code/set4_goldfish.py

"""SET 4: Goldfish monolingual -> bilingual merge on the REAL composition models.
goldfish-models/eng_latn_1000mb x goldfish-models/{nld,spa,ell,pol}_*_1000mb (GPT-2, 125M each,
SEPARATE monolingual tokenizers). Rungs: M0 naive average (the merge the manuscript reports as
failing) vs M1 vocab-remapped + unit-aligned (permutation / Procrustes on the residual basis,
free MLP axis, attention heads).

METRIC: Delta-floor in NATS PER UTF-8 BYTE on FLORES-200 devtest. Bytes, not tokens: the two
parents use different tokenizers, so nats/token is not comparable across them. This is a
LIKELIHOOD metric, not benchmark accuracy."""
import os, sys, json, time, argparse, gc
sys.path.insert(0, "/root/compose-audit")
from common import *
import gpt2_align as G2
from mergeschool.core.models import load_hf

ap = argparse.ArgumentParser()
ap.add_argument("--pairs", default="nld_Latn:nld_latn,spa_Latn:spa_latn,ell_Grek:ell_grek,pol_Latn:pol_latn")
ap.add_argument("--n_sent", type=int, default=500)
ap.add_argument("--bs", type=int, default=8)
ap.add_argument("--barrier_n", type=int, default=7)
A = ap.parse_args()
OUT = "/root/compose-audit/results/set4_goldfish.jsonl"
DEV = "cuda"
ENG_REPO = "goldfish-models/eng_latn_1000mb"


def log(*a):
    print(f"[{time.strftime('%H:%M:%S')}]", *a, flush=True)


# ------------------------------------------------------------------ tokenizer-invariant eval
def build_blocks(tok, text, block=512, max_blocks=64):
    ids = tok(text)["input_ids"]
    n = max(1, min(max_blocks, len(ids) // block))
    ids = ids[: n * block]
    arr = torch.from_numpy(np.asarray(ids, dtype=np.int64).reshape(n, block))
    nbytes = sum(len(tok.decode(list(arr[i, 1:].numpy())).encode("utf-8")) for i in range(n))
    return arr, nbytes


@torch.no_grad()
def nll_total(model, blocks, dev, bs=8):
    tot, ntok = 0.0, 0
    for i in range(0, blocks.shape[0], bs):
        x = blocks[i:i + bs].to(dev)
        lp = torch.log_softmax(model(x).logits.float()[:, :-1], -1)
        tgt = x[:, 1:]
        tot += (-lp.gather(-1, tgt.unsqueeze(-1)).squeeze(-1)).sum().item()
        ntok += tgt.numel()
    return tot, ntok


@torch.no_grad()
def sent_acts(model, tok, lines, dev, bs=16, maxlen=128):
    """Mean-pooled per-sentence residual activations, {layer: (n_sent, d)} -- rows are matched
    ACROSS LANGUAGES by FLORES sentence id, which is what makes a cross-lingual basis map fittable."""
    outs = None
    for i in range(0, len(lines), bs):
        enc = tok(lines[i:i + bs], return_tensors="pt", padding=True, truncation=True, max_length=maxlen)
        ids = enc["input_ids"].to(dev); am = enc["attention_mask"].to(dev).float()
        hs = model(ids, attention_mask=enc["attention_mask"].to(dev), output_hidden_states=True).hidden_states
        if outs is None:
            outs = [[] for _ in hs]
        w = am / am.sum(1, keepdim=True).clamp(min=1)
        for j, h in enumerate(hs):
            outs[j].append((h.float() * w.unsqueeze(-1)).sum(1).cpu())
    return {j: torch.cat(o).numpy().astype(np.float64) for j, o in enumerate(outs)}


# ------------------------------------------------------------------ load English parent
log("loading eng parent")
m_e, tok_e = load_hf(ENG_REPO, dtype=torch.float32, device=DEV)
m_e.eval()
cfg = m_e.config
D, NH, NL, V = cfg.n_embd, cfg.n_head, cfg.n_layer, cfg.vocab_size
SD_E = sd_np(m_e)
log(f"gpt2 d={D} heads={NH} layers={NL} vocab={V}")

eng_lines = flores_lines("eng_Latn")[: A.n_sent]
eng_text = "\n".join(eng_lines)
bl_e_e, by_e_e = build_blocks(tok_e, eng_text)           # eng text, eng tokenizer
acts_e = sent_acts(m_e, tok_e, eng_lines, DEV)
shell = m_e                                              # reuse as the eval shell (eng tokenizer space)


def ev_np(sd, blocks):
    sd_load(shell, sd, DEV)
    t, n = nll_total(shell, blocks, DEV, bs=A.bs)
    return t, n


nll_e_eng_t, nll_e_eng_n = nll_total(m_e, bl_e_e, DEV, bs=A.bs)
PARENT_ENG = {"nats_per_byte": nll_e_eng_t / by_e_e, "nats_per_token": nll_e_eng_t / nll_e_eng_n}
log(f"eng parent on eng: {PARENT_ENG}")

done = set()
if os.path.exists(OUT):
    for line in open(OUT):
        try: done.add(json.loads(line)["lang"])
        except Exception: pass
fh = open(OUT, "a")

for spec in A.pairs.split(","):
    fcode, gcode = spec.split(":")
    if fcode in done:
        log("skip", fcode); continue
    t0 = time.time()
    repo = f"goldfish-models/{gcode}_1000mb"
    log(f"=== {fcode} <- {repo}")
    m_x, tok_x = load_hf(repo, dtype=torch.float32, device=DEV); m_x.eval()
    SD_X = sd_np(m_x)
    x_lines = flores_lines(fcode)[: A.n_sent]
    x_text = "\n".join(x_lines)
    bl_x_x, by_x_x = build_blocks(tok_x, x_text)         # X text, X tokenizer  (X parent's own floor)
    bl_x_e, by_x_e = build_blocks(tok_e, x_text)         # X text, ENG tokenizer (merged model's space)
    acts_x = sent_acts(m_x, tok_x, x_lines, DEV)
    tx, nx = nll_total(m_x, bl_x_x, DEV, bs=A.bs)
    parent_x = {"nats_per_byte": tx / by_x_x, "nats_per_token": tx / nx}
    del m_x; torch.cuda.empty_cache()
    te, ne = ev_np(SD_E, bl_x_e)                          # eng parent on X text
    eng_on_x = {"nats_per_byte": te / by_x_e, "nats_per_token": te / ne}
    log(f"  parents: eng/eng={PARENT_ENG['nats_per_byte']:.4f}  x/x={parent_x['nats_per_byte']:.4f}  "
        f"eng-on-x={eng_on_x['nats_per_byte']:.4f} nats/byte")

    # ------------- vocabulary transport (the OTHER axis: token ids, not the residual basis)
    vkeys = [k for k in SD_X if k.endswith("wte.weight") or k.endswith("lm_head.weight")]
    SD_X_V, cov = AL.remap_vocab_rows(SD_X, tok_e, tok_x, V, keys=vkeys)
    for k in vkeys:
        W = np.asarray(SD_X_V[k], float)
        bad = ~np.isfinite(W).all(axis=1) if W.shape[0] == V else ~np.isfinite(W).all(axis=0)
        if W.shape[0] == V:
            W[bad] = np.asarray(SD_E[k], float)[bad]     # unshared ids: keep English's row (no-op merge)
        SD_X_V[k] = W
    anchors = AL.vocab_anchors(tok_e, tok_x)
    log(f"  vocab anchors={len(anchors)} ({len(anchors)/V:.1%} of English ids)")

    BODY = [k for k in SD_E if not (k.endswith("wte.weight") or k.endswith("lm_head.weight"))]

    # ------------- alignments (fitted BEFORE merging)
    R_emb, n_anch = G2.emb_procrustes(SD_E, SD_X, tok_e, tok_x)
    sd_emb = G2.apply_resid(SD_X_V, D, R=R_emb)
    sd_emb2, _ = G2.align_full(SD_E, sd_emb, D, NH, None, None, "permutation", body_keys=BODY)
    sdp, ip = G2.align_full(SD_E, SD_X_V, D, NH, acts_e, acts_x, "permutation", body_keys=BODY)
    sdo, io = G2.align_full(SD_E, SD_X_V, D, NH, acts_e, acts_x, "orthogonal", body_keys=BODY)
    sdpf, ipf = G2.align_full(SD_E, SD_X_V, D, NH, acts_e, acts_x, "permutation", body_keys=BODY, accept_each=False)
    sdof, iof = G2.align_full(SD_E, SD_X_V, D, NH, acts_e, acts_x, "orthogonal", body_keys=BODY, accept_each=False)
    log(f"  align perm={ip} orth={io}")

    # ------------- predictors (pre-merge)
    KEYS = shared_keys(SD_E, SD_X)
    fa, fb = flat(SD_E, KEYS), flat(SD_X, KEYS)
    p = {"n_emb_anchors": n_anch, "weight_cosine": float(fa @ fb / (np.linalg.norm(fa) * np.linalg.norm(fb))),
         "vocab_overlap": len(anchors) / V}
    p["weight_cosine_body"] = float(np.mean([
        float(np.asarray(SD_E[k], float).ravel() @ np.asarray(SD_X[k], float).ravel() /
              (np.linalg.norm(SD_E[k]) * np.linalg.norm(SD_X[k]) + 1e-12)) for k in BODY]))
    q_p = MT.quotient_weight_distance(SD_E, SD_X_V, sdp, BODY)
    q_o = MT.quotient_weight_distance(SD_E, SD_X_V, sdo, BODY)
    p.update({"d_raw": q_p["d_raw"], "qmd_perm": q_p["qmd"], "coord_share_perm": q_p["coord_fraction"],
              "qmd_orth": q_o["qmd"], "coord_share_orth": q_o["coord_fraction"]})
    b_raw = AL.block_normalised_distance(SD_E, SD_X_V, BODY)
    b_p = AL.block_normalised_distance(SD_E, sdp, BODY)
    b_o = AL.block_normalised_distance(SD_E, sdo, BODY)
    p.update({"bnd_raw": b_raw, "bnd_perm": b_p, "bnd_orth": b_o,
              "coord_share_bnd_perm": float((b_raw - b_p) / b_raw),
              "coord_share_bnd_orth": float((b_raw - b_o) / b_raw)})
    ck, ckby = mean_cka(acts_e, acts_x)
    p["cka_mean"] = ck; p["cka_last"] = ckby[max(ckby)]
    for g in ("perm", "procrustes", "ot"):
        try:
            qr = MT.quotient_residual(acts_e[NL // 2], acts_x[NL // 2], group=g)
            p[f"qmd_act_{g}"] = qr["distance"]; p[f"aligned_cka_{g}"] = qr["aligned_cka"]
        except Exception:
            p[f"qmd_act_{g}"] = float("nan")

    # ------------- merge rungs
    rungs = {"M0_naive_avg": MG.average([SD_E, SD_X]),
             "M1a_vocab_avg": MG.average([SD_E, SD_X_V]),
             "M1b_vocab_perm_avg": MG.average([SD_E, sdp]),
             "M1c_vocab_orth_avg": MG.average([SD_E, sdo]),
             "M1d_vocab_perm_forced": MG.average([SD_E, sdpf]),
             "M1e_vocab_orth_forced": MG.average([SD_E, sdof]),
             "M1g_emb_procrustes": MG.average([SD_E, sd_emb]),
             "M1h_emb_proc_units": MG.average([SD_E, sd_emb2]),
             "M1f_perm_novocab": MG.average([SD_E, G2.align_full(SD_E, SD_X, D, NH, acts_e, acts_x, "permutation", body_keys=BODY)[0]])}
    res = {}
    for name, sd in rungs.items():
        t_e, n_e = ev_np(sd, bl_e_e)
        t_x, n_x = ev_np(sd, bl_x_e)
        res[name] = {
            "eng": {"nats_per_byte": t_e / by_e_e, "nats_per_token": t_e / n_e},
            "x":   {"nats_per_byte": t_x / by_x_e, "nats_per_token": t_x / n_x},
            "delta_floor_eng": t_e / by_e_e - PARENT_ENG["nats_per_byte"],
            "delta_floor_x": t_x / by_x_e - min(parent_x["nats_per_byte"], eng_on_x["nats_per_byte"]),
        }
        res[name]["delta_floor_mean"] = 0.5 * (res[name]["delta_floor_eng"] + res[name]["delta_floor_x"])
    for name in res:
        res[name]["delta_vs_naive_mean"] = res[name]["delta_floor_mean"] - res["M0_naive_avg"]["delta_floor_mean"]

    r = {"set": "set4_goldfish", "lang": fcode, "repo_a": ENG_REPO, "repo_b": repo,
         "corpus": "flores200_devtest", "n_sent": A.n_sent,
         "metric": "nats_per_utf8_byte (likelihood, NOT benchmark accuracy)",
         "parents": {"eng_on_eng": PARENT_ENG, "x_on_x": parent_x, "eng_on_x": eng_on_x},
         "floor_eng": PARENT_ENG["nats_per_byte"],
         "floor_x": min(parent_x["nats_per_byte"], eng_on_x["nats_per_byte"]),
         "align_info": {"perm": ip, "orth": io, "perm_forced": ipf, "orth_forced": iof}, "predictors": p, "rungs": res}

    # ------------- barriers on the mean nats/byte
    def ev_mean(sd):
        t_e, _ = ev_np(sd, bl_e_e); t_x, _ = ev_np(sd, bl_x_e)
        return 0.5 * (t_e / by_e_e + t_x / by_x_e)
    try:
        bn = EV.merge_barrier(SD_E, SD_X, ev_mean, n=A.barrier_n)
        r["barrier_naive"] = {"barrier": bn["barrier"], "losses": list(map(float, bn["losses"]))}
        bp = EV.merge_barrier(SD_E, sdp, ev_mean, n=A.barrier_n)
        r["barrier_perm"] = {"barrier": bp["barrier"], "losses": list(map(float, bp["losses"]))}
    except Exception as e:
        log("barrier failed", e)

    r["secs"] = time.time() - t0
    fh.write(json.dumps(r) + "\n"); fh.flush()
    log(f"  {fcode}: M0 dfloor_mean={res['M0_naive_avg']['delta_floor_mean']:+.4f}  "
        f"M1a={res['M1a_vocab_avg']['delta_floor_mean']:+.4f}  "
        f"M1b_perm={res['M1b_vocab_perm_avg']['delta_floor_mean']:+.4f}  "
        f"M1c_orth={res['M1c_vocab_orth_avg']['delta_floor_mean']:+.4f}  ({r['secs']:.0f}s)")
    del rungs, sdp, sdo, sdpf, sdof, sd_emb, sd_emb2, SD_X, SD_X_V; gc.collect()
fh.close()
log("DONE set4")