Completes the #14 close-by-construction begun by the helper extraction (e7fefa3): every <=24B aggregate register-store now routes through cg_agg_reg_store/cgaggregstore and handles all tail sizes. B/C/D/G fix a silent both-stage drop of a 3/5/6/7-byte tail (byte-id-blind: both stages dropped identically, so the gate could not see it). A/F enable a previously loud-rejected shape (a cgen backend gap, not a type rejection; harec accepts and lowers it). G (global g=f() array) routes symmetrically, dest_padded=false. The #11 arr[i].f scratch loops fold into the helper (dest_padded=true, byte-id zero-change), completing the grep-audit. Pins value-assert each eightbyte (the class is byte-id-blind) and redden under each stage's independent revert; site H's 3/5/6/7 let-receive stays a loud fatal (#22).
A stack array literal returned into a tagged-union slice success variant (fn mk() ([]i32|e) = { return [10,20,30]; }) slipped past reject_arrlit_borrow — it bailed when the dst was not TY_SLICE, but a union dst is TY_TAGGED — so cgen built an all-zeros slice header: a silent both-stage miscompile (and the .ptr would dangle anyway, no outliving backing). Extend the reject to chase a TY_TAGGED dst to its slice success variant, then apply the existing reject; this is the #25/#31 treatment seen through the union, and matches Hare (rule-9). Reached by all acceptance sites (return/assign/call-arg) so the class closes by construction. Both stages converge on an identical accept/reject decision (an array literal assignable to a union is assignable to a slice or array variant; neither stage can accept it). Full support — promoting the literal to an outliving backing — is the separate #33 arc. Compile-error fixture + a positive over-reach guard (a real slice into the union still compiles). No asm emitted by a reject, so byte-id is unchanged (no floor ratchet).
cg_structlit_fill/cgstructlitfill dispatched scalar field stores as {1->MOVB, 4->MOVL, else->MOVQ} with no fsz==2 case, so a 2-byte field was stored with an 8-byte MOVQ. Interior over-stores were harmlessly overwritten by the next field, but the LAST field at the frame edge corrupted the saved base pointer: an (S|e) union success variant places the struct payload after the 8B tag, landing the last field at -4(BP), so MOVQ AX,-4(BP) wrote into saved [BP] and POPQ BP restored garbage — a silent both-stage caller-frame clobber. Route the scalar store through the existing fldstoreop/fieldstoreop helper ({1->MOVB,2->MOVW,4->MOVL,else->MOVQ}), both stages; the #13 graduation comments already pre-documented this resolution. Pure width fix, no loud-stop (scalar widths are always {1,2,4,8} and narrowing is always correct). Value-asserting pin: an i64 sentinel live across the union-maker call (detects the clobber directly) + all members, with a non-union control.
A struct/array success variant in an (S|e)! / r? unwrap dropped eightbytes on BOTH stages (byte-id blind). Two layers: (L1) the unwrap success shuffle (cgtrytaggedshift) matched no arm for a struct/array success and fell to a bare MOVQ DX,AX, materializing only w0 — widen the existing nested-TAGGED shift's gate to admit TY_STRUCT/TY_ARRAY (the in-cap union packs the payload as raw GP words past the tag, so that shift is exact); (L2) the aggregate store arms gated on rhs.kind==N_CALL and stored one word for an unwrap rhs — relax to also admit N_TRYUNW/N_TRYPROP at the three silent store shapes (arr[i]=, single-dot field, indexed-field), reusing the materialise scratch path (now #10-correct). Rule-7 LOUD-STOP for a float-bearing success variant (an SSE eightbyte cannot ride the GP {AX,DX,CX} shift, #165). The four already-loud unwrap consumers (let-receive #7, call-arg #271, assign-existing #49, resolver-field #24) stay loud; global/chained single-dot field (#16) and the sub-8-tail-through-unwrap union-maker frame clobber (#15) are separate follow-ups. Value-asserting pin, reddens under each stage's independent revert.
The in-cap aggregate-receive materialise emitted a single narrow tail MOV that fell to MOVB for a 3/5/6/7-byte sub-8 tail, storing one byte while the scratch->dest copy read the full tail from uninitialised scratch — silently dropping members at the C2c whole-element arm (arr[i]=mk()) and loud-stopping at the #11 field arm. The scratch slot is ceil-8 padded (local_alloc/localadd round to 8) and the copy reads only tsz bytes, so flipping the tail default MOVB->MOVQ stores the full register harmlessly into the slot's own pad (in-bounds for in-cap <=24B); 1/2/4-byte tails stay byte-identical. Both stages symmetric. Removes the now-redundant #11 sub-8-tail loud-stop (keeps the float #165 and over-cap #234 loud-stops). The same narrow-tail materialise recurs at 6 other cstage sites (task #14).
Retires the obsolete idx_dot_aggret_subtail_loud //ww:error fixture (both stages now compile the case) and converts it to a positive cstage run-test; the struct-field shape is byte-id-divergent only via the pre-existing #9 frame-size bug, so the value pin uses array-field shapes. Value-asserting, reddens under each stage's independent revert.
The N_TRYUNW/N_TRYPROP success shuffle materialized {ptr,len,cap} into {AX,BX,CX} only when the success variant was a str; a slice success got only MOVQ DX,AX (ptr), leaving every slice-unwrap consumer (call-arg push, let-receive store, ident-source) reading junk .len/.cap — silent on BOTH stages (byte-id blind, cstage not the oracle). Widen the success gate to type_isstr||type_isslice (cstage) / typeisstr||typeisslice (wwstage) at all four shuffle sites; str and slice share the identical 24B header shuffle. Stays str||slice-specific — a struct success variant uses a different {AX,DX,CX} ABI (task #12). Value-asserting pin (len!=cap, poison-decoy) reddens under each stage's independent revert.
Follows #6 Mech A (Fix-R); order forced (C1 first or the slice call-arg push reddens byte-id).
nodeisslice/nodeisstr lacked an N_TRYUNW/N_TRYPROP arm, so a str/slice produced by an unwrap (f()!, r!, r?) and passed as a call arg fell to the 1-word scalar push, dropping .len/.cap; cstage's type-keyed node_isslice/node_isstr already pushed 3 words. Add the type-keyed arm reading the checker-stamped success-variant n.type_, mirroring #9's N_UN/TK_STAR arm. Fixes the str case (wwstage align-up to cstage); the slice success shuffle that both stages still get wrong is fixed in the Mech B follow-up.
The arr[i].f=src legacy assign block enumerated scalar field-type arms then fell to a 1-word scalar default, so a non-call aggregate source (ident/dot/index) cgexpr'd only its first word into AX and stored one eightbyte — silent on BOTH stages (byte-id blind). The non-indexed bases (local/deref/chained/global) reach the general assign resolver's canonical aggargsrcaddr+aggcopy; the indexed arm short-circuited before it. Route the indexed base through the block's own proven &arr[i] spine into the same aggargsrcaddr+aggcopy emitters (DRY — no third copy), dual-site symmetric. Unlike #11's in-cap arm, the source is a memory address so aggcopy is a pure memcpy: float bits and the sub-8 tail transport verbatim, no loud-stop needed. Did not fall through to the general resolver because its cgplaceaddr N_INDEX arm rejects a *[N]S (TY_PTR) base (latent resolver gap, filed separately).
Contained to the indexed base + non-call aggregate-field rhs; value-asserting pins redden under each stage's independent revert.
The arr[i].f=mk() assign arm had no aggregate-field sub-arm, so a by-value aggregate field receive fell to the scalar default (one MOVQ, dropping DX/CX) — silent on BOTH stages (byte-id blind). Add a dual-site symmetric in-cap N_CALL arm mirroring C2c (c83a340): scratch-first materialise AX/DX/CX, then word-copy to (fi.foff+k*8) within &arr[i], sizing from the natural field size fi.fsz (not slotsize). Rule-7 LOUD-STOP for the three cases the in-cap GP path cannot transport: over-cap sret (#11c/#234), a float-bearing field whose eightbyte classifies SSE (#11/#165), and a 3/5/6/7-byte sub-8 tail the single narrow tail MOV cannot express (the general cascade tail is the shared C2c/#11 follow-up, task #10). Value-asserting pins (poison-seeded, redden under each stage's independent revert) plus cfail pins for the three loud-stops.
Contained to the indexed base + in-cap call rhs; arr[i].f=src (#11b) and over-cap (#11c) are separate.
nodeisslice/nodeisstr lacked an N_UN(TK_STAR) arm, so a deref-source slice/str call arg (f(*h), h:*[]T) fell to the scalar single-PUSHQ default — marshalling only .ptr and dropping .len/.cap. Add the type-keyed arm (read checker-stamped n.type_, mirror cstage node_isslice/node_isstr and the sibling N_DOT/N_INDEX arms). cgen already loads the full 24B header (C1b c67f362); this fixes only the call-arg push/pop count. wwstage-only align-up; cstage was always correct.
cstage rejected a deref-less function-pointer call `f(21)` (f: *fn...) with
"calling non-function" while wwstage accepted it and ran correctly -- a
cs!=ww divergence. Hare auto-dereferences a pointer callee to its fn type
before the call. Peel one pointer level after the named-type chase so
cstage accepts a `*fn` callee, matching wwstage and Hare.
One level only, deliberately: the #181-cgen indirect-call path lowers the
callee VALUE as the target (CALL AX), which is the fn address for a single
`*fn` but only the address-of the fn-ptr for `**fn`. A multi-level peel
would accept `**fn` past what cgen can lower -- a silent both-stage
miscompile (returns garbage). cstage stays loud on `**fn` (rule 7);
wwstage's loop-accept of all levels (check.ww:3763) is the over-permissive
side, filed for align-down plus the deeper cgen multi-level autoderef.
Surfaced by the codegen miscompile hunt (finding C6a). Pinned by
test/lang/fnptr_derefless_call_test.ww (deref-less + canonical (*f)(21),
multi-arg, alias-chain, tuple-return; reverting the peel reds the
deref-less rows at compile).
`alloc(Outer{ x = Inner{q=10} })` dropped the nested struct-literal field:
the alloc path had its own inline fill loop with only scalar/float/str
arms, so a field whose value is itself an N_STRUCTLIT fell to the scalar
tail and stored MOVQ $0 (cgexpr leaves a whole aggregate in no register)
over the inner slot. Both stages emitted the identical wrong fill, so the
byte-id gate was blind to it.
Route alloc's fill through the existing shared structlit-fill helper (the
one the BP-relative/global/local structlit sites already use -- it handles
nested-struct recursion, N_ARRLIT, str/slice and tagged) via a new 4th
destination mode DST_PTR_SP that reloads the heap base from (SP). This
deletes alloc's divergent inline loop, the lone site lacking the recursion.
As a side effect it also fixes a latent slice-field drop in the driver's
own alloc(sepgraph{...}) (pkg.len/.cap were dropped; the consumer reads
neither -- g.n is the count SSoT). Nested-array fields are closed in-class;
a nested tuple-LITERAL field now errors loudly and symmetrically (the #49
non-addressable gap, previously dropped silently at alloc only).
Surfaced by the codegen miscompile hunt (finding C7c). Pinned by
test/lang/alloc_nested_field_test.ww (nested struct depth 1+2, nested
array, adjacent multi-nested, sibling-no-clobber; reddens on revert).
Routing preservation proven: the whole test/lang corpus is byte-identical
HEAD vs fixed except the new pin; self-compile byte-id (990-996) green.
`arr[i] = mk()` where mk returns an in-cap (<=24B) struct/tuple/array
left the result in the #4 cgreturn registers (AX/DX/CX), but the
N_ASSIGN-into-N_INDEX path had no arm for an N_CALL rhs, so it fell to
the scalar store tail: only member 0 was written and the index scale
clobbered CX. Both stages emitted byte-identical wrong code (the
documented-but-silent #31-G gap), so the byte-id gate was blind to it.
Add an in-cap N_CALL-rhs arm: materialise the return into a frame scratch
first (keeping the CALL at the frame's natural 16B alignment), resolve
&arr[i], then word-copy the full eightbyte count + sub-8 tail -- mirroring
the #4 receive shape and the #270-1b copy. The eightbyte count derives
from the element size in the type table. Over-cap returns (#234),
non-call rhs (#270-1b) and tuple literals (#121) are unaffected; the
sibling field/deref shapes stay loud (#24).
Surfaced by the codegen miscompile hunt (finding C2c). Pinned by
test/lang/idx_aggret_recv_test.ww (10 value-asserting rows: 2/3-eightbyte
structs+tuples, array elem, sub-8 tail, const/runtime index, all four
base shapes; reddens on revert).
An untyped float literal defaults to f64, so in an f32 context it was
materialized as f64 then bit-truncated by a raw MOVSS (low-32 reinterpret)
rather than narrowed -- e.g. `let x: f32 = 2.0f32; x * 3.0` multiplied by
0.0f. Twelve byte-id-gate-blind both-wrong miscompiles, all this one cause
(compare, binop, call-arg, struct-field, array-elem against an untyped
literal).
Broaden coerce_floatlit to stamp the untyped fconst type_=f32 across the
f32-context sites (assign rhs, call-arg, struct-field, array-elem) and to
descend the implicit-cast shapes (peel unary +/-/cast, recurse binop
operands AND the binop node, recurse arrlit elems), mirroring harec's
lower_implicit_cast. The existing CVTSD2SS gate then fires; cgen is
unchanged. f64 contexts are untouched -- the stamp is gated on TY_F32.
Surfaced by the float codegen sub-hunt (= the deferred #120). Pinned by
test/lang/f32_untyped_narrow_test.ww (22 value-asserting rows incl. f64
controls; reddens on revert).
`let s: str = *h` (a str/slice loaded by value through *str / *[]T)
fell through the N_UN deref arm to the scalar load, emitting a single
MOVQ that read only the 8B .ptr and left .len/.cap from stale registers,
so len(*p) returned garbage. Both stages emitted byte-identical wrong
code, so the self-compile byte-id gate was blind to it. Add a str/slice
arm that loads the full {ptr,len,cap} via cgslicehdr when the chased
pointee is TY_STR/TY_SLICE.
Surfaced by the codegen miscompile hunt (finding C1b). Pinned by
test/lang/deref_hdr_test.ww, which interposes a different-sized decoy
header so the test reddens when the arm is reverted.
wwstage rejected a module-level `const/let []T = [arrlit]` global with "let: not assignable"; cstage accepts (textbook Hare, ref/hare/path/stack.ha:30). The arrlit->slice admission in checkletassign was gated local-only; lift it to module scope too, aligning wwstage UP to cstage's arrlit_init_fits (check.c:3406-3409, slice arm 519-520). cstage unchanged.
Two guards the un-gating requires: the n.rhs.lhs=arr stash stays local-only (a module decl keeps its raw N_ARRLIT for DATA emit, so stashing would leave an untyped count node for the pass-3 asserttyped walker); and tuple-element slice globals are excluded at module scope, because the synthesis delegates element checks to isassignable which lacks a strict tuple arm (#38) -- a [](str,*fn) table would over-accept a sig-mismatched &fn that cstage's strict type_assignable rejects (#124) -- so they stay on the existing typeeqast path.
Closes two divergences 944_alias_emit_b7 pinned: Group A (cstage-runs/ww-rejects) migrates to test/lang/slice_global_arg_test.ww (promoted from _runonly, now cs==ww byte-id); Group B converges to a shared emit_slice_data reject with the identical diagnostic.
fold-2 chunk C5 (drew's Fam8-13 plan), the highest-risk chunk: 21 match/tagged
value-row C drivers re-homed. 20 -> test/lang/*_test.ww @test row-tables + 12
runww //ww:error carriers (both stages reject). The global-tag cluster
(globtag*/globstructwiden/taggedderefstore/...), which sits on the #15/#17
global-ptr fix, was empirically probed byte-id CLEAN -- the predicted hotspot
surfaced ZERO fresh cs!=ww. Carves: variant_chain_b95 #81 -> _runonly (genuinely
diverges at HEAD); callret_bound277 #277 -> slim C pin (cs-runs/ww-rejects),
mutation-gated. 929_tagged_memarg kept whole (SSE-ABI asm conformance). 19
drivers deleted, 944_variant_chain slimmed to the #277 pin.
The match-on-tagged-struct-field divergence (former #26) probed RESOLVED for all
its cited shapes (938 voidstr_field/recursion_torture, tagnorm dedup_match all
byte-id cs==ww + value-correct) -- closed no-reproducer-at-HEAD, attribution to
#15/#17 INFERRED. Those rows migrate as normal byte-id @test and serve as the
REGRESSION SENTINEL for the inferred close (a resurgence trips the gate).
LANGBYTEID floor 93->113; test count 374->355 (19 deleted; 929 + 944_variant_chain
kept). do-not-auto-batch (926_tagscr/940_global_sret/940_str_forrange) untouched.
fold-2 chunk C2 (drew's Fam8-13 plan): 14 tuple value-row C drivers migrate to
15 test/lang/*_test.ww @test row-tables (the +1 is 954_tuprecv, slimmed not
deleted -- its value rows split out while the asserttyped-stamp dimension stays
as a carrier-split C pin, mutation-proven non-vacuous). Reject rows move to 32
test/wcc/data/*/case.ww //ww:error carriers (runww asserts the substring in
BOTH stages). The test-lang byte-id (LANGBYTEID) gate gives cs==ww automatically
and is strictly more sensitive than re-running the wwstage leg; floor 59->74.
Tuple surfaced zero cs!=ww as the plan predicted -- no value-only carve. The 945
trio folds in here; 940_global_sret / 940_str_forrange / 926_tagscr untouched
(routed to drew per-file). Test count 402->388 = the 14 retired drivers.
fold-2 chunk C1 (drew's Fam8-13 plan): 960_opaque_decl_run.c and
962_opaque_assign_cast_run.c were value-row C drivers. Migrate their 3+3
cases to test/lang/opaque_decl_test.ww and opaque_assign_cast_test.ww as
@test row-tables. The test-lang byte-id (LANGBYTEID) gate gives cs==ww
automatically -- 960 was cstage-only-run before, so this strengthens it.
Both byte-id clean, no cs!=ww carve. Retire the 2 C drivers (LANGBYTEID floor
57->59) and repoint a dead comment ref in lib/sort/sort.ww. 961_opaque_guards
(reject/guards) stays in C -- fold-3 territory, not in the Fam12 fold-2
worklist.
fold-6 carrier-split (drew's ruling): the 6 uniesc value rows (rune/string
escape decode) are already covered 1:1 by test/lang/uniesc_test.ww @test rows
-- same escape forms, same expected codepoints/bytes, same lexer escape-decode
path, and dual-stage via test-lang-byteid (frontend-swap .s byte-id proves
wwstage decode transitively, strictly more sensitive than re-running). So drop
the duplicate value rows from the C driver; 110_uniesc_run.c slims to just the
.wwi roundtrip -- a 2-package sep-build observer that can't be an in-language
@test and isn't a reject case (its eventual runww home tracked as #19). The
carrier still runs both stages for the roundtrip; no coverage lost, test count
unchanged (404).
#18 verified there is no spurious load-narrow on a chained global-ptr field
read into an i64 sink -- the only MOVSXD is the legitimate :i32 return cast,
byte-identical in both stages. Lock it: a chain_i64_sink row reads q:i64 =
0x1_0000_0001 and asserts the high word == 1. A truncating load-narrow would
drop the high word to 0, so the row pins the spine-narrow family (runtime +
byte-id, both stages).
A >32B tagged-union field (slice payload) read through a direct *struct
pointer byte-diverged: wwstage's cgloadtaggedfield always loaded R8@+24
before CX@+16, but cstage's direct-*struct-ptr arm (cgen.c ~11926) loads in
offset order CX@+16 then R8@+24. Both ran correct -- a pre-existing rule-10
asm divergence, for a local *struct ptr as well as a global one.
Thread a cxlast flag through cgloadtaggedfield: the direct-ptr site
(cgptrfieldload, the shared local+global chokepoint) passes cxlast=false to
match cstage's offset order; the other 5 callers keep cxlast=true (byte
unchanged). A global flip was rejected -- it would clobber the CX-base
callers (CX@+16 first destroys the base before the R8@+24 read), and the
chained-BX caller must stay R8-first to mirror cstage's chained twin
(cgen.c ~12021); the order is a genuine per-arm property of cstage, not
derivable from the base register.
Test: +2 rows (tagged_slice_field via global *struct ptr, _local via local
*struct ptr), runtime + byte-id; both proven to fail byte-id with only the
compiler files reverted.
