Hojun-Cho
0763377806
The chained value-struct spine-walker resolved root + total offset + leaf type via structinfo/fieldinfo (slot-padded foff). Swap its guts onto the stamped root-ident type_: peel TY_NAMED to TY_STRUCT (one TY_PTR hop for a *struct root) and accumulate tfield.offset down the spine, mirroring cstage's cur->lhs->type fields walk (cmd/w6c/cgen.c:3156-3216 write, :1955-2030 AMP/ read). Leaf out-param becomes *tinfo; the three callers read leaf-ness via typeis*/loadopsz, and the cgassign struct-terminal recovers the struct name from the leaf tinfo's NAMED wrapper for the still-structinfo cgstructlitfill. Root classification (local/ptr/global) is unchanged, so the firing set and addressing mode stay byte-identical; the global-root path remains its pre- existing shared breakage (#27), untouched. Natural tfield.offset equals the old slot-padded foff for every shape the byte-id gate exercises -- and since cstage already reads the natural offset and ww-old==cstage held, the flip is structurally identical, not coincidental. Latent (off-corpus, byte-id-neutral): the tinfo-peel now fires the str/slice pseudo-leaf on an aliased-str/slice field where the old structinfo path bailed -- a faithful-toward-cstage gap closure, filed for a probe + sentinel. make test 134/134, byte-id 950+990-997 hold.
3323 lines
123 KiB
Plaintext
3323 lines
123 KiB
Plaintext
// selfhost/cmd/wcc/cgenutil.ww — split out of cgen.ww.
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//
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// General helpers used across cgenexpr / cgenstmt / cgendecl:
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// - pushargsrev: per-call arg pushing
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// - type predicates: isstr*/isslice*/istagged*/nodeis* families
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// - field ops: fieldloadop, fieldstoreop
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// - index helpers: indexbaseesz, elemsizeof
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// - slot sizing: structlookup, primsize, slotsize, fieldsize,
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// registerstruct, collectstructs
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// - rhs helpers: taggedvariantindex
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//
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// Bundler pulls this in transitively via cgen.ww; consumers don't
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// need to `use cgenutil;` directly.
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package wcc;
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import os;
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import ast;
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import tok;
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import typ;
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import sym;
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import strconv;
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// ---- variadic-call helpers (Hare-style `T...` param) -----------------
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// slicewrap — synthesise an N_TSLICE node wrapping the given element
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// type AST. Used by the Hare-style variadic path so the local entry
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// for the param (callee side) and the call-site slice descriptor
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// (caller side) both advertise their effective type as []ELEM —
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// every isslicetype / nodeisslice check then succeeds naturally.
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fn slicewrap(c: *cgen, elem: *node) *node = {
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let s: *node = newnode(nkind.N_TSLICE, "", 0, 0);
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s.lhs = elem;
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return s;
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};
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// findvariadicparam — walk a param-list head and return the variadic
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// param node (the one with op == TK_ELLIPSIS) plus the count of
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// non-variadic params before it. Returns nil/0 when no variadic.
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// nfixed_out cannot be nil.
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fn findvariadicparam(ps: *node, nfixed_out: *i32) *node = {
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*nfixed_out = 0;
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let p: *node = ps;
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for (p != nil) {
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if (p.kind == nkind.N_PARAM) {
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if (p.op == tkind.TK_ELLIPSIS) {
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return p;
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};
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*nfixed_out += 1;
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};
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p = p.next;
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};
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return nil;
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};
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// callee_variadic_param — convenience wrapper: looks up the callee
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// by name and finds its variadic param + nfixed. Returns nil if the
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// callee isn't registered or has no variadic param.
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//
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// N_DOT routes through fnparamslookupmod with the module hint
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// (callee.lhs.str) — bare fnparamslookup walks same-module-first
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// (#4d) which is wrong for a cross-module N_DOT call into a module
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// whose same-leaf fn has divergent variadic-vs-non-variadic shape.
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// #4d explicitly deferred this re-routing; surfaced by #16 when
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// strings.contains gained a variadic shape and a caller's
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// bytes.contains call site picked strings.contains' variadic
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// params for arg-prep while emitting CALL bytes.contains.
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fn callee_variadic_param(c: *cgen, callee: *node, nfixed_out: *i32) *node = {
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*nfixed_out = 0;
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if (callee == nil) { return nil; };
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let ps: *node = nil;
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if (callee.kind == nkind.N_IDENT) {
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if (callee.str.len == 0) { return nil; };
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ps = fnparamslookup(c, callee.str);
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} else { if (callee.kind == nkind.N_DOT) {
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if (callee.str.len == 0) { return nil; };
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let cmod: str;
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cmod.ptr = nil; cmod.len = 0;
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if (callee.lhs != nil) {
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if (callee.lhs.kind == nkind.N_IDENT) {
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cmod = callee.lhs.str;
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};
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};
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ps = fnparamslookupmod(c, callee.str, cmod);
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}; };
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return findvariadicparam(ps, nfixed_out);
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};
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// mkvarargname — fresh local-slot name "<prefix><seq>". Used for
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// the per-variadic-call scratch buffers (`@vararg_d_N` for the
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// element-data buffer, `@vararg_sl_N` for the 24B slice descriptor).
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// N is recorded on the N_CALL node at first emit so re-entry into
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// cgcall picks the same names regardless of walk order.
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fn mkvarargname(c: *cgen, prefix: str, seq: i32) str = {
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let buf: [128]u8;
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let i: i32 = 0;
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let j: i32 = 0;
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for (j < prefix.len) {
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buf[i] = prefix[j];
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i += 1; j += 1;
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};
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let ns: str = strconv.i64tos(seq: i64, strconv.base.DEC);
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let n: i32 = ns.len;
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let dk: i32 = 0;
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for (dk < n) { buf[i + dk] = ns.ptr[dk]; dk += 1; };
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let total: i32 = i + n;
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let p: []u8 = alloc([], (total: u64) + 1u64)!;
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let k: i32 = 0;
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for (k < total) { p[k] = buf[k]; k += 1; };
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p[total] = 0u8;
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let r: str;
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r.ptr = p.ptr;
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r.len = total;
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return r;
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};
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// ---- expression cgen -------------------------------------------------
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// pushargsrev — recursively walks the arg list, evaluates rightmost
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// first, and pushes. str args take two slots (ptr in AX, len in BX);
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// the order on the stack so a left-to-right pop into argregs lands
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// (ptr, len) correctly is: PUSHQ BX (top), PUSHQ AX (above) — the
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// pop sequence then yields AX, then BX.
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//
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// `param` is the corresponding declared parameter for `arg` (N_PARAM
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// node from the callee's signature) or nil. When param's type is a
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// tagged union and `arg`'s surface type is a concrete variant of it,
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// we materialise (tag, value-words, pad) for the parameter slot before
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// pushing — mirrors cmd/w6c/cgen.c's call-arg widening.
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fn pushargsrev(c: *cgen, arg: *node, param: *node) i32 = {
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if (arg == nil) { return 0; };
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let nextparam: *node = nil;
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if (param != nil) { nextparam = param.next; };
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let rest: i32 = pushargsrev(c, arg.next, nextparam);
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// Implicit widening from a concrete variant to a tagged-union
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// parameter slot. Skips when the arg is already a tagged local
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// (line 121's slice-or-tagged shortcut handles that).
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let widensz: i32 = 0;
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let widentag: i32 = 0;
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if (param != nil) {
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if (param.kind == nkind.N_PARAM) {
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// Hare-style variadic `T...`: effective param type is
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// []T (slice). The arg here is the synthesised slice
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// descriptor (or a forwarded `xs...` slice), not a
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// value of T being widened into a tagged slot — skip
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// the widening detection so the slice-ident fast path
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// at the bottom of pushargsrev gets the push.
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if (param.op == tkind.TK_ELLIPSIS) {
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widensz = 0;
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} else {
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let ptype: *node = param.lhs;
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if (istaggedtype(c, ptype)) {
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let aistagged: bool = false;
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if (arg.kind == nkind.N_IDENT) {
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let lc: *local = localfindnode(c, arg.str);
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if (lc != nil) {
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aistagged = istaggedtype(c, lc.tnode);
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};
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};
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// #21: a CALL returning a tagged-union must
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// skip widening — cgexpr leaves AX=tag,
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// DX=word0, CX=word1, R8=word2 per the
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// tagged-return ABI; the widening branch would
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// treat AX as a concrete payload and silently
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// drop DX/CX/R8. Restrict to the matching-slot
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// case (mirrors cstage type_eq at
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// cmd/w6c/cgen.c:4216-4221); tagged-source
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// widening into a wider slot is out of scope.
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if (taggedcallslot(c, arg) == slotsize(c, ptype)) {
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aistagged = true;
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};
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// #12: N_INDEX of a sum-typed slice element —
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// cgindex emits the same AX/DX/CX/R8 tagged ABI.
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// Without this gate the widening scalar branch
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// hardcodes the param's first-variant tag and
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// the callee reads a fixed arm on garbage.
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// #60: arg.type_ is the checker-stamped element
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// tinfo (check.ww indexresult); istaggedtype/
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// slotsize read .type_, so feed the N_INDEX node
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// directly. cstage reads the element via
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// base->type->sub (cmd/w6c/cgen.c:3518).
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if (arg.kind == nkind.N_INDEX) {
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if (istaggedtype(c, arg)) {
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if (slotsize(c, arg) == slotsize(c, ptype)) {
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aistagged = true;
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};
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};
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};
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if (!aistagged) {
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widensz = slotsize(c, ptype);
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let tagged: *node = resolvetagged(c, ptype);
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let t: i32 = taggedvariantindex(c, tagged, arg);
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if (t < 0) { t = 0; };
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widentag = t;
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};
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};
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};
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};
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};
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if (widensz == 8) {
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// Nullable fold: pointer value IS the discriminator. No
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// separate tag word.
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cgexpr(c, arg);
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emitline("\tPUSHQ\tAX\n");
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return rest + 1;
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};
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if (widensz > 0) {
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// Struct-payload widening into a tagged-union param uses
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// @tagscr (zero + cgwidentaggedstore writes fields + tag,
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// then push slot words high → low). Scalar / str go via
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// the direct push fast path below — keeps wwstage's asm
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// byte-identical to cstage for selfhost source.
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let pname: str = rhsstructpayload(c, arg);
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if (pname.len > 0) {
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let ptype: *node = param.lhs;
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let scroff: i32 = localadd(c, "@tagscr", widensz, nil);
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emitline("\tXORQ\tAX, AX\n");
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let zz: i32 = 0;
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for (zz < widensz) {
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emitline("\tMOVQ\tAX, ");
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emitoff((scroff + zz): i64);
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emitline("(BP)\n");
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zz += 8;
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};
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cgwidentaggedstore(c, ptype.type_: *tinfo, arg, "BP", scroff, widensz);
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let pp: i32 = widensz - 8;
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for (pp >= 0) {
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emitline("\tMOVQ\t");
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emitoff((scroff + pp): i64);
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emitline("(BP), AX\n");
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emitline("\tPUSHQ\tAX\n");
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pp -= 8;
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};
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return rest + widensz / 8;
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};
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cgexpr(c, arg);
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if (nodeisslice(c, arg)) {
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// Slice payload (24B): cgexpr leaves (AX=ptr, BX=len,
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// CX=cap). Slot layout: [+0]=tag, [+8]=ptr, [+16]=len,
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// [+24]=cap. Push high→low so pop drains tag first.
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// Requires widensz >= 32; a smaller slot would mean the
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// destination union doesn't list slice as a variant
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// (caller should have flagged a type error).
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emitline("\tPUSHQ\tCX\n");
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emitline("\tPUSHQ\tBX\n");
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emitline("\tPUSHQ\tAX\n");
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emitline("\tMOVQ\t$");
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emitint(widentag: i64);
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emitline(", AX\n");
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emitline("\tPUSHQ\tAX\n");
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} else { if (nodeisstr(c, arg)) {
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// slot 24: [+0]=tag,[+8]=ptr,[+16]=len. Push high→low
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// so pop drains tag first into arg-reg[0].
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emitline("\tPUSHQ\tBX\n");
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emitline("\tPUSHQ\tAX\n");
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emitline("\tMOVQ\t$");
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emitint(widentag: i64);
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emitline(", AX\n");
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emitline("\tPUSHQ\tAX\n");
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} else {
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// Scalar variant: single value word at +8. Pad a zero
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// high word when slot is 24B (some other variant of
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// the union is 16B-shaped).
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let pp: i32 = widensz - 8;
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for (pp > 8) {
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emitline("\tXORQ\tDX, DX\n");
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emitline("\tPUSHQ\tDX\n");
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pp -= 8;
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};
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emitline("\tPUSHQ\tAX\n");
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emitline("\tMOVQ\t$");
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emitint(widentag: i64);
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emitline(", AX\n");
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emitline("\tPUSHQ\tAX\n");
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};};
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return rest + widensz / 8;
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};
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// nkind.N_SLICE expression as arg: `buf[lo:hi]` builds a slice header
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// on the stack matching C cgen's sequence — push base, push hi,
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// compute lo, pop into BX/CX, derive len/ptr, push (cap, len, ptr).
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if (arg.kind == nkind.N_SLICE) {
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let base: *node = arg.lhs;
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let lo: *node = arg.rhs;
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let hi: *node = arg.cond;
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let baselocal: *local = nil;
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let globaltn: *node = nil;
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let globalname: str;
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globalname.ptr = nil; globalname.len = 0;
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if (base != nil) {
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if (base.kind == nkind.N_IDENT) {
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let bn: str = base.str;
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baselocal = localfindnode(c, bn);
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if (baselocal == nil) {
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let gt: *node = letvartnode(c, bn);
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if (gt != nil) {
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globaltn = gt;
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globalname = bn;
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};
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};
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};
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};
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// base address → push
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if (baselocal != nil) {
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let tn: *node = baselocal.tnode;
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if (tn != nil) {
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if (tn.kind == nkind.N_TARRAY) {
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emitline("\tLEAQ\t");
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emitoff(baselocal.off: i64);
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emitline("(BP), AX\n");
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} else {
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emitline("\tMOVQ\t");
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emitoff(baselocal.off: i64);
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emitline("(BP), AX\n");
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};
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} else {
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emitline("\tMOVQ\t");
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emitoff(baselocal.off: i64);
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emitline("(BP), AX\n");
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};
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} else { if (globaltn != nil) {
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if (globaltn.kind == nkind.N_TARRAY) {
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emitline("\tLEAQ\t");
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emitsymname(c, globalname);
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emitline("(SB), AX\n");
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} else {
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emitline("\tMOVQ\t");
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emitsymname(c, globalname);
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emitline("(SB), AX\n");
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};
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} else {
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cgexpr(c, base);
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};};
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emitline("\tPUSHQ\tAX\n");
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// hi (default base length) → push
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if (hi != nil) {
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cgexpr(c, hi);
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} else { if (baselocal != nil) {
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let tn: *node = baselocal.tnode;
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if (tn != nil) {
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if (tn.kind == nkind.N_TARRAY) {
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let lenn: *node = tn.rhs;
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if (lenn != nil) {
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if (lenn.kind == nkind.N_INTLIT) {
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emitline("\tMOVQ\t$");
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emituint(lenn.uval);
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emitline(", AX\n");
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};
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};
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} else { if (tn.kind == nkind.N_TSLICE) {
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emitline("\tMOVQ\t");
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emitoff((baselocal.off + 8): i64);
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emitline("(BP), AX\n");
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} else { if (tn.kind == nkind.N_TNAME) {
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if (streq(tn.str, "str")) {
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emitline("\tMOVQ\t");
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emitoff((baselocal.off + 8): i64);
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emitline("(BP), AX\n");
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};
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};};};
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};
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} else { if (globaltn != nil) {
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if (globaltn.kind == nkind.N_TARRAY) {
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let lenn: *node = globaltn.rhs;
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if (lenn != nil) {
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if (lenn.kind == nkind.N_INTLIT) {
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emitline("\tMOVQ\t$");
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emituint(lenn.uval);
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emitline(", AX\n");
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};
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};
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} else { if (globaltn.kind == nkind.N_TSLICE) {
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emitline("\tLEAQ\t");
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emitsymname(c, globalname);
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emitline("(SB), CX\n");
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emitline("\tMOVQ\t8(CX), AX\n");
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};};
|
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} else {
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emitline("\tMOVQ\t$0, AX\n");
|
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};};};
|
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emitline("\tPUSHQ\tAX\n");
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// lo (default 0) → AX
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if (lo != nil) { cgexpr(c, lo); }
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else { emitline("\tMOVQ\t$0, AX\n"); };
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emitline("\tPOPQ\tBX\n"); // hi
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emitline("\tPOPQ\tCX\n"); // base
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emitline("\tMOVQ\tBX, DX\n"); // DX = hi
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emitline("\tSUBQ\tAX, DX\n"); // DX = hi - lo = len
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emitline("\tADDQ\tAX, CX\n"); // CX = base + lo = ptr
|
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emitline("\tPUSHQ\tDX\n"); // cap
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emitline("\tPUSHQ\tDX\n"); // len
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emitline("\tPUSHQ\tCX\n"); // ptr (top)
|
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return rest + 3;
|
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};
|
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// Slice/tagged ident args: emit per-register MOVQ+PUSHQ pairs in
|
||
// reverse order (cap/v1, len/v0, ptr/tag) so a left-to-right pop
|
||
// into argregs lands the canonical (ptr/tag, len/v0, cap/v1).
|
||
// For tagged ident with a >24B slot (slice-payload variant),
|
||
// push a fourth word from off+24.
|
||
if (arg.kind == nkind.N_IDENT) {
|
||
let nm: str = arg.str;
|
||
let lc: *local = localfindnode(c, nm);
|
||
if (lc != nil) {
|
||
let off: i32 = lc.off;
|
||
if (isslicetype(c, lc.tnode) || istaggedtype(c, lc.tnode)) {
|
||
let nwords: i32 = 3;
|
||
if (istaggedtype(c, lc.tnode)) {
|
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let ssz: i32 = slotsize(c, lc.tnode);
|
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nwords = ssz / 8;
|
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};
|
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let w: i32 = nwords - 1;
|
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for (w >= 0) {
|
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emitline("\tMOVQ\t");
|
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emitoff((off + w*8): i64);
|
||
emitline("(BP), AX\n");
|
||
emitline("\tPUSHQ\tAX\n");
|
||
w -= 1;
|
||
};
|
||
return rest + nwords;
|
||
};
|
||
// By-value struct ident: load qword(s) from the slot
|
||
// and push high → low so left-to-right pop on the
|
||
// callee side lands word 0 / word 1 into the SysV arg
|
||
// register pair. Mirrors cstage cgen.c §4240 (call
|
||
// site) so the wwstage prologue's new struct spill arm
|
||
// (cgendecl.ww structparamsize branch) sees the same
|
||
// reg layout. Pre-#11 the call-site fell through to
|
||
// `cgexpr(c, arg)` + scalar PUSHQ AX — only the first
|
||
// 8B word made it across, and the callee's second-arg
|
||
// slots picked up the wrong neighbour's value.
|
||
let stsz: i32 = structparamsize(c, lc.tnode);
|
||
if (stsz > 0) {
|
||
if (stsz > 8) {
|
||
emitline("\tMOVQ\t");
|
||
emitoff((off + 8): i64);
|
||
emitline("(BP), AX\n");
|
||
emitline("\tPUSHQ\tAX\n");
|
||
};
|
||
emitline("\tMOVQ\t");
|
||
emitoff(off: i64);
|
||
emitline("(BP), AX\n");
|
||
emitline("\tPUSHQ\tAX\n");
|
||
let nw: i32 = 1;
|
||
if (stsz > 8) { nw = 2; };
|
||
return rest + nw;
|
||
};
|
||
};
|
||
};
|
||
// Float arg: cgexpr leaves the value in X0. Push 8 bytes from
|
||
// X0 via SUBQ+MOVSD so cgcall's pop side can drain into the
|
||
// XMM stream (X0..X7). f32 still occupies 8B on the stack —
|
||
// the MOVSS load on the pop side touches only the low 4.
|
||
let fk: i32 = exprfloatkind(c, arg);
|
||
if (fk != 0) {
|
||
cgexpr(c, arg);
|
||
let mov: str = "MOVSD";
|
||
if (fk == 1) { mov = "MOVSS"; };
|
||
emitline("\tSUBQ\t$8, SP\n");
|
||
emitline("\t");
|
||
emitline(mov);
|
||
emitline("\tX0, (SP)\n");
|
||
return rest + 1;
|
||
};
|
||
cgexpr(c, arg);
|
||
if (nodeisslice(c, arg)) {
|
||
emitline("\tPUSHQ\tCX\n");
|
||
emitline("\tPUSHQ\tBX\n");
|
||
emitline("\tPUSHQ\tAX\n");
|
||
return rest + 3;
|
||
};
|
||
if (nodeisstr(c, arg)) {
|
||
emitline("\tPUSHQ\tBX\n");
|
||
emitline("\tPUSHQ\tAX\n");
|
||
return rest + 2;
|
||
};
|
||
// #21: CALL returning a tagged-union — the aistagged guard
|
||
// above kept us out of the widening path. Push the tagged-
|
||
// return ABI registers (AX=tag, DX=word0, CX=word1, R8=word2)
|
||
// high → low so the left-to-right POPQ into argregs drains the
|
||
// tag first. Mirrors cstage at cmd/w6c/cgen.c:4373-4387.
|
||
let tcs: i32 = taggedcallslot(c, arg);
|
||
if (tcs > 0) {
|
||
if (tcs > 24) { emitline("\tPUSHQ\tR8\n"); };
|
||
if (tcs > 16) { emitline("\tPUSHQ\tCX\n"); };
|
||
if (tcs > 8) { emitline("\tPUSHQ\tDX\n"); };
|
||
emitline("\tPUSHQ\tAX\n");
|
||
return rest + tcs / 8;
|
||
};
|
||
// #12: N_INDEX of a sum-typed slice element. cgindex above left
|
||
// the tagged-CALL ABI in AX/DX/CX/R8; the bare PUSHQ AX below
|
||
// would only carry the tag word and drop the payload. #60:
|
||
// arg.type_ is the element tinfo (istaggedtype/slotsize read
|
||
// .type_) — feed the N_INDEX node directly, dropping the
|
||
// indexvaluetnode walk.
|
||
if (arg.kind == nkind.N_INDEX) {
|
||
if (istaggedtype(c, arg)) {
|
||
let isz: i32 = slotsize(c, arg);
|
||
if (isz > 24) { emitline("\tPUSHQ\tR8\n"); };
|
||
if (isz > 16) { emitline("\tPUSHQ\tCX\n"); };
|
||
if (isz > 8) { emitline("\tPUSHQ\tDX\n"); };
|
||
emitline("\tPUSHQ\tAX\n");
|
||
return rest + isz / 8;
|
||
};
|
||
};
|
||
emitline("\tPUSHQ\tAX\n");
|
||
return rest + 1;
|
||
};
|
||
|
||
// taggedcallslot — if `n` is an N_CALL whose callee returns a tagged
|
||
// type, returns the slot size in bytes; else 0. Used by pushargsrev's
|
||
// aistagged guard and natural-push arm, and by cgcall's pop sizer, to
|
||
// route a tagged-return call result through the AX/DX/CX/R8 high→low
|
||
// push convention rather than the concrete-variant widening path
|
||
// (which drops DX/CX/R8). See task #21.
|
||
export fn taggedcallslot(c: *cgen, n: *node) i32 = {
|
||
if (n == nil) { return 0; };
|
||
if (n.kind != nkind.N_CALL) { return 0; };
|
||
let callee: *node = n.lhs;
|
||
if (callee == nil) { return 0; };
|
||
if (callee.kind != nkind.N_IDENT) { return 0; };
|
||
let rtyp: *node = fnretlookup(c, callee.str);
|
||
if (!istaggedtype(c, rtyp)) { return 0; };
|
||
return slotsize(c, rtyp);
|
||
};
|
||
|
||
fn nodeisslice(c: *cgen, n: *node) bool = {
|
||
if (n == nil) { return false; };
|
||
let k: nkind = n.kind;
|
||
if (k == nkind.N_IDENT) {
|
||
let nm: str = n.str;
|
||
let lc: *local = localfindnode(c, nm);
|
||
if (lc != nil) { return isslicetype(c, lc.tnode); };
|
||
return false;
|
||
};
|
||
if (k == nkind.N_SLICE) { return true; };
|
||
if (k == nkind.N_CAST) { return isslicetype(c, n.rhs); };
|
||
// #24: N_CALL returning a slice — cgexpr leaves (AX=ptr,
|
||
// BX=len, CX=cap); pushargsrev's slice arm pushes CX/BX/AX
|
||
// and cgcall pops 3 words. Without this arm the natural-push
|
||
// fallthrough emits one PUSHQ AX (loses .len/.cap) and the pop
|
||
// side under-drains by 2 words, leaving R8/R9 unset for the
|
||
// receiver. Mirrors nodeisstr's N_CALL arm just below.
|
||
// N_DOT (cross-module callee, #34): route through fnretlookupmod
|
||
// so a same-leaf caller-module fn with diverging return shape
|
||
// doesn't shadow the explicit `mod.f()` qualifier — surfaced by
|
||
// strings.slice returning `frombytes(utf8.slice(...))`
|
||
// where strings.slice itself returns str.
|
||
if (k == nkind.N_CALL) {
|
||
let callee: *node = n.lhs;
|
||
if (callee != nil) {
|
||
if (callee.kind == nkind.N_IDENT) {
|
||
let rtyp: *node = fnretlookupmod(c, callee.str, c.curmod);
|
||
return isslicetype(c, rtyp);
|
||
};
|
||
if (callee.kind == nkind.N_DOT) {
|
||
let cmod: str;
|
||
cmod.ptr = nil; cmod.len = 0;
|
||
if (callee.lhs != nil) {
|
||
if (callee.lhs.kind == nkind.N_IDENT) {
|
||
cmod = callee.lhs.str;
|
||
};
|
||
};
|
||
let rtyp: *node = fnretlookupmod(c, callee.str, cmod);
|
||
return isslicetype(c, rtyp);
|
||
};
|
||
};
|
||
return false;
|
||
};
|
||
// N_DOT: read the checker-stamped n.type_. Struct field, nested
|
||
// dot, value-struct hops, and pseudo-fields (.ptr/.len/.cap) all
|
||
// resolve to the right tinfo via check.ww:1947-1978 (pseudo-field
|
||
// + struct-field stamps). Cstage cgen.c:182-184 node_isslice =
|
||
// type_isslice(n->type) — same shape. Collapsed per A.6.3h (#56).
|
||
if (k == nkind.N_DOT) {
|
||
return typeisslice(n.type_: *tinfo);
|
||
};
|
||
return false;
|
||
};
|
||
|
||
// nodeisstr — best-effort surface check: does this expression
|
||
// evaluate to a str value? Used to drive the call-arg push convention
|
||
// (str args take two slots: ptr + len).
|
||
//
|
||
// TODO(#11): every consumer of "is-str" here reconstructs the answer
|
||
// from raw N_kind because wwstage has no typed AST. Each new expression
|
||
// shape needs an explicit arm or it silently falls through to false,
|
||
// which downstream drops the second slot (BX/len) at the call site.
|
||
// A typed AST check (cstage reads n->type) would replace this whole
|
||
// function. Covered arms below: N_STRLIT, N_IDENT (local/let-typed),
|
||
// N_CALL (return type), N_INDEX (element type of [N]T / []T / *T base),
|
||
// N_DOT (reads checker-stamped n.type_ — #56 A.6.3h), N_CAST.
|
||
// Not covered (separate bugs / out of scope):
|
||
// - N_UN(TK_STAR) of `*str` — cgun itself emits only `MOVQ (AX), AX`
|
||
// and never loads .len into BX; fixing the recognizer alone won't
|
||
// help. Tracked alongside the broader cgun-load-shape gap.
|
||
fn nodeisstr(c: *cgen, n: *node) bool = {
|
||
if (n == nil) { return false; };
|
||
let k: nkind = n.kind;
|
||
if (k == nkind.N_STRLIT) { return true; };
|
||
if (k == nkind.N_IDENT) {
|
||
let nm: str = n.str;
|
||
let lc: *local = localfindnode(c, nm);
|
||
if (lc != nil) {
|
||
// Use isstrtype so `!str` aliases (parserr = !str) and
|
||
// `type foo = str;` chains resolve through. The bare
|
||
// `streq("str", ...)` test missed them and dropped the
|
||
// MOVQ BX,CX shuffle on returns of str-aliased locals.
|
||
if (isstrtype(c, lc.tnode)) { return true; };
|
||
};
|
||
return false;
|
||
};
|
||
if (k == nkind.N_CALL) {
|
||
let callee: *node = n.lhs;
|
||
if (callee != nil) {
|
||
if (callee.kind == nkind.N_IDENT) {
|
||
let rtyp: *node = fnretlookupmod(c, callee.str, c.curmod);
|
||
return isstrtype(c, rtyp);
|
||
};
|
||
// #34: cross-module N_DOT — route through fnretlookupmod
|
||
// so a same-leaf caller-module fn (different return shape)
|
||
// doesn't shadow the explicit qualifier.
|
||
if (callee.kind == nkind.N_DOT) {
|
||
let cmod: str;
|
||
cmod.ptr = nil; cmod.len = 0;
|
||
if (callee.lhs != nil) {
|
||
if (callee.lhs.kind == nkind.N_IDENT) {
|
||
cmod = callee.lhs.str;
|
||
};
|
||
};
|
||
let rtyp: *node = fnretlookupmod(c, callee.str, cmod);
|
||
return isstrtype(c, rtyp);
|
||
};
|
||
};
|
||
return false;
|
||
};
|
||
// N_INDEX: `arr[i]` whose base is an indexable type carrying a
|
||
// str element. cgindex correctly loads (AX=ptr, BX=len) for a
|
||
// 16B element; without this arm pushargsrev only pushes AX and
|
||
// the call-arg pop reads .len from stack residue. Mirror of
|
||
// cstage's node_isstr → type_isstr(n->type), where n->type is
|
||
// the resolved element type after check.
|
||
if (k == nkind.N_INDEX) {
|
||
let base: *node = n.lhs;
|
||
if (base != nil) {
|
||
if (base.kind == nkind.N_IDENT) {
|
||
let bt: *node = nil;
|
||
let lc: *local = localfindnode(c, base.str);
|
||
if (lc != nil) { bt = lc.tnode; }
|
||
else { bt = letvartnode(c, base.str); };
|
||
if (bt != nil) {
|
||
let elem: *node = nil;
|
||
let bk: nkind = bt.kind;
|
||
if (bk == nkind.N_TARRAY) { elem = bt.lhs; };
|
||
if (bk == nkind.N_TSLICE) { elem = bt.lhs; };
|
||
if (bk == nkind.N_TPTR) { elem = bt.lhs; };
|
||
if (elem != nil) {
|
||
return isstrtype(c, elem);
|
||
};
|
||
};
|
||
};
|
||
// N_INDEX through a struct field: e.g. cmd.argsptr[i]
|
||
// where argsptr: *str. cgindex correctly loads the
|
||
// (ptr, len) pair via indexbaseesz; without this arm
|
||
// pushargsrev would only push AX and lose the .len.
|
||
if (base.kind == nkind.N_DOT) {
|
||
let fld: str = base.str;
|
||
if (streq(fld, "ptr")) { return false; };
|
||
if (streq(fld, "len")) { return false; };
|
||
if (streq(fld, "cap")) { return false; };
|
||
let inner: *node = base.lhs;
|
||
if (inner != nil) {
|
||
if (inner.kind == nkind.N_IDENT) {
|
||
let lc: *local = localfindnode(c, inner.str);
|
||
if (lc != nil) {
|
||
let tn: *node = lc.tnode;
|
||
let sname: str;
|
||
sname.ptr = nil; sname.len = 0;
|
||
if (tn != nil) {
|
||
if (tn.kind == nkind.N_TNAME) { sname = tn.str; };
|
||
if (tn.kind == nkind.N_TPTR) {
|
||
let pinner: *node = tn.lhs;
|
||
if (pinner != nil) {
|
||
if (pinner.kind == nkind.N_TNAME) {
|
||
sname = pinner.str;
|
||
};
|
||
};
|
||
};
|
||
};
|
||
if (sname.len > 0) {
|
||
let si: *structinfo = structlookup(c, sname);
|
||
if (si != nil) {
|
||
let fi: *fieldinfo = si.fields;
|
||
for (fi != nil) {
|
||
if (streq(fi.fname, fld)) {
|
||
let ft: *node = fi.tnode;
|
||
if (ft != nil) {
|
||
let elem: *node = nil;
|
||
let fk: nkind = ft.kind;
|
||
if (fk == nkind.N_TPTR) { elem = ft.lhs; };
|
||
if (fk == nkind.N_TSLICE) { elem = ft.lhs; };
|
||
if (fk == nkind.N_TARRAY) { elem = ft.lhs; };
|
||
if (elem != nil) {
|
||
return isstrtype(c, elem);
|
||
};
|
||
};
|
||
};
|
||
fi = fi.finext;
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
return false;
|
||
};
|
||
// N_DOT: read the checker-stamped n.type_. Struct field, nested
|
||
// dot, value-struct hops, and pseudo-fields (.ptr/.len/.cap) all
|
||
// resolve to the right tinfo via check.ww:1947-1978. Cstage
|
||
// cgen.c:168-170 node_isstr = type_isstr(n->type) — same shape.
|
||
// Collapsed per A.6.3h (#56).
|
||
if (k == nkind.N_DOT) {
|
||
return typeisstr(n.type_: *tinfo);
|
||
};
|
||
if (k == nkind.N_CAST) {
|
||
return isstrtype(c, n.rhs);
|
||
};
|
||
return false;
|
||
};
|
||
|
||
// typeis8byteprimitive — does this type take exactly one 8-byte
|
||
// slot rather than a wider aggregate? One-liner via typeis8byteprim
|
||
// (cstage N_LET sz==8 ladder SSoT). t.type_ is stamped at check.ww
|
||
// L426-436 for every type-AST kind callers reach. Collapsed onto the
|
||
// tinfo helper per A.6.3b (#46).
|
||
fn typeis8byteprimitive(c: *cgen, t: *node) bool = {
|
||
if (t == nil) { return false; };
|
||
return typeis8byteprim(t.type_: *tinfo);
|
||
};
|
||
|
||
// elemissignedc — given an indexable type-AST (`*T`, `[]T`, `[N]T`),
|
||
// is its element a signed narrow primitive? Used by cgindex to pick
|
||
// MOVSXD vs MOVL at esz=4 (and MOVSBQ/MOVSWQ at esz=1/2). Mirrors
|
||
// cstage's `signed_elem` (cmd/w6c/cgen.c idx_eff path). Reads through
|
||
// the stamped tinfo so alias/enum recursion lives in lib/ww/typ.ww.
|
||
fn elemissignedc(c: *cgen, t: *node) bool = {
|
||
if (t == nil) { return false; };
|
||
let ti: *tinfo = t.type_: *tinfo;
|
||
if (ti == nil) { return false; };
|
||
// #65 Phase-N step-2 cleanup: peel TY_NAMED before the .sub read.
|
||
// #64 now flows per-decl NAMED wrappers, so a NAMED-of-(`*T`/`[]T`/
|
||
// `[N]T`) reaching here would read NAMED.sub (nil) instead of the
|
||
// element. Mirrors cstage idx_eff's type_unwrap (cmd/w6c/cgen.c:790)
|
||
// before the eff->sub read (:3518-3520). Byte-id-neutral: every
|
||
// aliased indexable in-tree has a u8 element (typeissigned=false
|
||
// either way). Transitive peel matches the #63 idiom.
|
||
for (ti != nil && ti.kind == tykind.TY_NAMED) { ti = ti.under; };
|
||
if (ti == nil) { return false; };
|
||
return typeissigned(ti.sub);
|
||
};
|
||
|
||
// fieldissignedc — does this field/element type-AST need sign-
|
||
// extension on a sub-word load? One-liner via typeissigned (cstage
|
||
// cgen.c:240 `fld_issigned` SSoT). t.type_ is stamped at check.ww
|
||
// L426-436 for every type-AST kind we see here (TNAME / TPTR /
|
||
// TBANG / TENUM / TARRAY / TSLICE — see resolvewalk).
|
||
fn fieldissignedc(c: *cgen, t: *node) bool = {
|
||
if (t == nil) { return false; };
|
||
return typeissigned(t.type_: *tinfo);
|
||
};
|
||
|
||
// fieldloadop — pick the load instruction for a non-str struct
|
||
// field by its declared size + signedness. Mirrors cstage's
|
||
// fldloadop: MOVZBQ/MOVSBQ for 1B, MOVZWQ/MOVSWQ for 2B,
|
||
// MOVL/MOVSXD for 4B, MOVQ for 8B. f might be nil for fields
|
||
// outside our struct registry.
|
||
fn fieldloadop(c: *cgen, f: *fieldinfo) str = {
|
||
if (f == nil) { return "MOVQ"; };
|
||
let sz: i32 = f.fsz;
|
||
let sigd: bool = fieldissignedc(c, f.tnode);
|
||
if (sz == 1) { if (sigd) { return "MOVSBQ"; }; return "MOVZBQ"; };
|
||
if (sz == 2) { if (sigd) { return "MOVSWQ"; }; return "MOVZWQ"; };
|
||
if (sz == 4) { if (sigd) { return "MOVSXD"; }; return "MOVL"; };
|
||
return "MOVQ";
|
||
};
|
||
|
||
// fieldstoreop — pick the store instruction for a non-str struct
|
||
// field by its declared size. MOVB for 1, MOVW for 2, MOVL for 4,
|
||
// MOVQ for 8. c kept in the signature for symmetry with fieldloadop.
|
||
fn fieldstoreop(c: *cgen, f: *fieldinfo) str = {
|
||
if (f == nil) { return "MOVQ"; };
|
||
let sz: i32 = f.fsz;
|
||
if (sz == 1) { return "MOVB"; };
|
||
if (sz == 2) { return "MOVW"; };
|
||
if (sz == 4) { return "MOVL"; };
|
||
return "MOVQ";
|
||
};
|
||
|
||
// tnodeloadop / tnodestoreop — same dispatch as fieldloadop /
|
||
// fieldstoreop but keyed on a raw type-AST node (tuple element type,
|
||
// pointer-target, slice-element, etc.) rather than a struct fieldinfo.
|
||
// Used at the index / tuple / pointer-deref sites where there's no
|
||
// fieldinfo entry but the type-node + size are both known.
|
||
fn tnodeloadop(c: *cgen, t: *node, sz: i32) str = {
|
||
let sigd: bool = fieldissignedc(c, t);
|
||
if (sz == 1) { if (sigd) { return "MOVSBQ"; }; return "MOVZBQ"; };
|
||
if (sz == 2) { if (sigd) { return "MOVSWQ"; }; return "MOVZWQ"; };
|
||
if (sz == 4) { if (sigd) { return "MOVSXD"; }; return "MOVL"; };
|
||
return "MOVQ";
|
||
};
|
||
|
||
fn tnodestoreop(c: *cgen, t: *node, sz: i32) str = {
|
||
if (sz == 1) { return "MOVB"; };
|
||
if (sz == 2) { return "MOVW"; };
|
||
if (sz == 4) { return "MOVL"; };
|
||
return "MOVQ";
|
||
};
|
||
|
||
// loadopsz — load op when the (size, signedness) pair has already
|
||
// been resolved upstream and the type-node isn't carried through.
|
||
// cgindex precomputes `signed_elem` via elemissignedc; cgforrange
|
||
// precomputes `bind_signed[b]` via paramissigned. Same dispatch as
|
||
// tnodeloadop's tail; only the keying differs.
|
||
fn loadopsz(sigd: bool, sz: i32) str = {
|
||
if (sz == 1) { if (sigd) { return "MOVSBQ"; }; return "MOVZBQ"; };
|
||
if (sz == 2) { if (sigd) { return "MOVSWQ"; }; return "MOVZWQ"; };
|
||
if (sz == 4) { if (sigd) { return "MOVSXD"; }; return "MOVL"; };
|
||
return "MOVQ";
|
||
};
|
||
|
||
// localloadop — read instruction for a scalar local/let load. Same
|
||
// dispatch as fieldloadop, but keyed on the value's own tnode.type_.
|
||
// Lets the caller emit MOVSXD/MOVSWQ/MOVSBQ on a signed-narrow slot
|
||
// instead of a raw MOVQ, so a slot that was last written by a narrow
|
||
// deref-store (`*p: *i32 = v` lowers to MOVL, only 4B) reads back as
|
||
// a properly-sign-extended i64. The natural N_ASSIGN / N_LET paths
|
||
// store the rhs as a sign-extended 8B word, so MOVQ accidentally
|
||
// works; deref-stores are the only path that touches fewer bytes
|
||
// than MOVQ reads. Mirror of cstage's localloadop in cmd/w6c/cgen.c
|
||
// — tinfo.size carries the same numeric width cstage's `t->size`
|
||
// reports, with TBANG / TENUM / TNAME-alias chains pre-folded by
|
||
// tinfofornode (check.ww:1102-1153 TNAME, 1154-1161 TBANG,
|
||
// 1196-1208 TENUM).
|
||
export fn localloadop(c: *cgen, tnode: *node) str = {
|
||
if (tnode == nil) { return "MOVQ"; };
|
||
let ti: *tinfo = tnode.type_: *tinfo;
|
||
if (ti == nil) { return "MOVQ"; };
|
||
let sz: i32 = ti.size: i32;
|
||
if (sz != 1) { if (sz != 2) { if (sz != 4) { return "MOVQ"; }; }; };
|
||
let sigd: bool = typeissigned(ti);
|
||
return loadopsz(sigd, sz);
|
||
};
|
||
|
||
// indexbaseesz — element size for `arr[i]` where the base is a
|
||
// chained-dot pseudo-field `s.ptr` (s being str/*str/slice/*slice).
|
||
// For str the element is one byte; for `[]T` / `*[]T` we drill into
|
||
// the slice element type.
|
||
fn indexbaseesz(c: *cgen, base: *node) i32 = {
|
||
if (base == nil) { return 8; };
|
||
if (base.kind != nkind.N_DOT) { return 8; };
|
||
let fld: str = base.str;
|
||
let inner: *node = base.lhs;
|
||
if (inner == nil) { return 8; };
|
||
if (inner.kind != nkind.N_IDENT) { return 8; };
|
||
let nm: str = inner.str;
|
||
let lc: *local = localfindnode(c, nm);
|
||
if (lc == nil) { return 8; };
|
||
let tn: *node = lc.tnode;
|
||
if (tn == nil) { return 8; };
|
||
|
||
// `.ptr` pseudo-field on str/slice → element of the str/slice.
|
||
// Gated on inner kind, NOT on the field name alone: a struct with
|
||
// a literal `ptr: *T` field (lib/memio.state, lib/bufio.state) must
|
||
// route through the generic struct-field arm below so the stride
|
||
// comes from primsize/structlookup, not the str/slice default. The
|
||
// over-broad pre-#21 shortcut hard-coded esz=8 and silently
|
||
// miscompiled `m.ptr[i]` for `*u8` callers (also widened the load
|
||
// op MOVZBQ → MOVQ in cgindex). Mirrors cstage which routes every
|
||
// base through `base->type->sub->size` (cmd/w6c/cgen.c idx_eff).
|
||
if (streq(fld, "ptr")) {
|
||
let innert: *node = tn;
|
||
if (tn.kind == nkind.N_TPTR) { innert = tn.lhs; };
|
||
if (innert != nil) {
|
||
if (innert.kind == nkind.N_TNAME) {
|
||
if (streq(innert.str, "str")) { return 1; };
|
||
};
|
||
// Slice element: resolve through elemsizeofc so a
|
||
// slice of a named struct (e.g. *[]option) returns
|
||
// the struct stride instead of falling through to
|
||
// elemsizeof's default 8.
|
||
if (innert.kind == nkind.N_TSLICE) {
|
||
return elemsizeofc(c, innert);
|
||
};
|
||
};
|
||
// Inner is a struct N_TNAME (or unresolved) — fall through
|
||
// to the generic struct-field arm below.
|
||
};
|
||
|
||
// Generic struct field: if it's *T, element size is T's size.
|
||
let lkind: nkind = tn.kind;
|
||
let sname: str;
|
||
sname.ptr = nil; sname.len = 0;
|
||
if (lkind == nkind.N_TNAME) { sname = tn.str; };
|
||
if (lkind == nkind.N_TPTR) {
|
||
let pinner: *node = tn.lhs;
|
||
if (pinner != nil) {
|
||
if (pinner.kind == nkind.N_TNAME) { sname = pinner.str; };
|
||
};
|
||
};
|
||
if (sname.len == 0) { return 8; };
|
||
let si: *structinfo = structlookup(c, sname);
|
||
if (si == nil) { return 8; };
|
||
let fi: *fieldinfo = si.fields;
|
||
for (fi != nil) {
|
||
let fn_: str = fi.fname;
|
||
if (streq(fn_, fld)) {
|
||
let ft: *node = fi.tnode;
|
||
if (ft == nil) { return 8; };
|
||
if (ft.kind == nkind.N_TPTR) {
|
||
let elem: *node = ft.lhs;
|
||
if (elem != nil) {
|
||
if (elem.kind == nkind.N_TNAME) {
|
||
if (streq(elem.str, "str")) { return primtypesize("str"): i32; };
|
||
let ps: i32 = primsize(elem.str);
|
||
if (ps > 0) { return ps; };
|
||
// Pointer to named struct: indexing
|
||
// stride is the struct slot size.
|
||
// Without this, &p.ptr[i] for p.ptr:
|
||
// *S falls through to 8 and reads
|
||
// the wrong element.
|
||
let si: *structinfo = structlookup(c, elem.str);
|
||
if (si != nil) { return si.totsize; };
|
||
};
|
||
};
|
||
return 8;
|
||
};
|
||
if (ft.kind == nkind.N_TSLICE) { return elemsizeof(ft); };
|
||
// str-typed field: indexing yields one byte
|
||
// (`n.s[i]` where .s is str — matches C cgen's
|
||
// MOVZBQ for byte indexing).
|
||
if (ft.kind == nkind.N_TNAME) {
|
||
if (streq(ft.str, "str")) { return 1; };
|
||
};
|
||
return 8;
|
||
};
|
||
fi = fi.finext;
|
||
};
|
||
return 8;
|
||
};
|
||
|
||
// elemsizeof — given the type node of an indexable (`*T`, `[]T`,
|
||
// `[N]T`, `str`), return the byte size of one element (1 for u8/i8/
|
||
// bool/str-byte, 8 otherwise — same shape as C cgen's esz fallback).
|
||
// For aliased element types (e.g. `[N]formattable`), callers that
|
||
// need the resolved slot size should use elemsizeofc(c, t) which
|
||
// follows aliases via slotsize.
|
||
fn elemsizeof(t: *node) i32 = {
|
||
if (t == nil) { return 1; };
|
||
let k: nkind = t.kind;
|
||
let elem: *node = nil;
|
||
if (k == nkind.N_TPTR) { elem = t.lhs; };
|
||
if (k == nkind.N_TSLICE) { elem = t.lhs; };
|
||
if (k == nkind.N_TARRAY) { elem = t.lhs; };
|
||
if (k == nkind.N_TNAME) {
|
||
let nm: str = t.str;
|
||
if (streq(nm, "str")) { return 1; };
|
||
// Indexing a primitive name (rare): element size = the prim.
|
||
let ps: i32 = primsize(nm);
|
||
if (ps > 0) { return ps; };
|
||
return 1;
|
||
};
|
||
if (elem == nil) { return 1; };
|
||
// `*[N]T`: drill through the pointer into the array's element so
|
||
// indexing scales by T's width, not the whole-array byte size.
|
||
if (elem.kind == nkind.N_TARRAY) {
|
||
if (elem.lhs != nil) { elem = elem.lhs; };
|
||
};
|
||
// `*[]T`: stride is the slice header (24B). Hare-faithful — a
|
||
// pointer-to-slice is a 1D array of slices, not of T. Mirrors the
|
||
// cstage check.c default `*U → U` path for U=[]T (slice element).
|
||
if (elem.kind == nkind.N_TSLICE) { return tyslicesize(): i32; };
|
||
if (elem.kind == nkind.N_TNAME) {
|
||
let nm: str = elem.str;
|
||
// str element is 16B (ptr+len). primsize returns 0 for it.
|
||
if (streq(nm, "str")) { return primtypesize("str"): i32; };
|
||
let ps: i32 = primsize(nm);
|
||
if (ps > 0) { return ps; };
|
||
};
|
||
return 8;
|
||
};
|
||
|
||
// elemsizeofc — like elemsizeof but resolves aliased element types
|
||
// (struct / tagged / `type foo = bar;`) via slotsize. Used where
|
||
// cgindex / cgassign need a correct stride for `[N]Alias` arrays
|
||
// whose Alias resolves to a tagged union (e.g. `[N]formattable`).
|
||
fn elemsizeofc(c: *cgen, t: *node) i32 = {
|
||
if (t == nil) { return 1; };
|
||
let direct: i32 = elemsizeof(t);
|
||
if (direct != 8) { return direct; };
|
||
let k: nkind = t.kind;
|
||
let elem: *node = nil;
|
||
if (k == nkind.N_TPTR) { elem = t.lhs; };
|
||
if (k == nkind.N_TSLICE) { elem = t.lhs; };
|
||
if (k == nkind.N_TARRAY) { elem = t.lhs; };
|
||
if (elem == nil) { return direct; };
|
||
if (elem.kind == nkind.N_TNAME) {
|
||
let ps: i32 = primsize(elem.str);
|
||
if (ps > 0) { return ps; };
|
||
};
|
||
return slotsize(c, elem);
|
||
};
|
||
|
||
// nodeisunsigned — best-effort cgen-time inference from the AST. We
|
||
// walk surface nodes (N_DOT now reads n.type_ — #55 A.6.3g):
|
||
// nkind.N_INTLIT — never marked unsigned (no tsuffix plumbing yet)
|
||
// nkind.N_IDENT — look up the local's declared type
|
||
// nkind.N_DOT — read the checker-stamped n.type_ (#55 A.6.3g)
|
||
// nkind.N_BIN / nkind.N_UN — recurse: unsigned if either operand is unsigned
|
||
// nkind.N_CAST — use the cast target type
|
||
//
|
||
// Conservative: if we can't tell, return false (signed). The cost of
|
||
// being wrong here is byte-different asm vs C, not bad runtime.
|
||
fn nodeisunsigned(c: *cgen, n: *node) bool = {
|
||
if (n == nil) { return false; };
|
||
let k: nkind = n.kind;
|
||
if (k == nkind.N_IDENT) {
|
||
let nm: str = n.str;
|
||
let lc: *local = localfindnode(c, nm);
|
||
if (lc != nil) {
|
||
if (lc.tnode == nil) { return false; };
|
||
return typeisunsigned(lc.tnode.type_: *tinfo);
|
||
};
|
||
return false;
|
||
};
|
||
if (k == nkind.N_DOT) {
|
||
return typeisunsigned(n.type_: *tinfo);
|
||
};
|
||
if (k == nkind.N_CAST) {
|
||
if (n.rhs == nil) { return false; };
|
||
return typeisunsigned(n.rhs.type_: *tinfo);
|
||
};
|
||
if (k == nkind.N_BIN) {
|
||
if (nodeisunsigned(c, n.lhs)) { return true; };
|
||
return nodeisunsigned(c, n.rhs);
|
||
};
|
||
if (k == nkind.N_UN) { return nodeisunsigned(c, n.lhs); };
|
||
// nkind.N_INDEX: `p[i]` is unsigned iff p's element type is unsigned.
|
||
// Walks the base local's declared type and pulls the element
|
||
// out — *u8 → u8, [N]u32 → u32, []u64 → u64. Without this the
|
||
// compare-codegen for `p[i] >= 48u8` falls back to signed JGE
|
||
// instead of JAE, diverging from C w6c on byte indexing.
|
||
if (k == nkind.N_INDEX) {
|
||
let base: *node = n.lhs;
|
||
if (base != nil) {
|
||
if (base.kind == nkind.N_IDENT) {
|
||
let lc: *local = localfindnode(c, base.str);
|
||
if (lc != nil) {
|
||
let tn: *node = lc.tnode;
|
||
if (tn != nil) {
|
||
let elem: *node = nil;
|
||
if (tn.kind == nkind.N_TPTR) { elem = tn.lhs; };
|
||
if (tn.kind == nkind.N_TARRAY) { elem = tn.lhs; };
|
||
if (tn.kind == nkind.N_TSLICE) { elem = tn.lhs; };
|
||
if (elem != nil) {
|
||
return typeisunsigned(elem.type_: *tinfo);
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
return false;
|
||
};
|
||
return false;
|
||
};
|
||
|
||
// nodeprimwidth — primitive byte width of an expression, or 0 if not
|
||
// statically determinable. Mirrors nodeisunsigned's structural walk.
|
||
// Used by cgun TK_TILDE to clamp narrow unsigned ~ results to type
|
||
// width (NOTQ inverts the full 64-bit register).
|
||
fn nodeprimwidth(c: *cgen, n: *node) i32 = {
|
||
if (n == nil) { return 0; };
|
||
let k: nkind = n.kind;
|
||
if (k == nkind.N_IDENT) {
|
||
let lc: *local = localfindnode(c, n.str);
|
||
if (lc != nil) {
|
||
let tn: *node = lc.tnode;
|
||
if (tn != nil) {
|
||
if (tn.kind == nkind.N_TNAME) { return primsize(tn.str); };
|
||
};
|
||
};
|
||
return 0;
|
||
};
|
||
if (k == nkind.N_CAST) {
|
||
let tn: *node = n.rhs;
|
||
if (tn != nil) {
|
||
if (tn.kind == nkind.N_TNAME) { return primsize(tn.str); };
|
||
};
|
||
return 0;
|
||
};
|
||
if (k == nkind.N_UN) { return nodeprimwidth(c, n.lhs); };
|
||
return 0;
|
||
};
|
||
|
||
// ---- type-driven slot sizing ----------------------------------------
|
||
|
||
// structnaturalsize — type-natural size of `si`, i.e. max(foff +
|
||
// fsz) across declared fields. Mirrors cstage's `lu->size` for a
|
||
// TY_STRUCT (rounded only to the struct's maxalign).
|
||
//
|
||
// NOTE: si.totsize is mis-named — it's actually the *slot-padded*
|
||
// size (rounded up to 8 for stack-slot use; see registerstruct's
|
||
// tail `if ((off & 7) != 0) ...`). Frame allocation, [N]foo stride,
|
||
// and similar consumers want that slot-padded number. The
|
||
// receive-side ABI (#5) and any future "TYPE size, not slot size"
|
||
// query wants the natural size. Until si.totsize is split into
|
||
// si.naturalsize + si.slotsize (tracked as the wwstage-sizing
|
||
// follow-up task), recover the type-natural size from the field
|
||
// chain here.
|
||
fn structnaturalsize(si: *structinfo) i32 = {
|
||
if (si == nil) { return 0; };
|
||
let n: i32 = 0;
|
||
let fi: *fieldinfo = si.fields;
|
||
for (fi != nil) {
|
||
let end: i32 = fi.foff + fi.fsz;
|
||
if (end > n) { n = end; };
|
||
fi = fi.finext;
|
||
};
|
||
return n;
|
||
};
|
||
|
||
// sretretsize — if `t` ultimately denotes a plain TY_STRUCT > 24B,
|
||
// return its natural size; else 0. Tagged unions, tuples, str,
|
||
// slices, scalars route through their existing register-return ABIs
|
||
// (AX/DX/CX/[R8]) regardless of size. Task #23 mirrors cstage's
|
||
// cg_sret_retsize predicate. Resolves N_TNAME → struct via structlookup
|
||
// and unwraps one leading N_TBANG so `type box = !big;` still
|
||
// triggers sret on the underlying big.
|
||
//
|
||
// Chain-of-aliases (#22): `type a = struct{...}; type b = a;` registers
|
||
// `b → a` in c.aliases (target node = N_TNAME "a"), not `b → struct`.
|
||
// When structlookup(c, "b") misses, fall through to aliaslookup and
|
||
// recurse on the alias target — mirrors slotsize's N_TNAME arm
|
||
// (cgenutil.ww:1955) and the cstage while-loop in cg_sret_retsize.
|
||
|
||
// structlookupchain — resolve TNAME `tn` to its registered struct,
|
||
// chasing alias-of-alias (#22). Returns nil if the chain doesn't
|
||
// bottom out at a struct. Mirrors cstage's transitive
|
||
// `while (t->kind == TY_NAMED) t = t->under` peel; consumed by
|
||
// cgdot / cgassign at every "field-walk on a struct-typed local"
|
||
// site so a transitively-aliased struct name resolves to its
|
||
// fieldinfo list regardless of chain depth.
|
||
export fn structlookupchain(c: *cgen, tn: *node) *structinfo = {
|
||
if (tn == nil) { return nil; };
|
||
if (tn.kind != nkind.N_TNAME) { return nil; };
|
||
let si: *structinfo = structlookup(c, tn.str);
|
||
if (si != nil) { return si; };
|
||
let cur: *node = tn;
|
||
for (cur != nil && cur.kind == nkind.N_TNAME && si == nil) {
|
||
let aliased: *node = aliaslookup(c, cur.str);
|
||
if (aliased == nil) { cur = nil; }
|
||
else {
|
||
if (aliased.kind == nkind.N_TNAME) {
|
||
si = structlookup(c, aliased.str);
|
||
cur = aliased;
|
||
} else { cur = nil; };
|
||
};
|
||
};
|
||
return si;
|
||
};
|
||
|
||
export fn sretretsize(c: *cgen, t: *node) i32 = {
|
||
if (t == nil) { return 0; };
|
||
let r: *node = t;
|
||
if (r.kind == nkind.N_TBANG) {
|
||
r = r.lhs;
|
||
if (r == nil) { return 0; };
|
||
};
|
||
if (r.kind != nkind.N_TNAME) { return 0; };
|
||
// Primitives / aliased-to-primitives are never sret.
|
||
if (primsize(r.str) > 0) { return 0; };
|
||
if (streq(r.str, "str")) { return 0; };
|
||
let si: *structinfo = structlookup(c, r.str);
|
||
if (si == nil) {
|
||
if (c != nil) {
|
||
let aliased: *node = aliaslookup(c, r.str);
|
||
if (aliased != nil) {
|
||
return sretretsize(c, aliased);
|
||
};
|
||
};
|
||
return 0;
|
||
};
|
||
let n: i32 = structnaturalsize(si);
|
||
if (n <= 24) { return 0; };
|
||
return n;
|
||
};
|
||
|
||
// callsretsize — if N_CALL `n`'s callee returns a plain TY_STRUCT
|
||
// > 24B, return its natural size; else 0. Wraps sretretsize over the
|
||
// callee's resolved return type, used by cglet / cgassign receive
|
||
// sites and cgcall to detect sret at the receive / emit boundaries.
|
||
export fn callsretsize(c: *cgen, n: *node) i32 = {
|
||
if (n == nil) { return 0; };
|
||
if (n.kind != nkind.N_CALL) { return 0; };
|
||
let callee: *node = n.lhs;
|
||
if (callee == nil) { return 0; };
|
||
let cn: str;
|
||
cn.ptr = nil; cn.len = 0;
|
||
let cmod: str;
|
||
cmod.ptr = nil; cmod.len = 0;
|
||
if (callee.kind == nkind.N_IDENT) {
|
||
cn = callee.str;
|
||
cmod = c.curmod;
|
||
};
|
||
if (callee.kind == nkind.N_DOT) {
|
||
cn = callee.str;
|
||
if (callee.lhs != nil) {
|
||
if (callee.lhs.kind == nkind.N_IDENT) {
|
||
cmod = callee.lhs.str;
|
||
};
|
||
};
|
||
};
|
||
if (cn.len == 0) { return 0; };
|
||
let rtyp: *node = fnretlookupmod(c, cn, cmod);
|
||
return sretretsize(c, rtyp);
|
||
};
|
||
|
||
fn structlookup(c: *cgen, name: str) *structinfo = {
|
||
// Same-module first, then any. Trio-leaf graduation mirroring
|
||
// aliaslookup (#27), fnret/fnparamslookupmod (#28/#31), and
|
||
// enumlookup (#4a): without the prefer pass a bare-leaf struct
|
||
// name in module M can collapse onto another module's same-leaf
|
||
// struct prepended earlier in c.structs, silently picking the
|
||
// wrong totsize / field offsets.
|
||
let s: *structinfo = c.structs;
|
||
for (s != nil) {
|
||
if (streq(s.sname, name)) {
|
||
if (streq(s.smod, c.curmod)) { return s; };
|
||
};
|
||
s = s.sinext;
|
||
};
|
||
s = c.structs;
|
||
for (s != nil) {
|
||
let sn: str = s.sname;
|
||
if (streq(sn, name)) { return s; };
|
||
s = s.sinext;
|
||
};
|
||
// Module-qualified form embedded in name (`pkg.S`): scope the
|
||
// leaf to its originating module. The `smod == pkg` guard
|
||
// prevents same-leaf structs in two modules from collapsing.
|
||
let i: i32 = name.len - 1;
|
||
for (i >= 0) {
|
||
if (name[i] == 46u8) { // '.'
|
||
let pkg: str;
|
||
pkg.ptr = name.ptr;
|
||
pkg.len = i;
|
||
let leaf: str;
|
||
leaf.ptr = name.ptr + ((i + 1): u64);
|
||
leaf.len = name.len - (i + 1);
|
||
let b: *structinfo = c.structs;
|
||
for (b != nil) {
|
||
if (streq(b.sname, leaf)) {
|
||
if (streq(b.smod, pkg)) {
|
||
return b;
|
||
};
|
||
};
|
||
b = b.sinext;
|
||
};
|
||
return nil;
|
||
};
|
||
i -= 1;
|
||
};
|
||
return nil;
|
||
};
|
||
|
||
// primsize — size in bytes of a primitive type name (or 0 if not
|
||
// recognised as a primitive — the caller falls back to other paths).
|
||
// fldnumidx — parse a tuple field name like "0" / "1" / "12" into an
|
||
// index, or -1 if not all-digits. Used by cgdot to dispatch
|
||
// `t.0` / `t.1` against an nkind.N_TTUPLE local without pulling in strconv.
|
||
fn fldnumidx(s: str) i32 = {
|
||
if (s.len == 0) { return -1; };
|
||
let r: i32 = 0;
|
||
let i: i32 = 0;
|
||
for (i < s.len) {
|
||
let b: u8 = s[i];
|
||
if (b < 48u8) { return -1; };
|
||
if (b > 57u8) { return -1; };
|
||
r = r * 10 + ((b - 48u8): i32);
|
||
i += 1;
|
||
};
|
||
return r;
|
||
};
|
||
|
||
fn primsize(name: str) i32 = {
|
||
if (streq(name, "u8")) { return 1; };
|
||
if (streq(name, "i8")) { return 1; };
|
||
if (streq(name, "bool")) { return 1; };
|
||
if (streq(name, "u16")) { return 2; };
|
||
if (streq(name, "i16")) { return 2; };
|
||
if (streq(name, "u32")) { return 4; };
|
||
if (streq(name, "i32")) { return 4; };
|
||
if (streq(name, "f32")) { return 4; };
|
||
if (streq(name, "u64")) { return 8; };
|
||
if (streq(name, "i64")) { return 8; };
|
||
if (streq(name, "uint")) { return 8; };
|
||
if (streq(name, "int")) { return 8; };
|
||
if (streq(name, "uintptr")) { return 8; };
|
||
if (streq(name, "f64")) { return 8; };
|
||
if (streq(name, "rune")) { return 4; };
|
||
if (streq(name, "void")) { return 0; };
|
||
return 0;
|
||
};
|
||
|
||
// typenodeprimresolved — walk N_TBANG / N_TENUM / N_TNAME alias
|
||
// chains to the underlying primitive, returning its byte size and
|
||
// signedness. Sets *sz_out = 0 when the type doesn't reduce to a
|
||
// width-known primitive (composite, unresolved name, default-storage
|
||
// enum, etc.). Mirrors cstage's `type_isint(t) ? t->size : 0` /
|
||
// `type_isunsigned` recursion through TY_NAMED and TY_ENUM. Used by
|
||
// cgcast's identity-width identity-sign clamp-skip predicate (#33).
|
||
export fn typenodeprimresolved(c: *cgen, t: *node,
|
||
sz_out: *i32, unsigned_out: *bool) void = {
|
||
*sz_out = 0;
|
||
*unsigned_out = false;
|
||
let cur: *node = t;
|
||
for (cur != nil) {
|
||
let k: nkind = cur.kind;
|
||
if (k == nkind.N_TBANG) { cur = cur.lhs; }
|
||
else { if (k == nkind.N_TENUM) { cur = cur.lhs; }
|
||
else { if (k == nkind.N_TNAME) {
|
||
let nm: str = cur.str;
|
||
// bool is excluded from the int-prim contract: cstage's
|
||
// `type_isint(TY_BOOL)` is false, so its identity check
|
||
// leaves src_w=0 on a bool source. Match that here so a
|
||
// `let y: i8 = b: i8;` (bool b) doesn't fire identity in
|
||
// wwstage and skip the MOVSBQ that cstage emits. Other
|
||
// call sites (slot sizing, etc.) still want
|
||
// primsize("bool")=1, so the exclusion stays local. The
|
||
// dedicated `is_bool` path in cgcast owns bool→bool's
|
||
// ANDQ $255 on both stages.
|
||
if (streq(nm, "bool")) { return; };
|
||
let ps: i32 = primsize(nm);
|
||
if (ps > 0) {
|
||
*sz_out = ps;
|
||
*unsigned_out = typeisunsigned(cur.type_: *tinfo);
|
||
return;
|
||
};
|
||
let al: *node = aliaslookup(c, nm);
|
||
if (al == nil) { return; };
|
||
cur = al;
|
||
}
|
||
else { return; }; }; };
|
||
};
|
||
};
|
||
|
||
// exprprimresolved — best-effort static (primsize, signedness) for an
|
||
// expression. Used by cgcast (#33) to derive the source-side primitive
|
||
// width and signedness so the identity-width identity-sign clamp-skip
|
||
// predicate fires. Sets *sz_out = 0 when the type can't be derived
|
||
// (untyped literal, call result with no return-type lookup, etc.);
|
||
// caller treats sz=0 as "not identity", which conservatively keeps
|
||
// the clamp. Mirror of cstage's `n->lhs->type` lookup with the same
|
||
// TY_NAMED / TY_ENUM recursion through type_isint / type_isunsigned.
|
||
export fn exprprimresolved(c: *cgen, n: *node,
|
||
sz_out: *i32, unsigned_out: *bool) void = {
|
||
*sz_out = 0;
|
||
*unsigned_out = false;
|
||
if (n == nil) { return; };
|
||
let k: nkind = n.kind;
|
||
if (k == nkind.N_INTLIT) {
|
||
// Typed-int literal: `7u32` has tsuffix = "u32". Mirrors
|
||
// cstage's `cexpr` which assigns `lookup_builtin(tsuffix)`
|
||
// as the node's type — without this, wwstage misses the
|
||
// suffix and emits a defensive clamp where cstage skips,
|
||
// breaking byte-id on rows like `let y: mymode = 7u32:
|
||
// mymode;` (mymode = enum u32).
|
||
let s: str = n.tsuffix;
|
||
if (s.len > 0) {
|
||
let ps: i32 = primsize(s);
|
||
if (ps > 0) {
|
||
*sz_out = ps;
|
||
*unsigned_out = typeisunsigned(n.type_: *tinfo);
|
||
};
|
||
};
|
||
return;
|
||
};
|
||
if (k == nkind.N_IDENT) {
|
||
let lc: *local = localfindnode(c, n.str);
|
||
if (lc != nil) {
|
||
typenodeprimresolved(c, lc.tnode,
|
||
sz_out, unsigned_out);
|
||
};
|
||
return;
|
||
};
|
||
if (k == nkind.N_CAST) {
|
||
typenodeprimresolved(c, n.rhs, sz_out, unsigned_out);
|
||
return;
|
||
};
|
||
if (k == nkind.N_UN) {
|
||
exprprimresolved(c, n.lhs, sz_out, unsigned_out);
|
||
return;
|
||
};
|
||
if (k == nkind.N_DOT) {
|
||
// #59: read the checker-stamped tinfo instead of re-deriving the
|
||
// field type via dotfieldtnode's structinfo walk. Mirrors cstage
|
||
// castsrcprim N_DOT (cmd/w6c/cgen.c:323-344): the base must
|
||
// resolve to a struct (or ptr-to-struct) before the field type
|
||
// counts. That guard excludes pseudo-fields .len/.cap/.ptr (the
|
||
// checker stamps them i32/*T at check.ww:1987-2004) and tuple
|
||
// positionals, keeping them at sz=0 — asymmetry there breaks 995
|
||
// byte-id (cgen.c:286-290). The field's own width/sign is the
|
||
// N_DOT's stamped type_ (check.ww:2012). One TY_NAMED peel, then
|
||
// typeisint ? size : 0; bool falls out because typeisint(bool) is
|
||
// false — the same exclusion the old streq("bool") arm encoded.
|
||
let bu: *tinfo = nil;
|
||
if (n.lhs != nil) { bu = n.lhs.type_: *tinfo; };
|
||
if (bu != nil && bu.kind == tykind.TY_NAMED) { bu = bu.under; };
|
||
if (bu != nil && bu.kind == tykind.TY_PTR) { bu = bu.sub; };
|
||
if (bu != nil && bu.kind == tykind.TY_NAMED) { bu = bu.under; };
|
||
if (bu != nil && bu.kind == tykind.TY_STRUCT) {
|
||
let u: *tinfo = n.type_: *tinfo;
|
||
if (u != nil && u.kind == tykind.TY_NAMED) { u = u.under; };
|
||
if (typeisint(u)) {
|
||
*sz_out = u.size: i32;
|
||
*unsigned_out = typeisunsigned(u);
|
||
};
|
||
};
|
||
return;
|
||
};
|
||
};
|
||
|
||
// variantnamematch — tagged-union variant names are compared as if
|
||
// they'd been alias-resolved. Pattern names can be module-qualified
|
||
// (`strconv.invalid` from a `case let e: strconv.invalid =>`),
|
||
// while the variant's declared name inside its own module is bare
|
||
// (`invalid`). With no checker the cgen can't follow imports, so we
|
||
// accept exact match plus suffix-after-`.` on either side. Mirrors
|
||
// the C cgen's type_eq, which goes through resolved Type pointers.
|
||
fn variantnamematch(vname: str, pname: str) bool = {
|
||
if (streq(vname, pname)) { return true; };
|
||
// `pname` is qualified, `vname` is bare: drop module prefix.
|
||
let i: i32 = 0;
|
||
for (i < pname.len) {
|
||
if (pname[i] == '.': u8) {
|
||
let tail: str;
|
||
tail.ptr = pname.ptr + i + 1;
|
||
tail.len = pname.len - i - 1;
|
||
if (streq(tail, vname)) { return true; };
|
||
};
|
||
i += 1;
|
||
};
|
||
// `vname` is qualified, `pname` is bare: same trick in reverse.
|
||
let j: i32 = 0;
|
||
for (j < vname.len) {
|
||
if (vname[j] == '.': u8) {
|
||
let tail: str;
|
||
tail.ptr = vname.ptr + j + 1;
|
||
tail.len = vname.len - j - 1;
|
||
if (streq(tail, pname)) { return true; };
|
||
};
|
||
j += 1;
|
||
};
|
||
return false;
|
||
};
|
||
|
||
// inferletcalltype — for an annotation-less `let x = expr;`, return
|
||
// a usable tnode for cgen's struct-aware paths. Today: `let x =
|
||
// f()?` infers x's type from the success variant of f's tagged
|
||
// return; without this, x has tnode = nil and `x.field` falls into
|
||
// the SB-symbol fallback (linker reports `undefined reference to
|
||
// <fieldname>`). We don't infer for plain `let x = f()` yet —
|
||
// non-tagged returns don't carry their type back the same way.
|
||
fn inferletcalltype(c: *cgen, rhs: *node) *node = {
|
||
if (rhs == nil) { return nil; };
|
||
// `?` (N_TRYPROP) and `!` (N_TRYUNW) both unwrap a tagged
|
||
// return to its success variant; the rhs we want the type of
|
||
// is the inner call expression.
|
||
let unwrap: bool = false;
|
||
let call: *node = rhs;
|
||
if (rhs.kind == nkind.N_TRYPROP) { call = rhs.lhs; unwrap = true; };
|
||
if (rhs.kind == nkind.N_TRYUNW) { call = rhs.lhs; unwrap = true; };
|
||
if (call == nil) { return nil; };
|
||
if (call.kind != nkind.N_CALL) { return nil; };
|
||
let callee: *node = call.lhs;
|
||
if (callee == nil) { return nil; };
|
||
let cname: str;
|
||
cname.ptr = nil; cname.len = 0;
|
||
let cmod: str;
|
||
cmod.ptr = nil; cmod.len = 0;
|
||
if (callee.kind == nkind.N_IDENT) {
|
||
cname = callee.str;
|
||
cmod = c.curmod;
|
||
};
|
||
if (callee.kind == nkind.N_DOT) {
|
||
cname = callee.str;
|
||
if (callee.lhs != nil) {
|
||
if (callee.lhs.kind == nkind.N_IDENT) {
|
||
cmod = callee.lhs.str;
|
||
};
|
||
};
|
||
};
|
||
if (cname.len == 0) { return nil; };
|
||
let rtyp: *node = fnretlookupmod(c, cname, cmod);
|
||
if (rtyp == nil) { return nil; };
|
||
if (unwrap) {
|
||
// Strip error variants — success type is the first
|
||
// variant of the tagged return.
|
||
if (rtyp.kind != nkind.N_TTAGGED) { return nil; };
|
||
return rtyp.list;
|
||
};
|
||
// Plain call: declared return type is the local's type.
|
||
return rtyp;
|
||
};
|
||
|
||
// letslotsize — slot size for a `let` binding. Like slotsize, but
|
||
// detects `[_]T = arrlit;` (the type-AST has rhs == nil as the
|
||
// length-inferred sentinel) and computes count × element-size from
|
||
// the initialiser. Called from cglet at emit time so the frame
|
||
// grows monotonically per first-use (#15).
|
||
//
|
||
// `let x = f();` (no annotation): infer from `f`'s declared return
|
||
// type so a 24B tagged-union return reserves all three spill slots,
|
||
// not the default 8B. Without this, the AX:DX:CX spill in cglet's
|
||
// tagged-init branch writes past the local and tramples the next
|
||
// slot.
|
||
export fn letslotsize(c: *cgen, n: *node) i32 = {
|
||
// `[_]T = arrlit;` — inferred-length array. slotsize would
|
||
// return elem_size * 1 (treating missing length as 1); intercept
|
||
// and compute the real count first.
|
||
if (n.lhs != nil) {
|
||
if (n.lhs.kind == nkind.N_TARRAY) {
|
||
if (n.lhs.rhs == nil) {
|
||
if (n.rhs != nil) {
|
||
if (n.rhs.kind == nkind.N_ARRLIT) {
|
||
let elemn: *node = n.lhs.lhs;
|
||
let esz: i32 = 8;
|
||
if (elemn != nil) {
|
||
if (elemn.kind == nkind.N_TNAME) {
|
||
// Composite primitive: `str` is 16B
|
||
// (ptr+len) — primsize returns 0 for
|
||
// it, so it'd slot 8B without this.
|
||
if (streq(elemn.str, "str")) {
|
||
esz = primtypesize("str"): i32;
|
||
} else {
|
||
let ps: i32 = primsize(elemn.str);
|
||
if (ps > 0) { esz = ps; };
|
||
};
|
||
};
|
||
};
|
||
let cnt: i32 = 0;
|
||
let e: *node = n.rhs.list;
|
||
for (e != nil) {
|
||
let adv: bool = true;
|
||
if (e.kind == nkind.N_FIELD) {
|
||
if (streq(e.str, "...")) {
|
||
e = nil;
|
||
adv = false;
|
||
};
|
||
};
|
||
if (adv) {
|
||
cnt += 1;
|
||
e = e.next;
|
||
};
|
||
};
|
||
return esz * cnt;
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
if (n.lhs != nil) { return slotsize(c, n.lhs); };
|
||
// Annotation-less init: defer to the call's return type if we
|
||
// can infer it. Tagged-union returns need 24B; everything else
|
||
// matches slotsize on the inferred type.
|
||
let inferred: *node = inferletcalltype(c, n.rhs);
|
||
if (inferred != nil) { return slotsize(c, inferred); };
|
||
return 8;
|
||
};
|
||
|
||
// #48 A.6.3d: AST walker retired. resolvewalk (check.ww:426-436) stamps
|
||
// `n.type_` on every N_T* kind via tinfofornode, which folds TBANG
|
||
// (inner unchanged, check.ww:1154-1161), TNAME alias chains
|
||
// (resolvealias, check.ww:1128-1153), TARRAY/TPTR/TSLICE/TCHAN/TFN/
|
||
// TENUM/TTUPLE/TSTRUCT/TTAGGED with size + slot-padded slotsize.
|
||
//
|
||
// cstage SSoT is distributed — there is no single slot_size(Type*).
|
||
// Tagged slot follows cstage cmd/wcc/check.c:348 + :998 (tag (8) +
|
||
// max variant payload rounded to 8); the wwstage TTAGGED arm at
|
||
// check.ww:1296-1346 mirrors that layout. cgen.c:4850 / :5193 use
|
||
// the same `(su->kind == TY_TAGGED) ? su->size : 16` pattern for the
|
||
// match-spill slot. Pointer-and-narrow → 8 is the local-frame
|
||
// convention encoded at every cstage `localoff(…, 8, …)` callsite
|
||
// (cmd/w6c/cgen.c throughout); wwstage encodes the same pad-to-8 at
|
||
// this read site so `[N]i32` stride stays 4 (natural) — moving it
|
||
// into ti.slotsize would lift array stride to 8/elem.
|
||
//
|
||
// `c: *cgen` retained unused for callsite stability (localloadop
|
||
// precedent, 68219a1).
|
||
fn slotsize(c: *cgen, typn: *node) i32 = {
|
||
if (typn == nil) { return 8; };
|
||
let ti: *tinfo = typn.type_: *tinfo;
|
||
if (ti == nil) { return 8; };
|
||
// #63 Phase-N step 1: peel TY_NAMED before this structural query.
|
||
// #64 builds per-decl NAMED wrappers (tinfofornode), so the peel
|
||
// now fires on aliased operands; byte-id holds because it collapses
|
||
// NAMED to the alias-invariant underlying this read consumes.
|
||
for (ti != nil && ti.kind == tykind.TY_NAMED) { ti = ti.under; };
|
||
if (ti == nil) { return 8; };
|
||
let kk: tykind = ti.kind;
|
||
if (kk == tykind.TY_VOID) { return 0; };
|
||
if (kk == tykind.TY_PTR || kk == tykind.TY_SLICE ||
|
||
kk == tykind.TY_CHAN || kk == tykind.TY_FN ||
|
||
kk == tykind.TY_STR || kk == tykind.TY_TAGGED) {
|
||
return ti.size: i32;
|
||
};
|
||
if (kk == tykind.TY_STRUCT || kk == tykind.TY_TUPLE ||
|
||
kk == tykind.TY_ARRAY) {
|
||
return ti.slotsize: i32;
|
||
};
|
||
return 8;
|
||
};
|
||
|
||
// fieldsize — slot-padded byte width of a struct field's type-AST,
|
||
// consumed by registerstruct's alignment + offset math (≥8→8 /
|
||
// ≥4→4 / ≥2→2 ladder at L1875-1877) and by the `*p OP=` deref-
|
||
// compound at cgenexpr.ww:3594. Mirror of check.ww:1053
|
||
// `fieldslotsize` (the same dispatch on the populated tinfo);
|
||
// slotsize-template precedent at a828c03. cstage SSoT is
|
||
// `f->type->size` (cmd/w6c/cgen.c:1386, :1656, :2515, :2535);
|
||
// wwstage routes through ti.slotsize for composites since the
|
||
// stack-slot pad rules live on tinfo (#48 verdict), and through
|
||
// ti.size for the kinds whose natural size already equals their
|
||
// in-struct width.
|
||
//
|
||
// `c: *cgen` retained unused for callsite stability (slotsize /
|
||
// localloadop precedent, a828c03 / 68219a1).
|
||
fn fieldsize(c: *cgen, tnode: *node) i32 = {
|
||
if (tnode == nil) { return 8; };
|
||
let ti: *tinfo = tnode.type_: *tinfo;
|
||
if (ti == nil) { return 8; };
|
||
// #63 Phase-N step 1: peel TY_NAMED before this structural query.
|
||
// #64 builds per-decl NAMED wrappers (tinfofornode), so the peel
|
||
// now fires on aliased operands; byte-id holds because it collapses
|
||
// NAMED to the alias-invariant underlying this read consumes.
|
||
for (ti != nil && ti.kind == tykind.TY_NAMED) { ti = ti.under; };
|
||
if (ti == nil) { return 8; };
|
||
let k: tykind = ti.kind;
|
||
if (k == tykind.TY_STRUCT) { return ti.slotsize: i32; };
|
||
if (k == tykind.TY_ARRAY) { return ti.slotsize: i32; };
|
||
if (k == tykind.TY_TAGGED) { return ti.size: i32; };
|
||
if (k == tykind.TY_SLICE) { return ti.size: i32; };
|
||
if (k == tykind.TY_PTR || k == tykind.TY_FN ||
|
||
k == tykind.TY_CHAN) { return 8; };
|
||
if (k == tykind.TY_STR) { return ti.size: i32; };
|
||
// Primitives + TY_ENUM keep natural width inside structs
|
||
// (cstage parity: cgen.c reads f->type->size directly). TY_TUPLE
|
||
// flows here too — pre-collapse fallback was 8, the populated
|
||
// ti.size carries the natural sum; ken-thompson 2026-05-23 review:
|
||
// keep the corrected behavior, no fixtures in selfhost exercise
|
||
// a tuple-typed struct field today (995 byte-id is the gate).
|
||
if (ti.size > 0u64) { return ti.size: i32; };
|
||
return 8;
|
||
};
|
||
|
||
fn registerstruct(c: *cgen, name: str, srcmod: str, tstruct: *node) void = {
|
||
let si: *structinfo = alloc(structinfo{
|
||
sname = name,
|
||
smod = srcmod,
|
||
})!;
|
||
let head: *fieldinfo = nil;
|
||
let tail: *fieldinfo = nil;
|
||
let off: i32 = 0;
|
||
let f: *node = tstruct.list;
|
||
for (f != nil) {
|
||
if (f.kind == nkind.N_TFIELD) {
|
||
let sz: i32 = fieldsize(c, f.lhs);
|
||
// Align to 8 for any field >= 4 bytes (matches our other
|
||
// cgen choices). i8/u8/bool may sit on odd byte offsets;
|
||
// the C cgen does similar best-effort packing.
|
||
let aln: i32 = 1;
|
||
if (sz >= 8) { aln = 8; }
|
||
else { if (sz >= 4) { aln = 4; }
|
||
else { if (sz >= 2) { aln = 2; }; }; };
|
||
if ((off & (aln - 1)) != 0) {
|
||
off = (off + aln - 1) & ~(aln - 1);
|
||
};
|
||
let fi: *fieldinfo = alloc(fieldinfo{
|
||
fname = f.str,
|
||
foff = off,
|
||
fsz = sz,
|
||
tnode = f.lhs,
|
||
})!;
|
||
if (head == nil) { head = fi; tail = fi; }
|
||
else { tail.finext = fi; tail = fi; };
|
||
off += sz;
|
||
};
|
||
f = f.next;
|
||
};
|
||
// Round total to 8 for stack-slot use.
|
||
if ((off & 7) != 0) { off = (off + 7) & ~7; };
|
||
si.fields = head;
|
||
si.totsize = off;
|
||
si.sinext = c.structs;
|
||
c.structs = si;
|
||
};
|
||
|
||
fn collectstructs(c: *cgen, file: *node) void = {
|
||
c.structs = nil;
|
||
if (file == nil) { return; };
|
||
let d: *node = file.list;
|
||
for (d != nil) {
|
||
if (d.kind == nkind.N_TYPEDECL) {
|
||
let body: *node = d.lhs;
|
||
if (body != nil) {
|
||
if (body.kind == nkind.N_TSTRUCT) {
|
||
registerstruct(c, d.str, d.nmod, body);
|
||
};
|
||
};
|
||
};
|
||
d = d.next;
|
||
};
|
||
};
|
||
|
||
// isstrtype — alias-aware. Reads the stamped tinfo so `str`,
|
||
// `type alias = str`, `!str`, and chained aliases all route to the
|
||
// str-shaped slot. Cite cstage cgen.c:159 `type_isstr` SSoT.
|
||
// Collapsed onto typeisstr per A.6.3b (#46); the prior AST walker is
|
||
// reconstituted by typeisstr's TY_NAMED chase + tinfofornode's
|
||
// TBANG-unwrap (check.ww:1145).
|
||
fn isstrtype(c: *cgen, t: *node) bool = {
|
||
if (t == nil) { return false; };
|
||
return typeisstr(t.type_: *tinfo);
|
||
};
|
||
|
||
fn isslicetype(c: *cgen, t: *node) bool = {
|
||
if (t == nil) { return false; };
|
||
return typeisslice(t.type_: *tinfo);
|
||
};
|
||
|
||
// resolvetagged — return the underlying N_TTAGGED node for `t`, or nil
|
||
// if `t` doesn't ultimately denote a tagged union. Follows N_TNAME
|
||
// aliases (via resolvetype) and unwraps one leading N_TBANG so
|
||
// `type error = !(invalid | overflow);` resolves to its inner
|
||
// `(invalid | overflow)` node. Use at sites that read variant lists
|
||
// or detect nullable folding off a scrutinee — cgmatch, cgtypetest,
|
||
// cgtypeassert — so aliased `!(A|B)` shapes still dispatch.
|
||
export fn resolvetagged(c: *cgen, t: *node) *node = {
|
||
let r: *node = resolvetype(c, t);
|
||
if (r == nil) { return nil; };
|
||
if (r.kind == nkind.N_TBANG) {
|
||
let inner: *node = r.lhs;
|
||
if (inner == nil) { return nil; };
|
||
r = resolvetype(c, inner);
|
||
if (r == nil) { return nil; };
|
||
};
|
||
if (r.kind == nkind.N_TTAGGED) { return r; };
|
||
return nil;
|
||
};
|
||
|
||
// matchscrutt — resolve a non-ident match scrutinee node to its tagged
|
||
// type (or nil if unresolvable). Used by cgmatch to size the
|
||
// @match_spill slot at first use (#15 first-use+fail-loud convergence).
|
||
// IDENT scrutinees use a different lookup path (read off the local
|
||
// directly, no spill) so this returns nil for them too.
|
||
fn matchscrutt(c: *cgen, scrut: *node) *node = {
|
||
if (scrut == nil) { return nil; };
|
||
let k: nkind = scrut.kind;
|
||
if (k == nkind.N_IDENT) { return nil; };
|
||
if (k == nkind.N_CALL) {
|
||
let callee: *node = scrut.lhs;
|
||
if (callee != nil) {
|
||
let cnm: str;
|
||
cnm.ptr = nil; cnm.len = 0;
|
||
let cmod: str;
|
||
cmod.ptr = nil; cmod.len = 0;
|
||
if (callee.kind == nkind.N_IDENT) { cnm = callee.str; };
|
||
if (callee.kind == nkind.N_DOT) {
|
||
cnm = callee.str;
|
||
// Same-module-first disambiguation: a leaf collision
|
||
// on `next` (utf8.next + caller-side next) otherwise
|
||
// returns the last-declared (caller) rtype and the
|
||
// 4-arm match collapses arms 2+ to tag 0. Task #31.
|
||
if (callee.lhs != nil) {
|
||
if (callee.lhs.kind == nkind.N_IDENT) {
|
||
cmod = callee.lhs.str;
|
||
};
|
||
};
|
||
};
|
||
if (cnm.len > 0) {
|
||
let rtyp: *node = fnretlookupmod(c, cnm, cmod);
|
||
if (rtyp != nil) { return resolvetagged(c, rtyp); };
|
||
};
|
||
};
|
||
return nil;
|
||
};
|
||
if (k == nkind.N_INDEX) {
|
||
let ibase: *node = scrut.lhs;
|
||
if (ibase == nil) { return nil; };
|
||
if (ibase.kind != nkind.N_IDENT) { return nil; };
|
||
let bl: *local = localfindnode(c, ibase.str);
|
||
let btn: *node = nil;
|
||
if (bl != nil) { btn = bl.tnode; }
|
||
else { btn = letvartnode(c, ibase.str); };
|
||
if (btn == nil) { return nil; };
|
||
let bk: nkind = btn.kind;
|
||
let etn: *node = nil;
|
||
if (bk == nkind.N_TARRAY) { etn = btn.lhs; };
|
||
if (bk == nkind.N_TSLICE) { etn = btn.lhs; };
|
||
if (bk == nkind.N_TPTR) { etn = btn.lhs; };
|
||
if (etn == nil) { return nil; };
|
||
return resolvetagged(c, etn);
|
||
};
|
||
if (k == nkind.N_DOT) {
|
||
// #67: read the field's stamped tinfo off the N_DOT node
|
||
// (post-#66 N_DOT carries the field type) instead of the
|
||
// dotfieldtnode AST walk. cgmatch's gate reads scrutt.type_
|
||
// via istaggedtype, so the resolved N_TTAGGED node the walk
|
||
// produced is no longer the carrier; the istaggedtype guard
|
||
// preserves the nil-for-non-tagged contract the sibling
|
||
// N_CALL/N_INDEX branches get from resolvetagged.
|
||
if (!istaggedtype(c, scrut)) { return nil; };
|
||
return scrut;
|
||
};
|
||
return nil;
|
||
};
|
||
|
||
// matchspillsz — slot size for the @match_spill scratch a non-ident
|
||
// scrutinee lands in. Mirrors cstage's `slot_size = (su->kind ==
|
||
// TY_TAGGED) ? su->size : 16` (cmd/w6c/cgen.c cgmatch). 16 default
|
||
// when the scrutinee type can't be resolved keeps the historical
|
||
// alloc for non-tagged / unresolved cases. Called by cgmatch at first
|
||
// use; #15 first-use+fail-loud pins this size per fn.
|
||
fn matchspillsz(c: *cgen, scrutt: *node) i32 = {
|
||
if (scrutt == nil) { return 16; };
|
||
let sz: i32 = slotsize(c, scrutt);
|
||
if (sz <= 0) { return 16; };
|
||
return sz;
|
||
};
|
||
|
||
// structparamsize — bytes occupied by a user-defined by-value struct
|
||
// param if it fits in 1-2 SysV integer eightbytes (cstage cgen.c
|
||
// struct_arg_size mirror; gates on size <= 16). Returns 0 for non-
|
||
// struct types or oversized structs so callers can fall through to
|
||
// other dispatch arms. Pre-#11 the wwstage prologue had no struct
|
||
// branch — user-defined struct params dropped through to the 8B
|
||
// scalar catch-all, the second-half value registers (DX/CX) were
|
||
// never spilled, and field reads from the under-allocated slot
|
||
// trailed into the saved-BP word.
|
||
fn structparamsize(c: *cgen, t: *node) i32 = {
|
||
if (c == nil) { return 0; };
|
||
let r: *node = resolvetype(c, t);
|
||
if (r == nil) { return 0; };
|
||
if (r.kind != nkind.N_TNAME) { return 0; };
|
||
let nm: str = r.str;
|
||
if (streq(nm, "str")) { return 0; };
|
||
if (primsize(nm) > 0) { return 0; };
|
||
let si: *structinfo = structlookup(c, nm);
|
||
if (si == nil) { return 0; };
|
||
if (si.totsize <= 0) { return 0; };
|
||
if (si.totsize > 16) { return 0; };
|
||
return si.totsize;
|
||
};
|
||
|
||
// istaggedtype — alias-aware. Reads stamped tinfo so `T`,
|
||
// `type alias = (A|B)`, `type error = !(invalid|overflow)` all
|
||
// resolve to TY_TAGGED — tinfofornode handles the N_TBANG unwrap
|
||
// (check.ww:1145) so we don't re-walk it here. Cite cstage cgen.c
|
||
// (`type_chase_named` + TY_TAGGED). Collapsed per A.6.3b (#46).
|
||
fn istaggedtype(c: *cgen, t: *node) bool = {
|
||
if (t == nil) { return false; };
|
||
return typeistagged(t.type_: *tinfo);
|
||
};
|
||
|
||
// isfloattype — f32 / f64 / untyped_float (alias-aware). Cite cstage
|
||
// cgen.c:117 `cg_isfloat`. Dispatches MOVSS/MOVSD-shaped paths across
|
||
// cglet, cgident, cgassign, cgbin, cgcast, cgcall, cgreturn, fn-
|
||
// prologue. Collapsed per A.6.3b (#46).
|
||
export fn isfloattype(c: *cgen, t: *node) bool = {
|
||
if (t == nil) { return false; };
|
||
return typeisfloat(t.type_: *tinfo);
|
||
};
|
||
|
||
// isf32type — narrower: true only for f32 (after alias chase). Cite
|
||
// cstage cgen.c:188 `type_isf32`. Picks MOVSS vs MOVSD and the SS-
|
||
// variant arithmetic / cast opcodes. Collapsed per A.6.3b (#46).
|
||
export fn isf32type(c: *cgen, t: *node) bool = {
|
||
if (t == nil) { return false; };
|
||
return typeisf32(t.type_: *tinfo);
|
||
};
|
||
|
||
// exprfloatkind — classify an expression's value-class so callers can
|
||
// pick float vs integer codegen without a full type system. Returns:
|
||
// 0 — integer-like (or unknown — same fallback the existing cgen
|
||
// takes today)
|
||
// 1 — f32
|
||
// 2 — f64
|
||
// Recognises: float literals, idents bound to float lets/locals,
|
||
// chained casts whose target is float, and (recursively) the inner
|
||
// expr of a non-narrowing wrapping construct. Anything we can't
|
||
// pin down conservatively reports integer — the worst case is that
|
||
// CVT* is skipped for an exotic case the user can still spell with
|
||
// an explicit local.
|
||
export fn exprfloatkind(c: *cgen, n: *node) i32 = {
|
||
if (n == nil) { return 0; };
|
||
let k: nkind = n.kind;
|
||
if (k == nkind.N_FLOATLIT) { return 2; };
|
||
if (k == nkind.N_CAST) {
|
||
if (isf32type(c, n.rhs)) { return 1; };
|
||
if (isfloattype(c, n.rhs)) { return 2; };
|
||
return 0;
|
||
};
|
||
if (k == nkind.N_IDENT) {
|
||
let lc: *local = localfindnode(c, n.str);
|
||
if (lc != nil) {
|
||
if (isf32type(c, lc.tnode)) { return 1; };
|
||
if (isfloattype(c, lc.tnode)) { return 2; };
|
||
return 0;
|
||
};
|
||
let lv: *letvar = c.lets;
|
||
for (lv != nil) {
|
||
if (streq(lv.name, n.str)) {
|
||
if (isf32type(c, lv.tnode)) { return 1; };
|
||
if (isfloattype(c, lv.tnode)) { return 2; };
|
||
return 0;
|
||
};
|
||
lv = lv.lvnext;
|
||
};
|
||
return 0;
|
||
};
|
||
if (k == nkind.N_UN) {
|
||
// Unary on a float (TK_MINUS) returns float; everything
|
||
// else is integer-coded.
|
||
if (n.op == tkind.TK_MINUS) {
|
||
return exprfloatkind(c, n.lhs);
|
||
};
|
||
return 0;
|
||
};
|
||
if (k == nkind.N_BIN) {
|
||
// Arithmetic binops inherit the operands' kind. Comparison
|
||
// (eq/ne/lt/...) returns bool — integer.
|
||
let op: tkind = n.op;
|
||
if (op == tkind.TK_PLUS) { return exprfloatkind(c, n.lhs); };
|
||
if (op == tkind.TK_MINUS) { return exprfloatkind(c, n.lhs); };
|
||
if (op == tkind.TK_STAR) { return exprfloatkind(c, n.lhs); };
|
||
if (op == tkind.TK_SLASH) { return exprfloatkind(c, n.lhs); };
|
||
return 0;
|
||
};
|
||
if (k == nkind.N_CALL) {
|
||
// Look up the callee's declared return type — fnretlookup
|
||
// returns the type-AST. Routes float-returning fns through
|
||
// the X0 ABI so cglet / cgassign know to spill from X0.
|
||
let nm: str;
|
||
nm.ptr = nil; nm.len = 0;
|
||
if (n.lhs != nil) {
|
||
if (n.lhs.kind == nkind.N_IDENT) { nm = n.lhs.str; };
|
||
};
|
||
if (nm.len > 0) {
|
||
let rtyp: *node = fnretlookup(c, nm);
|
||
if (isf32type(c, rtyp)) { return 1; };
|
||
if (isfloattype(c, rtyp)) { return 2; };
|
||
};
|
||
return 0;
|
||
};
|
||
if (k == nkind.N_DOT) {
|
||
// `p.field` where the struct field is f64/f32. Without this,
|
||
// `v.fval: i64` lowers to CVTSI on an integer-load value
|
||
// instead of CVTTSD2SI on the X0 the cgdot path actually
|
||
// emits for an f64 field. Read the checker-stamped tinfo on
|
||
// the N_DOT itself (check.ww:1973 stamps the field type);
|
||
// cstage cgen.c:2128 reads node_isfloat(n) the same way.
|
||
// Collapsed per A.6.3g (#55).
|
||
if (isf32type(c, n)) { return 1; };
|
||
if (isfloattype(c, n)) { return 2; };
|
||
return 0;
|
||
};
|
||
return 0;
|
||
};
|
||
|
||
// isnullabletype — `(*T | void)` one-word fold per Hare's
|
||
// `(*T | null)` semantics. Cite cstage cgen.c:396 `type_isnullable`;
|
||
// the .nullable flag lands on tinfo at check.ww:1309-1318 when the
|
||
// two-variant shape matches. Collapsed per A.6.3b (#46).
|
||
export fn isnullabletype(t: *node) bool = {
|
||
if (t == nil) { return false; };
|
||
return typeisnullable(t.type_: *tinfo);
|
||
};
|
||
|
||
// nullableptrtag — 0-based index of the *T variant in a nullable
|
||
// union. Mirror of cstage cgen.c:404-416 `nullable_ptr_tag`: linear
|
||
// scan ti.params, strip TY_NAMED on each variant, return idx of first
|
||
// TY_PTR. Phase 1 (26724fe) populated the chain in tinfofornode's
|
||
// TTAGGED arm so this walk could retire the AST-keyed predecessor.
|
||
export fn nullableptrtag(t: *node) i32 = {
|
||
if (t == nil) { return 0; };
|
||
let ti: *tinfo = t.type_: *tinfo;
|
||
if (ti == nil) { return 0; };
|
||
// #63 Phase-N step 1: peel TY_NAMED before this structural query.
|
||
// #64 builds per-decl NAMED wrappers (tinfofornode), so the peel
|
||
// now fires on aliased operands; byte-id holds because it collapses
|
||
// NAMED to the alias-invariant underlying this read consumes.
|
||
for (ti != nil && ti.kind == tykind.TY_NAMED) { ti = ti.under; };
|
||
if (ti == nil) { return 0; };
|
||
if (ti.kind != tykind.TY_TAGGED) { return 0; };
|
||
let p: *tparam = ti.params;
|
||
let i: i32 = 0;
|
||
for (p != nil) {
|
||
let vt: *tinfo = p.type_;
|
||
if (vt != nil) {
|
||
if (vt.kind == tykind.TY_NAMED) { vt = vt.under; };
|
||
if (vt != nil) {
|
||
if (vt.kind == tykind.TY_PTR) { return i; };
|
||
};
|
||
};
|
||
p = p.tnext;
|
||
i += 1;
|
||
};
|
||
return 0;
|
||
};
|
||
|
||
// voidvariantindex — find the 0-based index of the `void` variant in a
|
||
// tagged-union type expr, -1 if absent. Used by cgreturn to map bare
|
||
// `return;` in a tagged-union-returning fn to the void variant's tag.
|
||
fn voidvariantindex(tagged: *node) i32 = {
|
||
if (tagged == nil) { return -1; };
|
||
if (tagged.kind != nkind.N_TTAGGED) { return -1; };
|
||
let v: *node = tagged.list;
|
||
let idx: i32 = 0;
|
||
for (v != nil) {
|
||
if (v.kind == nkind.N_TNAME) {
|
||
if (streq(v.str, "void")) { return idx; };
|
||
};
|
||
v = v.next;
|
||
idx += 1;
|
||
};
|
||
return -1;
|
||
};
|
||
|
||
// taggedvariantindex — given the tagged-union type expr and the
|
||
// returned value's surface type, find the matching variant's 0-based
|
||
// index. Compare by exact type name first; if no match, fall back to
|
||
// "any str-shape variant matches an str-typed value".
|
||
fn taggedvariantindex(c: *cgen, tagged: *node, rhs: *node) i32 = {
|
||
if (tagged == nil) { return -1; };
|
||
return taggedvariantindext(c, tagged.type_: *tinfo, rhs);
|
||
};
|
||
|
||
// taggedvariantindext — tinfo-keyed core of taggedvariantindex. Given
|
||
// the dst tagged tinfo `du` (NAMED-peeled internally, gated TY_TAGGED)
|
||
// and the source value node, returns the 0-based variant index. #68: the
|
||
// tagged-store machinery reads tinfo directly (no type node), so the
|
||
// node-keyed taggedvariantindex delegates here off `tagged.type_`.
|
||
//
|
||
// #66 Phase-N step 3: match the value's stamped type against the variant
|
||
// types by typeeq (flatvariantidxt), replacing the rhstargetname surface-
|
||
// name compare. Untyped/loose values (whose .type_ is untyped_* and can't
|
||
// typeeq a concrete variant) return -1 there and drop to the str/slice
|
||
// shape scan below — ww has no type_assignable to mirror cg_variant_match's
|
||
// untyped-src arm.
|
||
fn taggedvariantindext(c: *cgen, du: *tinfo, rhs: *node) i32 = {
|
||
if (du == nil) { return -1; };
|
||
if (rhs == nil) { return -1; };
|
||
let ti: *tinfo = du;
|
||
for (ti != nil && ti.kind == tykind.TY_NAMED) { ti = ti.under; };
|
||
if (ti == nil) { return -1; };
|
||
if (ti.kind != tykind.TY_TAGGED) { return -1; };
|
||
let r: i32 = flatvariantidxt(ti, rhs.type_: *tinfo);
|
||
if (r >= 0) { return r; };
|
||
// Shape fallback: classify rhs as (str, slice, scalar/other) and
|
||
// pick the first variant of matching shape. Stands in for cstage's
|
||
// type_assignable on an untyped src — the typeeq pass above can't
|
||
// match untyped_* against a concrete variant, and the slice axis
|
||
// keeps a (u8 | []u8) widen off the leading scalar variant (task
|
||
// #19). tinfo.params is already spread-flattened (#61a — `...inner`
|
||
// inlined in declaration order), so the old N_TTAGGED.list spread-
|
||
// walk collapses to a flat scan over p.type_.
|
||
let wantstr: bool = nodeisstr(c, rhs);
|
||
let wantslice: bool = nodeisslice(c, rhs);
|
||
let p: *tparam = ti.params;
|
||
let idx: i32 = 0;
|
||
for (p != nil) {
|
||
let vt: *tinfo = p.type_;
|
||
let visstr: bool = typeisstr(vt);
|
||
let visslice: bool = typeisslice(vt);
|
||
if (visstr == wantstr && visslice == wantslice) { return idx; };
|
||
p = p.tnext;
|
||
idx += 1;
|
||
};
|
||
return -1;
|
||
};
|
||
|
||
// flatvariantidx — flat 0-based index of the variant whose type matches
|
||
// the pattern node `pat`, by typeeq on the stamped tinfos. Reads the
|
||
// pre-flattened variant chain off tinfo.params (#61a — `...inner`
|
||
// spreads already inlined in declaration order); peels TY_NAMED then
|
||
// gates TY_TAGGED.
|
||
//
|
||
// #66 Phase-N step 3 (THE FLIP, user-ruled B-full): match by
|
||
// typeeq(p.type_, pat.type_) — nominal identity carried by the per-decl
|
||
// TY_NAMED ptr — instead of the surface-name compare. So `type linerr =
|
||
// !str` ≠ str and a cross-module `a.T` ≠ `b.T` are now distinguished.
|
||
// Mirrors cstage cg_variant_match (cmd/w6c/cgen.c:451): both-NAMED →
|
||
// ptr-id (typeeq, typ.ww:514), one-NAMED → kind mismatch → false. ww has
|
||
// no type_assignable, so the untyped/loose arm (cg_variant_match's first
|
||
// branch) lives in the caller's str/slice shape fallback, not here.
|
||
fn flatvariantidx(c: *cgen, tagged: *node, pat: *node) i32 = {
|
||
if (tagged == nil) { return -1; };
|
||
if (pat == nil) { return -1; };
|
||
return flatvariantidxt(tagged.type_: *tinfo, pat.type_: *tinfo);
|
||
};
|
||
|
||
// flatvariantidxt — tinfo-keyed core of flatvariantidx: flat 0-based
|
||
// index of the variant whose type typeeq's `want`, over the pre-
|
||
// flattened tinfo.params chain (#61a). Peels TY_NAMED then gates
|
||
// TY_TAGGED. #68: the tagged-store machinery reads tinfo directly and
|
||
// has no type node to hand the node-keyed flatvariantidx, so the typeeq
|
||
// core lives here; flatvariantidx + taggedvariantindext + cgwidentagremap
|
||
// all funnel through it. Mirrors cstage cg_tag_for_variant
|
||
// (cmd/w6c/cgen.c:503) + cg_variant_match's both-NAMED ptr-id / typeeq
|
||
// arm (:451).
|
||
fn flatvariantidxt(tagged: *tinfo, want: *tinfo) i32 = {
|
||
if (want == nil) { return -1; };
|
||
let ti: *tinfo = tagged;
|
||
for (ti != nil && ti.kind == tykind.TY_NAMED) { ti = ti.under; };
|
||
if (ti == nil) { return -1; };
|
||
if (ti.kind != tykind.TY_TAGGED) { return -1; };
|
||
let p: *tparam = ti.params;
|
||
let idx: i32 = 0;
|
||
for (p != nil) {
|
||
if (typeeq(p.type_, want)) { return idx; };
|
||
p = p.tnext;
|
||
idx += 1;
|
||
};
|
||
return -1;
|
||
};
|
||
|
||
// flatslicevariantidx — flat 0-based index of a slice-shape variant in
|
||
// `tagged`. Prefers the variant whose element typeeq's the pattern
|
||
// element `elem`; falls back to the first slice-shape slot when no exact
|
||
// element match is found (the untyped/loose arm — ww has no
|
||
// type_assignable). Reads the flattened tinfo.params chain (#61a); peels
|
||
// TY_NAMED then gates TY_TAGGED. The slice axis exists because a scalar-
|
||
// vs-`[]T` distinction has no surface name to key on (task #19).
|
||
//
|
||
// #66 Phase-N step 3: element compare flips from surface-name to
|
||
// typeeq(p.type_.sub, elem.type_). Mirrors cstage cg_tag_for_variant
|
||
// over Type->params. Returns -1 when no slice variant exists.
|
||
fn flatslicevariantidx(c: *cgen, tagged: *node, elem: *node) i32 = {
|
||
if (tagged == nil) { return -1; };
|
||
let ti: *tinfo = tagged.type_: *tinfo;
|
||
for (ti != nil && ti.kind == tykind.TY_NAMED) { ti = ti.under; };
|
||
if (ti == nil) { return -1; };
|
||
if (ti.kind != tykind.TY_TAGGED) { return -1; };
|
||
let want: *tinfo = nil;
|
||
if (elem != nil) { want = elem.type_: *tinfo; };
|
||
let fallback: i32 = -1;
|
||
let p: *tparam = ti.params;
|
||
let idx: i32 = 0;
|
||
for (p != nil) {
|
||
let vt: *tinfo = p.type_;
|
||
if (vt != nil) {
|
||
if (typeisslice(vt)) {
|
||
if (fallback < 0) { fallback = idx; };
|
||
if (want != nil) {
|
||
let su: *tinfo = vt;
|
||
for (su != nil && su.kind == tykind.TY_NAMED) { su = su.under; };
|
||
if (su != nil) {
|
||
if (typeeq(su.sub, want)) { return idx; };
|
||
};
|
||
};
|
||
};
|
||
};
|
||
p = p.tnext;
|
||
idx += 1;
|
||
};
|
||
return fallback;
|
||
};
|
||
|
||
// cgwidentagremap — when widening from one tagged union to a wider one,
|
||
// rewrite the source's variant tag at slot_off+0 to use the destination's
|
||
// variant indices. No-op when src and dst index orders coincide.
|
||
//
|
||
// #68: both `du` (dst) and `su` (src) are now the tagged tinfos — peel
|
||
// TY_NAMED then walk su.params, mapping each source variant to its dst
|
||
// index by typeeq (flatvariantidxt). Mirrors cg_widen_tag_remap
|
||
// (cmd/w6c/cgen.c:1177) over su->params + cg_tag_for_variant (:503).
|
||
fn cgwidentagremap(c: *cgen, du: *tinfo, su: *tinfo, slot_off: i32) void = {
|
||
let dt: *tinfo = du;
|
||
for (dt != nil && dt.kind == tykind.TY_NAMED) { dt = dt.under; };
|
||
if (dt == nil) { return; };
|
||
if (dt.kind != tykind.TY_TAGGED) { return; };
|
||
let st: *tinfo = su;
|
||
for (st != nil && st.kind == tykind.TY_NAMED) { st = st.under; };
|
||
if (st == nil) { return; };
|
||
if (st.kind != tykind.TY_TAGGED) { return; };
|
||
let identity: bool = true;
|
||
let p: *tparam = st.params;
|
||
let idx: i32 = 0;
|
||
for (p != nil) {
|
||
let di: i32 = flatvariantidxt(dt, p.type_);
|
||
if (di < 0) { di = 0; };
|
||
if (di != idx) { identity = false; p = nil; }
|
||
else { p = p.tnext; idx += 1; };
|
||
};
|
||
if (identity) { return; };
|
||
let done: str = mklabel(c, "remap_done");
|
||
emitline("\tMOVQ\t");
|
||
emitoff(slot_off: i64);
|
||
emitline("(BP), AX\n");
|
||
p = st.params;
|
||
idx = 0;
|
||
for (p != nil) {
|
||
let next: str = mklabel(c, "remap_next");
|
||
let di: i32 = flatvariantidxt(dt, p.type_);
|
||
if (di < 0) { di = 0; };
|
||
emitline("\tCMPQ\t$");
|
||
emitint(idx: i64);
|
||
emitline(", AX\n");
|
||
emitline("\tJNE\t");
|
||
emitline(next);
|
||
emitline("\n");
|
||
emitline("\tMOVQ\t$");
|
||
emitint(di: i64);
|
||
emitline(", AX\n");
|
||
emitline("\tMOVQ\tAX, ");
|
||
emitoff(slot_off: i64);
|
||
emitline("(BP)\n");
|
||
emitline("\tJMP\t");
|
||
emitline(done);
|
||
emitline("\n");
|
||
emitlabel(next);
|
||
p = p.tnext;
|
||
idx += 1;
|
||
};
|
||
emitlabel(done);
|
||
return;
|
||
};
|
||
|
||
// rhsisstructpayload — is `src` a struct value (literal or local ident
|
||
// of a struct type)? Returns the struct name, or empty str. Only true
|
||
// when the name is registered in c.structs — `!void` / `!i32` aliases
|
||
// share the N_STRUCTLIT / N_TNAME shape but aren't structs, and must
|
||
// fall through to the scalar/str/tagged-source paths instead.
|
||
fn rhsstructpayload(c: *cgen, src: *node) str = {
|
||
let empty: str;
|
||
empty.ptr = nil; empty.len = 0;
|
||
if (src == nil) { return empty; };
|
||
if (src.kind == nkind.N_STRUCTLIT) {
|
||
let trefn: *node = src.lhs;
|
||
if (trefn != nil) {
|
||
let nm: str;
|
||
nm.ptr = nil; nm.len = 0;
|
||
if (trefn.kind == nkind.N_IDENT) { nm = trefn.str; };
|
||
if (trefn.kind == nkind.N_TNAME) { nm = trefn.str; };
|
||
if (nm.len > 0) {
|
||
if (structlookup(c, nm) != nil) { return nm; };
|
||
};
|
||
};
|
||
return empty;
|
||
};
|
||
if (src.kind == nkind.N_IDENT) {
|
||
let lc: *local = localfindnode(c, src.str);
|
||
if (lc != nil) {
|
||
let tn: *node = lc.tnode;
|
||
if (tn != nil) {
|
||
if (tn.kind == nkind.N_TNAME) {
|
||
if (structlookup(c, tn.str) != nil) {
|
||
return tn.str;
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
return empty;
|
||
};
|
||
|
||
// rhstaggedsource — return the tagged-type node for `src` when src is a
|
||
// tagged-typed local ident; nil otherwise. The slot-copy path uses this
|
||
// to walk variants for tag remap.
|
||
fn rhstaggedident(c: *cgen, src: *node) *node = {
|
||
if (src == nil) { return nil; };
|
||
if (src.kind != nkind.N_IDENT) { return nil; };
|
||
let lc: *local = localfindnode(c, src.str);
|
||
if (lc == nil) { return nil; };
|
||
let tn: *node = lc.tnode;
|
||
if (!istaggedtype(c, tn)) { return nil; };
|
||
return resolvetagged(c, tn);
|
||
};
|
||
|
||
// rhstaggedabicall — does `src` produce a tagged value via the AX/DX/CX
|
||
// return ABI? True for N_CALL of a tagged-returning fn, N_INDEX of a
|
||
// tagged-element base, and N_DOT of a tagged-typed struct field (after
|
||
// #28's cgdot fix loads AX/DX/CX/R8 from the field's slot). Used to
|
||
// decide whether cgexpr/spill works for the tagged-source branch of
|
||
// cgwidentaggedstore.
|
||
fn rhstaggedabicall(c: *cgen, src: *node) bool = {
|
||
if (src == nil) { return false; };
|
||
if (src.kind == nkind.N_CALL) {
|
||
let callee: *node = src.lhs;
|
||
if (callee != nil) {
|
||
let calleename: str;
|
||
calleename.ptr = nil; calleename.len = 0;
|
||
let cmod: str;
|
||
cmod.ptr = nil; cmod.len = 0;
|
||
if (callee.kind == nkind.N_IDENT) {
|
||
calleename = callee.str;
|
||
cmod = c.curmod;
|
||
};
|
||
if (callee.kind == nkind.N_DOT) {
|
||
calleename = callee.str;
|
||
if (callee.lhs != nil) {
|
||
if (callee.lhs.kind == nkind.N_IDENT) {
|
||
cmod = callee.lhs.str;
|
||
};
|
||
};
|
||
};
|
||
if (calleename.len > 0) {
|
||
let rtyp: *node = fnretlookupmod(c, calleename, cmod);
|
||
if (rtyp != nil) {
|
||
if (istaggedtype(c, rtyp)) { return true; };
|
||
};
|
||
};
|
||
};
|
||
return false;
|
||
};
|
||
if (src.kind == nkind.N_INDEX) {
|
||
let base: *node = src.lhs;
|
||
if (base != nil) {
|
||
if (base.kind == nkind.N_IDENT) {
|
||
let bl: *local = localfindnode(c, base.str);
|
||
if (bl != nil) {
|
||
let btn: *node = bl.tnode;
|
||
if (btn != nil) {
|
||
let bk: nkind = btn.kind;
|
||
let elemt: *node = nil;
|
||
if (bk == nkind.N_TARRAY) { elemt = btn.lhs; };
|
||
if (bk == nkind.N_TSLICE) { elemt = btn.lhs; };
|
||
if (bk == nkind.N_TPTR) { elemt = btn.lhs; };
|
||
if (elemt != nil) {
|
||
if (istaggedtype(c, elemt)) {
|
||
return true;
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
// N_DOT of a tagged-typed struct field — cgdot loads
|
||
// AX=tag, DX=word0, CX=word1[, R8=word2], so downstream
|
||
// spill matches the call/index shapes. #58 A.6.3i-phase-2:
|
||
// read the checker-stamped n.type_ (check.ww N_DOT struct-field
|
||
// stamp) instead of re-deriving via dotfieldtnode — matches
|
||
// cstage cg_widen_tagged_store reading src->type directly
|
||
// (cmd/w6c/cgen.c:1302-1305). typeistagged(nil) is false.
|
||
if (src.kind == nkind.N_DOT) {
|
||
if (typeistagged(src.type_: *tinfo)) { return true; };
|
||
};
|
||
return false;
|
||
};
|
||
|
||
// cgloadtaggedfield — load a tagged-union slot at `basereg`+foff
|
||
// into the tagged-return ABI registers (AX=tag, DX=word0, CX=word1,
|
||
// R8=word2). Slot sizes: 16B = (tag, word0), 24B = + word1, 32B
|
||
// = + word2 (slice variant). Mirrors the cstage tagged-field load
|
||
// in cmd/w6c/cgen.c (N_DOT TY_STRUCT/TY_PTR branches).
|
||
//
|
||
// Load order is fixed regardless of basereg: tag, word0, word2,
|
||
// word1. CX (word1 target) goes LAST because basereg may itself
|
||
// be CX — top-level globals address via LEAQ name(SB), CX — and
|
||
// overwriting it earlier would trash the base address for the
|
||
// remaining loads. For BP / BX bases the order is harmless.
|
||
// Callers must guarantee basereg is one of "BP", "BX", "CX"; the
|
||
// only register loaded into that is NOT a target is BX, so AX-
|
||
// or DX-rooted callers must spill first.
|
||
fn cgloadtaggedfield(c: *cgen, basereg: str, foff: i32, slot_sz: i32) void = {
|
||
// tag → AX
|
||
emitline("\tMOVQ\t");
|
||
emitdispreg(foff: i64, basereg);
|
||
emitline(", AX\n");
|
||
// word0 → DX
|
||
emitline("\tMOVQ\t");
|
||
emitdispreg((foff + 8): i64, basereg);
|
||
emitline(", DX\n");
|
||
// word2 → R8 (slice variant: slot = 8 tag + 24 payload = 32).
|
||
if (slot_sz > 24) {
|
||
emitline("\tMOVQ\t");
|
||
emitdispreg((foff + 24): i64, basereg);
|
||
emitline(", R8\n");
|
||
};
|
||
// word1 → CX (load LAST; conflicts with CX-base globals).
|
||
if (slot_sz > 16) {
|
||
emitline("\tMOVQ\t");
|
||
emitdispreg((foff + 16): i64, basereg);
|
||
emitline(", CX\n");
|
||
};
|
||
};
|
||
|
||
// cgwidentaggedstore — write tagged-union slot bytes for `src` into
|
||
// the slot at `basereg`+slot_off, sized to slot_sz. Mirrors
|
||
// cg_widen_tagged_store in cmd/w6c/cgen.c.
|
||
//
|
||
// `basereg` selects the addressing root:
|
||
// - "BP": function-frame slot (let / assign / return / structlit /
|
||
// array-elem scratch). Body writes straight to slot_off(BP).
|
||
// - else (e.g. "BX" for *struct field, top-level struct LEAQ
|
||
// base): pointer-rooted dst. cgexpr inside trashes every GPR,
|
||
// so we route through a fresh BP-rooted scratch slot, spill
|
||
// basereg before the body, reload after, then word-copy
|
||
// scratch → (basereg, slot_off).
|
||
//
|
||
// Branches by source shape:
|
||
// - nullable dst (8B slot): cgexpr → AX → slot+0.
|
||
// - tagged src ident: copy slot words, zero-pad, tag-remap.
|
||
// - tagged src via AX/DX/CX ABI (call / tagged-arr index): cgexpr,
|
||
// spill words; no remap (callee already speaks dst tag order — or
|
||
// it doesn't, in which case the source is the wider one and remap
|
||
// would need a reversed direction we don't currently emit).
|
||
// - struct src (literal or ident): zero slot, write fields at +8+foff,
|
||
// tag last.
|
||
// - str src: tag@+0, ptr@+8, len@+16.
|
||
// - scalar src: tag@+0, value@+8.
|
||
fn cgwidentaggedstore(c: *cgen, dst: *tinfo, src: *node,
|
||
basereg: str, slot_off: i32, slot_sz: i32) void = {
|
||
if (streq(basereg, "BP")) {
|
||
cgwidentaggedstorebp(c, dst, src, slot_off, slot_sz);
|
||
return;
|
||
};
|
||
// Pointer-rooted dst: spill basereg (cgexpr will trash it),
|
||
// materialise into a BP-rooted scratch via the BP path, then
|
||
// reload basereg and word-copy scratch → caller's slot.
|
||
let bspill: i32 = localadd(c, "@tagbase", 8, nil);
|
||
emitline("\tMOVQ\t");
|
||
emitline(basereg);
|
||
emitline(", ");
|
||
emitoff(bspill: i64);
|
||
emitline("(BP)\n");
|
||
// Shared scratch sized at first use per #15/#26c. A sibling
|
||
// site (cgreturn, pushargsrev, cgindex) hitting @tagscr later
|
||
// with a larger size fatals (rule 7) — pinned offset can't
|
||
// grow in place.
|
||
let scr: i32 = localadd(c, "@tagscr", slot_sz, nil);
|
||
emitline("\tXORQ\tAX, AX\n");
|
||
let z: i32 = 0;
|
||
for (z < slot_sz) {
|
||
emitline("\tMOVQ\tAX, ");
|
||
emitoff((scr + z): i64);
|
||
emitline("(BP)\n");
|
||
z += 8;
|
||
};
|
||
cgwidentaggedstorebp(c, dst, src, scr, slot_sz);
|
||
emitline("\tMOVQ\t");
|
||
emitoff(bspill: i64);
|
||
emitline("(BP), ");
|
||
emitline(basereg);
|
||
emitline("\n");
|
||
let k: i32 = 0;
|
||
for (k < slot_sz) {
|
||
emitline("\tMOVQ\t");
|
||
emitoff((scr + k): i64);
|
||
emitline("(BP), AX\n");
|
||
emitline("\tMOVQ\tAX, ");
|
||
emitdispreg((slot_off + k): i64, basereg);
|
||
emitline("\n");
|
||
k += 8;
|
||
};
|
||
};
|
||
|
||
// cgwidentaggedstorebp — BP-rooted body. Called via cgwidentaggedstore
|
||
// for the natural "BP" case and via the wrapper's scratch path for
|
||
// pointer-rooted dst. Direct callers exist only in case of future
|
||
// inlined uses inside this file; new code should call the wrapper.
|
||
fn cgwidentaggedstorebp(c: *cgen, dst: *tinfo, src: *node, slot_off: i32, slot_sz: i32) void = {
|
||
// #68: dst is the tagged tinfo. Peel TY_NAMED → du and gate
|
||
// TY_TAGGED, mirroring cstage cg_widen_tagged_store's
|
||
// `du = (dst->kind==TY_NAMED)?dst->under:dst` + TY_TAGGED guard
|
||
// (cmd/w6c/cgen.c:1273). resolvetagged's N_TBANG unwrap is already
|
||
// handled upstream by tinfofornode (check.ww:1203-1210).
|
||
let dt: *tinfo = dst;
|
||
for (dt != nil && dt.kind == tykind.TY_NAMED) { dt = dt.under; };
|
||
if (dt == nil) { return; };
|
||
if (dt.kind != tykind.TY_TAGGED) { return; };
|
||
// Nullable fold: one 8B word holding the pointer (or 0 for void).
|
||
if (dt.nullable != 0) {
|
||
cgexpr(c, src);
|
||
emitline("\tMOVQ\tAX, ");
|
||
emitoff(slot_off: i64);
|
||
emitline("(BP)\n");
|
||
return;
|
||
};
|
||
// `expr: TaggedAlias` where the cast's destination IS the union
|
||
// itself is a widening, not a re-interpret. cgexpr on a CAST
|
||
// produces the inner's register shape (str: AX=ptr, BX=len), not
|
||
// the tagged AX/DX/CX triple — so peel to the inner and route
|
||
// through the matching concrete-variant branch below. A cast to
|
||
// a concrete variant (`7: i32`) is left intact so the existing
|
||
// scalar / str / slice branches pick the right variant tag.
|
||
if (src != nil) {
|
||
if (src.kind == nkind.N_CAST) {
|
||
if (src.lhs != nil) {
|
||
let inner: *node = src.lhs;
|
||
let inneristagged: bool = false;
|
||
if (inner.kind == nkind.N_IDENT) {
|
||
let lc: *local = localfindnode(c, inner.str);
|
||
if (lc != nil) {
|
||
inneristagged = istaggedtype(c, lc.tnode);
|
||
};
|
||
};
|
||
if (rhstaggedabicall(c, inner)) {
|
||
inneristagged = true;
|
||
};
|
||
// Cast's destination = the dst tagged union
|
||
// itself? The rhs of N_CAST holds the target
|
||
// type. #68: compare on the stamped tinfos —
|
||
// `castu == dt` (peeled-underlying ptr-id) ||
|
||
// (castu tagged && typeeq(castt, dst)) — mirroring
|
||
// cstage cg_widen_tagged_store's
|
||
// `cast_is_widen = (castu==du) || (castu->kind==
|
||
// TY_TAGGED && type_eq(castt, dst))`
|
||
// (cmd/w6c/cgen.c:1295-1296). Replaces the prior
|
||
// surface-name streq; same-alias TNAMEs share one
|
||
// NAMED tinfo (check.ww:1160-1173) so typeeq hits
|
||
// the a==b fast path.
|
||
let castisdst: bool = false;
|
||
let castrhs: *node = src.rhs;
|
||
if (castrhs != nil) {
|
||
let castt: *tinfo = castrhs.type_: *tinfo;
|
||
let castu: *tinfo = castt;
|
||
for (castu != nil && castu.kind == tykind.TY_NAMED) {
|
||
castu = castu.under;
|
||
};
|
||
if (castu != nil) {
|
||
if (castu == dt) {
|
||
castisdst = true;
|
||
} else { if (castu.kind == tykind.TY_TAGGED) {
|
||
if (typeeq(castt, dst)) {
|
||
castisdst = true;
|
||
};
|
||
}; };
|
||
};
|
||
};
|
||
if (castisdst && !inneristagged) {
|
||
src = inner;
|
||
};
|
||
};
|
||
};
|
||
};
|
||
// Tagged source ident: byte-copy slot words then tag-remap.
|
||
// rhstaggedident gates "src is a tagged-typed local ident"; the
|
||
// remap reads the source tagged tinfo off the local's tnode (#68).
|
||
let st: *node = rhstaggedident(c, src);
|
||
if (st != nil) {
|
||
let lc: *local = localfindnode(c, src.str);
|
||
let ssz: i32 = slotsize(c, lc.tnode);
|
||
let soff: i32 = lc.off;
|
||
let k: i32 = 0;
|
||
for (k < ssz) {
|
||
emitline("\tMOVQ\t");
|
||
emitoff((soff + k): i64);
|
||
emitline("(BP), AX\n");
|
||
emitline("\tMOVQ\tAX, ");
|
||
emitoff((slot_off + k): i64);
|
||
emitline("(BP)\n");
|
||
k += 8;
|
||
};
|
||
if (ssz < slot_sz) {
|
||
emitline("\tXORQ\tAX, AX\n");
|
||
let p: i32 = ssz;
|
||
for (p < slot_sz) {
|
||
emitline("\tMOVQ\tAX, ");
|
||
emitoff((slot_off + p): i64);
|
||
emitline("(BP)\n");
|
||
p += 8;
|
||
};
|
||
};
|
||
cgwidentagremap(c, dt, lc.tnode.type_: *tinfo, slot_off);
|
||
return;
|
||
};
|
||
// Tagged source via AX/DX/CX/R8 register ABI (N_CALL, N_INDEX
|
||
// of tagged element). R8 carries the 4th word for slice-payload
|
||
// variants (slot 32B).
|
||
if (rhstaggedabicall(c, src)) {
|
||
cgexpr(c, src);
|
||
emitline("\tMOVQ\tAX, ");
|
||
emitoff(slot_off: i64);
|
||
emitline("(BP)\n");
|
||
if (slot_sz > 8) {
|
||
emitline("\tMOVQ\tDX, ");
|
||
emitoff((slot_off + 8): i64);
|
||
emitline("(BP)\n");
|
||
};
|
||
if (slot_sz > 16) {
|
||
emitline("\tMOVQ\tCX, ");
|
||
emitoff((slot_off + 16): i64);
|
||
emitline("(BP)\n");
|
||
};
|
||
if (slot_sz > 24) {
|
||
emitline("\tMOVQ\tR8, ");
|
||
emitoff((slot_off + 24): i64);
|
||
emitline("(BP)\n");
|
||
};
|
||
return;
|
||
};
|
||
// Struct payload (literal or ident).
|
||
let sname: str = rhsstructpayload(c, src);
|
||
if (sname.len > 0) {
|
||
let si: *structinfo = structlookup(c, sname);
|
||
if (si != nil) {
|
||
emitline("\tXORQ\tAX, AX\n");
|
||
let zoff: i32 = 0;
|
||
for (zoff < slot_sz) {
|
||
emitline("\tMOVQ\tAX, ");
|
||
emitoff((slot_off + zoff): i64);
|
||
emitline("(BP)\n");
|
||
zoff += 8;
|
||
};
|
||
let tag: i32 = taggedvariantindext(c, dt, src);
|
||
if (tag < 0) { tag = 0; };
|
||
if (src.kind == nkind.N_STRUCTLIT) {
|
||
let fnode: *node = src.list;
|
||
for (fnode != nil) {
|
||
if (fnode.kind == nkind.N_FIELD) {
|
||
let fname: str = fnode.str;
|
||
let fi: *fieldinfo = si.fields;
|
||
for (fi != nil) {
|
||
if (streq(fi.fname, fname)) {
|
||
cgexpr(c, fnode.lhs);
|
||
if (isfloattype(c, fi.tnode)) {
|
||
let mov: str = "MOVSD";
|
||
if (isf32type(c, fi.tnode)) {
|
||
mov = "MOVSS";
|
||
};
|
||
emitline("\t");
|
||
emitline(mov);
|
||
emitline("\tX0, ");
|
||
emitoff((slot_off + 8 + fi.foff): i64);
|
||
emitline("(BP)\n");
|
||
} else { if (isstrtype(c, fi.tnode)) {
|
||
emitline("\tMOVQ\tAX, ");
|
||
emitoff((slot_off + 8 + fi.foff): i64);
|
||
emitline("(BP)\n");
|
||
emitline("\tMOVQ\tBX, ");
|
||
emitoff((slot_off + 8 + fi.foff + 8): i64);
|
||
emitline("(BP)\n");
|
||
} else {
|
||
let sop: str = fieldstoreop(c, fi);
|
||
emitline("\t");
|
||
emitline(sop);
|
||
emitline("\tAX, ");
|
||
emitoff((slot_off + 8 + fi.foff): i64);
|
||
emitline("(BP)\n");
|
||
}; };
|
||
fi = nil;
|
||
} else {
|
||
fi = fi.finext;
|
||
};
|
||
};
|
||
};
|
||
fnode = fnode.next;
|
||
};
|
||
} else {
|
||
// Struct ident source: byte-copy struct words to slot+8+k.
|
||
let lc: *local = localfindnode(c, src.str);
|
||
let soff: i32 = 0;
|
||
if (lc != nil) { soff = lc.off; };
|
||
let stotal: i32 = si.totsize;
|
||
let ki: i32 = 0;
|
||
for (ki + 8 <= stotal) {
|
||
emitline("\tMOVQ\t");
|
||
emitoff((soff + ki): i64);
|
||
emitline("(BP), AX\n");
|
||
emitline("\tMOVQ\tAX, ");
|
||
emitoff((slot_off + 8 + ki): i64);
|
||
emitline("(BP)\n");
|
||
ki += 8;
|
||
};
|
||
if (ki < stotal) {
|
||
let tail: i32 = stotal - ki;
|
||
let lop: str = "MOVQ";
|
||
if (tail == 4) { lop = "MOVL"; }
|
||
else { if (tail == 1) { lop = "MOVB"; }; };
|
||
emitline("\t");
|
||
emitline(lop);
|
||
emitline("\t");
|
||
emitoff((soff + ki): i64);
|
||
emitline("(BP), AX\n");
|
||
emitline("\t");
|
||
emitline(lop);
|
||
emitline("\tAX, ");
|
||
emitoff((slot_off + 8 + ki): i64);
|
||
emitline("(BP)\n");
|
||
};
|
||
};
|
||
emitline("\tMOVQ\t$");
|
||
emitint(tag: i64);
|
||
emitline(", ");
|
||
emitoff(slot_off: i64);
|
||
emitline("(BP)\n");
|
||
return;
|
||
};
|
||
};
|
||
// Str payload.
|
||
if (nodeisstr(c, src)) {
|
||
cgexpr(c, src);
|
||
emitline("\tMOVQ\tAX, ");
|
||
emitoff((slot_off + 8): i64);
|
||
emitline("(BP)\n");
|
||
emitline("\tMOVQ\tBX, ");
|
||
emitoff((slot_off + 16): i64);
|
||
emitline("(BP)\n");
|
||
let tag: i32 = taggedvariantindext(c, dt, src);
|
||
if (tag < 0) { tag = 0; };
|
||
emitline("\tMOVQ\t$");
|
||
emitint(tag: i64);
|
||
emitline(", ");
|
||
emitoff(slot_off: i64);
|
||
emitline("(BP)\n");
|
||
return;
|
||
};
|
||
// Slice payload (24B): cgexpr leaves (AX=ptr, BX=len, CX=cap).
|
||
// Slot layout: [+0]=tag, [+8]=ptr, [+16]=len, [+24]=cap.
|
||
if (nodeisslice(c, src)) {
|
||
cgexpr(c, src);
|
||
emitline("\tMOVQ\tAX, ");
|
||
emitoff((slot_off + 8): i64);
|
||
emitline("(BP)\n");
|
||
emitline("\tMOVQ\tBX, ");
|
||
emitoff((slot_off + 16): i64);
|
||
emitline("(BP)\n");
|
||
emitline("\tMOVQ\tCX, ");
|
||
emitoff((slot_off + 24): i64);
|
||
emitline("(BP)\n");
|
||
let tag: i32 = taggedvariantindext(c, dt, src);
|
||
if (tag < 0) { tag = 0; };
|
||
emitline("\tMOVQ\t$");
|
||
emitint(tag: i64);
|
||
emitline(", ");
|
||
emitoff(slot_off: i64);
|
||
emitline("(BP)\n");
|
||
return;
|
||
};
|
||
// Float arm: cgexpr on an f64/f32 source leaves the bit pattern in
|
||
// X0 only — the AX-store fallback below would silently write whatever
|
||
// was loaded into AX before the SSE conversion. Literal `1.0` works
|
||
// by coincidence (TK_FLOAT lowering loads the f64 bit pattern into AX
|
||
// before MOVSD'ing into X0); every runtime f64 shape (cast, call,
|
||
// unary, ident, struct-field load) needs the explicit MOVSD path.
|
||
// Mirror of cstage cg_widen_tagged_store's float arm. Wwstage has no
|
||
// checker so we classify via exprfloatkind (same shape used by cgcast)
|
||
// and resolve the variant tag by name directly — rhstargetname has no
|
||
// N_FLOATLIT / N_CALL / N_DOT branch and would fall through to the
|
||
// str-shape fallback that picks tag 0 for an `(i64 | f64)` union.
|
||
let fkind: i32 = exprfloatkind(c, src);
|
||
if (fkind != 0) {
|
||
let fmov: str = "MOVSD";
|
||
if (fkind == 1) { fmov = "MOVSS"; };
|
||
cgexpr(c, src);
|
||
emitline("\t");
|
||
emitline(fmov);
|
||
emitline("\tX0, ");
|
||
emitoff((slot_off + 8): i64);
|
||
emitline("(BP)\n");
|
||
// #66 Phase-N step 3: the float arm has no pattern node to ride
|
||
// the typeeq flatvariantidx path, so pick the variant by float
|
||
// kind (f32 vs f64) over tinfo.params — a shape classification
|
||
// like the slice axis, not nominal identity.
|
||
let wantf32: bool = (fkind == 1);
|
||
let ftag: i32 = -1;
|
||
let fti: *tinfo = dt;
|
||
for (fti != nil && fti.kind == tykind.TY_NAMED) { fti = fti.under; };
|
||
if (fti != nil) { if (fti.kind == tykind.TY_TAGGED) {
|
||
let fp: *tparam = fti.params;
|
||
let fidx: i32 = 0;
|
||
for (fp != nil) {
|
||
let fvt: *tinfo = fp.type_;
|
||
for (fvt != nil && fvt.kind == tykind.TY_NAMED) { fvt = fvt.under; };
|
||
if (fvt != nil) {
|
||
if (typeisfloat(fvt)) {
|
||
if (typeisf32(fvt) == wantf32) { ftag = fidx; break; };
|
||
};
|
||
};
|
||
fp = fp.tnext;
|
||
fidx += 1;
|
||
};
|
||
}; };
|
||
if (ftag < 0) { ftag = 0; };
|
||
emitline("\tMOVQ\t$");
|
||
emitint(ftag: i64);
|
||
emitline(", ");
|
||
emitoff(slot_off: i64);
|
||
emitline("(BP)\n");
|
||
return;
|
||
};
|
||
// Scalar payload.
|
||
cgexpr(c, src);
|
||
emitline("\tMOVQ\tAX, ");
|
||
emitoff((slot_off + 8): i64);
|
||
emitline("(BP)\n");
|
||
let tag: i32 = taggedvariantindext(c, dt, src);
|
||
if (tag < 0) { tag = 0; };
|
||
emitline("\tMOVQ\t$");
|
||
emitint(tag: i64);
|
||
emitline(", ");
|
||
emitoff(slot_off: i64);
|
||
emitline("(BP)\n");
|
||
return;
|
||
};
|
||
|
||
// Spine-walk a chained N_DOT (n) inward to a root ident, summing field
|
||
// offsets through value-struct intermediates. Optional slice/str leaf
|
||
// pseudo-field (.ptr / .len / .cap) on the last segment is folded into
|
||
// *outslicedelta (0/8/16); otherwise *outleaftype is the leaf *tinfo
|
||
// and *outslicedelta stays -1. Returns true on success; on false the
|
||
// caller falls through to other branches.
|
||
//
|
||
// Mirrors cmd/w6c/cgen.c's N_DOT chained walker; both stages must agree
|
||
// on the same shapes so the bootstrap fixed-point holds. The chain
|
||
// depth is capped at 16 — deeper chains are vanishingly rare and fall
|
||
// through.
|
||
//
|
||
// On success the caller emits one load/store at root_base + *outtotaloff
|
||
// (+ slicedelta for pseudo leaf). Root resolves as: local frame slot
|
||
// (*outisglobal false, base = *outrootoff(BP)) or top-level let
|
||
// (*outisglobal true, base reached via LEAQ *outrootname(SB), CX).
|
||
//
|
||
// Numeric out-params are i32 — offsets fit naturally and the post-#19
|
||
// localloadop sign-extends i32 deref-stored slots on read, so negative
|
||
// frame offsets round-trip intact.
|
||
// #71 (A.6.3j): the spine offset-sum + leaf-type now read off
|
||
// tinfo.fields (natural layout) instead of the structinfo/fieldinfo
|
||
// walk. Mirror of cstage cmd/w6c/cgen.c:3156-3216 which walks
|
||
// `cur->lhs->type` fields. Root resolution (the local/ptr/global split
|
||
// and the rootoff/ptrroot/isglobal flags) stays on localfindnode/
|
||
// letvarstructinfo unchanged, so the firing set + addressing mode are
|
||
// byte-identical to the structinfo era; only the layout SOURCE moves.
|
||
// The slot-padded foff and the natural tfield.offset coincide for every
|
||
// shape the byte-id gate exercises (cstage already reads the natural
|
||
// offset), so this is offset-preserving. Leaf out-param is the field's
|
||
// stamped *tinfo (was *fieldinfo); the str/slice pseudo-leaf leaves it
|
||
// nil and the callers gate on slicedelta>=0 first.
|
||
export fn dotchainresolve(c: *cgen, n: *node,
|
||
outrootname: *str, outrootoff: *i32, outtotaloff: *i32,
|
||
outleaftype: **tinfo, outslicedelta: *i32,
|
||
outisglobal: *bool, outptrroot: *bool) bool = {
|
||
*outrootname = "";
|
||
*outrootoff = 0;
|
||
*outisglobal = false;
|
||
*outptrroot = false;
|
||
*outtotaloff = 0;
|
||
*outleaftype = nil;
|
||
*outslicedelta = -1;
|
||
if (n == nil) { return false; };
|
||
if (n.kind != nkind.N_DOT) { return false; };
|
||
let stk: [16]*node;
|
||
let nsteps: i32 = 0;
|
||
let cur: *node = n;
|
||
for (cur != nil) {
|
||
if (cur.kind != nkind.N_DOT) { break; };
|
||
if (nsteps >= 16) { return false; };
|
||
stk[nsteps] = cur;
|
||
nsteps += 1;
|
||
cur = cur.lhs;
|
||
};
|
||
if (nsteps < 2) { return false; };
|
||
if (cur == nil) { return false; };
|
||
if (cur.kind != nkind.N_IDENT) { return false; };
|
||
*outrootname = cur.str;
|
||
let resolved: bool = false;
|
||
let lc: *local = localfindnode(c, cur.str);
|
||
if (lc != nil) {
|
||
if (lc.tnode != nil) {
|
||
if (lc.tnode.kind == nkind.N_TNAME) {
|
||
*outrootoff = lc.off;
|
||
resolved = true;
|
||
};
|
||
// `*T` root (param/local): dereference at emit time;
|
||
// pointee struct supplies the field layout. Callers
|
||
// that opt in via *outptrroot emit a MOVQ load of the
|
||
// slot before indexing.
|
||
if (lc.tnode.kind == nkind.N_TPTR) {
|
||
let pe: *node = lc.tnode.lhs;
|
||
if (pe != nil) {
|
||
if (pe.kind == nkind.N_TNAME) {
|
||
*outrootoff = lc.off;
|
||
*outptrroot = true;
|
||
resolved = true;
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
if (!resolved) {
|
||
let gsi: *structinfo = letvarstructinfo(c, cur.str);
|
||
if (gsi != nil) {
|
||
*outisglobal = true;
|
||
resolved = true;
|
||
};
|
||
};
|
||
if (!resolved) { return false; };
|
||
// Root struct layout = the stamped root-ident type_, peeled NAMED
|
||
// (plus one TY_PTR hop for a `*struct` root). tfield.type_ then
|
||
// supplies each nested struct directly, so no name re-lookup.
|
||
let curstruct: *tinfo = cur.type_: *tinfo;
|
||
for (curstruct != nil && curstruct.kind == tykind.TY_NAMED) {
|
||
curstruct = curstruct.under;
|
||
};
|
||
if (*outptrroot) {
|
||
if (curstruct == nil) { return false; };
|
||
if (curstruct.kind != tykind.TY_PTR) { return false; };
|
||
curstruct = curstruct.sub;
|
||
for (curstruct != nil && curstruct.kind == tykind.TY_NAMED) {
|
||
curstruct = curstruct.under;
|
||
};
|
||
};
|
||
let i: i32 = nsteps - 1;
|
||
for (i >= 0) {
|
||
if (curstruct == nil) { return false; };
|
||
if (curstruct.kind != tykind.TY_STRUCT) { return false; };
|
||
if (stk[i] == nil) { return false; };
|
||
let stepnm: str = stk[i].str;
|
||
let tf: *tfield = curstruct.fields;
|
||
let found: *tfield = nil;
|
||
for (tf != nil) {
|
||
if (streq(tf.name, stepnm)) { found = tf; break; };
|
||
tf = tf.tnext;
|
||
};
|
||
if (found == nil) { return false; };
|
||
let foff: i32 = found.offset: i32;
|
||
if (i == 0) {
|
||
*outtotaloff = *outtotaloff + foff;
|
||
*outleaftype = found.type_;
|
||
return true;
|
||
};
|
||
let ft: *tinfo = found.type_;
|
||
for (ft != nil && ft.kind == tykind.TY_NAMED) { ft = ft.under; };
|
||
if (ft == nil) { return false; };
|
||
if (ft.kind == tykind.TY_STR) {
|
||
if (i != 1) { return false; };
|
||
let pseudo: str = stk[0].str;
|
||
let delta: i32 = -1;
|
||
if (streq(pseudo, "ptr")) { delta = 0; }
|
||
else { if (streq(pseudo, "len")) { delta = 8; }; };
|
||
if (delta < 0) { return false; };
|
||
*outtotaloff = *outtotaloff + foff;
|
||
*outslicedelta = delta;
|
||
return true;
|
||
};
|
||
if (ft.kind == tykind.TY_SLICE) {
|
||
if (i != 1) { return false; };
|
||
let pseudo: str = stk[0].str;
|
||
let delta: i32 = -1;
|
||
if (streq(pseudo, "ptr")) { delta = 0; }
|
||
else { if (streq(pseudo, "len")) { delta = 8; }
|
||
else { if (streq(pseudo, "cap")) { delta = 16; }; }; };
|
||
if (delta < 0) { return false; };
|
||
*outtotaloff = *outtotaloff + foff;
|
||
*outslicedelta = delta;
|
||
return true;
|
||
};
|
||
if (ft.kind != tykind.TY_STRUCT) { return false; };
|
||
*outtotaloff = *outtotaloff + foff;
|
||
curstruct = ft;
|
||
i -= 1;
|
||
};
|
||
return false;
|
||
};
|
||
|
||
// cgstructlitfill — fill a struct-typed slot from an N_STRUCTLIT
|
||
// value into one of three destination flavors. Mirror of cstage
|
||
// cgen.c's cg_structlit_fill. Used by cglet, cgreturn N_STRUCTLIT,
|
||
// cgassign N_IDENT-lhs N_STRUCTLIT (BP-rel) AND cgassign N_DOT-lhs
|
||
// N_STRUCTLIT (BP-rel / via *struct local / via struct global) at
|
||
// single-dot and chained-dot sites.
|
||
//
|
||
// Destination modes:
|
||
// 0 = DST_BP — base = BP, no reload. Stores at disp+i(BP).
|
||
// srcoff/srcname unused.
|
||
// 1 = DST_PTR_LOCAL — base = BX, reloaded from srcoff(BP) before
|
||
// the ELLIPSIS zero-fill loop and before EVERY
|
||
// field store (cgexpr clobbers BX between
|
||
// fields). Stores at disp+i(BX). srcname
|
||
// unused.
|
||
// 2 = DST_GLOBAL — base = BX, reloaded via `LEAQ srcname(SB),
|
||
// BX` with the same cadence as DST_PTR_LOCAL.
|
||
// srcoff unused.
|
||
//
|
||
// Param semantics (locked in here so the recursion contract is
|
||
// clear):
|
||
// - `disp` is the per-recursion accumulator — grows by `fi.foff`
|
||
// as we descend into a nested struct-typed structlit field.
|
||
// - `srcoff` (DST_PTR_LOCAL) and `srcname` (DST_GLOBAL) are
|
||
// *constant* across the whole call tree — they identify the
|
||
// root dst, which doesn't change with depth.
|
||
// - `totsize` is also constant; pass the natural size for dot
|
||
// sites (structnaturalsize) and si.totsize for BP-rel sites,
|
||
// matching each site's pre-#18 zero-fill bound.
|
||
//
|
||
// Why a helper? The inline field-walk previously did
|
||
// `cgexpr(field.lhs); store AX sized`. For struct-typed fields whose
|
||
// value is itself a nested N_STRUCTLIT, cgexpr has no whole-struct-
|
||
// in-register convention — it lands AX = first qword and the
|
||
// trailing bytes silently stay zero. #17 fixed the BP-rel sites;
|
||
// #18 extends the same recursion to the four cgassign N_DOT-lhs
|
||
// structlit walks (single-dot via_ptr/global/local + chained
|
||
// depth>=2).
|
||
//
|
||
// The non-BP modes emit a redundant BX reload at the start of each
|
||
// recursive nested zero-fill / each recursive scalar store — this is
|
||
// correctness-by-construction (BX is always freshly loaded right
|
||
// before use), and the redundancy only fires on the nested-STRUCTLIT
|
||
// shapes that didn't compile before. Byte-identity for the no-
|
||
// nested case (the only shape selfhost source uses today) is
|
||
// preserved because the existing inline code's reload-before-each-
|
||
// store pattern matches the helper's per-store reload exactly.
|
||
//
|
||
// Graduation note (task #13): the scalar store currently uses the
|
||
// explicit {1→MOVB, 4→MOVL, else MOVQ} dispatch to match cstage
|
||
// byte-identically — cstage hasn't yet learned MOVW for fsz==2. Once
|
||
// #13 aligns both stages, the dispatch can switch to fieldstoreop
|
||
// which already returns MOVW where appropriate.
|
||
fn cgstructlitfill(c: *cgen, si: *structinfo, lit: *node,
|
||
mode: i32, srcoff: i32, srcname: str,
|
||
disp: i32, totsize: i32) void = {
|
||
if (si == nil) { return; };
|
||
let basereg: str = "BP";
|
||
if (mode != 0) { basereg = "BX"; };
|
||
if (lit.op == tkind.TK_ELLIPSIS) {
|
||
// `..., ...` autofill — zero the entire slot first so
|
||
// unmentioned fields read as 0. Sized stores: 8/4/1. For
|
||
// non-BP modes, reload BX once before the loop (cgexpr-free
|
||
// region between iterations, so one reload is enough).
|
||
emitline("\tXORQ\tAX, AX\n");
|
||
if (mode == 1) {
|
||
emitline("\tMOVQ\t");
|
||
emitoff(srcoff: i64);
|
||
emitline("(BP), BX\n");
|
||
};
|
||
if (mode == 2) {
|
||
emitline("\tLEAQ\t");
|
||
emitsymname(c, srcname);
|
||
emitline("(SB), BX\n");
|
||
};
|
||
let zi: i32 = 0;
|
||
for (zi + 8 <= totsize) {
|
||
emitline("\tMOVQ\tAX, ");
|
||
if (mode == 0) {
|
||
emitoff((disp + zi): i64);
|
||
emitline("(BP)\n");
|
||
} else {
|
||
emitdispreg((disp + zi): i64, basereg);
|
||
emitline("\n");
|
||
};
|
||
zi += 8;
|
||
};
|
||
for (zi + 4 <= totsize) {
|
||
emitline("\tMOVL\tAX, ");
|
||
if (mode == 0) {
|
||
emitoff((disp + zi): i64);
|
||
emitline("(BP)\n");
|
||
} else {
|
||
emitdispreg((disp + zi): i64, basereg);
|
||
emitline("\n");
|
||
};
|
||
zi += 4;
|
||
};
|
||
for (zi < totsize) {
|
||
emitline("\tMOVB\tAX, ");
|
||
if (mode == 0) {
|
||
emitoff((disp + zi): i64);
|
||
emitline("(BP)\n");
|
||
} else {
|
||
emitdispreg((disp + zi): i64, basereg);
|
||
emitline("\n");
|
||
};
|
||
zi += 1;
|
||
};
|
||
};
|
||
let fieldnode: *node = lit.list;
|
||
for (fieldnode != nil) {
|
||
if (fieldnode.kind == nkind.N_FIELD) {
|
||
let fname: str = fieldnode.str;
|
||
let fi: *fieldinfo = si.fields;
|
||
for (fi != nil) {
|
||
let fn_: str = fi.fname;
|
||
if (streq(fn_, fname)) {
|
||
// Tagged-union field: delegate to the shared
|
||
// widening writer (handles str/scalar/struct
|
||
// literal/ident payload + tagged-subset tag
|
||
// remap). For non-BP modes, reload BX first so
|
||
// the widener sees a valid base reg.
|
||
if (istaggedtype(c, fi.tnode)) {
|
||
if (mode == 1) {
|
||
emitline("\tMOVQ\t");
|
||
emitoff(srcoff: i64);
|
||
emitline("(BP), BX\n");
|
||
};
|
||
if (mode == 2) {
|
||
emitline("\tLEAQ\t");
|
||
emitsymname(c, srcname);
|
||
emitline("(SB), BX\n");
|
||
};
|
||
cgwidentaggedstore(c, fi.tnode.type_: *tinfo,
|
||
fieldnode.lhs, basereg,
|
||
disp + fi.foff, fi.fsz);
|
||
fi = nil;
|
||
} else {
|
||
// Nested struct-typed structlit value: look up
|
||
// the inner struct's metadata and recurse at the
|
||
// field's offset. Pre-#17/#18 the cgexpr-then-
|
||
// store below would land AX = first qword and
|
||
// the rest silently stayed zero.
|
||
let nested: bool = false;
|
||
if (fieldnode.lhs != nil) {
|
||
if (fieldnode.lhs.kind == nkind.N_STRUCTLIT) {
|
||
if (fi.tnode != nil) {
|
||
if (fi.tnode.kind == nkind.N_TNAME) {
|
||
if (primsize(fi.tnode.str) == 0) {
|
||
let isi: *structinfo = structlookup(c, fi.tnode.str);
|
||
if (isi != nil) {
|
||
// Nested fill: pick the size
|
||
// discipline matching the outer
|
||
// site — dot sites pass natural
|
||
// size, BP-rel sites pass
|
||
// totsize. Mirror it.
|
||
let inner_tot: i32 = isi.totsize;
|
||
if (mode != 0) { inner_tot = structnaturalsize(isi); };
|
||
cgstructlitfill(c, isi,
|
||
fieldnode.lhs,
|
||
mode, srcoff, srcname,
|
||
disp + fi.foff, inner_tot);
|
||
nested = true;
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
// Nested struct-typed CALL value (#20). cgexpr
|
||
// leaves AX=bytes[0..7], DX=bytes[8..15], CX=
|
||
// bytes[16..23] per #4's cgreturn ABI. Pre-#20
|
||
// the cgexpr-then-AX-store fallthrough below
|
||
// silently dropped past the first qword for any
|
||
// fsz > 8 (only AX got stored).
|
||
//
|
||
// Sized stores: MOVQ for full 8B chunks plus a
|
||
// sized tail (MOVL/MOVW/MOVB) by `tail = fsz%8`.
|
||
// Mirror of cstage cg_structlit_fill's #20 branch.
|
||
// MOVW-for-tail==2 only fires on shapes that
|
||
// didn't compile before, so no #13 byte-identity
|
||
// concern.
|
||
//
|
||
// Guard `fsz <= 24 && fsz%8 ∈ {0,1,2,4}` matches
|
||
// #4's cgreturn ABI: >24B falls through (sret
|
||
// deferred); fsz%8 ∈ {3,5,6,7} would need shift-
|
||
// store and is also unsupported by #4 — falls
|
||
// through to the existing AX-only wrongness
|
||
// (consistent, tracked as follow-up).
|
||
//
|
||
// INVARIANT: between cgexpr(N_CALL) and the
|
||
// AX/DX/CX stores below, NO instruction may touch
|
||
// AX/DX/CX. The BX reload is safe; any other
|
||
// emission added here will silently corrupt the
|
||
// return value.
|
||
let callwhole: bool = false;
|
||
if (!nested) {
|
||
if (fieldnode.lhs != nil) {
|
||
if (fieldnode.lhs.kind == nkind.N_CALL) {
|
||
if (fi.tnode != nil) {
|
||
if (fi.tnode.kind == nkind.N_TNAME) {
|
||
if (primsize(fi.tnode.str) == 0) {
|
||
let csi: *structinfo = structlookup(c, fi.tnode.str);
|
||
if (csi != nil) {
|
||
// Use the inner struct's
|
||
// NATURAL size (no 8B slot
|
||
// rounding) so MOVL/MOVW/
|
||
// MOVB tail dispatch matches
|
||
// cstage's fl->type->size
|
||
// (which is natural per
|
||
// check.c). fi.fsz here is
|
||
// wwstage's slot-padded
|
||
// totsize — using it would
|
||
// emit 2× MOVQ where cstage
|
||
// emits MOVQ+MOVL for a
|
||
// 12B inner, etc. (task #15
|
||
// territory; sidestepped
|
||
// locally.)
|
||
let cfsz: i32 = structnaturalsize(csi);
|
||
let crem: i32 = cfsz - (cfsz / 8) * 8;
|
||
if (cfsz <= 24) {
|
||
if (crem == 0 || crem == 1
|
||
|| crem == 2 || crem == 4) {
|
||
cgexpr(c, fieldnode.lhs);
|
||
if (mode == 1) {
|
||
emitline("\tMOVQ\t");
|
||
emitoff(srcoff: i64);
|
||
emitline("(BP), BX\n");
|
||
};
|
||
if (mode == 2) {
|
||
emitline("\tLEAQ\t");
|
||
emitsymname(c, srcname);
|
||
emitline("(SB), BX\n");
|
||
};
|
||
let full: i32 = cfsz / 8;
|
||
let ci: i32 = 0;
|
||
for (ci < full) {
|
||
let r: str = "AX";
|
||
if (ci == 1) { r = "DX"; };
|
||
if (ci == 2) { r = "CX"; };
|
||
emitline("\tMOVQ\t");
|
||
emitline(r);
|
||
emitline(", ");
|
||
if (mode == 0) {
|
||
emitoff((disp + fi.foff + ci * 8): i64);
|
||
emitline("(BP)\n");
|
||
} else {
|
||
emitdispreg((disp + fi.foff + ci * 8): i64, basereg);
|
||
emitline("\n");
|
||
};
|
||
ci += 1;
|
||
};
|
||
if (crem > 0) {
|
||
let top: str = "MOVB";
|
||
if (crem == 4) { top = "MOVL"; };
|
||
if (crem == 2) { top = "MOVW"; };
|
||
let tr: str = "AX";
|
||
if (full == 1) { tr = "DX"; };
|
||
if (full == 2) { tr = "CX"; };
|
||
emitline("\t");
|
||
emitline(top);
|
||
emitline("\t");
|
||
emitline(tr);
|
||
emitline(", ");
|
||
if (mode == 0) {
|
||
emitoff((disp + fi.foff + full * 8): i64);
|
||
emitline("(BP)\n");
|
||
} else {
|
||
emitdispreg((disp + fi.foff + full * 8): i64, basereg);
|
||
emitline("\n");
|
||
};
|
||
};
|
||
callwhole = true;
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
if (nested) {
|
||
fi = nil;
|
||
} else if (callwhole) {
|
||
fi = nil;
|
||
} else {
|
||
cgexpr(c, fieldnode.lhs);
|
||
// For non-BP modes, cgexpr just clobbered
|
||
// BX; reload it before the store.
|
||
if (mode == 1) {
|
||
emitline("\tMOVQ\t");
|
||
emitoff(srcoff: i64);
|
||
emitline("(BP), BX\n");
|
||
};
|
||
if (mode == 2) {
|
||
emitline("\tLEAQ\t");
|
||
emitsymname(c, srcname);
|
||
emitline("(SB), BX\n");
|
||
};
|
||
if (isfloattype(c, fi.tnode)) {
|
||
let mov: str = "MOVSD";
|
||
if (isf32type(c, fi.tnode)) { mov = "MOVSS"; };
|
||
emitline("\t");
|
||
emitline(mov);
|
||
emitline("\tX0, ");
|
||
if (mode == 0) {
|
||
emitoff((disp + fi.foff): i64);
|
||
emitline("(BP)\n");
|
||
} else {
|
||
emitdispreg((disp + fi.foff): i64, basereg);
|
||
emitline("\n");
|
||
};
|
||
fi = nil;
|
||
} else {
|
||
// Explicit {1→MOVB, 4→MOVL, else MOVQ}
|
||
// dispatch (not fieldstoreop) to match
|
||
// cstage byte-identically. wwstage's
|
||
// fieldstoreop would return MOVW for
|
||
// fsz==2 which cstage doesn't emit —
|
||
// tracked as task #13.
|
||
let fsz: i32 = fi.fsz;
|
||
let op: str = "MOVQ";
|
||
if (fsz == 1) { op = "MOVB"; };
|
||
if (fsz == 4) { op = "MOVL"; };
|
||
emitline("\t");
|
||
emitline(op);
|
||
emitline("\tAX, ");
|
||
if (mode == 0) {
|
||
emitoff((disp + fi.foff): i64);
|
||
emitline("(BP)\n");
|
||
} else {
|
||
emitdispreg((disp + fi.foff): i64, basereg);
|
||
emitline("\n");
|
||
};
|
||
fi = nil;
|
||
};
|
||
};
|
||
};
|
||
} else {
|
||
fi = fi.finext;
|
||
};
|
||
};
|
||
};
|
||
fieldnode = fieldnode.next;
|
||
};
|
||
};
|
||
|
||
// Thin wrapper preserving the BP-rel call shape used by cglet,
|
||
// cgreturn, and cgassign N_IDENT-lhs N_STRUCTLIT. Byte-identical to
|
||
// the pre-#18 cgstructlitfillbp.
|
||
fn cgstructlitfillbp(c: *cgen, si: *structinfo, lit: *node, bpoff: i32) void = {
|
||
if (si == nil) { return; };
|
||
cgstructlitfill(c, si, lit, 0, 0, "", bpoff, si.totsize);
|
||
};
|