatch's operand.)* For `switch (p)` with
|
||||
minval != 0:
|
||||
|
||||
s16 param: addiu $a0,$a0,-MINVAL ; sll $a0,$a0,16 ; sra $a0,$a0,16 ; sltiu $v0,$a0,MAXVAL
|
||||
s32 param: addiu $a0,$a0,-MINVAL ; sltiu $v0,$a0,MAXVAL
|
||||
|
||||
The `sll/sra` pair **straddling the minval subtract** is a 2-instruction signature of the switch
|
||||
parameter's DECLARED WIDTH — it is the HImode re-extension of the truncated subtract result and
|
||||
exists only for a short. **Tell:** a jump-table function off by ±2 ins with the drift starting at the
|
||||
`sltiu` — read the extension around the subtract before touching anything else. (`func_80189540`.)
|
||||
|
||||
**§163c — `case_values_threshold` IS 5: AN EMPTY CASE LABEL GLUED TO `default:` CAN BE THE ONLY THING
|
||||
THAT EMITS A TABLE AT ALL.** *(extends §162a from the table's BOUND to its COUNT.)* A switch with
|
||||
four live cases `{0,1,3,4}` emits a DECISION TREE, not a tablejump — so a 5-entry table in the target
|
||||
is unreachable until an explicit `case 2:` label is added onto the default body. **Read the table's
|
||||
ENTRY VALUES, not just its length:** `jtbl[k] == the default label` is the fingerprint of a case
|
||||
label sharing the default body, and that empty label is LOAD-BEARING. Took a draft from 43 mismatches
|
||||
to 1. (`func_80181BE4`, ov_SC01_077.)
|
||||
|
||||
**§163d — cse DELETES A REG-REG COPY BY REWRITING THE *PREVIOUS* INSN'S DESTINATION.** *(the missing
|
||||
sibling of §162j — same symptom, DIFFERENT PASS. §162j is local-alloc's `optimize_reg_copy_1`; this
|
||||
one fires earlier, in cse, and the two need different levers.)* Mechanism read out of the pinned gcc
|
||||
source, not inferred: `cse.c:7440-7477` (`cse_insn`, "special handling for `(set REG0 REG1)` where
|
||||
REG0 is the cheapest") validates a change of the PREVIOUS insn's `SET_DEST` to REG0 and rewrites this
|
||||
insn to `(set REG1 REG0)`, which becomes a dead store and disappears — so **both** the copy and its
|
||||
defining insn's destination change, and the source pseudo vanishes from the function entirely. The
|
||||
canonical-quantity choice is `make_regs_eqv` (`cse.c:826-855`), and the dial is **last-use order, not
|
||||
set count**. A prior agent had declared this residual "unsteerable — 30 variants all ≥17"; it was a
|
||||
false wall, closed by source-shape edits alone with NO pins (229 → 15 → 8 → 0). (`func_8017C3BC`,
|
||||
ov_MAIN_012, 407 ins.)
|
||||
|
||||
**§163e — THE FRAME IS A PSEUDO-NUMBER ORACLE, AND DEAD-LOCAL SLOT ORDER IS NOT DECLARATION ORDER.**
|
||||
*(sharpens §162i, the unreferenced-local frame oracle — that entry gets the SIZE right and the
|
||||
PLACEMENT wrong.)* `reload1.c:658` runs `alter_reg(i,-1)` over pseudos in NUMBER order, so slots fall
|
||||
out of pseudo numbering, not source order. Two independent measurements: a BLKmode local is 8-ALIGNED
|
||||
with its size CEIL_ROUNDed to 8 (`assign_stack_temp` → `assign_stack_local(mode,size,-1)`) while a
|
||||
scalar `s32` gets only 4-byte alignment — which is why a bare `s32 sz` can never land on 0x30 and
|
||||
must be written `s32 sz[1]`; and the dead pad is allocated BEFORE a later-declared live aggregate, so
|
||||
`sz[1]; sv; pad[6]` and `sz[1]; pad[6]; sv` both emit slot order sz,pad,sv. **Practical rule:** place
|
||||
the §162i pad IMMEDIATELY BEFORE the local you want pushed DOWN, then VERIFY with `grep '\.frame'`
|
||||
plus the sp-relative store offsets — never by reasoning about declaration order. (`func_80184BD8`
|
||||
ov_SC02_000; `func_8017C294` ov_SC01_077.)
|
||||
|
||||
### §163z — THE UNVETTED REMAINDER (do not cite as law; each needs a dedupe pass)
|
||||
~35 further claims sit in the wave note-sets (`.run/jr48/wave2_result.json`,
|
||||
`.run/jr48/wave3_result.json`) and in the run transcripts. The ones whose stated mechanism looked
|
||||
strongest, by function, so a future harvest can go straight to them:
|
||||
`func_8018FF98` (cross-jump reconstruction is NOT optional even when a shared tail "obviously" wants
|
||||
a goto — the §162g lever half) · `func_8017FFD0` (same axis, "the missing LEVER half") ·
|
||||
`func_80183324` (N distinct jtbl labels pointing at the SAME block = a positive tell) ·
|
||||
`func_80192B60` (fold's PLUS/MINUS re-association is source-form invariant — only a statement
|
||||
boundary breaks it; two-armed constant select; "a re-read is not redundant") · `func_8017DEFC`
|
||||
(2-D vs 1-D spelling kills/creates a LICM movable — sharpens §162e in the OPPOSITE direction; loop
|
||||
FORM as a delay-slot declaration; a shared temp as a SCHEDULING barrier) · `func_8017DD28` (three
|
||||
spellings of one subtraction give three codegens) · `func_80185EF8` (`fold_range_test` defeats `||`
|
||||
bound-chains) · `func_8017FDF8` (the mult/LO tie-break) · `func_8017CA18` (found via gdb-on-cc1 in
|
||||
`sched.c` `priority()`/`rank_for_schedule()`) · `func_8018E8A0`, `func_8017D7C0`, `func_8017F83C`,
|
||||
`func_80184944`, `func_80186C4C`, `func_801823E8`, `func_80192768`, `func_8017EB44`, `func_8017EB70`.
|
||||
**R14 applies to every one of them: they are one agent's reconstruction until re-measured.**
|
||||
|
||||
Reference in New Issue
Block a user