feat(codegen): gen-zig tuple lowering (return type + literal + destructuring)

[gHashTag]

Part 4 of the tuple-support workstream (#1702). Parser + gen-rust (#1710, #1716) + gen-verilog (#1718) already landed; this is gen-zig.

Closes #1724.

Before (master) — invalid Zig

pub fn dm(a: u32, b: u32) (u32, u32) { return ; }
pub fn use_it(a: u32, b: u32) u32 { const  = dm(a, b); return s + d; }

Change (3 touchpoints, additive)

1. gen_fn_decl — tuple return type (T, U) → Zig anonymous tuple struct struct { T, U }.
2. gen_expr ExprTuple — tuple literal → .{ e0, e1 }.
3. gen_stmt StmtLocal — let (s, d) = call() → const s, const d = call();.

After

pub fn dm(a: u32, b: u32) struct { u32, u32 } { return .{ a + b, a - b }; }
pub fn use_it(a: u32, b: u32) u32 { const s, const d = dm(a, b); return s + d; }

Verification

• Emitted Zig compiles under Zig 0.15.2 (zig build-obj) and comptime-evaluates: use_it(5, 3) == 10, dm(7, 2) == (9, 5).
• New unit test test_tuple_literal_and_destructuring_zig; full unit suite 1499/0.
• FROZEN_HASH re-sealed; docs/NOW.md prepended (no shrink).

Pre-existing unrelated failures bitnet_top::{top_busy_from_current_layer_or_layer_start, top_mem_outputs_tied_off} reproduced on clean origin/master — not introduced here (they were previously masked because bitnet_pipeline aborted the run first). Will be tracked/fixed separately.

gen-c is the last remaining backend on #1702.

🤖 Generated with Claude Code

[github-actions]

📓 NotebookLM Notebook linked to this PR

• Notebook ID: b83263109fb055dc
• URL: https://notebooklm.google.com/notebook/b83263109fb055dc

This notebook contains session context, decisions, and artifacts for this work.

[github-actions]

PR Dashboard

Generated at: 2026-08-05 15:58:52 UTC

• feat(codegen): gen-zig tuple lowering (return type + literal + destructuring) #1725 feat(codegen): gen-zig tuple lowering (return type + literal + destructuring) | Created: 2026-08-05 | Updated: 2026-08-05 | 4 failing / 19 total
• feat(igla): Wave Loop 880 — module-scope [579][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1720 feat(igla): Wave Loop 880 — module-scope [579][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-05 | Updated: 2026-08-05 | 1 failing / 4 total
• feat(igla): Wave Loop 879 — module-scope [577][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1711 feat(igla): Wave Loop 879 — module-scope [577][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-05 | Updated: 2026-08-05 | 1 failing / 3 total
• feat(igla): Wave Loop 878 — module-scope [575][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1707 feat(igla): Wave Loop 878 — module-scope [575][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-05 | Updated: 2026-08-05 | 1 failing / 3 total
• feat(igla): Wave Loop 877 — module-scope [573][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1705 feat(igla): Wave Loop 877 — module-scope [573][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-05 | Updated: 2026-08-05 | 1 failing / 3 total
• feat(igla): Wave Loop 876 — module-scope [571][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1704 feat(igla): Wave Loop 876 — module-scope [571][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-05 | Updated: 2026-08-05 | 1 failing / 3 total
• feat(igla): Wave Loop 875 — module-scope [569][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1700 feat(igla): Wave Loop 875 — module-scope [569][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-05 | Updated: 2026-08-05 | 1 failing / 3 total
• feat(igla): Wave Loop 874 — module-scope [567][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1698 feat(igla): Wave Loop 874 — module-scope [567][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-05 | Updated: 2026-08-05 | 1 failing / 4 total
• feat(igla): Wave Loop 873 — module-scope [565][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1695 feat(igla): Wave Loop 873 — module-scope [565][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-05 | Updated: 2026-08-05 | 1 failing / 4 total
• feat(igla): Wave Loop 872 — module-scope [563][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1693 feat(igla): Wave Loop 872 — module-scope [563][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-05 | Updated: 2026-08-05 | 1 failing / 4 total
• feat(igla): Wave Loop 871 — module-scope [561][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1692 feat(igla): Wave Loop 871 — module-scope [561][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-05 | Updated: 2026-08-05 | 1 failing / 4 total
• feat(igla): Wave Loop 870 — module-scope [559][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1689 feat(igla): Wave Loop 870 — module-scope [559][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-05 | Updated: 2026-08-05 | 1 failing / 4 total
• feat(igla): Wave Loop 869 — module-scope [557][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1687 feat(igla): Wave Loop 869 — module-scope [557][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-05 | Updated: 2026-08-05 | 1 failing / 4 total
• feat(igla): Wave Loop 868 — module-scope [555][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1685 feat(igla): Wave Loop 868 — module-scope [555][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-05 | Updated: 2026-08-05 | 1 failing / 4 total
• feat(igla): Wave Loop 867 — module-scope [553][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1683 feat(igla): Wave Loop 867 — module-scope [553][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-05 | Updated: 2026-08-05 | 1 failing / 4 total
• feat(igla): Wave Loop 866 — module-scope [551][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1681 feat(igla): Wave Loop 866 — module-scope [551][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-05 | Updated: 2026-08-05 | 1 failing / 4 total
• feat(igla): Wave Loop 865 — module-scope [549][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1679 feat(igla): Wave Loop 865 — module-scope [549][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-05 | Updated: 2026-08-05 | 1 failing / 4 total
• feat(igla): Wave Loop 864 — module-scope [547][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1677 feat(igla): Wave Loop 864 — module-scope [547][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-05 | Updated: 2026-08-05 | 1 failing / 4 total
• feat(igla): Wave Loop 863 — module-scope [545][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1671 feat(igla): Wave Loop 863 — module-scope [545][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-05 | Updated: 2026-08-05 | 1 failing / 4 total
• feat(igla): Wave Loop 862 — module-scope [543][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1669 feat(igla): Wave Loop 862 — module-scope [543][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-05 | Updated: 2026-08-05 | 1 failing / 4 total
• feat(igla): Wave Loop 861 — module-scope [541][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1667 feat(igla): Wave Loop 861 — module-scope [541][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-05 | Updated: 2026-08-05 | 1 failing / 4 total
• Wave Loop 860 — module-scope [539][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1665 Wave Loop 860 — module-scope [539][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-05 | Updated: 2026-08-05 | 1 failing / 4 total
• Wave Loop 859 — module-scope [537][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1663 Wave Loop 859 — module-scope [537][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-05 | Updated: 2026-08-05 | 1 failing / 4 total
• Wave Loop 858 — module-scope [535][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1661 Wave Loop 858 — module-scope [535][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-05 | Updated: 2026-08-05 | 1 failing / 4 total
• feat(igla): Wave Loop 857 — module-scope [533][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1657 feat(igla): Wave Loop 857 — module-scope [533][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-05 | Updated: 2026-08-05 | 1 failing / 3 total
• feat(igla): Wave Loop 856 — module-scope [531][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1655 feat(igla): Wave Loop 856 — module-scope [531][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-05 | Updated: 2026-08-05 | 1 failing / 4 total
• feat(igla): Wave Loop 855 — module-scope [529][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1651 feat(igla): Wave Loop 855 — module-scope [529][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-05 | Updated: 2026-08-05 | 1 failing / 4 total
• feat(igla): Wave Loop 854 — module-scope [527][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1649 feat(igla): Wave Loop 854 — module-scope [527][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-05 | Updated: 2026-08-05 | 1 failing / 4 total
• feat(igla): Wave Loop 853 — [525][2]^6 Pt module-scope AoS variable from call with indexed signed writes #1647 feat(igla): Wave Loop 853 — [525][2]^6 Pt module-scope AoS variable from call with indexed signed writes | Created: 2026-08-05 | Updated: 2026-08-05 | 1 failing / 4 total
• feat(igla): Wave Loop 852 — [523][2]^6 Pt module-scope AoS variable from call with indexed signed writes #1645 feat(igla): Wave Loop 852 — [523][2]^6 Pt module-scope AoS variable from call with indexed signed writes | Created: 2026-08-04 | Updated: 2026-08-04 | 1 failing / 4 total
• feat(igla): Wave Loop 851 — [521][2]^6 Pt module-scope AoS variable from call with indexed signed writes #1643 feat(igla): Wave Loop 851 — [521][2]^6 Pt module-scope AoS variable from call with indexed signed writes | Created: 2026-08-04 | Updated: 2026-08-04 | 1 failing / 4 total
• feat(igla): Wave Loop 850 — module-scope [519][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1641 feat(igla): Wave Loop 850 — module-scope [519][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-04 | Updated: 2026-08-04 | 1 failing / 4 total
• Wave Loop 849 — module-scope [517][2]^6 Pt packed AoS variable from call with indexed signed writes #1639 Wave Loop 849 — module-scope [517][2]^6 Pt packed AoS variable from call with indexed signed writes | Created: 2026-08-04 | Updated: 2026-08-04 | 1 failing / 4 total
• Wave Loop 848 — module-scope [515][2]^6 Pt packed AoS variable from call with indexed signed writes #1637 Wave Loop 848 — module-scope [515][2]^6 Pt packed AoS variable from call with indexed signed writes | Created: 2026-08-04 | Updated: 2026-08-04 | 1 failing / 4 total
• Wave Loop 847 — [513][2]^6 Pt non-power-of-two AoS call-write witness (1-MiBit boundary) #1635 Wave Loop 847 — [513][2]^6 Pt non-power-of-two AoS call-write witness (1-MiBit boundary) | Created: 2026-08-04 | Updated: 2026-08-04 | 1 failing / 3 total
• Wave Loop 846 — [511][2]^6 Pt non-power-of-two AoS call-write witness #1633 Wave Loop 846 — [511][2]^6 Pt non-power-of-two AoS call-write witness | Created: 2026-08-04 | Updated: 2026-08-04 | 1 failing / 3 total
• feat(igla): Wave Loop 845 — module-scope [509][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1631 feat(igla): Wave Loop 845 — module-scope [509][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-04 | Updated: 2026-08-04 | 1 failing / 3 total
• feat(igla): Wave Loop 844 — module-scope [507][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1629 feat(igla): Wave Loop 844 — module-scope [507][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-04 | Updated: 2026-08-04 | 1 failing / 3 total
• feat(igla): Wave Loop 843 — module-scope [505][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1627 feat(igla): Wave Loop 843 — module-scope [505][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-04 | Updated: 2026-08-04 | 1 failing / 3 total
• feat(igla): Wave Loop 842 — module-scope [503][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1625 feat(igla): Wave Loop 842 — module-scope [503][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-04 | Updated: 2026-08-04 | 1 failing / 3 total
• feat(igla): Wave Loop 841 — module-scope [501][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1623 feat(igla): Wave Loop 841 — module-scope [501][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-04 | Updated: 2026-08-04 | 1 failing / 3 total
• feat(igla): Wave Loop 840 — module-scope [499][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1621 feat(igla): Wave Loop 840 — module-scope [499][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-04 | Updated: 2026-08-04 | 1 failing / 3 total
• feat(igla): Wave Loop 839 — module-scope [497][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1619 feat(igla): Wave Loop 839 — module-scope [497][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-04 | Updated: 2026-08-04 | 1 failing / 3 total
• feat(igla): Wave Loop 838 — module-scope [495][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1617 feat(igla): Wave Loop 838 — module-scope [495][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-04 | Updated: 2026-08-04 | 1 failing / 3 total
• feat(igla): Wave Loop 837 — module-scope [493][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1615 feat(igla): Wave Loop 837 — module-scope [493][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-02 | Updated: 2026-08-02 | 1 failing / 3 total
• feat(igla): Wave Loop 836 — module-scope [491][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1613 feat(igla): Wave Loop 836 — module-scope [491][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-02 | Updated: 2026-08-02 | 1 failing / 3 total
• feat(igla): Wave Loop 835 — module-scope [489][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1611 feat(igla): Wave Loop 835 — module-scope [489][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-02 | Updated: 2026-08-02 | 1 failing / 3 total
• feat(igla): Wave Loop 834 — module-scope [487][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1609 feat(igla): Wave Loop 834 — module-scope [487][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-01 | Updated: 2026-08-01 | 1 failing / 4 total
• feat(igla): Wave Loop 833 — module-scope [485][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1607 feat(igla): Wave Loop 833 — module-scope [485][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-01 | Updated: 2026-08-01 | 1 failing / 3 total
• feat(igla): Wave Loop 832 — module-scope [483][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1605 feat(igla): Wave Loop 832 — module-scope [483][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-01 | Updated: 2026-08-01 | 1 failing / 3 total

Summary

Status	Count
Total Open PRs	50
PRs with Failing Checks	0
PRs with All Checks Green	50
READY	0
FAILING	0
PENDING	0

Seal Status

• ⚠️ STALE -- sha256(compiler.rs)=72259bcd33d7 != manifest seal=87e5cbd3ad94.
  The committed NMSE numbers were certified against an older compiler.rs.
  Run scripts/reseal-check.sh locally for the two-step reseal command (advisory; not a merge gate).