Two cgen/check bugs surfaced by new lib modules, plus the modules
themselves (crc64, siphash, random, base64, base32).
1. `(big_u64): u32` (and `: u16`, `: u8`, `: bool`) didn't truncate.
N_CAST emitted nothing for int↔int; the value stayed in AX with
its upper bits intact and downstream CMPQ/DIVQ misread the slot.
The TK_TILDE path already had clamp logic for the same reason —
N_CAST was the missing case. Both stages now MOVL r,r for u32 and
ANDQ $mask for u8/u16/bool. Signed-narrow (i8/i16/i32) stays
no-op until w6a grows reg-reg MOVSBQ/MOVSWQ/MOVSXD. selfhost
cgcast walks alias chains via aliaslookup before checking
primsize/typenameisunsigned so `(u: random)` where
`type random = u64` still bypasses the clamp.
See cmd/w6c/cgen.c N_CAST and selfhost/cmd/wcc/cgenexpr.ww cgcast.
2. `mod.mod` type refs (`random.random` when the imported module
declares `export type random = u64;`) failed with "unknown type".
The driver concatenates imports into one flat scope, so SK_USE
`random` collided with SK_TYPE `random` and scope_define silently
dropped the use. resolve_typename's leaf lookup required
`kind == SK_USE` and gave up. Adds a `use_alias` flag to Sym; the
pass-1 decl scan now marks colliding syms in both directions
(use-after-type and type-after-use). resolve_typename and the
N_DOT cexpr branch treat `use_alias` like SK_USE for qualified
lookup. selfhost check.ww was already lenient on this path so no
ww-side change was needed; bootstrap fixed point (990-995) holds.
See cmd/wcc/check.c installdecl pass + N_DOT/resolve_typename and
cmd/wcc/ww.h Sym.use_alias.
New modules under lib/, each with @test vectors in *_test.ww and wired
into test/wcc/900_stdlib.c (26 modules → all compile):
- lib/hash/crc64 ECMA, ISO (mirror of crc32 shape)
- lib/hash/siphash SipHash-2-4, buffer-based sum/sum24
- lib/math/random SplitMix64 (init, next, u32n, u64n)
- lib/encoding/base64 RFC 4648 std + url-safe encode/decode + sizes
- lib/encoding/base32 RFC 4648 std + base32hex encode/decode + sizes
Seven fixes across the toolchain, plus three new lib/hash modules
(adler32, crc16, crc32) that surfaced them.
1. `~x` on u8/u16/u32 left the upper bits set: NOTQ inverts the
whole 64-bit register and nothing trimmed it back to type
width, so a returned `u16` would compare 64-bit against a
typed literal and disagree. Both stages now mask after NOTQ
for narrow unsigned: AND $0xFF/0xFFFF for u8/u16, MOVL r,r for
u32 (ANDQ $0xFFFFFFFF sign-extends imm32 and is a no-op).
Signed narrows stay sign-extended and need no fix-up. See
cmd/w6c/cgen.c N_UN TK_TILDE and selfhost cgenexpr.ww cgun
TK_TILDE with new nodeprimwidth helper.
2. w6a had no D_CONST immediate path for ANDQ / ORQ. cgen would
emit `ANDQ $65535, AX` and the rr encoder silently wrote
`21 /r` with garbage reg fields — the mask never happened.
Added `81 /4` (AND) and `81 /1` (OR) imm32 paths in both
cstage and selfhost w6a. The ~width fix above depends on this.
3. `s: []u8` cast as a direct fn argument produced a 0-length
slice. cgexpr for N_CAST left (AX=ptr, BX=len) from the str
source but never set CX (cap), and the arg-push fallback only
pushed AX. cgcast now synthesises CX=BX when target is slice
and source is str; node_isslice / arg-push recognise
cast-to-slice and emit the full (cap, len, ptr) triple. Both
stages.
4. `*[N]T` element-store used 8-byte stride + MOVQ regardless of
T's width. Indexing `buf: *[4]u16` would step 8 bytes and
write 8 bytes per element. Added idx_eff (drills *[N]T → T)
in cstage and the matching pointer-array drill in selfhost
elemsizeof. Also added MOVW / MOVZWQ / MOVSWQ to w6c, w6a,
and selfhost mirrors so 2-byte element stores/loads use the
right opcode (was falling through to MOVQ and trailing 6 bytes
into the next slot).
5. Slicing a top-level fixed array (`g[0:n]` where `g: [N]T` is
a global) computed the base from BP instead of the symbol —
localfind returned 0 and the cgen treated it as a local at
offset 0. Both N_SLICE-as-expression (cgslice) and N_SLICE-
as-call-arg paths now check let_islet / letvartnode and emit
LEAQ name(SB) when the base is a global array (or MOVQ
name(SB) for a global slice/pointer base). Both stages.
6. Top-level `let arr: [N]T = [v0, v1, ...]` link-failed on
cstage — emit_lets bailed when it saw N_ARRLIT init on an
array type, and the sz==8 scalar path then misemitted any
8-byte-sized array (e.g. [4]u16, [8]u8) as a single quad.
emit_lets now walks N_ARRLIT, evaluates each element as an
int/rune/bool/nil literal, packs per-element bytes
little-endian, and honours the trailing `...` repeat marker.
Selfhost already handled the literal-init path; fixed the
parallel sz==8 duplicate-DATAW emit on its side (the array
and the scalar paths both fired, last write winning at link
but the duplicate broke cross-stage byte-identicality on user
code with this shape).
7. w6a's per-line input buffer was a 1KB stack `char buf[1024]`.
A `DATAW` for a [256]u16 emits ~2080 bytes on one line, which
truncated mid-escape; the assembler then re-parsed the
remaining tail as garbage opcodes ("unknown opcode"). Bumped
cstage w6a to a 32K static buffer (selfhost w6a already
allocated per-line via amalloc).
lib: lib/hash/adler32, lib/hash/crc16, lib/hash/crc32 — pure
buffer-subset shape (matching lib/hash/fnv), with per-module
*_test.ww runnable via `ww test lib/hash/<name>`. Adler-32 plus
CRC-16 (CCITT/CMDA2000/DECT/ANSI) and CRC-32 (IEEE/Castagnoli/
Koopman) cover Hare's reference vectors bit-for-bit. Wired into
test/wcc/900_stdlib.c. .gitignore: lib/**/*.s,*.o so `ww test`
droppings stay untracked.
`make test` (26/26), `make bootstrap` (ww2≡ww3≡ww4), and per-module
`ww test` all pass. cgen output is byte-identical across cstage and
selfhost for every repro that previously diverged.
