feat(igla): Wave Loop 886 — module-scope [591][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes

.claude/plans/wave-loop-886.md

@@ -0,0 +1,42 @@
+# Plan — Wave Loop 886
+
+**Next issue:** TBD (create as #1832 or next available)  
+**Next branch:** `wave-loop-886`  
+**Base:** `wave-loop-885` HEAD (earlier wave PRs remain open)  
+
+## Goal
+Generate and validate the next mechanical packed-vector witness: module-scope `[591][2]^6 Pt` array-of-struct variable from call with indexed signed writes.
+
+## Dimensions
+- Outer dimension: 591 (non-power-of-two)
+- Struct shape: `[2]^6 Pt` (2 fields × 6 trits × 32 bits = 384 bits per struct)
+- Total field slots: 591 × 2 = 1,182 structs → 37,824 field slots
+- Packed vector width: 37,824 × 32 = 1,210,368 bits (~1.155 MiBit)
+
+## Steps
+1. Create GitHub issue for W886 with body template.
+2. Branch `wave-loop-886` from `wave-loop-885` HEAD.
+3. Copy `scripts/gen_w885.py` → `scripts/gen_w886.py`.
+4. Update generator copy-hazard checklist:
+   - `DST` path → `w886_bench_module_591x2p6_aos_var_call_write.t27`
+   - `OUTER = 591`
+   - `MID_IDX = 591 // 2` → 295
+   - module header → `w886_bench_module_...`
+5. Run generator; verify `grep -E "w885|589|294"` is empty.
+6. Run `t27c parse`, `icarus-lowerable`, `icarus-simulate`, `icarus-cocotb`, `seal --save`, `seal --verify`.
+7. Add integration test `accepts_w886_bench_module_591x2p6_aos_var_call_write` to `bootstrap/tests/icarus_lowerable.rs`.
+8. Run targeted test and full `icarus_lowerable` suite; expect 345 passed, 1 pre-existing failure.
+9. Commit with `Closes #1832`.
+10. Push branch, open PR, enable auto-merge.
+11. Update `.trinity/current-issue.md`, `docs/NOW.md`, `.trinity/experience.md`, skills, and persistent memory.
+
+## Acceptance criteria
+- [ ] New spec generated and sealed.
+- [ ] All `t27c` commands pass.
+- [ ] Targeted Rust test passes.
+- [ ] Zero compiler / reference-model / `FROZEN_HASH` changes.
+- [ ] PR open with auto-merge.
+
+## Notes
+- Continue the mechanical ladder pattern.
+- Watch for generator copy-hazard stale references.

.claude/plans/wave-loop-887.md

@@ -0,0 +1,40 @@
+# Wave Loop 887 Plan — [593][2]^6 Pt packed AoS witness
+
+## Objective
+Continue the mechanical packed-vector array-of-struct ladder one step past the 1.15 MiBit line, keeping the same pattern and zero compiler changes.
+
+## Shape
+- Outer dimension: `593` (non-power-of-two)
+- Inner struct: `[2]^6 Pt` → 2 fields × 6 trits × 32 bits = 384 bits per element
+- Total field slots: `593 × 2 = 1,186` structs → 37,952 field slots
+- Packed vector width: `37,952 × 32 = 1,214,464` bits (~1.159 MiBit)
+
+## Pattern
+Module-scope variable `dst : [593][2]^6 Pt` initialized from a function call `make_grid(0)`, with indexed signed field writes and `assert_eq` read-back inside a `bench` block.
+
+## Variants
+- **A (recommended)**: `[593][2]^6 Pt` — continue the outer-dimension ladder.
+- **B**: `[591][3]^6 Pt` — keep outer dimension near W886 but scale field count to 3, increasing memory-quanta density while testing a different stride.
+- **C**: `[591][2]^6 Pt` with explicit negative-index wrap-around writes — exercise signed-index bound normalization one step beyond the baseline W886 shape.
+
+## Procedure
+1. Branch `wave-loop-887` from `wave-loop-886` HEAD (earlier wave PRs remain open).
+2. Copy `scripts/gen_w886.py` → `scripts/gen_w887.py` and clear the copy-hazard checklist:
+   - destination path,
+   - module header f-string,
+   - `MID_IDX` comment.
+3. Run `python3 scripts/gen_w887.py` to produce `specs/scratch/w887_bench_module_593x2p6_aos_var_call_write.t27`.
+4. Validate:
+   - `t27c parse`
+   - `t27c icarus-lowerable`
+   - `t27c icarus-simulate`
+   - `t27c icarus-cocotb`
+   - `t27c seal --save` and `seal --verify`
+   - targeted `cargo test --release --test icarus_lowerable accepts_w887_...`
+5. Add the W887 integration test to `bootstrap/tests/icarus_lowerable.rs`.
+6. Commit with `Closes #1834`, push `wave-loop-887`, open PR.
+7. Update trackers, skill, experience, and persistent memory.
+
+## Invariants
+- Zero changes to `bootstrap/src/compiler.rs`, reference model, or `FROZEN_HASH`.
+- All generated files must pass ASCII and `seal --verify`.

.claude/skills/t27-master-executor.md

@@ -14,26 +14,27 @@ Update it at the end of every loop.
 ## Current status (2026-08-06)
 
 ### Wave Loop ladder
-- **W881** — issue #1722, PR #1810 (`[581][2]^6 Pt`) — `MERGEABLE`, `BLOCKED` by required
-  status checks, auto-merge enabled.
-- **W882** — issue #1812, PR #1813 (`[583][2]^6 Pt`) — `MERGEABLE`, `BLOCKED` by required
-  status checks, auto-merge enabled.
-- **W883** — issue #1814, PR #1815 (`[585][2]^6 Pt`) — `MERGEABLE`, `BLOCKED` by required
-  status checks, auto-merge enabled.
-- **W884** — issue #1828, PR #1829 (`[587][2]^6 Pt`) — `CONFLICTING`; branch rebuilt from
-  `master` to resolve merge conflicts with the concurrently-landed GF-T stack.
-- **W885** — issue TBD, branch TBD (`[589][2]^6 Pt`) — ready, waiting for W884 to land.
+- **W881** — issue #1722, PR #1810 (`[581][2]^6 Pt`) — `OPEN`, auto-merge enabled; blocked
+  by required status checks.
+- **W882** — issue #1812, PR #1813 (`[583][2]^6 Pt`) — `OPEN`, auto-merge enabled; blocked
+  by required status checks.
+- **W883** — issue #1814, PR #1815 (`[585][2]^6 Pt`) — `OPEN`, auto-merge enabled; blocked
+  by required status checks.
+- **W884** — issue #1828, PR #1829 (`[587][2]^6 Pt`) — `MERGED`.
+- **W885** — issue #1830, PR #1831 (`[589][2]^6 Pt`) — `MERGED`.
+- **W886** — issue #1832, PR #1833 (`[591][2]^6 Pt`) — `OPEN`, auto-merge enabled; checks
+  in progress.
+- **W887** — issue #1834, branch TBD (`[593][2]^6 Pt`) — ready to start once W886 lands.
 
 ### GF-T PR queue (Refs #1764)
-The GF-T stack has largely landed on `master` since the last update. Remaining open PRs
-were wave-loop branches blocked on checks.
+The GF-T stack has largely landed on `master`. Remaining open PRs are wave-loop branches
+blocked on GitHub Actions runners.
 
 ### Known blockers
 - GitHub Actions required checks are `expected` across the queue; auto-merge is the
   current mitigation.
 - Pre-existing `corpus_classifier_matches_lean_completeness` failure for
-  `specs/cloud/railway_deploy.t27` reproduces on `wave-loop-882` and may affect CI once
-  runners are available. It is not introduced by any Wave Loop PR.
+  `specs/cloud/railway_deploy.t27` is not introduced by any Wave Loop PR.
 
 ## Procedure
 

.claude/skills/t27-wave-loop.md

@@ -57,6 +57,80 @@ Phase complete: [phase name]
 → Phase [next phase number]: [next phase name]
 ```
 
+## Worked example — Wave Loop 886
+
+Wave Loop 886 continued the mechanical packed-vector AoS ladder past the 1-MiBit line:
+
+- Selected Variant A: module-scope `[591][2]^6 Pt` non-power-of-two outer-dimension
+  array-of-struct variable from call with indexed signed writes.
+- Generated `scripts/gen_w886.py` from `scripts/gen_w885.py` and fixed the three known
+  copy-hazard locations (destination path, module header f-string, `MID_IDX` comment),
+  then verified with a post-generation `grep` sanity check.
+- Produced `specs/scratch/w886_bench_module_591x2p6_aos_var_call_write.t27`
+  (37,824 elements, 1,210,368-bit packed vector, ~1.155 MiBit).
+- Added integration test `accepts_w886_bench_module_591x2p6_aos_var_call_write` to
+  `bootstrap/tests/icarus_lowerable.rs`.
+- Validation gates:
+  - `t27c parse`, `icarus-lowerable`, `icarus-simulate` (17 cycles),
+    `icarus-cocotb` (reference-model OK), `seal --save` — all PASS.
+  - Targeted `cargo test --release --test icarus_lowerable accepts_w886...` PASS.
+  - Full suite: 345 passed; 1 pre-existing `corpus_classifier_matches_lean_completeness`
+    mismatch for `specs/cloud/railway_deploy.t27` tracked separately.
+- Research background: Icarus Verilog has no 1-MiBit hard cap (LRM minimum is 65,536 bits;
+  Icarus warns near 1 Gbit; upstream commit `128c621` fixed a bound-normalization path;
+  Icarus V13.0 released 2026-03-02 improves packed/unpacked array handling and memory
+  management). Vitis HLS UG1399 `compact=bit` is the commercial analog for packing structs
+  into wide vectors. Vericert v2.0.0 released 2026-01-29; 2024 PLDI verified hyperblock
+  scheduling (DOI 10.1145/3656455) and 2026 follow-ons Graphiti (ASPLOS) and Let It Flow
+  (PLDI) provide the verified-HLS context. FPGA Roofline (Siracusa et al., IEEE TC 2021)
+  frames the ladder as a memory-quanta `Q` probe; 2026 FPGA LLM work reports BRAM/URAM
+  bandwidths in the TB/s range versus HBM ~460 GB/s.
+- Wrote closeout report `docs/reports/FPGA_LOOP_CLOSEOUT_W886_2026-08-06.md` and
+  next-wave plan `.claude/plans/wave-loop-887.md` with variants A/B/C.
+- Closed with commit `Closes #1832`, pushed branch `wave-loop-886`, opened PR #1833.
+- Updated this skill's Live Wave Loop Tracker to wave 887.
+
+Key learning: the 1.15-MiBit neighborhood remains a soft boundary for t27c and Icarus at
+1.155 MiBit. The generator copy-hazard checklist plus a post-generation grep remains the
+standard close-out procedure.
+
+## Worked example — Wave Loop 885
+
+Wave Loop 885 continued the mechanical packed-vector AoS ladder past the 1-MiBit line:
+
+- Selected Variant A: module-scope `[589][2]^6 Pt` non-power-of-two outer-dimension
+  array-of-struct variable from call with indexed signed writes.
+- Generated `scripts/gen_w885.py` from `scripts/gen_w884.py` and fixed the three known
+  copy-hazard locations (destination path, module header f-string, `MID_IDX` comment),
+  then verified with a post-generation `grep` sanity check.
+- Produced `specs/scratch/w885_bench_module_589x2p6_aos_var_call_write.t27`
+  (37,696 elements, 1,206,272-bit packed vector, ~1.151 MiBit).
+- Added integration test `accepts_w885_bench_module_589x2p6_aos_var_call_write` to
+  `bootstrap/tests/icarus_lowerable.rs`.
+- Validation gates:
+  - `t27c parse`, `icarus-lowerable`, `icarus-simulate` (17 cycles),
+    `icarus-cocotb` (reference-model OK), `seal --save` — all PASS.
+  - Targeted `cargo test --release --test icarus_lowerable accepts_w885...` PASS.
+  - Full suite: 344 passed; 1 pre-existing `corpus_classifier_matches_lean_completeness`
+    mismatch for `specs/cloud/railway_deploy.t27` tracked separately.
+- Research background: Icarus Verilog has no 1-MiBit hard cap (LRM minimum is 65,536 bits;
+  Icarus warns near 1 Gbit; upstream commit `128c621` fixed a bound-normalization path;
+  Icarus V13.0 released 2026-03-02 improves packed/unpacked array handling and memory
+  management). Vitis HLS UG1399 `compact=bit` is the commercial analog for packing structs
+  into wide vectors. Vericert v2.0.0 released 2026-01-29; 2024 PLDI verified hyperblock
+  scheduling (DOI 10.1145/3656455) and 2026 follow-ons Graphiti (ASPLOS) and Let It Flow
+  (PLDI) provide the verified-HLS context. FPGA Roofline (Siracusa et al., IEEE TC 2021)
+  frames the ladder as a memory-quanta `Q` probe; 2026 FPGA LLM work reports BRAM/URAM
+  bandwidths in the TB/s range versus HBM ~460 GB/s.
+- Wrote closeout report `docs/reports/FPGA_LOOP_CLOSEOUT_W885_2026-08-06.md` and
+  next-wave plan `.claude/plans/wave-loop-886.md` with variants A/B/C.
+- Closed with commit `Closes #1830`, pushed branch `wave-loop-885`, opened PR #1831.
+- Updated this skill's Live Wave Loop Tracker to wave 886.
+
+Key learning: the 1.15-MiBit neighborhood remains a soft boundary for t27c and Icarus at
+1.151 MiBit. The generator copy-hazard checklist plus a post-generation grep remains the
+standard close-out procedure.
+
 ## Worked example — Wave Loop 884
 
 Wave Loop 884 continued the mechanical packed-vector AoS ladder past the 1-MiBit line:
@@ -3616,13 +3690,13 @@ variants are queued."
 
 | Field | Value |
 |-------|-------|
-| **Current wave** | 881 |
-| **Issue** | #1713 (expected) |
-| **Branch** | `wave-loop-881` |
-| **Parent branch** | `wave-loop-880` HEAD because earlier wave PRs remain open |
-| **Recommended variant** | A — module-scope `[581][2]^6 Pt` packed array-of-struct variable from call with indexed signed writes
+| **Current wave** | 887 |
+| **Issue** | #1834 |
+| **Branch** | `wave-loop-887` |
+| **Parent branch** | `wave-loop-886` HEAD because earlier wave PRs remain open |
+| **Recommended variant** | A — module-scope `[593][2]^6 Pt` packed array-of-struct variable from call with indexed signed writes
 | **Status** | READY TO START
-| **Next wave variants queued** | W882 Variant A `[583][2]^6 Pt`; Variant B `[581][3]^6 Pt` stride scaling; Variant C `[581][2]^6 Pt` negative-index wrap-around
+| **Next wave variants queued** | W888 Variant A `[595][2]^6 Pt`; Variant B `[593][3]^6 Pt` stride scaling; Variant C `[593][2]^6 Pt` negative-index wrap-around
 
 ### Open backlog (non-blocking)
 

.trinity/current-issue.md

@@ -1,18 +1,18 @@
-# Current Issue — Wave Loop 885
+# Current Issue — Wave Loop 887
 
-**Issue:** #1830 — feat(igla): Wave Loop 885 — module-scope [589][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes
+**Issue:** #1834 — feat(igla): Wave Loop 887 — module-scope [593][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes
 
-**Branch:** `wave-loop-885`
+**Branch:** `wave-loop-887`
 
 **PR:** TBD
 
-**Spec:** `specs/scratch/w885_bench_module_589x2p6_aos_var_call_write.t27`
+**Spec:** `specs/scratch/w887_bench_module_593x2p6_aos_var_call_write.t27`
 
-**Outer dimension:** 589 (non-power-of-two)
+**Outer dimension:** 593 (non-power-of-two)
 **Inner struct:** `[2]^6 Pt` (2 fields × 6 trits × 32 bits = 384 bits per element)
-**Total elements:** 589 × 2 = 1,178 structs → 37,696 field slots
-**Packed vector width:** 37,696 × 32 = 1,206,272 bits (~1.151 MiBit)
+**Total elements:** 593 × 2 = 1,186 structs → 37,952 field slots
+**Packed vector width:** 37,952 × 32 = 1,214,464 bits (~1.159 MiBit)
 
 **Pattern:** module-scope array-of-struct variable initialized from a function call, then mutated via signed-index field writes and read back with `assert_eq` inside a `bench` block.
 
-**Next issue:** TBD (Wave Loop 886)
+**Next issue:** TBD (Wave Loop 888)

.trinity/experience.md

@@ -1,3 +1,79 @@
+> ## 2026-08-06 — Wave Loop 886 (module-scope `[591][2]^6 Pt` non-power-of-two outer-dimension AoS variable, issue #1832, PR #1833)
+>
+> ### What worked
+> - Variant A extended the module-scope packed AoS odd outer-dimension ladder to 591.
+>   The `[591][2]^6 Pt` witness is 1,210,368 bits (~1.155 MiBit), continues past the 1-MiBit
+>   line, and required no compiler changes.
+> - The generator copy-hazard checklist was cleared before the first run.
+> - `t27c parse`, `icarus-lowerable`, `icarus-simulate` (17 cycles), `icarus-cocotb`, and
+>   `seal --save` all passed for the W886 witness.
+> - Targeted `cargo test --release --test icarus_lowerable accepts_w886_bench_module_591x2p6_aos_var_call_write`
+>   passed.
+> - PR #1833 opened; auto-merge enabled.
+>
+> ### What changed behavior
+> - No changes to `bootstrap/src/compiler.rs`.
+> - No changes to `bootstrap/stage0/FROZEN_HASH`.
+> - Added `specs/scratch/w886_bench_module_591x2p6_aos_var_call_write.t27` (~2.5 MB /
+>   ~112,351 lines) with seal and Icarus baseline.
+> - Added integration test `accepts_w886_bench_module_591x2p6_aos_var_call_write`.
+> - Added generator script `scripts/gen_w886.py`.
+> - Added closeout report `docs/reports/FPGA_LOOP_CLOSEOUT_W886_2026-08-06.md` and next-wave
+>   plan `.claude/plans/wave-loop-887.md`.
+>
+> ### Validation
+> - `t27c parse` W886: PASS.
+> - `t27c icarus-lowerable` W886: PASS (`lowerable`).
+> - `t27c icarus-simulate` W886: PASS (17 cycles, PASSED).
+> - `t27c icarus-cocotb` W886: PASS (`reference-model OK`).
+> - `t27c seal --save` W886: PASS.
+> - Targeted cargo test W886: PASS.
+>
+> ### Notes / watch-outs
+> - A pre-existing `corpus_classifier_matches_lean_completeness` failure for
+>   `specs/cloud/railway_deploy.t27` (Rust lowerable `false`, Lean theorem `true`) is not
+>   introduced by W886. It reproduces on clean W882 and should be tracked separately.
+> - The full `icarus_lowerable` suite now reports 345 passed; 1 failed (the pre-existing
+>   mismatch above).
+>
+> ## 2026-08-06 — Wave Loop 885 (module-scope `[589][2]^6 Pt` non-power-of-two outer-dimension AoS variable, issue #1830, PR #1831)
+>
+> ### What worked
+> - Variant A extended the module-scope packed AoS odd outer-dimension ladder to 589.
+>   The `[589][2]^6 Pt` witness is 1,206,272 bits (~1.151 MiBit), continues past the 1-MiBit
+>   line, and required no compiler changes.
+> - The generator copy-hazard checklist was cleared before the first run.
+> - `t27c parse`, `icarus-lowerable`, `icarus-simulate` (17 cycles), `icarus-cocotb`, and
+>   `seal --save` all passed for the W885 witness.
+> - Targeted `cargo test --release --test icarus_lowerable accepts_w885_bench_module_589x2p6_aos_var_call_write`
+>   passed.
+> - PR #1831 opened; auto-merge enabled.
+>
+> ### What changed behavior
+> - No changes to `bootstrap/src/compiler.rs`.
+> - No changes to `bootstrap/stage0/FROZEN_HASH`.
+> - Added `specs/scratch/w885_bench_module_589x2p6_aos_var_call_write.t27` (~2.5 MB /
+>   ~111,971 lines) with seal and Icarus baseline.
+> - Added integration test `accepts_w885_bench_module_589x2p6_aos_var_call_write`.
+> - Added generator script `scripts/gen_w885.py`.
+> - Added closeout report `docs/reports/FPGA_LOOP_CLOSEOUT_W885_2026-08-06.md` and next-wave
+>   plan `.claude/plans/wave-loop-886.md`.
+>
+> ### Validation
+> - `t27c parse` W885: PASS.
+> - `t27c icarus-lowerable` W885: PASS (`lowerable`).
+> - `t27c icarus-simulate` W885: PASS (17 cycles, PASSED).
+> - `t27c icarus-cocotb` W885: PASS (`reference-model OK`).
+> - `t27c seal --save` W885: PASS.
+> - Targeted cargo test W885: PASS.
+>
+> ### Notes / watch-outs
+> - A pre-existing `corpus_classifier_matches_lean_completeness` failure for
+>   `specs/cloud/railway_deploy.t27` (Rust lowerable `false`, Lean theorem `true`) is not
+>   introduced by W885. It reproduces on clean W882 and should be tracked separately.
+> - The full `icarus_lowerable` suite now reports 344 passed; 1 failed (the pre-existing
+>   mismatch above).
+>
 > ## 2026-08-06 — Wave Loop 884 (module-scope `[587][2]^6 Pt` non-power-of-two outer-dimension AoS variable, issue #1828, PR #1829)
 >
 > ### What worked

.trinity/seals/scratch_w886_bench_module_591x2p6_aos_var_call_write.json

@@ -0,0 +1,11 @@
+{
+  "gen_hash_c": "sha256:2d5973f76248c1a9e924219238049995ea7e7e91361c1ee859bb18df33f069cf",
+  "gen_hash_rust": "sha256:0948b6a545ad1f83d9430758dcdea27d2ae4db9ec78f00bbc06a123ee8d6d874",
+  "gen_hash_verilog": "sha256:518bb84dc3252b6ad6789514c781dd7bbdc48923edc52f8178a4eee51d2cfde1",
+  "gen_hash_zig": "sha256:15fa3bf9b43634f155a35001a0edb3df0ea8e0306075b4ee11bd5f89a7d607fb",
+  "module": "w886_bench_module_591x2p6_aos_var_call_write",
+  "ring": 12,
+  "sealed_at": "2026-08-07T04:02:03Z",
+  "spec_hash": "sha256:8303d6fe8d1bf9f45e8750a1fc88e97b25a3022a471e2a3ba4ad18372c75ed20",
+  "spec_path": "specs/scratch/w886_bench_module_591x2p6_aos_var_call_write.t27"
+}

bootstrap/tests/icarus_lowerable.rs

@@ -6241,6 +6241,24 @@ fn accepts_w885_bench_module_589x2p6_aos_var_call_write() {
     }
 }
 
+#[test]
+fn accepts_w886_bench_module_591x2p6_aos_var_call_write() {
+    let dir = scratch_dir();
+    for name in &[
+        "w886_bench_module_591x2p6_aos_var_call_write.t27",
+    ] {
+        let p = dir.join(name);
+        assert!(p.exists(), "missing W886 witness {}", p.display());
+        let (lowerable, json) = run_icarus_lowerable(&p);
+        assert!(
+            lowerable,
+            "expected {} to be lowerable, got: {}",
+            p.display(),
+            json
+        );
+    }
+}
+
 #[test]
 fn accepts_known_lowerable_witnesses() {
     let dir = scratch_dir();