Three wwstage cgen sites still used the unrounded structnaturalsize where cstage
rounds via lu->size (check.c:760), pre-existing gate-blind cs!=ww latents
flagged in #169's reviewer notes: cgenexpr DOT register-RECV for obj.f = mk()
(~5175/5393/5628/6164); cgstructlitfill's TK_ELLIPSIS zero-fill branch
(cgenutil); and cglet bare 'let z: T;' zero-init of a maxalign<8 struct
(cgenstmt). Each produced MOVQ-vs-MOVL or wider-write divergence vs cstage on
the trailing word of a sub-eightbyte tail.
Converge all three onto the maxalign-rounded structabisize the #169 work
established at the register-ABI sites (cite cstage cgen.c:7720 RECV twin +
cgen.c:2085 cg_structlit_fill). cgstructlitfill's signature drops the external
totsize parameter in favor of one internal source; the field-walk path is
untouched, only the ELLIPSIS zero-fill uses the ABI size. cglet's slot
allocation stays on the frame size; only the zero-fill extent uses ABI.
Gate-blind (the bootstrap exercises none of these shapes); covered by 5 new
rows in probe 698 with cs==ww .s byte-cmp and a pre-fix-rebuild proving the
exact MOVQ-vs-MOVL discrimination. 990-997 byte-id hold.
exprfloatkind was wwstage cgen's structural float-classifier — a workaround for
the checker stamp being untrustworthy. With the previous commit arming the
asserttyped bail, every checked value-node is now stamped (or cited-exempt),
so its job collapses to a 2-liner reading n.type_ — the same path cstage cgen
has always taken. Retire it: inline the stamp-read at its eight sites (cgcast,
cgun, cgbin lhs+rhs, cgcall pop, pushargsrev, cgwidentaggedstorebp, cgreturn
x2 collapsed), delete the wrapper, and delete the two residual
sibling-evidence loud-aborts (cgbin float-arith, cgwidentaggedstorebp
float-arm) — their operands are real source value-exprs the armed bail now
stamps, so the guards can never fire.
One synth-post-checker value-node remained outside the bail's reach: the
variadic-slice descriptor pushed in pushargsrev/cgcall (cgenexpr.ww). Stamp
it at synthesis with the variadic param's []T slice tinfo so the inlined
reads see a stamped node, no nil special-case. Byte-id-neutral by design
(slice tinfo and nil both read non-float); 990-997 confirm.
Closes the bail-rearm arc — wwstage now reads the same float-class SSoT
cstage does, the gate-blind float-classification family is closed, and the
build+test corpus is asserttyped-clean by construction.
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.
wwstage struct-return RECV and RETURN used unrounded / round-to-8 sizes where
cstage uses the maxalign-rounded lu->size / rt->size, so a struct with maxalign
8 and a sub-8 tail (e.g. struct{i64,i32}) — or a maxalign<8 struct on the
return path — unpacked with a different trailing-word width (MOVL vs MOVQ)
between stages. Value-correct either way, but a cs!=ww asm divergence.
Add a dedicated structabisize = round(natural, maxalign) used only at the two
register-ABI sites. structnaturalsize stays unrounded: cstage's >24B sret and
memory-move path (cgen.c:8150, Task #33) genuinely uses the unrounded natural
size, so the two are different sizes — rounding the shared metric breaks 995.
maxalign derives from each field's tinfo.align (mirrors cstage check.c:708),
not an fsz ladder (a ladder over-rounds composite [N]u8 fields).
Gate-blind (no bootstrap struct hits the maxalign-8+tail shape) — the
discriminator is the cs==ww .s byte-cmp; covered by probe 698.
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).
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.
`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.
Float array-element stores (array-literal init, [v...] repeat-fill, and
arr[i]=v) now route from X0 via MOVSS/MOVSD in both stages; the AX path
stored the raw double low-bits, garbage for f32 (f64 worked by accident).
A clobbering call-index (a[geti()]=v) loses the X0 value — deferred to #125.
A (f64,i64)/(i64,f64) tuple returns its f64 word in X0 (the SSE return
reg) and its integer word in an integer reg (tuple_rseq AX/DX). All three
tuple-from-call receive forms — single-var (cglet), destructure (N_MLET),
reassign (N_MASSIGN) — share the #83 tuple_rseq cursor and all spilled
the f64 word via MOVQ from the integer cursor; that reg holds garbage
(the float is in X0), and #103-FACE-Z's field read (MOVSD slot,X0) then
reads it. A single-return callee masked it (a float-literal return leaves
the f64 bits in AX, and X0 stays live); a branched callee with a non-
literal f64 word has an inner CALL clobber AX, exposing the corruption.
Make every receive spill class-aware: an f64/f32 word spills MOVSD/MOVSS
from X0 (the single SSE return reg, which survives the reg->mem stores
regardless of the word's position), an integer word spills MOVQ from its
tuple_rseq reg as before. cstage applies this at all three inline sites
(cglet, N_MLET, N_MASSIGN); wwstage at the cglet branch and in the shared
tupstore helper (covering cgmlet and cgmassign). The integer/str/slice
path is byte-identical to before, so bootstrap codegen is unperturbed.
Multi-float tuples collide on X0 at the RETURN (#107), out of scope here.
wwstage-only. cglet had no 16B whole-tuple-from-call receive branch, so
`let t = call()` whose callee returns a 2-eightbyte (16B) tuple fell
through to the generic single-word store (MOVQ AX, off(BP)) and never
spilled word1 (the DX eightbyte) — silent loss of t.1. Align to cstage
cgen.c:6652, which spills both AX->off+0 and DX->off+8.
Not a tupstore cursor off-by-one and not f64-specific: the destructure
form `let (a,b) = call()` (cgmlet + tupstore cursor) was already byte-id;
only the whole-tuple N_LET receive dropped word1, for any element mix
incl. all-integer (i64,i64). An f64 element surfaced it first. The f64
element rides its eightbyte in AX/DX at receive and is re-read from
X0/XMM at field-read (already byte-id), so no SSE cursor is needed.
Replace the str-only XOR (e0_is_str ^ e1_is_str) at the tuple send
(N_RETURN) and receive (N_MLET/N_MASSIGN) sites with a positional
per-element register cursor, mirroring harec create_unpack_bindings
(ref/harec/src/check.c:1354-1416). Each element rides consecutive
eightbytes over [AX,DX,CX,R8]; a slice/str rides its 3-word
{ptr,len,cap} header (ref/hare/rt/ensure.ha:4-8), a scalar rides 1.
Send and receive walk the SAME type-table widths so element->register
agrees. This routes []u8 elements through the 3-word path (the XOR was
slice-blind, dropping len+cap to the scalar fallback) and closes the
pre-existing (scalar,slice) cs!=ww divergence by construction. cstage
and wwstage emit byte-identical asm.
Both receive sites derive each element's width from the rhs tuple's
element types (n->rhs->type->params / the callee return type) -- the
SAME producer view the send site walks -- NOT the binding type: a `_`
lvalue is an N_IDENT with empty str the checker never type-stamps, so a
binding-typed width mis-sized a wide `_` and desynced the cursor for the
next element (cstage read DX, wwstage R8). harec `_` skips the store but
CONSUMES its tuple offset; the cursor advance honours that.
Loud-stop (rule 7): the register file holds 4 eightbytes; a tuple whose
elements sum to >4 (([]u8,[]u8)/(str,str)=6) cannot be register-returned,
so the send site aborts at compile time citing the return-ABI capacity
(#10) rather than silently miscompiling. The receive loop guards the
same predicate (defense-in-depth). Routed through each stage's EXISTING
pinned-fatal idiom: cstage fatal() (cmd/wcc/err.c), wwstage the inline
os.write(2,...)+os.exit(1) at cgen.ww:604 -- no new diagnostics path.
N_MASSIGN (`a,b=f()`, bare comma, pre-declared) is a retained
ww-EXTENSION beyond Hare's binding-only tuple-unpack (Go/rob-pike
multi-assign, rule-9 carve-out); the loop covers it identically to
N_MLET.
Test 945_tuple_nary_destructure_run: (i64,[]u8)+(i64,str) store+read
len/cap for both N_MLET and N_MASSIGN, a single-str control, a wide-
first blank `_,a=f()` row (the cursor-desync discriminator), and a
([]u8,[]u8) row asserting the loud BUILDERR carries the cited
diagnostic; dual ww/ww_ww drivers.
Ranging a str (for (let b .. = s)) and reading the loop var back emitted MOVZBQ on cstage (correct u8 zero-extend) but MOVQ on wwstage (the missed case, #14). Align wwstage UP. ww cgforrange derived the element-type node only for slice/array; for a str scrutinee it left elemt=nil, so the loop var registered with no type and localloadop short-circuited to MOVQ. Fix: for a str scrutinee, synthesize a u8 element node (type_ = str.sub = u8, from F1) as elemt, so localadd hands the loop var a u8 tnode and the GENERIC narrow-load fires (MOVZBQ) -- consuming str.sub as F1 intended, mirroring how []u8 supplies its element node. NOT an if-str special-case. cstage already correct, untouched (ww-only). str's own type stays nominal.
GATE is the ASM SHAPE byte-id (cstage==wwstage at the loop-var read), NOT a runtime probe: the divergence is runtime-benign (MOVQ and MOVZBQ read the same zero-extended byte) so a runtime test passes both ways and cannot distinguish -- it was a byte-id-INVISIBLE divergence (990-997 green despite cstage!=ww, since no bootstrap input exercises a narrow-read str loop var). Verified fail-pre (the cstage-MOVZBQ vs wwstage-MOVQ 1-line diff) / pass-post (.s byte-identical). []u8/slice/array for-range emission unchanged. test/wcc/940 carries the fixture (runtime corpus coverage, both drivers).
main.combined.ww regenerated via the canonical make path.
Reassign-destructuring a (scalar,str) tuple (a, s = call(), N_MASSIGN) stored only the str's ptr (DX->slot+0), dropping len/cap -- the last STORE-cluster gap. Reachable (valid ww; checker accepts str tuple elements) but unexercised in bootstrap (all N_MASSIGN sites returned <=8B tuples). Mirror the N_MLET destructure-store oracle (cgen.c:7475): on the one-str XOR, route the str's 3 words DX/CX/R8 -> slot+0/+8/+16; the slot pre-exists (localfind, not localadd). wwstage has no checker, so it derives str-ness from the callee return-type tuple via fnretlookupmod (structurally identical to cgmlet). Both XOR positions (str at l0 and l1). Kind-gated, never size==24. cstage==wwstage byte-identical.
Scope = one-str only, matching N_MLET exactly; str+str-both is unhandled by N_MLET too and is filed as a shared gap (task #22), with WHY-comments at both destructure sites. N_MLET emission unchanged (its edit is comment-only, verified byte-identical).
test/wcc/939: table-driven write-then-read-cap over both XOR positions (a,s=mk() and s,a=mk2()); cap!=len via mutation (not a sub-slice, #20); pre-poisoned via a non-G3 let-init; full triple+scalar asserted; fail-before/pass-after on both drivers. Completes the str-cap STORE cluster -- the read/write round-trip is now whole. main.combined.ww regenerated via the canonical make path.
A ww `str` becomes a 24-byte {ptr,len,cap} value, identical in layout to
[]u8 -- the enabling prerequisite for the Phase 2 `str == []u8` collapse.
Both stages, atomically:
- ty_str 16->24B; str value flows 3-reg AX/BX/CX (was 2-reg); str literals
emit cap (=len).
- str in a tagged union grows to a 32B slot, using the AX/DX/CX/R8 4th-word
path already used by 32B slice-variant unions -- str-variant is now
structurally identical.
- tuple (scalar,str) return: 4-reg AX/DX/CX/R8 + 32B receive, extending the
existing type-keyed return (no sret).
- str == []u8 for index and .ptr/.len/.cap, kind-gated where size-based
dispatch collided at 24B; cstage and wwstage mirror exactly.
- table-driven runtime coverage: test/wcc/928_str_abi_run.c.
Cannot be split (rule 10/11): a 24B str and a 16B str cannot coexist across
the two compiler stages without breaking byte-identity, so the size change
and every dependent ABI/codegen site land in one atomic commit, both stages.
Known follow-ups (zero corpus impact, tracked): str-literal global .cap
static-init; >16B struct by-value (pre-existing); tagged-union
match-scrutinee stage divergence (pre-existing).
cgwidentaggedstore/storebp/cgwidentagremap took a type *node and re-derived
the tagged shape via resolvetagged + N_TTAGGED.list walks. Migrate them onto
the stamped tinfo (the store-side parallel of #66's match-side flip): dst is
now the tagged *tinfo (peel TY_NAMED->du, gate TY_TAGGED), variant lookup +
tag-remap read tinfo.params by typeeq, mirroring cstage cg_widen_tagged_store
/ cg_widen_tag_remap / cg_tag_for_variant (cmd/w6c/cgen.c:1273/1177/503). The
N_CAST widening test flips from surface-name streq to `castu==dt || (castu
tagged && typeeq(castt,dst))` (cgen.c:1295).
Node-form flatvariantidx/taggedvariantindex become thin shims over new tinfo
cores (flatvariantidxt/taggedvariantindext) so node-side callers (cgreturn
cgenstmt:269, pushargs cgenutil:192) are untouched. The 9 cgwidentaggedstore
callers pass node.type_ (each already istaggedtype/slotsize-gated). resolvetagged
is retained for its 7 match-side callers.
Incidentally retires two latent ww-vs-cstage divergences, both byte-id-neutral
on the corpus: the old N_CAST test set castisdst for ANY N_TTAGGED regardless
of type equality (cstage guards on type_eq), and the old remap walked the
UNflattened src.list (cstage walks the flattened params). Unblocks cgassign's
indexvaluetnode drop (#69/#61d). make test 134/134, byte-id 990-997 hold.
The user-ruled B-full semantic change: flip tagged-union variant matching
from surface-NAME to TYPE-identity (typeeq over tinfo.params), mirroring
cstage cg_variant_match (cmd/w6c/cgen.c:451). A cross-module `a.T` != `b.T`
and `type linerr=!str` != str are now distinguished by the per-decl TY_NAMED
pointer (Phase-N #64). ww has no type_assignable, so the untyped/loose arm
keeps the str/slice shape fallback (rule-10 align-down). The 5 helpers
(flatvariantidx, flatslicevariantidx, taggedvariantindex, cgtagvariantidx,
cgmatch dispatch) flip; nomem propagation (NAMED-name scan, no source value)
and the f64 widen arm (float-kind classification, no pattern node) are not
arm-by-value discrimination and stay name/kind-keyed.
The flip requires value nodes to carry nominal identity. exprtype's
N_STRUCTLIT arm stamped the flattened body, so `overflow{}` (overflow=!void)
got TY_VOID and missed its variant -- fixed to stamp the per-decl NAMED
(mktname(lhs.str) -> tinfofornode reuses the #64 NAMED build/cache, same ptr
the union variant resolved to), mirroring the N_CAST/N_IDENT arms + cstage.
Returns the body node unchanged (only e.type_ rides NAMED); struct-lit layout
is unaffected -- cgstructlitfill is structlookup(name)-keyed, never reads
NAMED.fields. The fix now hits all `T{}` stamps, kept byte-id by the #63/#65
structural-walker peels.
931_variant_typekey_run: table-driven, both stages, /tmp-isolated. Two rows
widen an alias-FIRST variant from a call (no surface name): `(linerr|str)`
str-via-call -> idx 1, `(ec|i32)` i32-via-call -> idx 1. Empirically
discriminating: FAILS pre-flip (wwstage falls to the leading-shape variant,
exit 10; cstage exit 0) and PASSES post-flip -- locking in the capability
byte-id can't reach (the corpus has no name-key/type-key-disagreeing
co-variant, which is why name-keying survived).
make test 134/134 (byte-id 990-997 green; 995 self-rebuild green).
The node-keyed kind helpers (typeis8byteprimitive, isstrtype/raw,
isslicetype/raw, istaggedtype/raw, isfloattype, isf32type/raw,
isf64typeraw, isnullabletype) each re-walked TNAME aliases via
aliaslookup and peeled TBANG by hand — duplicating cstage's single-
peel kind predicates at the AST level. After A.6.2 every type-AST
kind these read is tinfo-stamped at check.ww L426-436, and
tinfofornode collapses N_TBANG (check.ww:1145-1152) and the TY_NAMED
chain, so each predicate folds to one tinfo read.
Six new tinfo helpers in lib/ww/typ.ww mirror their cstage SSoT
verbatim:
typeisstr — cstage cgen.c:159 `type_isstr` (TY_STR / TY_UNTYPED_STR)
typeisslice — cstage cgen.c:174 `type_isslice`
typeistagged — cstage cgen.c:516 `type_istagged`
typeisf32 — cstage cgen.c:188 `type_isf32`
typeisnullable — cstage cgen.c:396 `type_isnullable` (reads tinfo.nullable
stamped at check.ww:1309-1318)
typeis8byteprim — cstage cgen.c N_LET sz==8 ladder (slot-pad set)
Rule 9 carve-out per the A.6.3a precedent: each helper has a named
cstage counterpart; the wwstage shape mirrors it directly. The five
dead AST-walking variants (isstrtyperaw, isslicetyperaw,
istaggedtyperaw, isf32typeraw, isf64typeraw) are deleted; the five
remaining callsites (cgenstmt cglet / cgmlet str-routing, cgenexpr
cgdot tuple-field) graduate to the alias-aware isstrtype(c, t).
nullableptrtag stays AST-keyed for now — tinfofornode doesn't
populate TY_TAGGED.params (check.ww:1287-1337 sets size / align /
nullable but not the variant chain), so the tinfo equivalent of
cstage cgen.c:405 `nullable_ptr_tag` can't read params today. WHY
comment at the site cites #50 / A.6.3f as the graduation point,
alongside the variant-index work and the tparam-population glue.
Byte-identity (994/995) is the behavior gate; full `make test` green
at 133/133 confirms.
A.6.2.0b worker hit a real shared-`.next`-aliasing bug and stopped
per rule 7. Wwstage's N_TTUPLE chained element type ASTs via the
nodes' own `.next` field. `exprtype` routinely returns shared
nodes (sym.decl.lhs, struct field's `.lhs`, another N_TTUPLE's
`.list` element). Naive chain construction in the checker
corrupts source ASTs.
Introduce N_TPARAM = 67 as a chain wrapper for N_TTUPLE.list:
- `.lhs` holds the (possibly-shared) element type AST.
- `.next` chains within the parent N_TTUPLE.
- Other fields unused; never appears outside N_TTUPLE.list.
Mirrors cstage's Tparam at cmd/wcc/check.c:1437-1451. Cstage
keeps it at the Type layer; wwstage has no separate type layer
for tuple chains so the wrapper sits at the AST. Hare's design
intent at ref/hare/hare/ast/type.ha:117 uses `[]*_type` slice-of-
pointer — same principle, slice-flavored.
Migrations:
- lib/ww/ast.ww: kind + nkname + pr() unwrap (transparent for
the 990 -a astprint byte-diff).
- lib/ww/parse/parse.ww: parsetype N_TTUPLE construction wraps
each element in N_TPARAM (sole construction site).
- selfhost/cmd/wcc/check.ww: 4 readers (astalign, astsize,
tinfofornode TY_TUPLE, exprtype N_DOT-tuple-positional). The
last change retires the latent A.6.1.5b shared-`p` return.
- selfhost/cmd/wcc/cgenutil.ww: slotsize TY_TUPLE arm.
- selfhost/cmd/wcc/cgenexpr.ww: cgdot tuple-positional
(size/load op + str-check).
- selfhost/cmd/wcc/cgenstmt.ww: cglet TTUPLE init, cgmlet
call-return walk, cgforrange elem-size + bind-walk.
Out of scope: N_TFN params, N_TTAGGED variants, N_TSTRUCT fields.
N_TFIELD already wraps struct fields; N_TFN/N_TTAGGED aren't
currently chain-mutated by checker synthesis. If they ever are,
the same pattern applies.
Unblocks A.6.2.0b stamp on a clean foundation. Retires task #16.
Verified 132/132 incl. 990 AST byte-diff (astprint unwrap) + 995
self-rebuild byte-identity.
Hare's canonical runtime allocator is rt::malloc with linker symbol
rt.malloc (ref/hare/rt/malloc.ha:27,78). ww kept the dot→underscore
Plan 9 convention (CLAUDE.md rule 4) so the linker symbol becomes
rt_malloc; the lib/rt exported function name becomes malloc; ww
callers say rt.malloc(...).
The language builtin keyword stays `alloc(T)!` — unchanged from Hare
(ref/hare/hare/lex/token.ha:21 ltok::ALLOC, parse/expr.ha:398
builtin()). The rename only touches the lowered linker symbol and the
exported function name behind it; the user-facing syntax for
heap-allocation is identical to Hare.
Surface:
- rt/alloc.s: TEXT rt_alloc → TEXT rt_malloc, labels updated
- lib/rt/malloc.ww: @symbol("rt_malloc") fn malloc(...) (was rt_alloc/alloc)
- rt/ensure.ww: local FFI decl + call site updated to malloc; `!` dropped
on the direct FFI call (rt_malloc returns *void, not a tagged union)
- 18 .ww callers: rt.alloc(...) → rt.malloc(...)
- cstage cmd/wcc/check.c + wwstage selfhost/cmd/wcc/check.ww
alloc-builtin suppression gate routes through ffi_resolve("malloc")
for the lowering; the user-shadow check still keys on the BUILTIN
KEYWORD "alloc" since that is what `alloc(...)` parses as. Adding
"malloc" to the user-shadow check was unnecessary and was reverted
during pre-commit review.
- cstage cmd/w6c/cgen.c: 2× ffi_resolve("alloc") → ffi_resolve("malloc")
- wwstage cgenexpr/cgenstmt: 2× ffiresolve(c, "alloc") → ffiresolve(c, "malloc")
- Test fixtures (700_e2e, 758_cgalloc_str_field, 990_selfhost, 992_w6l_ww,
selfhost/test/tagged_ptr_ret.ww): updated inline ww sources to the new
decl + call form
This is commit 2 of 3 in the lib/rt extraction (#38). Commit 3 closes
the OOM contract — return type becomes nullable *void and the builtin
lowering null-checks + propagates nomem.
Verified 132/132 + 995_self_rebuild byte-identity (5 wwstage tools
round-trip identical) + make clean cold rebuild.
Hare puts runtime allocation in rt::, not os:: (ref/hare/rt/malloc.ha:27,
README). ww's `@symbol("rt_alloc") fn alloc(n: u64) *void;` lived at
lib/os/os.ww as a historical bootstrap shortcut; this commit relocates
it to a new lib/rt/malloc.ww and sweeps every site that depended on
`import os` for the alloc decl over to `import rt`.
This is commit 1 of 3 in the lib/rt extraction (#35):
1. (this) move decl, sweep imports — preserves shape
2. rename rt_alloc → rt_malloc (#38)
3. nullable return type + OOM-propagating builtin lowering (#39)
No rename here. Symbol stays rt_alloc, function stays `alloc`, return
stays *void. Behavior identical — same ffi resolution outcome, just
sourced from a different module file. The rt::ensure runtime helper at
selfhost/rt/ensure.ww is its own compilation unit with a local decl and
is untouched.
Side effect: every wcc cgen file used `rt` as a local *node variable
name for "return type." `import rt;` shadows the module, so each
selfhost/cmd/wcc/{check,cgenstmt,cgenexpr,cgenutil}.ww site renamed
to `rtyp`. Mechanical follow-through; only the wcc module-import was
forced to do this rename.
Verified 132/132 + 995_self_rebuild byte-identity (5 wwstage tools
round-trip byte-identical).
Wwstage's cgalloc hardcoded `CALL rt_alloc(SB)` at cgenexpr.ww:2747 and
cgenstmt.ww:647. Cstage already routes through ffi_resolve("alloc")
at cmd/w6c/cgen.c:4149 — when a fixture lacks the @symbol("rt_alloc")
decl in scope, cstage falls back to `CALL alloc(SB)` while wwstage
still emits `CALL rt_alloc(SB)`. The divergence is dormant in
ww build (combined.ww always pulls lib/os/os.ww's decl) but activates
under direct `w6c file.ww` and any other single-file path.
Replace the hardcoded line with the ffiresolve(c, "alloc") pattern
already used for user-function calls. The @symbol decl in lib/os/os.ww
is unchanged and propagates via the combine step.
Extends test/wcc/758_cgalloc_str_field.c with 4 table-driven asm rows
that compile a fixture via direct w6c (no combine) and `cmp` the
CALL <sym>(SB) line between stages. The 3 noscope rows fail without
the fix and pass with it; the withsym row pins the positive ffi-hit
path. Test count internal: 12 → 16; total make test: 132/132.
#43 (8e93b31 + 087c85c) routed many sizeof(str) / sizeof(slice)
sites through primtypesize / tyslicesize / ty_*->size, but missed
the cgparam regs-fit, cgparam stack-stitch, cgmlet mixed
scalar+str receive, and vararg slice gather paths in both stages.
A bare #1 bump (str→24B) on top of #43 reds ~60 tests because
those paths still hardcoded 16/24.
Cstage:
- cgen.c:7360-7361 cgmlet: sz0/sz1 → (int)u0->size / (int)u1->size.
- cgen.c:7557 cgparam regs-fit: slice|is_str → (int)pu->size.
- cgen.c:7586 cgparam stack-stitch: same.
- cgen.c:4368 cgcall vararg gather: localoff slice descriptor →
(int)vsu->size (the cstage twin of cgenexpr.ww:3084).
Wwstage:
- cgendecl.ww:225, :243 cgfnparams: 16 → primtypesize("str"): i32.
- cgenexpr.ww:3084 cgcall vararg gather: 24 → tyslicesize(): i32.
Plus a latent-bug fix at cgenstmt.ww cglet :1031 / :1040: the
str-init and slice-init arms dispatched on size only. Under #1's
str→24, both arms would have fired on a str let (duplicate
MOVQ BX,off+8 + bogus MOVQ CX,off+8). Added isstrtype / isslicetype
kind gates mirroring cstage cgen.c:6439's
`type_isstr(lt) && sz == ty_str->size`. Zero asm change today
because the size constants implicitly disambiguate at 16 vs 24.
Probe with temporary #1 bump (str.size=24) confirms 990_selfhost +
994_w6c_ww go green — the cgen-routing slice for #1 is now
closed. Remaining red under bump is lib/ww/typ.ww's parallel SSoT
seed + stringstest cap*16u64 strides + w6l_ww runtime SIGSEGV;
all tracked separately.
EIGHTBYTES register-count sites (cgen.c:7553-7554, cgendecl.ww:224
/:260) intentionally NOT touched — those are str ABI in-flight
3-reg work (task #34), not slot-width SSoT.
Followup to 8e93b31 (#43). Audit caught dispatch-gate sites the
sweep missed:
- cgen.ww letpreintern's `sz == 16` str-let detector — would
desync from emitletdataw's matching `sz == primtypesize("str"):
i32` strlit-init branch under #1.
- cgenstmt.ww cglet str-init MOVQ-BX gate and slice-init MOVQ-BX/CX
gate (and the belt-and-suspenders N_TSLICE shape check at l.607).
- cgenexpr.ww cgindex str-element loads (3 sites: globalarr,
baselocal, generic fallback) and the matching cgassign N_INDEX
str-element write pair (BX spill + post-index store).
All gates now read `primtypesize("str"): i32` / `tyslicesize(): i32`,
so #1's ty_str.size bump propagates through the same two-place edit
the original commit advertised. Combined files (w6c/wwdump) updated
in lockstep.
131/131 + 994 + 995 byte-identity green; smoke.combined.ww (lib-only
consumer) emits the same asm pre vs post, confirming the change is
SSoT routing only (no behaviour shift).
Audit §1.1/§1.2 cataloged 17 wwstage sites hardcoding 16 for sizeof(str)
and ~10 hardcoding 24 for sizeof(slice), plus 4 cstage str-size sites
and the cstage let_emit_size str/slice arms. Each new size constant
required ~30 edits in both stages to bump cleanly — task #1 (str → 24B
{ptr,len,cap}) can't land until the literal sweep is done.
Track A — wwstage codegen (selfhost/cmd/wcc/*):
- check.ww introduces two stateless helpers next to astsize:
primtypesize(nm) — primitive-name → byte size (i64; -1 unknown)
tyslicesize() — slice-header bytes (i64; 24 today)
astsize now reads both for its N_TNAME-primitive and N_TSLICE arms,
so the size(T) fold gets the SSoT for free.
- cgen.ww, cgenutil.ww, cgenstmt.ww, cgendecl.ww: every `return 16`
/ `esz = 16` / `sz0 = 16` for str, every `return 24` /
`localadd(c, _, 24, _)` for slice, plus the matching `sz == 16` /
`sz == 24` / `for (i < 16/24)` gates in the global-let DATAW emit,
route through primtypesize / tyslicesize.
- Direct delegation slotsize→astsize would require restructuring
astsize to drop its *checker dep (resolvealias) — the leaf
primitive/slice cases factor out cleanly, the alias-chain leaves
diverge because cgen's aliaslookup/structlookup tables and check's
scope chain aren't unified yet (§1.8, task #50 follow-up). Sharing
the leaf table satisfies the SSoT promise without that refactor.
Track B — cstage (cmd/w6c/cgen.c):
- let_emit_size's TY_STR/TY_SLICE arms drop the hardcoded 16/24 and
fall to `(int)u->size` like the existing TY_STRUCT/TUPLE/TAGGED arms.
- N_LET cgstmt's per-kind `sz` cascade collapses to a single
`if (lu->kind ∈ {ARRAY,SLICE,STR,STRUCT,TUPLE,TAGGED}) sz = lu->size`.
- N_LET cgexpr's match-bind primitive sizing: `bsz = (int)bu->size`
drops the TY_STR/TY_SLICE special-cases (same outcome — ty_str/
ty_slice already have ->size set by type.c).
- Three `sz == 16` / `let_emit_size(d->type) != 16` gates against the
str slot width route through ty_str->size.
Cap-offset sites (cgen.c:2440/1994/3206/5517 `delta = 16` for
slice's .cap field-write) intentionally NOT touched: 16 there is the
*offset of .cap inside a slice header*, structurally always 16
regardless of str.size. #1 doesn't move the slice layout.
Track C — lib/ user code:
- lib/strings.freeall + appendstr, lib/shlex.freepartial + appendstr:
the four `16u64` literals (per-str-element stride for rt_ensure and
os.free) become `size(str): u64`. Check-time fold via #42's
intercept resolves to 16 today; #1 reroutes via the bumped tinfo.
After this commit, bumping ty_str to 24B for task #1 requires editing
exactly two places (cmd/wcc/type.c:64 ty_str.size, plus check.ww
primtypesize's "str" arm) for the SSoT to propagate.
Verification:
- 131/131 tests pass. 994_w6c_ww + 995_self_rebuild byte-identity
holds — each replacement evaluates to the same constant the
literal had today, so cgen output is unchanged.
- selfhost source's `size(str): u64` folds at check time (cstage
cmd/wcc/check.c:907-960 for the C-bootstrap of selfhost; wwstage
check.ww:898-942 for the rebuild path), no runtime call introduced.
`alloc([], n)` synthesizes ([]u8 | nomem) at expression level — that's
fine, since the slice form only legitimately appears in let-init
position where the LHS carries the real element type. In clet, after
type-checking the rhs, peel any N_TRYPROP/N_TRYUNW wrapper, match the
alloc-slice AST shape with the same-module shadow gate (from #23),
and retype the call's tagged return to ([]T | nomem) where T is the
declared LHS element. Then assignability sees []T vs []T and accepts.
Cgen N_LET shortcut gains a viatryprop arm next to the existing
viatryunw — on rt_alloc returning null, emits the tagged-return
nomem propagation (MOVQ $nidx, AX; epilogue) instead of exit(1).
nidx comes from cg_tag_for_variant on the enclosing fn's return type,
matching the existing TRYPROP propret path.
Wwstage mirrors all four hunks (check.ww + cgenstmt.ww). Promotes the
previously-silent conf=false skip into a confident accept.
Unblocks #6 (dupall) and lays the path for #4/#7. Byte-identity
holds modulo the pre-existing #44 alloc/rt_alloc symbol divergence.
Cstage's cmd/w6c/cgen.c:6363-6411 special-cases `let s: []T =
alloc([], n)!;` to inline rt_alloc + null-check + exit(1) + slice
header build, avoiding a generic call-then-store path. Wwstage's
cglet had no mirror — pre-#31 the path was rejected at check, but
once #31 made the check side accept it, the cgen side would have
silently miscompiled. Mirror added at cgenstmt.ww cglet rhs head,
emitting byte-identical asm.
Element size goes through elemsizeofc so str (16), structs, and
tagged aliases all match cstage's lu->sub->size uniformly — the
defensive path matters because check today only allows []u8, but
relaxing that is its own task.
Test exercises the path: writes to s[0] and s[15], reads back. Would
SIGSEGV on a junk header. 994 + 995 byte-identity green.
Structural close of the #4-trio convenience-wrapper audit. Session-6's
#4-trio + #11/#16 graduated individual lookup helpers (fnret/fnparams/
enum/struct/def) to same-module-first via *mod variants. The close
didn't enumerate every cgcall-context callsite — convenience wrappers
that take a *node callee and probe its return shape via bare-leaf
fnretlookup stripped the N_DOT module hint, same wedge shape as #16
(callee_variadic_param, d9b0c90) through a different family of
consumers.
Eight LATENT sites in selfhost/cmd/wcc fixed (each mirrors #34's
nodeisslice two-arm route — N_IDENT uses cmod=c.curmod, N_DOT uses
cmod=callee.lhs.str, terminal call routes through fnretlookupmod):
- cgenstmt.ww cgreturn forwardtagged probe
- cgenstmt.ww cgmlet tuple-return shape probe
- cgenexpr.ww cgdot fn-rvalue probe (mod.fn LEAQ)
- cgenexpr.ww cgtryprop succisstr probe
- cgenexpr.ww cgtryunw succisstr probe
- cgenutil.ww callsretsize (sret arg-prep)
- cgenutil.ww inferletcalltype (let x = f()? tnode)
- cgenutil.ww rhstaggedabicall N_CALL branch
cstage carries no sister bug: cmd/w6c/cgen.c reads every callee
return shape from the typed n->lhs->type per TY_FN sig. Mirror of
#4d/#28/#31/#34/#16 cstage no-sister notes.
753_convwrap_audit: table-driven sentinel exercising cgmlet's tuple-
shape probe. alpha exports foo() (i64, str); beta exports foo()
(i64, i64); main calls beta.foo() — source order puts alpha LAST so
alpha.foo prepends to head of c.fnrets, pre-fix bare walk picks
alpha's str-branch dispatch for beta's call. Post-fix routes to
beta.foo via fnretlookupmod. Asserts MOVQ\\tCX, absent in main.run
TEXT (no str.len store; would fire pre-fix). Remaining 7 sites
covered structurally by shape-mirror — single wedge shape, single
exercise.
make test 127/127; ww2==ww3==ww4 byte-id holds via 995_self_rebuild.
Subsumes #36. Drop wwstage scanlocals pre-pass; both stages converge on
first-use+fail-loud frame growth, rule-10 polarity DOWN to leaner side.
#36's surfaces (frame-total divergence on match-arm case-let; sibling
offset divergence in variadic+iter+match-prev compositions) close
naturally — running-max c.frame includes every first-use binding.
selfhost/cmd/wcc: add atlocals persistent @-prefix registry surviving
cgblock save/restore; add cgoutbuf/cgoutmode/cgout_enable/disable/flush
for deferred prologue (emit body to buffer, finalise c.frame, then
TEXT/SUBQ + flush); localadd @-prefix dedups against atlocals +
fail-louds on size-grow (rule 7 — no silent truncate); cgreturn-tagged
routes through @retscr (was colliding with @tagscr on arg-widen sizes);
variadic gather esz uses raw primsize (rune->4) not slotsize (rune->8)
— matches cstage and fixes the #36 sibling runtime miscompile in
non-leaf variadic+iter+match-prev callees.
cmd/w6c/cgen.c: drop the over-allocation hack ("for byte-id with
wwstage scanlocals reservation") since wwstage no longer over-reserves;
add fail-loud on @sretscr size-grow; @tagscr sites pass actual slot_sz
instead of stale c.tagscrsz.
748_size_strategy_convergence: table-driven 4 rows x 2 stages
(tag_variadic_runearm, trim_iter_match_prev, variadic_gather_rune_stride,
leaf_baseline). Each exercises a #36 surface shape; 8/8 ok.
Net -1565 lines. Sister latents filed as cosmetic (cs/ws frame size
drift on multiple-variadic-call fns): labelseq drift + varargseq
stuck at 0 — both bootstrap-byte-id safe (ww2==ww3==ww4 holds since
both ww2 and ww3 are wwstage outputs).
make test 122/122; ww2==ww3==ww4 byte-id holds via 995_self_rebuild.
let p2: T = p1; where T is a struct >8B and rhs is a local ident
silently dropped most of the copy. Cstage's N_LET fell past every
specialized rhs branch (str/tuple/tagged/structlit/call) without
matching the bare-ident case, then past the sz==8 fallback (false)
to the no-rhs zero-init (false: rhs present), emitting zero
instructions — the dest slot read fresh-stack zeros. Wwstage's
cglet fell to cgexpr+MOVQ AX which loads only the first qword
(cgident shape for struct ident), and for sz==16 slots the
str-init tail then stored a stale BX into +8. Reads after the
let saw whatever the stack held: silent partial copy.
Both stages now byte-copy src slot → dst slot per qword with
a sized tail (MOVL/MOVB) for natural sizes not 8-aligned.
Mirrors cg_widen_tagged_store's struct-ident payload copy.
744_letcopy_struct pins the four struct shapes (3×i32, i32+str,
i32+[]u8, i32+tagged) on asm-presence in both stages, cmp -s
byte-id, and runtime exit code via both drivers.
Scope: only N_IDENT rhs at the local-ident-found path. Filed as
siblings (no in-tree consumer today, bootstrap byte-id proves it):
- N_DOT / N_INDEX / N_UN(deref) struct rhs.
- Top-level (non-local) struct ident rhs.
- TY_TUPLE same-shape ident-copy bug.
Row (a) uses tri{a=11, b=22, c=33} structlit init for p1 to
isolate this fix from STATUS-3 #15/#26c (no-rhs zero-init sz=12
vs sz=16 slot-padded divergence between stages, separate task).
Row (d) runtime check uses only p2.a to isolate from match-on-
tagged-field scrutinee spill divergence (same task).
118/118 ok. ww2 == ww3 == ww4 byte-id holds.
User-mandated language redesign: source files declare their own
namespace via the new `package <name>;` keyword and pull dependencies
via `import <path>;`. Both keywords use Plan-9 `.` separator (user
override on Hare's `::` — `import encoding.utf8;`). Internal token-
kind enum values TK_MODULE=86 and TK_USE=17 kept stable for 990
wwdump byte-diff symmetry; only kwtab strings + tokname spellings
rotated. Executables (selfhost/cmd/{ww,w6c,w6a,w6l,wwdump}/main.ww)
declare `package main;` per Go convention; lib/ + selfhost/cmd/wcc/
files declare their parent-dir basename.
One-commit bundle per the brief's all-at-once directive: a per-stage
split breaks bootstrap byte-id mid-rewrite (cstage with new keyword
can't parse old `module`/`use` files and vice-versa). Body documents
the bundle per rule 11.
Two retained divergences from the user's stated ask, both filed per
rule 7 / rule 8 with inline task pointers at the deferred sites:
Task #22 — Directory-as-module enumeration in the driver. User
asked: "module is combination of files in directory" (golang/hare
shape). After this commit lib/ww/{ast,sym,typ}.ww all declare
`package ww;` but are still pulled into the compilation unit via
explicit sibling `import` chains (sym.ww does `import ast;` etc.),
not via dir enumeration. The cstage scaffold for true dir
enumeration was drafted and reverted because the symmetric wwstage
port requires a ww-side opendir/readdir wrapper around getdents64
(~150-200 lines new ww). Inline citation at locate_import_in /
locatein in both stages points to task #22.
Task #23 — Parser strict missing-`package` error. The original
brief mandated: parser errors when a .ww source omits `package
<name>;` as its first non-comment item. Softened here to silent-
default because 63 test wrappers (200_parse, 100_lex, 300_check,
400_w6c, ..., the inline-source-fragment family) build ad-hoc ww
source strings that lack `package` and the strict error cascaded
into 60+ test failures. Migration is mechanical-sed but deferred
so this commit ships green. Inline citation at parsefile in both
stages points to task #23.
Node.module renamed to Node.nmod and modent.module to modent.nmod
in wwstage source — the field name `module` would collide with the
freshly-reserved TK_MODULE token. The rename is left in place as
clean separator between AST-field-name and reserved-keyword
namespaces. Cstage's n->module retained — C has no `package` or
`module` keyword.
rt/ensure.ww deliberately ships WITHOUT a package declaration so
its `export fn rt_ensure` keeps the bare linker symbol; adding
`package rt;` would mangle to `rt.rt_ensure` and break libwwrt.a
linkage. Documented at the file head.
111/111 ok (110 + new 738_module_decl sentinel). 995_self_rebuild
byte-id holds (ww2 == ww3 == ww4). All 5 frozen
selfhost/cmd/*/main.combined.ww regenerated under the new driver.
CLAUDE.md rule 5 amended with the language-layer divergence note.
Class A compile-time fatal retirement — `return f()` from an sret
callee bailed both stages with "sret return-forwarding for >24B
struct not wired (task #23)" at every site, forcing every caller
into a `let r = f(); return r;` workaround that materialised an
intermediate >24B copy in outer's frame. Forwarding now elides the
copy: outer reloads its own @sretarg into RDI for the inner CALL
via `MOVQ @sretarg(BP), DI` (NOT `LEAQ <local>, DI`), inner writes
directly into outer's caller-prealloc dest, RAX (inner's returned
dest pointer per the sret discipline) is already outer's return
value.
Wires 2 sites × 2 stages (same triangle as #23): caller arg-shift
in cgcall/pushargsrev gains an RDI-source switch via
cg_sret_forward / c.sretforward; callee return-arm in cgreturn
replaces the fail-loud abort with cgexpr-into-cgcall + epilogue.
The @sretscr scratch slot is still pre-allocated on the forwarding
branch (unused) — eliding would need AST-walk awareness in
scanlocals; symmetric-allocate is the simpler path and keeps
byte-id with non-forwarding callers.
Latent surfaced and filed during probe (NOT in this commit's
scope): multi-sret-receive in a single fn diverges between stages
— cstage always allocates @sretscr on first sret CALL, wwstage
only when sretdestoff == 0. Bootstrap stays green because the
selfhost corpus has zero >1-sret-receive call sites.
Tests:
- 721_sret_struct_return gains 2 forwarding rows + a 4th asm-
presence sentinel: at the inner CALL site inside outer fn, the
RDI source must be `MOVQ -K(BP), DI` (reload of outer's saved
@sretarg) NOT `LEAQ -K(BP), DI` (a temporary local would write
inner's payload into outer's frame, not caller's dest).
- 925_sret_struct_return_run gains 3 forwarding rows: simple
quad forward, multi-arg inner (pair-by-value + scalar args
alongside the hidden RDI), and slice-payload (decoder
{ i64, []u8 } — the utf8 iterator shape, asserts ptr/len/cap
survive the @sretarg chain).
90/90 ok. 995_self_rebuild stays green (ww2==ww3==ww4 byte-id).
Class B shared miscompile pre-fix: cstage skipped the CALL emit at the
receive site (frame collapsed, exit 11); wwstage emitted CALL but
truncated 32B return to AX only (slice payload garbage, segfault on
g.b[0]). Both stages now lower plain TY_STRUCT > 24B through the SysV
sret discipline: caller pre-allocates dest, passes &dest in RDI as a
hidden first-arg (user args shift to SI/DX/CX/R8/R9/+stack), callee
saves RDI to @sretarg at the prologue and writes through it, returns
RDI in RAX. Surfaced by lib/encoding/utf8 pre-flight when the
Hoehrmann decoder (32B) hit 698_cgreturn_struct.c's OUT-OF-SCOPE
marker.
Scope: plain TY_STRUCT > 24B only — tagged unions, tuples, str, slice
keep their existing register-return ABIs. `return f()` forwarding
from a sret callee is fail-loud-not-wired (compile-time error in
both stages, follow-up filed); the workaround `let r = f(); return
r;` is wired and byte-identical. Discard-context calls (`f();` of an
sret-returning function) share a per-fn single-slot @sretscr;
consecutive discards reuse the same slot.
698_cgreturn_struct.c's OUT-OF-SCOPE marker retired in the same
commit; three positive rows (32B quad, 32B decoder, 40B five) now
assert the sret discipline across both stages via byte-id diff.
Tests:
- 721_sret_struct_return pins three asm-presence sentinels per
row: (a) LEAQ -K(BP), DI immediately before CALL at the receive
site, (b) MOVQ -K(BP), AX before RET in the callee (sret return-
the-pointer), (c) negative-assert no MOVQ AX, -K(BP) capture for
return type >8B. Three rows × both stages × cmp -s byte-id.
- 925_sret_struct_return_run runtime-pins 7 rows × 2 stages
including the collision row (25B+ struct BOTH returned AND passed
by-value as arg — catches arg-shift, sister site to #11), nested
struct payload, slice payload, reassign-receive, N_IDENT return
rhs.
89/89 ok. 995_self_rebuild stays green (ww2==ww3==ww4 byte-id).
Closes STATUS latent #1: @tagscr shared 24B reservation across the
four tagged-scratch sites (cgreturn, pushargsrev, cgindex
tagged-elem, pointer-rooted struct-field tagged write). Any fn that
needed >24B (e.g. slice-in-tagged-field 32B) silently overflowed
into the neighbor frame slot. Surfaced concretely as getopttest's
errortable wwstage exit 16 after #37 fixed the upstream gaps.
c.tagscrsz: i32 on the cgen struct is the single source of truth.
tagscrbump(c, need) in scanlocals raises the max across all 4
reservation sites and returns the frame delta. All emit sites
(cgreturn / pushargsrev / cgindex / cgwidentaggedstore pointer-
rooted) read c.tagscrsz instead of hardcoded 24. Mirrors the existing
cgwidentaggedstore precedent; @tagbase keeps its 8B scanseenmark
dedup (always 8B, correct).
Unmasked latent bug (now fixed): scanlocals's pointer-rooted struct-
field tagged-write detection uses localfindnode(c, base.str) to
resolve the *struct base. For `fn fill(h: *holder)`, h's scan-time
stub from scanseenmark had tnode=nil, so the @tagscr reservation
never fired. Pre-#38 the hardcoded 24B masked this; #38's correctly-
sized slot exposed it. cgfn's param scan loop now sets
c.locals.tnode = scanp.lhs after scanseenmark so localfindnode
resolves param types at scan time.
Test 714 (tagged_return_scratch): 4 rows × 2 stages = 8 fixtures.
Direct adjacency repro; match-arm field-by-field read; **mixed-
sizes-one-fn** (16B pushargsrev widen + 32B cgreturn widen in the
same body — pins the lockstep invariant that a sibling site can't
undersize the shared slot); call-site struct-payload widen. Row 3
specifically would regress if a future refactor ever forgets to
route an emit site through c.tagscrsz.
982 getopt_run green through both stages (was the original surface);
995 self_rebuild byte-id holds.
[N]str array literals wrote only the .ptr half of each element.
cstage used esz=16 from `lu->sub->size` and a single per-element
MOVQ → .len trailed uninitialized stack residue. Wwstage was worse:
primsize("str")=0 fell through to esz=8, so element i+1's ptr-MOVQ
clobbered element i's .len slot, scrambling everything.
Worker-18 sidestepped during #18 by rewriting array primer rows to
[N]i64.
cstage cgen.c N_ARRLIT TY_STR branch: emit AX → base+i*16 then
BX → base+i*16+8. Repeat-`...` path mirrored. type_isstr handles
TY_UNTYPED_STR + TY_NAMED-aliased-str.
Wwstage cgenstmt.ww: isstrel flag conditionally drives the two-MOVQ
store in both the per-element walk and the repeat fill. The dispatch
loop was refactored to unify FIELD/ellipsis branches via isellip,
cleaning up the duplicated arms.
Wwstage cgenutil.ww slotsize/letslotsize: TNAME-"str" element gets
esz=16, replacing the primsize=0 → 8B fallback. Without this the
frame collapsed to 24B for [3]str.
Slice (24B), struct, tuple, tagged element arrays have the same root
cause but distinct width/layout concerns — deferred to #35 per rob.
Test 711 (arrlit_str_full): 7 rows × 2 stages = 14 fixtures —
str_lens_3el, str_ptrs_3el, str_repeat_5el (TK_ELLIPSIS), bool_3el,
rune_3el, i32_3el, i64_3el. Rune relies on the pre-existing esz==4
→ MOVL path (incidental correctness); sibling slot types pinned as
regression nets.
Followups filed: #34 (wwstage cgindex truncate on [N]str bare-let
read side, surfaced by this fix), #35 (composite element types),
#36 (primsize-returns-0-default-to-8 cleanup).
localoff (cstage) / localadd (wwstage) deduped stack slots by name
alone, ignoring scope. Outer `let a: [128]u8` and an inner-block
`let a: *u8` shared one 8B slot; prologue truncated to inner size
and outer-scope writes past saved RIP corrupted the frame. Worker-19
hit it during #19 (selfhost/cmd/w6a/main.ww carries a defensive
asm→s rename pointing at this task).
Drop the name-dedup. Each let allocates fresh. Then preserve
outer-scope visibility across inner blocks: cgstmt's N_BLOCK case
saves `*locals` head, walks body, restores. cgfn iterates fn->body
->list directly (bypassing the outermost N_BLOCK) so defers and the
implicit-return epilogue still see fn-body locals after the loop.
Wwstage symmetric: localadd keeps dedup only for `@`-prefixed
synthetic scratches (`@tagscr` / `@retscr` / `@tagbase`) which need
single-slot semantics; user names get fresh stubs. scanlocals always
counts + always appends a fresh stub for N_LET / N_MLET / N_FORRANGE
so prologue SUBQ stays in sync with emit-time offsets. cgblock and
cgfn mirror cstage.
ww2 == ww3 == ww4 byte-identical post-fix.
Test 709 (localoff_scope): 8 rows × 2 drivers = 16 fixtures —
inner_first_outer_bigger, outer_first_inner_writes, nested_3_deep,
same_name_diff_type, same_block_redecl_pin, defer_shadow,
forrange_body_shadow, if_body_shadow. defer_shadow pins the cgfn
body-bypass; if_body_shadow pins the save/restore independently.
Asm byte-id not diffed in 709 — 995_self_rebuild covers cross-stage
drift more broadly.
Follow-ups (filed): #32 (check: refuse same-block let-redecl), w6a
`s`→`asm` revert sibling commit.
cgreturn's variant-widen arm only filled the registers each variant's
payload needed: scalar variants left CX and R8 stale; str variant
left R8 stale. The receiver (cg_widen_tagged_store non-N_IDENT
branch) writes all four ABI words to the dst slot unconditionally,
so caller-side residue in CX/R8 (the array-index IMULQ being the
canonical primer) landed at slot+16 and slot+24.
Worker-fmtparser surfaced this through fprintf's loop body where
array indexing primed CX and a 24B-return helper failed to clear
it; bug isn't loop-specific — straight-line repro at /tmp/wcrs_repro/
repro8.ww confirms.
Patch: emit `MOVQ $0, CX` after the variant's register shuffle when
the slot exceeds 16B and the variant doesn't fill CX; same for R8
when the slot exceeds 24B. Symmetric across cstage cgen.c and
wwstage cgenstmt.ww. Order: zero-MOVQs precede `MOVQ $tag, AX` so
AX-as-staging stays safe. Inline comment at cg_widen_tagged_store
non-N_IDENT branch documents the producer-zero contract.
Test 707 (cgreturn_variant_zero): 6 rows × both stages = 12 fixtures.
Covers scalar/bool/str returns after array-index priming in
straight-line / single-loop body / nested-loop body / mixed-variant
loop. Asm byte-identity check intentionally omitted; wwstage
taggedvariantindex divergence on str/bool N_IDENT is filed as task
#20. 995_self_rebuild covers the broader cross-stage drift surface.
ww2 == ww3 == ww4 byte-identical post-fix. 67/67 green.
Deferred (followups filed): #20 wwstage taggedvariantindex,
#21 [N]str/[N]bool array-literal non-pointer-half writes, #22
consolidate variant-widen into uniform scratch-slot path.
Pre-existing landmine surfaced by #5. For a struct literal whose
field value is itself an N_STRUCTLIT of a struct-typed field, the
inline field-walk did `cgexpr(field.lhs); store-AX-sized`. cgexpr
has no whole-struct-in-register convention, so the nested literal
landed AX = first qword and the trailing bytes silently stayed zero
(or stack garbage). Three BP-relative sites in each stage hit it:
N_LET, N_ASSIGN N_IDENT-lhs, and N_RETURN N_STRUCTLIT.
Fix: shared cg_structlit_fill_bp (cstage) / cgstructlitfillbp
(wwstage) helper handles TK_ELLIPSIS autofill, tagged-field
widening, float vs scalar store dispatch, AND recurses on
struct-typed N_STRUCTLIT field values at bp_off + field_off. All 3
sites in each stage now call the helper instead of the inline walk.
Scalar store dispatch is the explicit {1->MOVB, 4->MOVL, else MOVQ}
shape (not fieldstoreop, which would emit MOVW for fsz==2) to stay
byte-identical with cstage pending task #13. Sister N_ASSIGN N_DOT
structlit walks (via_ptr / global / BP-relative-through-N_DOT) keep
their inline walk and still drop nested-STRUCTLIT silently — tracked
as task #18.
703 covers 6 rows: let_nested_i64, let_nested_3deep, let_nested_i32,
let_nested_middle (i64; switch to i32 once #15 lands),
assign_ident_nested, return_nested. 995_self_rebuild byte-identity
preserved.
Receive side of #4's cgreturn ABI (aee8149) for TY_STRUCT lvalues of
size <=24B. Producer materialises rhs into AX=bytes[0..7], DX=[8..15],
CX=[16..23], zero-padded to 24B; receive sites here read the regs and
write only `declared sz` bytes — MOVQ for full 8B chunks plus a sized
tail (MOVL/MOVW/MOVB) by the *declared* struct size. ASYMMETRY: do NOT
mirror the sender's three uniform MOVQs, else trailing 1..7B chunks
overrun the next local slot. Tail chunks in {3,5,6,7} are unreachable
under WW struct align rules (size%align==0) and fall through.
Five sites wired in each stage (cstage cgen.c, wwstage cgenexpr.ww +
cgenstmt.ww), call-result + structlit rhs at each:
- N_LET `let s: T = bar()` / `= T{...}` cgenstmt cglet
- N_ASSIGN N_IDENT-lhs `s = bar()` / `= T{...}` cgenexpr cgassign
- N_ASSIGN single-DOT local-base `o.f = ...`
- N_ASSIGN single-DOT ptr-base auto-deref `p.f = ...`
- N_ASSIGN single-DOT global-base `g.f = ...`
- N_ASSIGN chained-DOT depth>=2 `o.m.in = ...`
(The four dot-flavors share one shape pattern, hence "5 sites".) Where
the dst addr needs scratch (ptr-base/global-base/via_cx), it is loaded
into BX after the call so CX stays as the third value word; for
structlit field-walks BX is reloaded before each store since cgexpr
clobbers AX/BX between fields.
wwstage needed a new `structnaturalsize(si)` helper (cgenutil.ww):
si.totsize is mis-named — it's slot-padded to 8 by registerstruct for
stack-slot use, while the receive ABI wants the type's natural size
(max(foff+fsz)). Splitting si.totsize into naturalsize + slotsize is
tracked as the wwstage struct sizing follow-up (task #15); until that
lands, the helper recovers the natural size at receive sites.
Test 701_cgassign_struct.c (18 rows, 3 checks each — cstage value,
wwstage value, asm byte-identity), wired in Makefile after 698. The
headline ASYMMETRY case is the 20B `{i32×5}` row: sender pads to 24B
via three MOVQs, receiver writes MOVQ AX +0, MOVQ DX +8, MOVL CX +16.
A regression to a MOVQ tail there overruns 4B past the slot and
flips the exit-code check.
smoke.combined.ww is the auto-regen ride-along of strings.freeall
landing in 714d089 (worker-shlex).
Pre-existing gaps surfaced and tracked separately (not fixed here,
out of scope):
- task #16: silent drop of `(*p).f = ...` explicit-deref dot lhs.
- task #17: silent zero of nested STRUCTLIT field in N_LET / N_ASSIGN
initializer — the field_chain and field_global test rows use
explicit field writes (`o.m.t = 10i64;`) rather than nested
literals as a fixture-level workaround.
- task #9: module-name-mangle for fn labels avoided in the
field_global_call fixture by `let g: outer;` (no init).
make test: 59/59. 994_w6c_ww + 995_self_rebuild PASS — bootstrap
byte-identity is the load-bearing proof for this commit's scope.
Whole-struct return ABI for sizes <=24B. Both stages materialise rhs
into a zero-padded 24B @retscr scratch slot, then load AX=bytes[0..7],
DX=bytes[8..15], CX=bytes[16..23] unconditionally — three MOVQs
regardless of declared struct size, so the receive side (landing in
task #5) can read all three words and mask by the declared size. R8
stays reserved for the tagged-return 4th word; the uniform-MOVQ shape
is cheap over a size-conditional partial-load and keeps the producer
diff vs the existing tagged-return AX/DX/CX/R8 path minimal.
Two rhs shapes wired this pass: N_IDENT (word-copy from rhs local slot,
MOVQ pairs + MOVL/MOVB tail bounded by declared struct size) and
N_STRUCTLIT (field-walk; tagged fields delegate to the existing tagged
widening helper, float fields go through X0, int fields use MOVQ/MOVL/
MOVB by field size). Sizes >24B fall through to the existing scalar
path (only AX gets the first qword), pending sret in a future task.
N_CALL chain-return (`return otherfn()`) is deferred to task #5's
receive side — until that lands the call-result lives in caller regs.
The wwstage mirror in cgenstmt.ww matches cgen.c byte-for-byte on the
new branch; cgendecl.ww's scanlocals pre-reserves 24B for @retscr under
the same predicate (N_RETURN, fnret is N_TNAME, structlookup hit,
totsize<=24, rhs is N_IDENT|N_STRUCTLIT) since wwstage writes its
prologue SUBQ from the upfront frame total — cstage patches SUBQ at fn
end so it can allocate inline.
Latent fsz==2 MOVW divergence between stages (cstage structlit int-
branch only special-cases fsz 1/4, wwstage's fieldstoreop also returns
MOVW for fsz==2) tracked as task #13; not exercised by the new fixtures
or by any current selfhost <=24B struct return.
main.combined.ww files also pick up worker-checkfix's wwstage
architectural comment from 7f60ebb (auto-regen ran after that commit).
Extended cg_widen_tagged_store (cstage) / cgwidentaggedstore (wwstage)
to take a base_reg/basereg parameter so the primitive supports non-BP
destinations. Cstage extends body in-place via via_outer gate +
spill+scratch+copy-out; wwstage splits into wrapper (non-BP) +
cgwidentaggedstorebp (BP-only) to dodge the no-goto constraint. New
N_ASSIGN field TY_TAGGED branch routes through the primitive for all
rhs shapes.
Scope-adjacent: fieldsize recurses through N_TTAGGED via slotsize and
TNAME-aliased-to-tagged via aliaslookup. Needed for the test fixtures.
Wwstage read-side N_DOT-of-tagged-field source is filed as task #28;
test rows use mark-canary verification until that lands.
type_isunsigned recurses TY_ENUM and includes TY_RUNE on both stages.
13 LOAD + 6 STORE ladder sites (cstage) plus 4 more wwstage stragglers
in cgindex/cgforrange collapsed to fldloadop/fldstoreop helpers. N_CAST
narrow gate symmetrised; task #1's literal-kind workaround retired.
bool kept out of type_isunsigned, special-cased in field helpers.
Retroactively fixes a u32 mis-sign-extend in deref-compound (sz=4
hardcoded MOVSXD), pinned by new 660_field_signed row.
`let x: T;` for str/slice/tuple/struct/tagged previously left the slot
holding stack garbage — only 8B-primitive slots were zeroed. This bit
`expectbindname` in lib/ww/parse: `let empty: str; *into = empty;` was
copying stack bytes (often a recently-vacated str descriptor) into the
caller's `id`, so wwstage emitted `_` discard nodes carrying random
text instead of "". Both stages now zero the full slot on no-rhs lets;
`[N]T` arrays keep the per-index-write contract.
Also tightens the two known buggy sites: parse.ww `expectbindname`
writes `*into = ""` directly, expr.ww `_` primary returns the bare
newnode (amalloc already zeroes).
Six fixes across the toolchain, surfaced by lib/lisp porting work.
1. f64 compound assigns (`acc += d`, `-=`, `*=`, `/=`). Both stages
load slot → X1, OP X0 into X1, store back (ADDSD/SUBSD/MULSD/
DIVSD are reg-reg only). Previous MOVSD-overwrite dropped the
OP. Locals and top-level lets.
2. Top-level `[N]u8` arrays + `&arr[i]`. let_emit_size grows a
TY_ARRAY branch so zero-init DATAW lands; cgindex / N_INDEX
store / `&base[i]` all detect a global array base and use
LEAQ name(SB) instead of LEAQ (BP). TK_AMP no longer pre-
evaluates the operand as a value-load — `&base[i]` computes
base + i*esz directly. Unblocks Hare's static-buffer pattern:
strconv.{u64,i64,f64}tos graduate to module-level `*_buf`
arrays and return owned views.
3. Cross-module `pkg.Enum.MEMBER`. Nested N_DOT chains that
don't fold to a known shape now emit `MOVQ <leaf>(SB), AX`
(mirrors the bare-IDENT unresolved fallback), so isolation
probes — and the test 990 cgen-match floor — stay consistent
across stages. strconv exposes `base` as a real `enum i32`;
callers updated. The `main` exemption (linker entry-point
keeps bare name even when not exported) mirrors C-side
collectmods into selfhost cgendecl.
4. Sum-typed parameter ABI. lib/bytes.{index,rindex} take
`(u8 | []u8)` needle; lib/strings.byteindex / rbyteindex take
`(str | rune)` needle (Hare-shaped; the byte-wise misnomer
`index` is dropped). tagged_arg_size cap bumps to 48 (6 int
regs), with a new partial-fit branch on the callee: when an
N-word tagged arg overflows remaining regs, fill what fits and
stitch the rest from positive BP offsets. scanlocals MCASE
handles slice binds (24B) and walks each arm with a saved /
restored seenmark set so two arms naming the same local each
get their own slot — matches cstage's per-arm scope reset.
5. 4-reg tagged-return ABI (AX=tag, DX=word0, CX=word1, R8=word2),
up from 3 regs. Slice-payload variants (`([]T | E)`, slot 32B)
round-trip ptr/len/cap end-to-end. Every receive site updates:
let-init via cgwidentaggedstore, match scrutinee spill, cgindex
tagged-element load (both N_IDENT and fallback bases),
pushargsrev tagged-ident arg (reads word count from slot size),
cgreturn slice variant in the shuffle path.
6. `expr: TaggedAlias` is a widening, not a re-interpret. C cgen +
selfhost cgwidentaggedstore peel an N_CAST whose destination IS
the union — so cgexpr's natural shape (str: AX=ptr, BX=len;
slice: AX=ptr, BX=len, CX=cap) is consumed by the matching
concrete-variant branch instead of being misread as a tagged
AX/DX/CX triple. Inner casts to a concrete variant (`7: i32`)
keep their type for proper tag lookup. `[N]Alias` arrays
resolve element size via slotsize + aliaslookup, and aliaslookup
strips a `pkg.` prefix so cross-module references work.
lib/fmt grows `formattable = (i64 | str | bool | rune)` plus
`printv` / `printlnv` taking an explicit `[]formattable` slice (the
receive side of Hare's `args: formattable...`). Call-site variadic
gather isn't wired — callers either hand-build the slice or compose
strconv.i64tos + strings.concat.
700_e2e: 114 → 123 rows (f64 compound, top-level u8 arrays + `&buf[i]`,
pkg.Enum.MEMBER, sum-typed (str|rune) and (u8|[]u8) params, 4-reg
slice-return ABI, formattable array). 26/26 tests, bootstrap stable
through ww4.
Closes the remaining tagged-union gaps after the prior two commits:
1. Tagged element in an array/slice (cstage). N_INDEX load now reads
slot words into AX/DX/CX, matching the tagged-return ABI so match
/ call-arg / let-init paths consume `arr[i]` uniformly. N_INDEX
store routes through a scratch slot + cg_widen_tagged_store +
byte-copy to &arr[i], so the full widening machinery (scalar /
str / struct payload / tagged subset / nullable fold) lights up
for element writes too.
2. Selfhost mirror — the cgen widen helpers (struct payload,
tagged-subset, spread-flatten) C cgen has had for two commits
finally land in selfhost:
cgwidentaggedstore — single writer for nullable / tagged ident /
tagged via AX:DX:CX / struct (lit + ident) /
str / scalar source shapes.
cgwidentagremap — CMPQ-chain tag remap for variant-subset.
rhsstructpayload — struct-name predicate; filters `!void` /
`!i32` aliases that share N_STRUCTLIT shape
but aren't structs.
rhstaggedident,
rhstaggedabicall — source-shape predicates.
flatvariantidx — spread-aware variant index lookup. Walks
`(...inner | T)` entries by resolving the
alias and inlining the inner's variants so
wwstage's tag order matches the check.c
flattening cstage does at type resolution.
cglet tagged init, cgassign tagged-ident reassign, cgreturn struct
/ subset payload, pushargsrev struct payload, cgindex tagged
element load, cgassign N_INDEX tagged element store all delegate
to these. cgmatch picks up scrutt from N_INDEX bases (element
type) and uses flatvariantidx for case dispatch.
3. Selfhost frame accounting: scanlocals reserves a 24B @tagscr slot
when the body contains a tagged-arr store, a struct-payload
tagged return, or a struct-payload call arg — dedup'd via
scanseenmark so multiple sites share one slot. N_LET stubs now
carry tnode so walk-time type checks see the array element type.
slotsize TARRAY learned to size tagged / struct / ptr / aliased
elements (was 8B-default for anything not N_TNAME-primitive,
undersizing tagged-element arrays).
Scalar / str call-arg widening keeps its direct-push fast path
(no scratch), so wwstage's asm on selfhost source remains
byte-identical to cstage's — 993/995 still pass.
700_e2e: 9 new rows — scalar/str/struct/subset/nullable variants in
arrays and slices, plus pass-arg / let-init / return / match shapes.
`type error = !(invalid | overflow)` miscompiled — istaggedtype
only matched N_TTAGGED directly, so an `e: error` param spilled
as 8B scalar and the match's slot+8 read trailed into saved BP.
Mirror isstrtype's alias+bang unwrap; add resolvetagged() for
is/as/match sites that need the inner N_TTAGGED. Frame scan
counts via slotsize so wwstage stays byte-identical to cstage.
Unblocks lib/strconv.strerror.
Surfaced via examples/lisp, which had to work around the following in
source. Each lowering now matches cstage on the same shape.
- cgassign / cgdot: two-level field through a non-pointer sub-struct.
`(*L).cur.kind = k` (cur a struct-by-value field of L) silently
dropped the store; the corresponding read fell into the SB-symbol
fallback and the linker reported `undefined reference to kind`. The
two new branches resolve outer-field offset + inner-field offset
and emit a single direct store/load at the combined slot, both for
T-by-value and *T-base shapes.
- cgdot: `xs[i].field` chains the trailing field load through the
N_INDEX result for [N]T / []T / *T element-of-struct-ptr. The
cgforrange loop variable now carries the elem tnode so the same
fast path covers `for (let x .. xs) { x.field }`.
- cgindex / cgassign: top-level `[N]T` array and `*T` pointer used
as an index base. cgindex now emits LEAQ name(SB) (array) or
MOVQ name(SB) (pointer) with the correct element scaling; without
this the fallback emitted neither base and walked off the saved
BP slot. Adds letvartnode() helper, an N_TARRAY branch to
letemitsize so the array shows up in c.lets, and an N_TARRAY
initialiser path in emitletdataw that lays the literal bytes into
DATAW.
- cglet / scanlocals: infer the local's tnode for an unannotated
`let x = f()` / `let x = f()?`. inferletcalltype() reads the
callee's declared return; `?` and `!` strip to the success variant
so a tagged-union let allocates the full 24B slot and the
struct-field dispatch in cgdot/cgassign sees the right type.
letslotsize now defers to slotsize on the inferred type.
- slotsize: follow type aliases for tagged-union variants. With
`type parserr = !str;`, the variant slot was 8B instead of the
required 16B; the tagged let stomped on the next slot at the
AX/DX/CX spill.
- cgreturn: tagged-union return forwarding. `return f();` where f
also returns a tagged union now passes the (tag, payload1,
payload2) triple through unchanged instead of re-wrapping it.
- cgreturn / cglet / taggedvariantindex: dispatch by variant name
with module-qualified-vs-bare matching, and recognise N_STRUCTLIT
as the variant tag for `return eof{};`. cgexpr default emits
`MOVQ $0, AX` so the surrounding return shuffle isn't left with
a stale AX.
- isstrtype / nodeisstr: resolve through `!T` aliases. `parserr =
!str` was not propagating the str-shape to the rhs check and the
MOVQ BX,CX shuffle was being dropped from str-typed local
returns.
- exprfloatkind: recognise `p.field` as f64/f32 when the struct
field is so declared, so `v.fval: i64` lowers to CVTTSD2SI on X0.
- cgassign: str field on a direct struct local writes both halves.
`L.src = s;` previously dropped s.len.
- cgcall: pop into the int reg window only up to 6 (DI..R9); rest
stays on the stack and the caller emits ADDQ to clean up.
cgfnparams accepts >6-arg signatures by registering the overflow
params at positive BP offsets (16+8*k(BP)), no spill instruction
emitted.
All 26 harness tests pass; bootstrap reaches a byte-stable fixed
point at ww3 == ww4.
cgexpr leaves float results in X0, not AX, but the struct-field paths
emitted MOVQ AX,off(BX) and MOVQ off(BX),AX — so every store wrote
garbage and every load read garbage, except by accidental register
survival across an unrelated call. examples/lisp only worked because
parsef's X0 happened to live across the broken MOVQ shuffle into
vfloat; any inserted f64 op between them would silently corrupt.
Wire MOVSD/MOVSS X0,… (and the matching loads) into eight field
sites on both compilers: alloc(T{...}), p.x = v through local/ptr/
global, chained r.sub.x = v, *p = v for *f64, let v: T = T{...},
base.x reads, *T.x reads, and chained a.b.c.x reads.
83/83 lisp_test probes still pass; bootstrap reaches a byte-stable
fixed point at ww3 == ww4.
