A `let c: T = *p` (T a struct or array, >8B) copied no full aggregate:
cstage dropped the init entirely (c read garbage); wwstage emitted only
the scalar `MOVQ AX,off(BP)` tail (first 8 bytes). Both wrong, differently
— converge BOTH stages on a size-driven slot-to-slot memcpy: cgexpr the
deref operand to the source address in AX, MOVQ AX,SI, then a MOVQ run
plus a sized MOVL/MOVW/MOVB tail over the #254 non-slot-padded ABI extent
(lu->size / structabisize for a struct, tinfo.size for an array). Mirror
arms in cgen.c N_LET and cgenstmt.ww cglet, byte-identical (rule-10).
Unblocks sha256's faithful `let copy = *h`. The by-value aggregate RETURN
ABI (array/struct return truncates to AX) is fold-2 (#267, deferred).
949 gains 6 full-readback rows (every member written distinct + summed,
so a truncated copy fails): struct{[4]u32} 16B, struct{[8]u32} 32B via
both *(&s) and *p (sha256 shape), bare [4]u32, and non-8-mult tails
([3]u32 12B → MOVL, [11]u8 11B → MOVW+MOVB). w6c+wwdump combined.ww regen
(#110). 61/61 949, test-unit 240, sizelint, smoke green.
cgreturn's passthrough predicate was TYPE-only (istagged && type-eq), with
no source-kind filter. It forwarded the source's AX/DX/CX unchanged, which
is correct ONLY when the source already materialized the full tagged slot
into registers — N_CALL / N_INDEX / N_DOT (the #261-broadened set). For a
tagged LOCAL ident, cgexpr loads only word0 (the tag) into AX, never the
payload into DX, so passthrough dropped the payload: `return v` of a
`(i32|void)=7i32` exited 0 instead of 7. wwstage was already correct — its
forwardtagged kind filter excludes N_IDENT, routing it through the
scratch-widen path. The runtime oracle (cstage 0, wwstage 7) proved cstage
is the bug; this aligns cstage UP.
Gate passthrough to {N_CALL,N_INDEX,N_DOT}; a tagged-ident return now falls
to the existing scratch-slot widen path (cg_widen_tagged_store tagged-subset
N_IDENT arm), byte-identical to wwstage's return scratch-widen. cstage-only
(no combined.ww regen — combined.ww embeds the unchanged wwstage source;
byte-id is blind here, the new 949 rows are the net).
test/949: tagged_ident_ret_i32 (7) + tagged_ident_ret_void (void tag
survives) + register-resident controls tagged_call_ret_ctrl /
tagged_dot_ret_ctrl (passthrough must still fire); INDEX control already
present. All dual-stage run + cs==ww byte-id.
Hare admits an array with a defined length wherever its element slice is
expected (assign / return / call-arg / init) as a borrow; ww rejected it
everywhere (the #108(c) exclusion), so base64 worked around the gap with
explicit a[0:n] slices.
type_assignable / isassignable now admit array->slice on an exact element
match (mirror ref/harec/src/types.c:1080-1097, the SLICE-dst arm). The four
acceptance sites route through one shared helper (desugar_arrayslice /
desugararrayslice) that rewrites the array expr to the explicit full slice
arr[0:len(arr)] — an N_SLICE over the array base. cgen is untouched: the
existing slice lowering (#252/#257/#135 made array bases, incl struct-field
arrays, correct) materialises the borrow header {.ptr=&arr[0], .len=N,
.cap=N}, byte-identically in both stages.
wwstage runs no general call-arg / N_ASSIGN typecheck, so checkassign +
desugarcallargs are added solely to route those two contexts through the
shared desugar (rule-10). desugarcallargs additionally loud-rejects an
element-MISMATCH array into a []T param, scoped to that shape so wwstage's
broader call-arg leniency is untouched.
953_arraytoslice_run covers the four contexts + a borrow-alias proof + the
i32/u8 element axis (dual-stage run + cs==ww byte-id), plus mismatch-reject
rows asserting both stages refuse [4]i32 -> []u8. Regen'd w6c + wwdump
combined.ww (#110).
#259: the tagged-union array-field indexed STORE arm computed &arr[i]
from a non-ident base (`x.o[1]=v` where o:[N](T|void)) with a plain
cgexpr(base) — the N_DOT array field auto-derefs (loads the field's
first 8 bytes AS a pointer) -> garbage dest -> SEGFAULT. Route the base
through the array-gated helper cg_dotbase_addr/dotbaseaddr (dst BX keeps
the scaled index live in AX; viaptr + chained handled by the shared
helper), mirroring #257. Symmetric both stages. This was the last
unrouted cgexpr(base) cell in the array-field-base-address family
(#135/#252/#253/#255/#257) — proof-grep of both stages now shows ZERO
unrouted base cells in the slice/decay/addr/index/store builders, so the
family is closed by construction. (The chained-ptr-field scalar/str/
float store sites at cgenexpr.ww:6489+ / cgen.c:4379+ correctly cgexpr
the pointer spine and are the #133 family, not array-field-address.)
#256: align wwstage dotchainaddr's N_IDENT non-local arm to carry
cstage cg_dotchain_addr's `let_islet || def_isstructdef` guard (here
isletvar || deflookup) instead of emitting LEAQ name(SB) unconditionally.
Unreachable on valid input (a struct-typed chain root is always local /
let-global / struct def) so zero divergent asm — never-silent ethos only.
Tests (949): store-only byte-id rows (tagged_store_own/_ptr) gate the
#259 store base-address emission cs==ww; store+readback rows
(tagged_store_*_rd) are run-only (cstage) proving the store wrote the
right slot (66/77) and no longer segfaults. byte-id on the readback rows
is blocked by an ORTHOGONAL newly-surfaced divergence in the N_DOT-base
tagged-element READ materialization (sibling of #255: wwstage loads one
word + zeroes the tag where cstage copies the full 16-byte slot) — the
store base is already byte-id; only the read-back diverges. Reported
separately for triage.
combined.ww regen'd (w6c + wwdump embed cgen).
An inline slice of a struct `[N]T`-field passed DIRECTLY as a call
argument (`rd(x.o[lo:hi])`) materialized the slice .ptr from the field
VALUE, not its ADDRESS: the pushargs/pushargsrev N_SLICE inline builder's
non-ident else-arm did plain cgexpr(base), so the N_DOT field auto-derefs
(MOVL field,AX used as .ptr) -> callee derefs garbage -> SEGFAULT. The
let-init / assign-rhs / return / hoist-to-local contexts already routed
through the cgslice #252 choke-point; only this call-arg builder kept a
private duplicate. cs==ww both segfaulted identically pre-fix (gate-blind).
Fix (symmetric both stages):
- route the else-arm through cg_dotbase_addr / dotbaseaddr (the cgslice
#252 choke-point: array-field-gated, so `[]T`/str/`*T` fields fall
through to cgexpr; chained inner `o.p.m` handled via its #253 arm);
- extend the N_IDENT-only esz gate to N_DOT bases, taking the element
width from the checker-stamped base->type (rule-13 type table), so
non-u8 call-arg slices scale stride.
Before: `MOVL -8(BP),AX; PUSHQ AX` (field value as .ptr). After:
`LEAQ -8(BP),AX; PUSHQ AX` (field address). cs==ww byte-identical.
Helper note: used dotbaseaddr (not dotchainaddr as first scoped) — it is
the established cgslice choke-point and is array-field-gated, so a slice/
str-typed field base keeps the correct cgexpr header-ptr load; bare
dotchainaddr lacks that gate and would mis-emit the field address for
those. dotbaseaddr already handles the chained `o.p.m` inner via #253.
Tests: test/wcc/949 gains 6 call-arg rows (u8, i32-esz-stride, via-*struct,
chained, + hoist-to-local and bare-local-array controls), each run-
correctness AND cs==ww byte-id.
PROOF-GREP residual: the tagged-union-element indexed-STORE arm
(cgen.c:~4972 / cgenexpr.ww:~5024) is the same N_DOT-base auto-deref shape,
still unrouted in BOTH stages (symmetric, segfaults) — a distinct
consumption axis filed separately; NOT fixed here.
cg_dotbase_addr / dotbaseaddr rejected a non-ident inner, so a chained
base (`o.p.m[i]` / `o.i.m[i]` / `o.a.b.m[i]`) fell to cgexpr(base) which
auto-derefs the array field's first 8 bytes AS a pointer -> garbage base
-> segfault (base64 fillobuf `s.enc.encmap[...]` blocker). Extend the one
helper per stage to accept a chained inner: a new cg_dotchain_addr /
dotchainaddr recovers the container base via the dot-chain spine (recurse
to &x, deref when x is a *struct, sum field offsets), keeping the same
no-AX/no-stack spill contract. dotbaseaddr then takes the pointer VALUE of
inner when viaptr, else its ADDRESS, and adds the field offset. One fix
closes every op (index r/w, addr-of, slice, compound) since all route
through the helper. Symmetric cs==ww byte-id.
test/949: +22 rows. Chained-PTR (rd/wr/addr/slice x2/compound), deeper
(value+ptr leaf links, triple-pointer exercising the internal deref),
non-u8 esz stride (i32 addr+slice), and single-level controls — all
byte-id. The chained VALUE-container arm (`o.i.m`) is run-only (byteid=0):
it needs a value nested-struct instance, which trips THREE orthogonal
pre-existing cs!=ww emission divergences (bare-let zero-init policy,
global DATAW byte count, i32 element-load opcode in the index fallback)
unrelated to #253. Run correctness proves the segfault is gone for that
cell; byte-id there awaits the separate wwstage value-nested-struct fix.
Taking &x.o[i] (address-of) or slicing x.o[lo:hi] / x.o[lo:] of a
struct's [N]T-typed FIELD computed the field's VALUE as the base
address (MOVL off(BP),AX) instead of its ADDRESS (LEAQ off(BP),AX) ->
garbage pointer -> segfault. The index read/write path was fixed in
#135; this is the unwired addr-of + slice sibling — both base-address
paths fell to the generic cgexpr(base) auto-deref.
Wire the #135 cg_dotbase_addr / dotbaseaddr helper into the addr-of
N_INDEX complex-base arm and the N_SLICE base arm, symmetric on both
stages (guarded if(!dotbase) cgexpr(base)). Extend the slice element
stride (esz) and default-hi length to an N_DOT array-field base too,
read from the field's element tinfo / array length via the type table
(rule-13) — so non-u8 element slices scale correctly and s.obuf[lo:]
gets the array's element count.
cstage already derived default-hi via base->type (alen); only wwstage
needed the N_DOT default-hi arm. cs==ww byte-identical on every shape.
test/949_dotbase_addr_slice_run: 7 dual-stage rows (addr-of local +
*struct param, explicit + default-hi u8 slice, non-u8 [4]i32 stride,
bare-local control), run + cs==ww byte-id. Regen w6c/wwdump combined.ww.
`let a:[4]u8=[65,66,67,68]`, `def D:[4]u8=['A',..]`, and `enc{m=[65,..]}`
rejected with "init [4]i32 not assignable to declared [4]u8": an array
literal's element type came from the elements via type_default (int-lit
-> i32, rune-lit -> rune) with no declared-element-type propagation. The
scalar path already narrows (`let c:u8='A'`); only array aggregation at
the let/def/struct-field sites #130 (test 920) left unwired did not.
Fix = the int/rune analogue of coerce_floatlit, realised as the EXISTING
#130 accept-if-fits range-check — NOT a node-type restamp. cgen drives
the array element WIDTH from the declared type at every site (cgen.c
local-let lu->sub, emit_array_data d->type), so a restamp would be dead
code (the array literal keeps its [N]i32/[N]rune node type; the cs==ww
byte-id gate confirms the bytes emit u8-wide regardless). Per element:
foldable int/rune literal -> defcastfits range-check vs declared T
(in-range accept, out-of-range REJECT loud, rule-7); non-foldable ->
type_assignable / isassignable.
cstage (check.c): wire arrlit_init_fits into clet (local let),
struct-field-init, and def-init — the three sites the #130 module-let
path already covered.
wwstage (check.ww): factor checkletassign's inline #130 block into
checkarrlitfits and call it from the let path, the def path, and a
TARGETED array-field walk in the N_STRUCTLIT arm. This also closes a
pre-existing rule-7 wwstage over-accept: the def path ran NO init
assignability check and the N_STRUCTLIT head-stamp parks field
assignability (#23), so out-of-range / str array elements silently
over-accepted (a truncating miscompile) at those two sites. The
struct-field walk is the array-field accept-if-fits ONLY — it reuses the
stable N_TSTRUCT field-list walk (astoffset precedent), isolated from
the broader parked #23 field-assignability walk.
Regenerated w6c + wwdump combined.ww (embed check.ww). New test 951
covers let/def/struct-field x int/rune accept (run + cs==ww byte-id) and
out-of-range/str reject (both stages). test-unit 237 + smoke green.
A struct literal initialising an array-typed field as a local
(`e{ encmap = [..] }`) silently dropped the initializer: cg_structlit_fill
(cstage) / cgstructlitfill (wwstage) had no TY_ARRAY field arm, so the
array field fell to the generic scalar tail — cgexpr the N_ARRLIT (→ AX≈0)
then store one sized word — losing every element. cstage returned 0;
wwstage emitted byte-identical wrong code. (The GLOBAL literal-init path
is unaffected: it goes through emit_struct_lit_bytes, already correct via
#129 A.3.)
Both stages now element-wise store the N_ARRLIT at base+field_off+i*esz,
reusing the proven N_LET array-init shape (cgen.c:8467 / cgenstmt.ww:1393)
for int and float elements plus its `...` repeat fill; esz routes through
the type table (rule 13). str/slice/struct/tagged ELEMENT arrays are the
N_LET path's documented multi-word gap (cgen.c:8462) — converted from the
silent drop to a LOUD rule-7 error in both stages, not left silent.
Symmetric both stages (rule 10), byte-identical .s.
The `...` repeat in a struct-literal array field is checker-unreachable
today (the field type-check rejects `[v...]` length inference — a
separate checker gap); the arm mirrors N_LET's repeat for symmetry.
Test 949_structlit_arrfield_run: +local literal-init reads (idx 0 / last
element), cstage run + cs==ww byte-id.
Reading an array-typed field of a module-global struct value (`G.arr[i]`)
silently miscompiled: the N_INDEX fallback's cg_dotbase_addr (cstage) /
dotbaseaddr (wwstage) helper — the #135 sibling that computes &(s.field)
for a `[N]T` field — had no module-global-struct base arm. cstage emitted
`LEAQ (BP)` (localfind returns 0 for a global, so it read the stack frame
→ 0); wwstage's localfindnode returned nil and the fallback keyed on the
FIELD name, so it returned false and the caller's cgexpr(N_DOT) loaded the
field VALUE as a pointer → SEGFAULT. The .data was already correct
(emit_struct_lit_bytes #129 A.3); only the READ base address was wrong.
Both stages now emit `LEAQ name(SB) (+ ADDQ field_off)` for a global
value-struct base, mirroring the scalar global-field read (cgen.c:7532);
const globals resolve via def_isstructdef. Symmetric both stages (rule
10), byte-identical .s. Unblocks base64's `const std_encoding.encmap[i]`
reads (#22).
Test 949_structlit_arrfield_run: global `let`/`def` struct array-field
read, cstage run + cs==ww byte-id.
cgexpr could not produce a tuple VALUE, so a destructure / let bind of an
RVALUE tuple read garbage past the first element (cstage) or left an untyped
binder aborting wwstage's asserttyped gate — a DANGEROUS gate-blind cs!=ww,
and the strconv-int blocker (Hare's stoi64/stou64 require
`let (sign, u) = parseint(s, base)?`). Three feeders, all routed at the same
SysV register-return cursor the cgmlet/cgmassign consumers already read:
- an N_TUPLE literal fell to the `cgexpr_int(0)` / `MOVQ $0, AX` default;
- a tuple-typed IDENT loaded only word0 into AX (`yield t`, `return t`,
`let q = t`), leaving DX/CX stale;
- the `?`/`!` unwrap of a tuple-in-union payload lifted only word0->AX,
stranding word1 in CX (the scalar/str success ABI).
Fix (both stages, byte-identical per rule 10):
- cgexpr packs an N_TUPLE literal into the cursor (cg_tuple_lit_to_cursor /
cgtuplelittocursor — a byte-identical reuse of cgreturn's in-register
N_TUPLE arm) and a tuple IDENT from its slot at the register-ABI stride
(cg_tuple_slot_to_cursor / cgtupleslottocursor);
- the ?/! unwrap shifts a tuple success payload down one integer reg past
the tag (cg_tagged_tuple_payload_shift / cgtaggedtuplepayloadshift),
loud-stopping a float/slice/str payload element (the SysV per-eightbyte
tagged-tuple-payload classification is #243);
- wwstage's checker recovers the popped match-arm binder type for a
`yield <binder>` operand (matchyieldtype's scope-free fallback to the
arm's declared type), so the destructured binders stamp — cstage reads
the operand's already-stamped ->type, wwstage caches only a tinfo.
Over-cap rvalue-tuple materialisation (no slot to sret a bare expression
value into) loud-stops both stages — the #10 follow-up.
NOT closed (distinct root, deferred to #238/task #6): single-var
`let q = (true, 9u64)` then `q.N` — the N_LET tuple-init sz==16||32 gate
drops a narrow-first mixed tuple, and the N_DOT tuple-field PACKED-offset
reader disagrees with tuple_store's 8B stride. Not the rvalue-into-cursor
fix and not a strconv blocker (strconv destructures); documented at the test
header.
Test 945_rvalue_tuple_destructure_run: literal destructure, match-yield
destructure, and the ?-call strconv shape, each run + cs==ww byte-id on both
drivers (9 checks). Embedded w6c/wwdump combined.ww regenerated.
A mixed-scalar tuple WRAPPED IN A TAGGED UNION (the (neg, n) shape Hare's
strconv parseint returns, ((bool,u64)|invalid|overflow)) miscompiled three
ways, all gate-blind (no bootstrap tuple-in-union):
(a) cstage CONSTRUCTION: a tuple variant fell through the N_RETURN scalar
shuffle, which ZEROED tag + payload — the operands were never packed.
Route the tuple variant through the scratch-slot widen path; add a
TY_TUPLE arm to cg_widen_tagged_store that packs each element into the
union payload at the register-ABI 8B stride + sets the variant tag.
(b) wwstage CHECKER: `let (a,b)=t` over a plain tuple ident (the match-
bound union payload) left the un-annotated binders UNTYPED, so the bin
node reading them was untyped -> asserttyped abort. The element-type
distribution only fired for an N_CALL rhs. Consume the rhs tuple type
for ANY rhs (mirror cstage check.c:2017).
(c) BOTH stages DESTRUCTURE: the register-cursor receive assumes the rhs
left every element in AX/DX/CX (a call's tuple-return ABI). For a tuple
IDENT cgexpr loads only word0->AX, so the 2nd binder read a STALE DX.
Copy each element from the ident's slot at the 8B stride.
Construction is correct at ANY variant position (the resolved tag, not a
default 0); wwstage resolves it via the typeeq core (flatvariantidxt), not
taggedvariantindext whose str/slice shape-fallback would mask a mismatch.
Two rule-7 loud-stops cover shapes this slotted packing can't yet handle,
on BOTH stages, so neither silently miscompiles:
- a tuple with a SysV-eightbyte-sharing narrow pair (e.g. (i32,i32,u64)),
caught by the 8+payload > slot-size guard (the eightbyte tuple
classification is #243);
- a tuple built from a BARE LITERAL element (`true`/`false`, suffix-less
`7`). cstage's cg_tag_for_variant can't type the literal (#241), returns
-1, and loud-stops. wwstage types `true` as bool and `7` as untyped_int,
so flatvariantidxt WOULD resolve the variant — a program cstage rejects
but wwstage accepts is the cs!=ww divergence rule 10 forbids. wwstage
mirrors cstage's CONDITION (a bare-literal element), not its -1
mechanism, with an explicit guard that aligns the richer side DOWN. Lift
BOTH guards together when #241 lands cstage literal typing -> symmetric
accept.
Test 940_tuple_in_union: 4 K_RUN rows (variant 0, void arm, tuple at
variant 1 two ways) x cstage-run + wwstage-run + cs==ww byte-id, plus 2
K_BUILDERR rows (eightbyte-share, bare-literal) asserting a loud stop with
the #242 diagnostic on BOTH drivers = 16 ok.
An over-cap tuple mixing a scalar with slices/str (e.g. (int,[]u8,str),
56B) laid out differently in the two stages — gate-blind, since no
bootstrap path returns such a tuple. Two silent cs!=ww bugs, one per
ABI side:
- callee SEND (cstage cgen.c N_RETURN over-cap-tuple arm): foff
advanced by the LITERAL expression's type size. A bare int literal
element is stamped TY_UNTYPED_INT (size 0), so `e->type->size`
added 0 for a leading scalar — the next element clobbered it at
offset 0 and every trailing element packed 8 bytes low. wwstage
already sized from the return-type tuple (c.fnret.list), so the
callee frames diverged. Fix: size foff from cg_ret_type's tuple
params (rule-13 type table), aligning cstage to wwstage and to the
t.N reader's f->offset.
- caller RECEIVE (wwstage cgenstmt.ww cglet N_TTUPLE arm): the
in-cap register tuple-receive branch had no capacity gate, so a
56B over-cap tuple was received via AX/DX/CX/R8 (+ R8 fill)
instead of from the sret dest the callee wrote. cstage gates the
twin branch on `sz == 16 || sz == 32` and falls over-cap tuples
through to the sret receive. Fix: add the same size gate to
wwstage, aligning it to cstage.
Both stages now emit byte-identical asm and the value round-trips.
Regen w6c + wwdump combined.ww (cgenstmt embeds in both).
New 940_mixed_scalar_tuple_sret_run: leading/trailing/middle scalar
shapes, annotated + inferred let, each self-asserting every element
(scalar direct, slice/str via len) — both drivers exit 0 + cs==ww
byte-id (12/12).
len() special-cased only a plain N_IDENT slice operand (load .len at
BP+off+8) and an array operand (fold $alen); every other shape fell back
to a bare cgexpr(operand), which for a slice leaves AX=.ptr. A tuple-
element read (t.N) loads only AX=.ptr, so len(t.N) on a slice/str tuple
element returned the slice's .ptr word AS its length — a silent
miscompile, gate-blind because the bootstrap never does len() on a
slice-typed tuple element (sibling of the #234/#237 tuple-sret cluster).
Both stages: detect a slice/str tuple-element len() operand and load the
element's .len word directly at BP + element_off + 8, mirroring the
N_IDENT slice arm and the tuple-field-offset walk (element_off sums
preceding element sizes through the type table). Byte-identical asm
(rule 10). The separate tuple-element-read full-header gap is #238; a
leading-scalar mixed-tuple has its own pre-existing sret-layout cs/ww
divergence, filed apart from #235.
Test 903_tuple_elem_slice_len_run: 4 slice/str-only tuple rows (two/
three slices, str+slice, slice+str; distinct lengths), build+run both
drivers + cs==ww byte-id. 12/12 ok.
The STORE-twin of the Fold-B over-cap-tuple sret RECEIVE (a937d67). Fold B
wired single-var-let / destructure / reassign / return-forward to receive a
> 4-eightbyte (sret) tuple-returning call, but a FIELD or INDEXED-lvalue
dest stayed unwired: the store dropped the callee's sret body (a truncated
MOVQ through a stale RDI) — a silent miscompile, gate-blind because the
bootstrap never field-stores a wide tuple.
Per Rob's ruling A (one class, one commit): convert the silent miscompile
into either a CORRECT store or a LOUD stop, never a fall-through.
- cstage cmd/w6c/cgen.c: the struct-field N_DOT store and the N_INDEX
lvalue store each gain an arm keyed on cg_sret_retsize(dest) > 0 &&
rhs == N_CALL. A LOCAL dest (BP-relative, not via_ptr / global) sets
cg_sret_dest_off so the callee's hidden RDI writes the WHOLE tuple
straight into the slot — field: boff + foff; indexed: boff + cidx*esz
(a CONSTANT index into a local value array, the only indexed form whose
dest is a static BP offset). Every other dest fatals "#234-tail".
- wwstage selfhost/cmd/wcc/cgenexpr.ww: symmetric (rule 10). The direct
struct-local field branch sets c.sretdestoff = lc.off + fi.foff; the
via_ptr branch, the global branch, and the N_INDEX arm hard-stop loud
with the same #234-tail diagnostic. The field branches key on
sretretsize(fi.tnode) > 0 (fi.tnode is a real type-AST node). The
N_INDEX arm keys its ENTRY on callsretsize(c, n.rhs) > 0 — the
callee-return-type SSoT (cgenutil.ww) the receive sites use — NOT on
sretretsize(elemtn): elemtn is only a type node for an N_IDENT base, a
VALUE node for an N_DOT base (`s.arr[i]`) / chained (`a[i][k]`), which
fell to sretretsize=0 and let those forms drop SILENTLY through to the
truncating store. The callee return type equals the dest-element type
(checker-guaranteed), so the verdict is byte-identical to cstage's
cg_sret_retsize, and the base-shape split then loud-stops every
non-local-array form, base-kind-independent.
Deferred (#234-tail): a via_ptr field (`p.f`), a global field (`g.f`), an
N_DOT-base index (`s.arr[i]`), a chained index (`a[i][k]`), and a runtime /
slice / pointer index all need a runtime RDI-pointer dest, which
cg_sret_dest_off (BP-relative only) can't express — they hard-error loud
(rule 7), never a truncating store.
Depends on #237 (committed first): the wwstage struct-field slot for a
tuple field is only correctly sized with that fix, so the struct-field arm
is byte-id-symmetric here.
Test 940: indexed-on-local and local-struct-field rows RUN on both stages
(exit 0) AND assert cs==ww byte-id; readback via a raw pointer
(`(&dest):*int; p[i]`) since a tuple-element read `dest.N` is a separate gap
(#238). Builderr rows assert the via_ptr / global / runtime-index /
N_DOT-base / chained-index forms loud-stop with #234-tail on BOTH drivers
(the N_DOT-base + chained rows are the regression witnesses for the wwstage
silent-store gap closed by the callsretsize re-key). The bootstrap exercises
no such store, so the w6c/wwdump combined amalgams regen with no asm change
(byte-id-neutral bootstrap; the new hard-error never fires self-compiling).
Fold A made the CALLEE emit an over-capacity tuple return (> 4 GP or > 2
SSE eightbytes) via sret, but every receive site stayed loud-stopped, so
such a fn was not yet usefully callable. Fold B wires the call/receive end
by aligning every receive gate UP to the shared cg_sret_retsize() /
callsretsize() > 0 predicate (never a kind), per Rob's (B) ruling:
- single-var-let `let t = f();` cstage gate generalised from
TY_STRUCT&&>24 to cg_sret_retsize(lt)>0; the let's slot IS the
sret dest, the callee writes the whole tuple there, t.0/t.1 read
by offset. wwstage already keyed callsretsize (verified).
- N_ASSIGN-ident `t = f();` same generalisation; global arm
kept TY_STRUCT-only (a tuple-global has no sret-to-symbol path in
either stage). wwstage grows a tuple-local arm (rettupleof gates
it apart from the >24B-struct recv, which keeps its own path).
- destructure `let (a,b) = f();` and `a,b = f();` — the genuinely
new wiring: the callee sret's into the @sretscr discard slot, then
a copy-out loop moves each element to its binding at the SAME
packed offset the SEND wrote (foff += element size), each at its
natural width (#169); a `_` binding skips its store but advances
foff. Both stages, byte-identical.
- return-forward `return f();` cstage forward gate generalised
to the predicate, reusing cg_sret_forward verbatim. wwstage
already keyed sretretsize (verified).
The escape boundary stays loud: arg-pass `g(f())` fatals identically in
both stages (tuple arg exceeds return-cursor ABI capacity).
Test 799 is the runtime net Fold A deferred (byte-id is blind to a
SEND/RECEIVE layout mismatch): the bytes.cut-shaped ([]u8,[]u8) round-trip
over destructure / single-var-let / reassign / return-forward, each both
RUN under cstage and asserted cs==ww byte-identical. Tests 945 (row F)
and 956 (f64x3) flip from asserting the old over-cap loud-stop to
asserting the now-working sret round-trip. combined.ww amalgams (w6c +
wwdump embed the wcc cgen) regenerated. Unblocks #4 bytes.cut/rcut.
A tuple return whose SysV register-return footprint exceeds the caps
(> 4 integer eightbytes or > 2 SSE eightbytes) previously LOUD-STOPPED
at the N_RETURN SEND. Fold A makes the CALLEE emit such a return through
the existing >24B-struct sret skeleton:
- classifier (cg_sret_retsize / sretretsize) grows a TY_TUPLE arm:
walk the element footprint over the SAME caps the SEND uses, and
return the tuple's natural total size (type table) when over-cap,
else 0. The gp/sse caps are factored to a single shared SSoT
(TUPLE_GPCAP / TUPLE_SSECAP — cgen.c macros in cstage, cgen.ww defs
in wwstage) consumed by the classifier AND every emit/receive site
(the SEND, the destructure guards, the cgcall arg guard) — so
classify and emit can't disagree in either stage.
- the SEND replaces the loud-stop with a write-through: cgexpr each
element, store it through *(@sretarg) at its packed layout offset
(the t.0/t.1 positional layout), each at its natural width so a
narrow tail stores MOVL/MOVB not an over-MOVQ (#169); the dest base
reloads into DX each step since a wide element clobbers AX/BX/CX.
Then the existing struct-sret epilogue (MOVQ @sretarg->AX; ret).
- the prologue already wires @sretarg when the classifier is nonzero.
The CALL/receive side is deliberately untouched: the N_MLET/N_MASSIGN
destructure loud-stops stay, so an over-cap tuple return is not yet
usefully callable. The end-to-end round-trip arrives with Fold B (#10-B).
Symmetric cstage (cmd/w6c/cgen.c) + wwstage (cgen.ww / cgenstmt.ww /
cgenutil.ww); combined.ww amalgams regenerated. Test 798 asserts the
callee now COMPILES (no loud-stop) and w6c vs w6c_ww .s byte-identical
across all-wide, str, narrow-tail, and float-over-cap shapes; no runtime
row (uncallable until Fold B). All 236 pass incl. 990-997 byte-id.
len(str-or-slice-global) was wrong in both stages, differently. cstage's
len() arm did a BP-relative slot load; localfind returns 0 for a global,
so it emitted `MOVQ 8(BP),AX` — a bogus stack slot. wwstage's arm only
handled locals; a global fell through to cgexpr, which loads the whole
header and leaves AX=.ptr, not .len.
Both stages now emit the global .len load — LEAQ name(SB),CX; MOVQ
8(CX),AX (.len field; header is ptr@0/len@8/cap@16). The LEAQ symbol
routes through the post-#1 value mangle (cstage mahint c->cur_mod,
wwstage emitsymnamehint c.curmod), not a raw name, so a private
same-module same-leaf str global can't re-open the #1 collision.
The local-str case is unchanged (control). Slice-global rows wait on
#233 (cstage rejects `let g: []u8 = [...]` init); the str global proves
the path. Byte-id-blind, so a committed runtime + cs==ww test (797) is
the net.
The cross-module dotted value-global read (`aa.v`) and addr-of (`&aa.v`)
still mangled their symbol via the non-preferring leaf lookup (cstage
masym / wwstage emitsymname), so they emitted `LEAQ main.v(SB)` — the
WRONG module's same-leaf global — returning 99 instead of 7. #1 fixed the
DATA def-site and the bare-ident load; these four dotted LOAD/addr sites
were the residual.
Thread the dotted module name (the `m` in `m.x`) — n->lhs->str /
opnd->lhs->str / lhs.str / basenm — into the existing value mangle
(cstage mahint, wwstage emitsymnamehint), the same polarity the TY_FN
branch beside each site already uses via mafn/emitfnname. The addr-of
spine-walk for a bare-root `&global.field` is a different shape and is
left untouched.
Byte-id-blind (the bootstrap has no colliding leaves), so a committed
runtime + cs==ww test (796) is the net.
A bare cross-module value-global load mis-qualified its symbol: cgen
mangled it with curmod via a non-preferring leaf lookup, so an exported
`let v` in module aa emitted both its DATA storage AND its bare-load as
main.v, colliding with main's private v. aa.getv() returned 99, not 7.
Functions were already correct (they thread a cur_mod hint via mafn /
emitfnname); value-globals did not. Both stages emitted IDENTICAL wrong
asm, so the byte-id gate was blind to it; combined.ww (frontend) is clean
-- the bug is purely in cgen. This is the cgen residual of #55 (#1 cgen
value-global module-qualifier).
Fix, symmetric in cmd/w6c/cgen.c + selfhost/cmd/wcc/{cgen,cgenexpr}.ww:
reference-site mangle uses the resolved module (curmod-prefer for bare
idents); definition/DATA-site mangle uses the decl's own module
(d->module / d.nmod) -- threaded per-site the way fns already do, via
mahint / emitsymnamehint. The fn-mangle path is left byte-for-byte
untouched.
Deviation from the signed-off spec (ratified by rob-pike after this
finding): the spec prescribed reusing the fn lookup (mod_mangle_fn /
modlookupforfn), but its first-match fallback mis-fires for value-
globals -- mod_collect export-skips exported non-fn decls (cgen.c:1059)
to keep their bare-name data ABI, so an exported leaf is absent from the
module map and the fallback grabs another module's same-leaf private
global. The value path therefore uses a distinct exact-(name,module)-or-
bare lookup (mod_lookup_value / modlookupvalue): mangle only on an exact
match, else stay bare. Byte-id-neutral on all existing single-owner code;
exported globals stay bare (ABI preserved), private stay module-qualified.
Honest boundary (rule 7): if two modules BOTH export the same value leaf,
both stay bare and the linker sees a duplicate symbol -- a correct, loud,
link-time ABI clash (like C), NOT a silent miscompile; left to the
linker, not papered over with a cgen heuristic.
Test: test/wcc/795_xmod_valglobal_run.c -- runtime (the exported global
read returns its own value, not the colliding private one) + cs==ww
byte-id, across i32-let / def-const / f64-let. Sibling to the checker
test 794_xmod_ident_prefer, which deliberately omitted byte-id because
this cgen bug diverged the asm independently.
cg_widen_tagged_store (cmd/w6c/cgen.c) and the wwstage twin cgwidentaggedstorebp (selfhost/cmd/wcc/cgenutil.ww) wrote only the tag (slot+0) and value (slot+8) in their scalar and float arms, leaving the high pad words (slot+16..sz) as stack garbage on the BP/let/assign/return-scratch path, which never pre-zeroes. A passthrough return or u8-reinterpret of a narrow scalar/float widened into a >16B union (fmt's field = (...formattable | *mods) is 32B via the str variant) then read that garbage. Both stages were wrong identically, so the byte-id gates stayed green while the runtime truncated; fmt's spread-union scalar widen is the first real consumer. Both arms now tail-zero slot+16..sz (gated size>16), mirroring the tagged-subset/struct tail-zeros and keeping the stages byte-identical (rule 10). Adds runtime test 793; regenerates w6c/wwdump combined.ww. fmt byte-id graduation still awaits the other residual, #226 (io.read nominal-remap).
resolve_typename used the kind-blind scope_lookup_prefer, so a same-named value binding (param/let) in a closer scope hid the type it shadowed, wrongly rejecting valid Hare like 'fn f(off: off)'. wwstage already separates type/value namespaces; this aligns the cstage frontend up. New scope_lookup_type skips non-SK_TYPE syms and keeps scanning, preserving same-module preference. Byte-id-neutral: the new branch fires only on the old 'unknown type' error path.
Variant selection (cg_tag_for_variant / flatvariantidxt) matched union variants by exact type only, so widening a bare value (e.g. *vtable) into a union with a NAMED ptr-alias variant (stream = *vtable, in handle = (file | stream)) found no match and the tag defaulted to 0 -- the wrong variant. In the compiler this hit emitbytes' io.write(&cgoutstream.vt) once io.write took a handle, writing the asm to a garbage fd -> empty .s -> w6c_ww miscompiled everything. Add a second selection pass: when the exact pass finds no variant, structurally compare the bare source against each NAMED-alias variant's unwrapped type; exact-match still wins in pass 1 (so a bare i64 stays the i64 variant, not oserror=!i64, which kept the os/errno union building). A >=2-structural-match collision guard (extending #218's) hard-errors LOUDLY on genuine nominal ambiguity (two ptr-aliases to the same struct) instead of silently first-picking, citing #199b/#10. Symmetric across cstage (cmd/w6c/cgen.c) and wwstage (selfhost/cmd/wcc/cgenutil.ww). One-level NAMED unwrap (chained ptr-aliases unmatched, unexercised -> #17). Adds test/wcc/789 (positive widen byte-id+runtime + degenerate-ambiguity reject guard, both stages). Unblocks post-eFinal #5's handle surface. rule-10 fix-up.
Assigning a >24B by-value struct-return into a GLOBAL lvalue dropped the
struct body: the sret dest was routed to a BP scratch temp and only the
8-byte return pointer was stored (`MOVQ AX, g(SB)`); the callee wrote the full
struct to the scratch, which never reached the global. A BP-relative dest
offset cannot name a global symbol. Pre-existing GATE-BLIND silent miscompile
— both stages emit the same broken store, so byte-id (990-997) stays green
while runtime is wrong — latent until the eFinal io surface put a global
`cgoutstream: memio.stream` (>24B) on the path, where it made cgen.ww's
self-built w6c_ww buffer every function body into a corrupt global (pos stayed
0) and emit prologue-only output.
Fix, both stages, byte-identical: route the sret dest pointer to the global
symbol so the callee writes the full struct through RDI straight into the
global. cstage adds cg_sret_dest_sym, mirroring the existing str/slice global
arm (skip the @sretscr scratch, emit `LEAQ masym(sym), DI`). wwstage carries
the lhs IDENT node (sretdestnode) and emits `LEAQ name(SB), DI` via emitsymname
— identical to cstage's symbol mangling, verified cs.s==ww.s on the probe and
across 990-997. #211-family (by-value struct + global/pointer), but a distinct
site: the cstage assignment-store into a global, not the wwstage call-return.
N_LET-global static-init (`let g: T = mk()` at top level) is a separate,
independently-broken path (#221) — link-fails for init-via-call, returns 0 for
constant init — not the sret-receive gap and not on the eFinal path; deferred.
test/wcc/940_global_sret_run: global assign (plus a branched callee to defeat
const-fold), through-pointer mutation (the io vtable-callback shape that
surfaced this), and local-init/assign regressions — runtime asserts on both
stages (the net, since byte-id is gate-blind here) plus cs.s==ww.s.
Discrimination confirmed by revert+rebuild: with the global arm disabled,
global_assign emits the truncated store and exits 1.
The outer widen of a NAMED multi-variant union value into an enclosing union
mis-tagged: the store took the tagged-subset path (inner value at slot+0 plus
a sub-variant remap, collapsing every inner sub-variant onto outer tag 0),
while the match-extract reads the nested layout (outer tag at +0, inner 16B
value at +8). Store and extract disagreed, so the match selected the first
arm. Pre-existing silent miscompile, latent because error-origination sites
(`let e: io.error = <leaf>; return e`) were gate-blind — no test discriminated
a freshly-originated error at a branched caller; the io vstream surface is the
first to do so.
Fix, both stages, byte-identical: cg_variant_match (cmd/w6c/cgen.c) and its
wwstage mirror cgvariantmatch (cgenutil.ww) fall back to structural equality
of the unwrapped tagged unions when the alias collapse loses nominal identity
(a NAMED outer variant vs an unwrapped-tagged source); the widen store now
writes the inner value at slot+8 and the outer tag at +0, matching the
extract. The inner union's build/payload/extract already worked (a destructure
through the outer round-trip recovers the inner payload) — only the
outer-widen store was wrong.
Collision guard (the fallback is unsound without it): structural matching
cannot disambiguate two nominally-distinct same-shape variants in one outer
union. That is unreachable under today's nominal-lossy collapse but inverts
the moment #199b lands the nominal layer, so if >=2 outer variants
structurally match the source we hard-error at compile time citing #199b —
both stages, an enforced invariant rather than a "rare, trust it" assumption.
Folds #219: the wwstage tinfo typeeq (lib/ww/typ.ww) had no TY_TAGGED branch
and fell through to `return true` (any two tagged unions compared equal);
cstage type_eq (type.c:269) has the structural branch. The structural fallback
above is the first and only caller to compare two bare tagged unions, so #219
is unexercised — and therefore ungateable — in isolation; it folds here per
the rule-11 couldn't-split carve-out (same structural reason as #206's
N_TTUPLE fold). The added branch mirrors cstage type_eq, tightening wwstage
into alignment.
test/wcc/925_nested_union_widen_run: outer-arm select, destructure-after-
propagation (payload survives the round-trip), destructure-let, single-variant
control, and the collision-guard compile-error, each with a cstage==wwstage
byte-id check (the path is gate-blind). Interim until #199b/B-full lands the
true nominal wrapped-slot layout.
A bare `&fn_name` was not assignable into a `*reader` / `(*reader | void)`
vtable field without an explicit cast: cstage type_eq on TY_NAMED is
pointer-identity, so a structural `*fn(...)` referent never matched the named
`*reader` variant; wwstage accepted it only via an accidental catch-all
leniency. harec accepts bare &fn through hint-directed alias adoption at the
address-of site (check.c:3594-3626) while keeping pointer assignability
strictly nominal (types.c:1039-1066), so a materialized `*fn` value never
launders across alias names.
Mirror that decision without threading a type hint through the bottom-up
cexpr: keep type_assignable / isassignable fully nominal, and add a
caller-site helper (assignable_addrfn) at the assignment boundaries
(let-init, struct-literal field-init, assign, return, call-arg, array
element) that accepts iff the rhs is a DIRECT &-of-fn-ident and the
destination (or exactly one tagged variant) is a pointer-to-fn-alias whose
underlying fn signature structurally matches. A materialized `*fn` value, a
distinct same-signature alias, and an ambiguous multi-variant target all stay
rejected. Both stages share the rule; wwstage's lenient pointer-fn punt
becomes a confident reject. ww has no methods, so a `value.leaf` slot is only
ever a fn-pointer field and this never over-admits.
The tightening surfaced a wwstage typeeqast gap: a TY_FN result that is a
tuple (`*fn(...)(i32,i32)`) compared false where cstage type_eq handled it,
newly rejecting a legitimate structural assign. Add the N_TTUPLE structural
case (rule-10), restoring test 766.
cgen-neutral (the cast was a no-op reinterpret); pre/post bootstrap .s
zero-delta. Test 783 covers the positive paths (incl. a byte-id-clean
three-field-vtable dispatcher) and the negatives. Tagged-slot negatives
(ambiguous / tagged-laundering) are rejected on cstage but wwstage's separate
`(X|void)` void-variant leniency (#214) still admits them; 783 pins them
cstage-only, to graduate when #214 closes (required before wwstage becomes
the authoritative selfhost checker).
Note: `make clean && make test` is RED at HEAD on 4 alloc fixtures
(700/748/758/915) via a pre-existing clean-build defect (#215, malloc vs
rt_malloc); identical with or without this change, so bisect-clean for #206.
The tagged→tagged subset arm walked src's leaves against dst's flat
variant list, so `let r: (size | eof | wrapper) = e` with e: wrapper
REJECTED at cstage's checker — wrapper's leaves (unsupported, underread,
nomem) aren't direct variants of dst. Wwstage's permissive tail
accepted silently but cgen then miscompiled the tag (#199b layout-
extension family, deferred).
Mirror the concrete→tagged fix from #199 (α) at type.c:316: when src is
a NAMED-tagged wrapper and dst has a direct NAMED-tagged variant equal
to src, accept by nominal identity BEFORE the subset loop. Wwstage's
isassignable mirrors the structural insertion before the existing
`*confident = false; return true;` tail (deferred-tightening per #202).
SSoT with `is`/`as` non-recursive variant lookup (#198 family).
Cgen's tag-remap for the wrapper-as-whole case still maps src variants
to dst tag 0 — the wrapped-slot layout for `dst.tag = variant_idx,
dst.payload = src` is #199b future-work. Probe verifies checker-accept
+ runtime exit-clean only; does NOT inspect the resulting variant tag.
Probe 774_tagged_widen_named_variant.c covers 5 rows: bug-repro,
nested-wrapper, pure-leaf subset (regression), concrete-unrelated
rejection (gate), branched callee. Two sibling cgen/checker bugs
surfaced (wwstage cgwidentaggedstorebp ssz<slot_sz pad gap; wwstage
isassignable !void-alias collapse) and documented inline at the
probe-row comment, kept in #202 family.
cgen has no wrapped-slot layout — the tagged-union slot is universally
[tag:8B][payload:up_to_24B], single level. The recursive walk admitted
let r: (size|io.eof|io.error) = u for u: io.underread (transitively
in io.error.params); cg_tag_for_variant + taggedvariantindext don't
recurse, returned -1, defaulted to tag=0, and the slot read back as
variant 0 = size at runtime.
Restores SSoT inside the checker pair: is / as / match variant
lookup is already non-recursive (#198 sibling), and the LET-init /
return / assign arms now agree. Aligns DOWN to the leaner side
(rule-10 stage symmetry). ww-stricter than Hare; harec keeps the
drill at ref/harec/src/types.c:702-739 (#199b is the deferred
wrapped-slot layout port).
Pre-flight audit (drew mandate): zero transitive-widen sites in
lib/ + selfhost/ + cmd/ + examples/. No wrapper-tagged variant
(io.error, strconv.error, fmt.field) is used as a variant of a
wider union anywhere in bootstrap. Mechanical fix.
Escape hatch for callers: spread (...wrapper) inlines the wrapper's
flat variants into the parent set at parse time. Wwstage's gate
additionally preserves the recursive drill on op == TK_ELLIPSIS
because wwstage stays AST-keyed (cstage flattens at resolve_type).
771_widen_transitive: 5 rows (reject_transitive_widen,
spread_alt_widen, direct_flat_variant, branched_callee_widen,
wrapper_typed_widen). Row 2 is CS-only — wwstage's is / match on
spread-expanded variants is open-bug #190/#198.
Pre-fix the N_UN TK_STAR arm applied the generic pointer-load
`MOVQ (AX), AX` to a *fn operand. cgexpr on the operand already
left AX = fn-addr (post-#180 LEAQ); the spurious second load
read the first instruction word, and the subsequent CALL AX
jumped through that junk address and segfaulted.
Cstage: cmd/w6c/cgen.c N_UN TK_STAR opens with a TY_NAMED-peel
+ TY_FN early-break — leave AX as the fn-addr cgexpr produced.
Wwstage twin in selfhost/cmd/wcc/cgenexpr.ww cgun TK_STAR walks
the n.type_ tinfo chain the same way (TY_NAMED peel then TY_FN
check) and returns before the generic load. Mirrors
ref/harec/src/check.c expr_call's STORAGE_POINTER→STORAGE_FUNCTION
path (harec skips the deref since the pointer IS the address).
Both stages must land together per rule-10 (cstage-only would
break 990-997 byte-id gates — same lesson as #180).
Probe: test/wcc/765_star_fn_deref.c, 5 rows table-driven —
minimal / branched-callee / alias-chain / fn-with-args /
fn-tuple-return. Every row is cstage-only via stage_mask
because wwstage's checker bails asserttyped on `(*f)(...)`
(filed as #181 — N_CALL type_ stamp gap on deref-call); #181's
own probe will lock the wwstage runtime once the bail lifts.
Gate-blind risk (ken's note): byte-id alone cannot catch this
class because both stages drop the SAME instruction
symmetrically, so cs.s == ww.s holds either way. Runtime
exit-code is the only correctness net here.
Combined.ww regenerated for selfhost/cmd/{w6c,wwdump}/main.
combined.ww per #110 freshness gate.
Pre-fix the N_UN TK_AMP arm fell through silently when the operand
was an N_IDENT naming a top-level function — the let/def cascade
had no TY_FN branch, so the store at the assign site picked up
whatever AX held from prior code (commonly a stale arg register).
A subsequent (*f)(...) jumped through that junk and segfaulted.
Cstage: cmd/w6c/cgen.c N_UN TK_AMP IDENT adds a TY_FN arm before
the let/def cascade, mirror of the read-arm at line 2330 — same
mafn(opnd->str, c->cur_mod) shape. Wwstage twin in selfhost/cmd/
wcc/cgenexpr.ww cgun TK_AMP IDENT uses the analogous predicate
fnretlookup(c, nm) != nil + emitfnname(c, nm, c.curmod), matching
the cstage emit on byte-id. Both stages must land together per
rule-10 (cstage-only breaks 990-997 byte-id gates).
Combined.ww regenerated for selfhost/cmd/{w6c,wwdump}/main.combined
.ww per #110 freshness gate.
Probe: test/wcc/764_amp_fn_ident.c, 6 rows table-driven —
minimal / branched-callee / alias-chain / fn-with-args / fn-tuple
-return / cross-module. Rows 1-5 gate both stages (run + .s LEAQ
check + cs.s == ww.s byte-id); row 6 cross-module is cstage-only
because wwstage bails asserttyped on `&mod.fn` (sibling project
#184, filed). Per drew option (b) the probe exercises the address
-of without (*f)(7) — deref-call runtime coverage stays with
project #181's probe once the wwstage asserttyped bail on
N_CALL(*f) is lifted.
Phase 1 cross-mod verdict = FINE for cstage (LEAQ emits via the
already-present N_DOT TK_AMP branch at cgen.c:2477-2493); WWSTAGE
fails asserttyped on the same shape → project #184.
The RETURN twin of #165: a qualifying float-struct was returned GP-only
(struct{f64,f64} in AX/DX instead of X0/X1) — value-correct via GP transport
but not SysV register-class conformant. Route each float eightbyte through the
SSE return cursor (X0/X1) and each integer eightbyte through GP (AX/DX) via
independent cursors, at the struct-return SEND and RECV, both stages, reusing
struct_float_class verbatim. Closes the temporary tuple-SSE/struct-GP
divergence opened across #164/#165.
A qualifying struct has >=1 lone f64 so maxalign is 8 and the ABI slot is an
8-multiple — no sub-8 tail — so #169's sized tail is unreachable here and the
integer eightbyte uses a full MOVQ (cstage agrees, proven by the f64i32
cs==ww byte-id). f32 / multi-float-per-eightbyte stays GP (deferred #171b);
>16B stays sret.
Gate-blind and value-correct, so the discriminator is the SEND/RECV register
class (MOVSD X0/X1 vs MOVQ AX/DX) — covered by probe 946_structret_run.
struct params were passed GP-only, so a struct{f64,f64} argument landed in
DI/SI instead of X0/X1 — value-correct for internal ww calls (the bits
round-trip) but not SysV register-class conformant. Add a per-eightbyte
classifier (struct_float_class) routing a qualifying struct's float eightbytes
through the SSE arg cursor, reusing #163's dual-cursor plumbing and #164's
field classification. A struct qualifies only when every eightbyte is
pure-integer or a lone f64 exactly filling it (and >=1 f64); anything else —
any f32, multiple floats per eightbyte, a straddling or aggregate field —
falls back to the unchanged GP path (f32 sub-eightbyte packing deferred #165b).
Both stages' predicates are alias-aware and identical in coverage.
Gate-blind and value-correct either way, so the discriminator is the callee's
receive instruction (MOVSD vs MOVQ), scoped per-function — covered by probe
946.
Tuples were unhandled as parameters — no tuple arm in arg-push, arg-pop, or
callee-recv in either stage — so a tuple param fell to the 1-GP-word else and
dropped all but its first element (integer tuple params too; floats doubly
lost). Add tuple-param arms (SEND push+pop, callee RECV) across both stages,
reusing #164's per-element SysV classify with the 6-GP (DI,SI,DX,CX,R8,R9) +
8-SSE (X0-X7) arg cursors. A frame slot @tupargscr decouples the producing
call's return cursor from the overlapping arg cursor (capture-before-clobber).
Overflow (>6 GP / >8 SSE) fails loud (rule 7). Scoped to the N_CALL producer;
first-class tuple values (ident/literal) remain a separate unimplemented gap.
Gate-blind (the bootstrap passes no tuple params) — covered by table-driven
probe 905, which proves pre-fix element-drop and the loud-stop.
A multi-float tuple return mis-routed: SEND pushed a stale AX leaving the
float stranded in X0, while RECV (#105) read every float from X0 — so a
(f64,f64) return collided both floats. Add an SSE cursor [X0,X1] parallel to
the GP cursor [AX,DX,CX,R8], placing each element by its SysV class +
within-class index (ref/qbe/amd64/sysv.c retr), symmetric send/recv across
both stages, via a generic tuple_store/tupstore+tupsse helper that #171 will
reuse for struct-return convergence. (f64,f64,f64) = 3 SSE eightbytes exceeds
the 2-register cap and now fails loud (rule 7) rather than colliding.
Unifying the 16B and 32B whole-tuple-single-var branches onto the dual cursor
was required for f64+str coexistence; it also fixes a latent str-first
single-var bug (the old 32B branch read .ptr from DX while the send placed it
in AX). No str-first or 32B tuple exists in-tree, so integer paths stay
byte-identical (990-997 green).
cstage spilled f32 args via MOVSD (8-byte); ABI-correct is MOVSS (4-byte,
single class) per SysV (ref/qbe amd64/emit.c:524 — slot-copy-through-XMM
follows the float class). wwstage already emitted MOVSS; align cstage up
via op_for(node_isf32) at the arg PUSH (cgen.c:5366) + POP (cgen.c:5469).
Byte-id-only divergence (callee reads the f32 param low-32 regardless),
but it blocked cs==ww — closes the f32-arg-push half of the float-register
family (#119/#122/#125/#157). Bootstrap-NEUTRAL (no f32-arg caller in the
990-997 gated path). Test 907_f32arg_run (f32-arg push single/multi/mixed/
stack, cs==ww byte-id). Make test 187/187 incl 990-997.
Unblocks fold-5b (strconv f32tos passes f32 to f32bits).
The N_RETURN tagged-pack scalar-variant arm did MOVQ AX,DX, but a float
variant's value is in X0 not AX -> packed stale int (broke stof64/stof32
return (f64|invalid|overflow)). Fix: float variant bridges X0->DX via a
stack slot (SUBQ $8,SP; MOVQ $0,(SP); MOVSS|MOVSD X0,(SP); MOVQ (SP),DX;
ADDQ $8,SP), gated type_isfloat/exprfloatkind. No MOVQ-xmm->gp form
exists, hence the spill (715-class, cgreturn-register-pack twin of 715's
store-to-slot). Zero-slot-first -> deterministic f32 high-4. AX-independent
-> also resolves the multi-variant cs!=ww. Bootstrap-NEUTRAL (compiler has
no float-tagged-return). Test 707 +3 rows (f64/f32/multi, slot+8 bit-exact;
f32 no-f32-arg to isolate #143). Make test 184/184 incl 990-997 byte-id.
Close A.3's deferred shape-14 (nested array). (a) emit_array_lit_bytes
gains a TY_ARRAY-element arm (mechanical clone of the TY_STRUCT-element
arm — recurses; esz=etype->size, rule-13; ...-nested loud-reject). (b)
double-index read tbl[i][j]: when the indexed element is TY_ARRAY, leave
the sub-array ADDRESS in AX instead of dereferencing (sister of #135's
N_DOT-base fix, on the N_INDEX path) — new elemisarrayc/tinfoisarray
helpers, both stages. Storage + read = one 2D-end-to-end concern (A.2/A.3
storage+LOAD precedent).
Unblocks strconv fold-4's powers_of_ten[596][2]u64 (direct double-index
access). Bootstrap-NEUTRAL (new arms gate on TY_ARRAY-element; 1D
consumers byte-identical, 990-997 green). Test 919 +2D rows + 3D +
...-nested-reject. Deferred siblings: #155 (sub-array bind / whole-
aggregate copy), #160 (global-struct-field index base).
Extract emit_array_data + emit_array_lit_bytes helpers (both stages,
mirrored) for module-level let/def with N_ARRLIT initializer or no-rhs
zero-init. Two-pass validate-then-emit: validate pass walks elements
and fails atomically on any non-foldable element (no partial-byte
emit on failure); emit pass writes element bytes after success.
Element-kind dispatch: integer via fold_int_literal byte-for-byte
preserved from pre-A.3 inline arm (bootstrap NEUTRAL — 6 live consumers
in lib/os/bufio/strings/encoding-utf8/strconv-stof_data), float via
inline bitcast + sign-XOR byte-loop (A.1 shape, no INT64_MIN — sibling
#144), struct via recursion into emit_struct_lit_bytes (A.2 helper).
Out-of-scope element kinds (ptr-elem, nested-array) rule-7 fatal.
emit_struct_lit_bytes gains TY_ARRAY field arm calling emit_array_lit_
bytes recursively — closes A.2 parked shape-15 (array-in-struct
`def D: dt = dt{tag=42, buf=[1u8,2u8,3u8,4u8]};`).
LOAD-side widened symmetric to A.2 precedent: cstage cgindex N_INDEX
direct-ident isglobal gate widened via new DefArray registry
(def_isarraydef populated in let_collect parallel to DefStruct);
wwstage cgindex N_INDEX falls through to defvartnode on letvartnode nil
(reads defent.dtnode field added in A.2). Both stages materialise
array-def via LEAQ name(SB) same as array-let.
Mid-impl rule-7 stop: refactor initially routed only rhs==N_ARRLIT
through emitarraydata, leaving nil-rhs zero-init arrays (e.g.
`let f64tos_buf: [64]u8;` in lib/strconv) silently SKIPPED → undef-ref
at link of wwstage-rebuilt selfhost binaries. Caught on first gate run
via bootstrap 994/995 RED. Fixed by adding nil-rhs branch to
emitarraydata (zero-fills arrt.size bytes) + widening wwstage caller
to route both N_ARRLIT and nil through helper. Same-class-lower-stratum
pattern (recurring across A.1 N_UN-peel, A.2 sz==8-short-circuit, A.3
nil-rhs-drop); banked as feedback memory.
Test 919 (11 rows: int-elem 1B/4B/8B + signed-N_UN-peel + float-elem
f64/f32 + def-int / def-float / struct-with-array-field shape-15 +
explicit-zero + single-elem-regression) registered. Make test:
182/182 incl. 990-997 byte-id + combined_ww_fresh.
Followups filed:
- #43 — wwstage emitletdataw str/slice-size arms lack !isarr guards;
hypothetical no-rhs [16/24]u8 triple-emits (NOT A.3-introduced;
no live consumer; 2-line parity fix)
Fix value-loss bug introduced as a #122 boundary in the float
arr[i]=v store: when the index sub-expr clobbers X0 (e.g.
`a[geti()]=1.5f32`), the value is lost. Mirror the scalar-deref
X0-spill template (cstage cgen.c:4187; line shifted from the brief's
stale :3859 cite by intervening #133/#135/#138 commits): for float
element only, replace PUSHQ AX (junk for floats — value is in X0)
with SUBQ $8,SP + MOVSS/MOVSD X0,(SP) before the idx/base eval;
mirror replace POPQ AX with MOVSS/MOVSD (SP),X0 + ADDQ $8,SP after.
Wwstage parallel. Non-float keeps PUSHQ/POPQ AX so the str/slice
3-word {ptr,len,cap} pop order at the end of the branch is preserved.
#122 trailing-store comment updated from "Deferred to #125" to a
positive cite.
Test 916: 5 rows — f64_call_index + f32_call_index canonical repros
(geti's body clobbers X0; pre-fix exit=2 from post-call residue,
post-fix exit=1 from the spilled 1.5) + f64_lit_index / _localvar /
_arith control rows for non-X0-clobbering index paths. f32_call_index
uses an int-arg call to dodge the sibling cs/ww f32-arg-push
MOVSD-vs-MOVSS divergence (#143, task #36 — orthogonal, filed).
Bootstrap NEUTRAL (zero current float arr[i]= callers in lib; only
[N]u8 byte-buffers like f64tos_buf). cs==ww byte-identical both
stages (990-997 + 916 inline cmp). Closes the #122 boundary-doc
loose end; completes the #122 family.
Fix segfault-class memory corruption on `module.array[i]` indexed-read
where both stages emitted MOVQ-not-LEAQ on the module-qualified base
plus wrong stride. Extends the #135 cg_dotbase_addr/dotbaseaddr helper
to handle the SK_USE module-ident-base case: when bt is NULL/ty_err
and let_islet(base.str) resolves to TY_ARRAY, emit LEAQ base(SB),dst
instead of MOVQ. Wwstage parallel via letvartnode/N_TARRAY check.
Stride fix via let_var_type fallback in cgindex when n.lhs.kind==N_DOT.
Use-site fix per #135 precedent (Option B); preserves cgdot's MOVQ
semantics for the whole-array-assign defensive case (zero current
consumers). Test 915 carries 3 module-u16 indexed-read rows
(strconv.left_shift_table[0/2/4]) + 2 local-array controls; the
strconv.left_shift_table[2]:u32 probe segfaulted (exit 139) pre-fix
and exits cleanly post-fix. Broader width-variation rows (u8/u32/i32
module-imported) deferred as informational enhancement. Test 915
skips its inline cs==ww .s cmp on needs_import rows (line 217-222)
since `ww build` only drives cstage; reviewer externally verified
byte-id on /tmp/k128probe.combined.ww (driver-expanded form, no
imports). Future enhancement: 915 could read the driver-emitted
combined.ww and add a cmp leg there.
Bootstrap NEUTRAL (zero current module.array[i] consumers; strconv
decimal.ww uses IDENT-base from within package). 178/178 incl.
990-997 + combined_ww_fresh green. Sibling bugs #137 (chained N_DOT)
/ #141 (variadic-gather esz==2) / #142 (wwstage primsize-on-alias)
properly deferred to backlog.
cstage cgen.c array-literal init dispatch now uses MOVW for esz==2
(u16/i16 element width). Was deferred (cgen.c:7194-7198 explicit
TODO: "Add MOVW to w6a if real i16 arrays land") until A_MOVW
landed in both stages' w6a; that prereq is now met. Fixes silent
partial-init clobber where MOVQ writes 8B over a 2B slot,
overwriting neighbouring elements/locals.
Wwstage was already correct (selfhost/cmd/wcc/cgenutil.ww:872-877
emits MOVW for sz==2 in tnodestoreop) — cstage aligns UP to
wwstage's correctness here, a rule-10 inversion from the usual
align-richer-DOWN.
Test 914 (4 rows: u16 full-init, u16 small-values, u8 control,
i16 signed) catches the bug via the rule-10 cs==ww byte-id gate.
Runtime is not a reliable lever — ww rejects truly-partial inits,
and fully-init [N]u16 accident-corrects via MOVQ-overlap (each
write rewrote the prior write's trailing 6B). Reviewer non-vacuity:
stash the fix → 3/4 rows fail on byte-id, restore → 4/4 green.
Bootstrap NEUTRAL: 990-997 byte-id + combined_ww_fresh green; zero
pre-existing partial-init narrow-element callers in lib/+selfhost/.
strconv stof_data tables emit DATAW (raw bytes) and bypass this
path, which is why fold-2 landed clean despite the bug.
Sibling bugs filed for backlog (reviewer-128a flag-don't-bundle per
rule-11): #141 (cgen.c:4894-4898 variadic-gather array-store has
the same dispatch gap) and #142 (wwstage cgenstmt.ww:976-990
primsize(elemn.str) returns 0 for TY_NAMED alias names → wrong-
stride store on [N]alias-of-u16; cstage already TY_NAMED-peeled).
Add SAR/SARQ to both assemblers' opcode tables (cstage cmd/w6a +
wwstage selfhost/cmd/w6a) — REX.W + D3 /7, parallel to SHR's D3 /5.
Encoding is the unary-on-CL form (SAR r/m64, CL), the only variant
the cgen emits today. cstage cgen + wwstage cgen sweep all 12 SHRQ
emission sites (6 per stage) so signed RSHIFT and signed RSHIFTEQ
route through SARQ (arithmetic, sign-extends MSB) instead of SHRQ
(logical, zero-fill). Pre-fix `let i: i32 = -200; i >>= 2;`
produced 0x3FFFFFCE (1073741774) instead of -50; cs==ww held because
BOTH stages emitted SHRQ, so the 990-997 byte-id gates were
gate-blind to this silent miscompile.
Sites covered (per stage 6, same shape in both):
- plain TK_RSHIFT (cgbin / N_BIN ordered binop) — derives unsignd
from operand types via type_isunsigned / nodeisunsigned, picks
SHRQ vs SARQ at emit
- chained-ptr-field compound RSHIFTEQ (cgen.c:3281-3317 area)
- N_INDEX-lhs compound RSHIFTEQ (#133-expanded N_INDEX site)
- deref-target compound RSHIFTEQ
- top-level let compound RSHIFTEQ
- IDENT-local compound RSHIFTEQ
All sites reuse the in-scope unsignd variable from the surrounding
SLASHEQ block (or derive one locally when not available). LSHIFTEQ
unchanged — SHL == SAL at the encoder, no signedness dispatch needed.
912_sar_shr_run: 5 rows. i32_neg_rshifteq (lead's repro, was wrong
1073741774 → now -50), i64_neg_rshifteq (wider type), i32_pos_
rshifteq (positive control, SARQ ≡ SHRQ on positives, no regression),
u32_rshifteq (unsigned control, still SHRQ), i32_neg_rshift_binop
(plain >> not compound, cgbin TK_RSHIFT site). Exit codes use small
absolute values with u8 wrap (-50 = 206) per Unix 8-bit exit.
Bootstrap-NEUTRAL — `grep -rE '>>=|>>\b'` in lib/+selfhost/ (excl.
combined.ww) returned zero callers of signed RSHIFT today; the only
asm shifts are on previously-broken paths. 990-997 + combined_ww_
fresh stay green. Closes the silent-misbehavior class on signed
right-shift across all 12 cgen emission paths in one fold per
rule-11. Foundation for Eisel-Lemire (strconv fold-4) big-int signed
shifts.
`for (init; cond; post) { ... continue; ... }` and `for (let i .. xs)
{ ... continue; ... }` now emit a `post` (3-clause) or `rpost` (range)
label between the body and the JMP back to the cond-test. `continue`
jumps to that label, runs the post-step, then re-tests the loop
condition — mirrors C/Go/Hare semantics. Pre-fix both stages emitted
`JMP loop_top` for continue, SKIPPING the post-step → the value that
triggered continue never advanced → silent infinite loop on the first
matching iteration. Found by impl-strconv-fold2 during the fold-3
decimal.ha port: `leftshift_newdigits`'s `for (... i+=1) { ... else
if (d.digits[i]==p5[i]) continue; ... }` would infinite-loop at the
first equal digit.
BOTH stages were identically buggy → 990-997 cs==ww byte-id held →
gate-blind. Bootstrap audit (`grep -rE 'for \(let .*\.\.' lib/
selfhost/`) confirmed zero existing callers with continue in either
the 3-clause or range form; bootstrap-NEUTRAL.
Sites: cmd/w6c/cgen.c N_FOR + N_FORRANGE; selfhost/cmd/wcc/
cgenstmt.ww cgfor + cgforrange. 1-clause `for (cond)` byte-id
preserved (cont_target stays = loop_top when n.rhs == nil). Rule-11
carve-out: 3-clause and range share the lowered structure; fixing
one without the other would leave the same silent miscompile in
N_FORRANGE — one-class closure on the continue-skips-post bug, same
precedent as #133-expanded.
911_continue_run: 4 rows. for3_skip_one (lead's repro, was infinite
loop, now 4), for3_skip_two (nested continues, 30), range_skip
(Hare-range continue, was infinite loop, now 120), for1_continue_
byteid (1-clause regression assertion — bootstrap shape unchanged).
Pre-existing parser-side divergences (cstage silently drops post in
the never-used 2-clause `for (cond; post)`; wwstage doesn't support
infinite `for {}`) deferred to #139 — not in decimal.ha, no shared
class with the cgen continue-skips-post.
Strategy (a) use-site fix: new helper cg_dotbase_addr (cstage) /
dotbaseaddr (wwstage) detects `base.kind == N_DOT` whose field type
is TY_ARRAY and emits the field's address inline — LEAQ inner_off+
field_off(BP) for a value-struct inner, MOVQ inner_off(BP),reg +
ADDQ field_off,reg for a *struct inner. The TY_ARRAY-only gate (after
TY_NAMED peel) keeps the helper INERT on TY_PTR/TY_SLICE/TY_STR/
TY_TAGGED field kinds where the existing cgexpr(base) path is
correct (loads pointer/header value, then adds scaled index). Wired
at 6 sites: cstage cgassign N_INDEX-lhs plain ASSIGN + #133 compound
arm + cgindex N_INDEX read fallback; wwstage twin × 3. Closes the
silent-segfault on `(*struct).array_field[i]` reads and writes —
pre-fix cgexpr on the N_DOT base auto-derefed and loaded the field's
first 8 bytes as if they were a pointer, faulting on packed [N]u8
arrays (small u64 → unmapped page).
Bootstrap-NEUTRAL: zero working callers in either direction pre-fix
(symmetric READ + WRITE segfault evidence). All corpus + 990-997
byte-id + combined_ww_fresh stay green post-fix.
949_dotbase_arr_run: 3 rows direct runtime + cs==ww byte-id (READ
u8, plain WRITE u8, compound WRITE u8). Wider element widths and
value-struct base / pointer-field-control rows deferred — blocked by
orthogonal pre-existing wwstage divergences (i32-return ABI MOVSXD
vs MOVL, uninit-struct-let zero-init asymmetry) documented in the
test body. The TY_ARRAY-gate no-over-fire is implicitly verified by
994/995 (corpus exercises thousands of struct.pointerfield[i]
shapes; any over-fire would shift bytes).
Chained N_DOT (`outer.inner.array[i]` depth ≥2) deferred to #137 —
confirmed not in ref/hare/strconv/decimal.ha or sibling strconv/.
Not a fold-3 blocker; helper bails (returns false) on chained shape,
caller falls back to existing cgexpr path.
Both stages had silent miscompiles on compound assignment for two
shapes: indexed lvalue (`arr[i] OP= v`) and chained-pointer-field
(`d.fld.fld OP= v` through a *struct chain). The cstage N_INDEX-lhs
branch did not gate on TK_ASSIGN and silently DEMOTED compound ops to
plain stores (RHS stored, no load, no op). The wwstage equivalents
silently DROPPED the line entirely (no instructions emitted). The
chained-pointer-field compound template at cgen.c:3281-3317 also
silently identity-stored on unwired compound ops (SLASHEQ / PERCENTEQ /
LSHIFTEQ / RSHIFTEQ all fell to the switch default = no-op = load, pop
RHS, store ORIGINAL value back) and silently no-op'd on float / str /
slice / tagged element compound; its wwstage twin at cgenexpr.ww:5471
only handled TK_ASSIGN, dropping any chained-ptr-field compound
entirely.
Wire all 10 integer compound ops (PLUSEQ MINUSEQ STAREQ AMPEQ PIPEEQ
CARETEQ SLASHEQ PERCENTEQ LSHIFTEQ RSHIFTEQ) at all 4 sites in both
stages: SLASHEQ/PERCENTEQ via CQO+IDIVQ (signed) or zero-DX+DIVQ
(unsigned), with PERCENTEQ moving DX->AX for the result; LSHIFTEQ/
RSHIFTEQ via SHLQ/SHRQ on CX (rhs already in CX after the pop).
Signedness keyed off the field/element type via type_isunsigned /
typeisunsigned. Float / str / slice / tagged element compound now
LOUD-ERRORS at codegen with a distinct per-site diagnostic citing
#133/rule-7 instead of silent fall-through. Site 3 (the wwstage
chained-pointer-field compound) is ADDED FROM SCRATCH alongside the
existing TK_ASSIGN-only arm — pre-#133 wwstage emitted zero
instructions for any `d.i.v OP= v` shape, a rule-10 silent divergence
from the cstage which handled the same shape correctly.
Multi-fix carve-out (rule 11): the 10 wired ops at 4 sites + hard-error
gate on 4 unwired payload kinds at 4 sites are ONE silent-misbehavior
class closure on indexed/chained-ptr-field compound assignment.
Splitting would muddle bisect on related cgen surfaces — the wired
ops, the hard-error gate, and the rule-10 cstage/wwstage symmetry are
inseparable correctness facts at each site. The inherited template
default-break silent-identity (cgen.c:3281-3317) was the originating
class root; close it everywhere or leave the class open.
948_idx_compound_run: 21 rows total. 11 runtime+byte-id rows for the
original 6 ops on u8/i32/i64/u32 array bases and one slice base, with
a plain-assign control row asserting the ASSIGN path is byte-id-
unchanged. 7 new runtime+byte-id rows for SLASHEQ/PERCENTEQ on signed
i32 + unsigned u32, LSHIFTEQ on i32, RSHIFTEQ on signed-positive i32
and unsigned u32. 3 builderr rows (he_float_indexed, he_str_indexed,
he_float_chained_ptr) asserting both stages exit non-zero AND stderr
carries the cited diagnostic substring (rule-7 — never silent).
Mirrors 945_tuple_nary's builderr/experr pattern.
Bootstrap NEUTRAL — `grep -rE '\][[:space:]]*(\+=|-=|\*=|/=|&=|\|=|\^=|<<=|>>=)' lib/ selfhost/`
(excluding combined.ww) returns ZERO existing callers for the indexed
compound shape, and the chained-ptr-field compound shape was silent-
no-op in wwstage pre-fix (no working caller possible). 990-997 byte-
id gates green, 994 explicit confirms 18 corpus inputs identical
pre/post. combined.ww (w6c + wwdump) regen deterministic across
re-touch+rebuild.
A_SARQ is not in w6a's opcode table; signed RSHIFTEQ uses SHRQ at all
4 sites for parity with the pre-existing deref-lvalue compound site
(TK_RSHIFTEQ→A_SHRQ at cgen.c:4145). Documented technical debt
filed as #136 — pre-existing concern that a fix would need w6a
opcode addition + cgen sweep across every SHRQ-for-signed-RSHIFT
site, out of scope for this fold.
TK_STAR integer arm now routes through localloadop (cstage cgen.c) /
localloadop (wwstage cgenexpr.ww) — load-twin of the landed signed-
narrow-scalar-reads fix, was omitting TK_STAR. Closes the *p (CMPQ,
full-width arith) miscompile family (#116 + 962/963 instances all
fixed by the same width-aware load). Float arm untouched (#96 already
routed via X0). New test 947 (10 rows): packed CMPQ + signed/unsigned
narrow widths + TY_NAMED/TBANG alias + TY_ENUM peel + i64/bool controls.
