func_8002C410 MATCHES 299/299 at -O0 and DIFFs 228-vs-299 at -O2 (verified
independently with match_one --o0 vs --no-auto-o0). gcc-2.7.2 has no
per-function optimize pragma, so opt level is per FILE, and the function needs
its own object. Main had no path to one: the Makefile's -O0 wildcard covered
src/ov_*/ and src/md_*/ but NOT top-level src/*.c, and o0_subsplit.py is
overlay-shaped -- it died on config/splat.main.yaml, which does not exist.
Measured the scope first (R37): the -O0 detector flags exactly TWO open main
stubs -- this one, and func_80011380, which already lives in -O0 boot.c and is
the proved floor. So this unblocks one function, not a class.
FIVE COUPLED PIECES, which is why the carve is worth recording:
1. splat code rows: 800_b cut 3 ways -- 800_b / 800_b_o0a / 800_b_2
2. splat .rodata: span B SPLIT, because the 3-way cut put its two jtbl owners
in different objects -- func_8002B0B4 into 800_b, func_800335B8 into
800_b_2 -- and one code object may contribute exactly ONE contiguous
.rodata run. The boundary is DERIVED, not guessed: 800_b.o's compiled
.rodata is 0xf8 bytes, so the front run ends at 0x80072E44+0xf8. The
build's own jtbl_rodata_pads caught the missing piece.
3. src/800_b.c split 3 ways -- 86-line prologue duplicated, 3 defs before the
island, 97 after
4. Makefile -O0 glob widened to top-level src/*_o0?.c
5. ld_interleave --order: 800_b_2.o inserted after 800_b.o. Missing this
floated the tail rodata and shifted every data symbol by exactly its size,
+0x204, across 704 two-byte runs -- which is how it was found.
o0_subsplit.py now REFUSES main loudly instead of dying on a missing file
(R43/R61a) and names the manual procedure.
VERIFIED BYTE-NEUTRAL BEFORE ANY BANKING: main builds
143dbb89f34491258bbc27810d0a12ec8b43a8dd with the split in place and
func_8002C410 still an INCLUDE_ASM stub.
Promotes the proven probe (commit:1266) into a real tool, and validates it FIRST-TRY on a
fresh overlay.
tools/o0_subsplit.py <ov> --lo <vram> --hi <vram>:
- derives the range's contents from the SOURCE ANCHORS (overlay_src_split.parse_overlay_c:
`asm` = unmatched stub, `define`/`def`/`nonmatch` = already matched), NEVER from an asm
scan -- a matched fn emits no .s, which is exactly the blindness that made the range look
like a clean contiguous run (SS126 / SS124's shape);
- computes the -O0 bound as (address range MINUS already-matched bodies) and emits ONE
sub-region per maximal run of unmatched anchors (K matched islands => K+1 regions);
- names each `<ov>_o0<letter>` picking free suffixes, so the widened Makefile glob selects
them; refuses loudly if it runs out or if the range spans >1 object or is already -O0;
- honours the one-carve-per-region law (forces a cut at every already-banked jr in the
object) and reuses jr_isolate_all's plan/build_new_config/ascending-unique validation
verbatim, so carve-repoint + source-repartition stay on the proven path;
- warns (does not refuse) when a stub in an -O0 run lacks the frame-pointer prologue --
the byte-gate is the arbiter, not the heuristic.
VALIDATION on ov_SC03_015 (untouched by the manual probe): the tool independently derived the
SAME structure found by hand on ov_SC03_014 -- 2 matched -O2 islands (func_80184440,
func_801848E4), 2 -O0 regions (8 + 7 fns), same 5 cuts. Sub-split -> BYTE-IDENTICAL. Then 3
drafts, each global DERIVED FROM THAT OVERLAY'S OWN ASM (%hi operand) rather than copied:
3/3 match_one --o0 MATCH (22 ins), 3/3 through the whole-binary gate.
BANKED this commit: func_801846E4 / func_8018473C / func_80184794 in ov_SC03_015 (6 across
the two overlays now). The other 24 stubs in the region are undrafted -- the route makes them
DRAFTABLE (they were un-bankable at any effort before); drafting them is crack-wave work.
R22 CLEAN-FLEET: extract-all 139/139 (+main); check-all 140 passed, 0 failed of 140.
cookbook SS126 (the address-range-is-not-an-optimization-region law + the probe ladder).
Drew T