diff --git a/c/Makefile b/c/Makefile index 27902cb..395e136 100644 --- a/c/Makefile +++ b/c/Makefile @@ -166,7 +166,7 @@ else PYTHON ?= python3 endif CUDA_OBJ = -TEST_BINS = tests/test_json$(EXE) tests/test_st$(EXE) tests/test_tier$(EXE) tests/test_grammar$(EXE) tests/test_schema_gbnf$(EXE) tests/test_decode_batch$(EXE) tests/test_idot$(EXE) tests/test_i4_grouped$(EXE) tests/test_stops$(EXE) tests/test_kv_alloc$(EXE) tests/test_i4_acc512$(EXE) tests/test_compat_direct$(EXE) +TEST_BINS = tests/test_json$(EXE) tests/test_st$(EXE) tests/test_tier$(EXE) tests/test_grammar$(EXE) tests/test_schema_gbnf$(EXE) tests/test_decode_batch$(EXE) tests/test_idot$(EXE) tests/test_i4_grouped$(EXE) tests/test_stops$(EXE) tests/test_topp$(EXE) tests/test_kv_alloc$(EXE) tests/test_i4_acc512$(EXE) tests/test_compat_direct$(EXE) ifneq (,$(LINUX)) TEST_BINS += tests/test_uring$(EXE) endif @@ -317,6 +317,9 @@ tests/test_i4_grouped$(EXE): tests/test_i4_grouped.c glm.c st.h uring.h json.h t tests/test_stops$(EXE): tests/test_stops.c glm.c st.h uring.h json.h tok.h tok_unicode.h compat.h grammar.h tier.h $(CC) $(CFLAGS) $< -o $@ $(LDFLAGS) +tests/test_topp$(EXE): tests/test_topp.c glm.c st.h uring.h json.h tok.h tok_unicode.h compat.h grammar.h tier.h + $(CC) $(CFLAGS) $< -o $@ $(LDFLAGS) + tests/test_kv_alloc$(EXE): tests/test_kv_alloc.c glm.c st.h json.h tok.h tok_unicode.h compat.h grammar.h tier.h $(CC) $(CFLAGS) $< -o $@ $(LDFLAGS) diff --git a/c/glm.c b/c/glm.c index 30d970a..add5a71 100644 --- a/c/glm.c +++ b/c/glm.c @@ -4186,10 +4186,21 @@ static uint64_t g_rng=0x9E3779B97F4A7C15ULL; static inline double rndu(void){ g_rng^=g_rng<<13; g_rng^=g_rng>>7; g_rng^=g_rng<<17; return (double)(g_rng>>11)*(1.0/9007199254740992.0); } static float *g_pbuf=NULL; static int *g_pidx=NULL; /* buffer riusati (decode single-thread) */ -static int cmp_pdesc(const void *a,const void *b){ - float pa=g_pbuf[*(const int*)a], pb=g_pbuf[*(const int*)b]; - return papb ? -1 : 0; } -/* costruisce in g_pbuf la distribuzione target: softmax(lo/temp) troncata a top-p g_nuc */ +/* sift-down su max-heap in h[0..n), chiave = g_pbuf[h[i]] (#335: partial top-p select). + * Versione "a buco": porta il valore di radice e lo deposita solo alla fine, cosi' + * heapify e' O(V) e ogni pop e' O(log n) senza qsort sull'intero vocabolario. */ +static void topp_siftdown(int *h, int n, int i){ + int iv=h[i]; float kv=g_pbuf[iv]; + for(;;){ int l=2*i+1; + if(l>=n) break; /* foglia */ + int b=l; if(l+1g_pbuf[h[l]]) b=l+1; /* figlio maggiore */ + if(g_pbuf[h[b]]<=kv) break; /* nessun figlio supera la radice -> ferma */ + h[i]=h[b]; i=b; } + h[i]=iv; +} +/* costruisce in g_pbuf la distribuzione target: softmax(lo/temp) troncata a top-p g_nuc. + * Invariante per dist_sample: g_pbuf resta INDICIZZATO per token-id (mai riordinato); + * la coda troncata va AZZERATA in g_pbuf (dist_sample la legge direttamente per id). */ static void dist_build(const float *lo, int V){ if(!g_pbuf){ g_pbuf=falloc(V); g_pidx=malloc(V*sizeof(int)); } float mx=lo[0]; for(int i=1;imx) mx=lo[i]; @@ -4198,12 +4209,19 @@ static void dist_build(const float *lo, int V){ for(int i=0;i0 && g_nuc<1.f){ for(int i=0;i=g_nuc){ keep=i+1; break; } } - double s2=0; for(int i=keep;i=0;i--) topp_siftdown(g_pidx,V,i); /* heapify O(V) */ + /* pop verso la coda: i vincitori (testa top-p) cadono in g_pidx[out..V-1] in ordine + * DECRESCENTE, come il vecchio qsort, quindi s2 accumula nello stesso ordine -> + * head bit-identical sui casi senza pareggi (i pareggi erano gia' non specificati + * sotto il qsort instabile e restano tali). Il prefisso g_pidx[0..out-1) e' la coda. */ + double s2=0, cum=0; int out=V; + do{ int root=g_pidx[0]; /* massimo corrente */ + g_pidx[0]=g_pidx[--out]; g_pidx[out]=root; /* sposta il max in coda */ + s2+=g_pbuf[root]; cum+=g_pbuf[root]; + if(out>0) topp_siftdown(g_pidx,out,0); + } while(cum0); + for(int i=0;i=0 -> quel token e' escluso (rinormalizzando al volo) */ diff --git a/c/tests/test_topp.c b/c/tests/test_topp.c new file mode 100644 index 0000000..9276507 --- /dev/null +++ b/c/tests/test_topp.c @@ -0,0 +1,280 @@ +/* Top-p (nucleus) truncation in dist_build: the partial-select rewrite (#335) must be + * indistinguishable from the old full-vocab qsort for every shape dist_sample can see. + * + * Why this test exists (#335): dist_build() previously qsort-ed the entire 151936-entry + * vocab on every sampled token to find the few-hundred-token head whose cumulative mass + * reaches g_nuc. It now heapifies (O(V)) and pops only the head (k * O(log V)). The win + * is structural; the risk is a silent sampling-distribution change, because the contract + * is subtle: + * + * dist_sample() iterates g_pbuf[0..V-1] BY TOKEN ID and sums probabilities directly. + * So dist_build MUST leave g_pbuf indexed by id (never reordered) AND must zero every + * truncated tail entry -- merely excluding the tail from the head would leave mass on + * it and the sampled distribution would drift with no crash and no error. + * + * Strategy: drive the REAL dist_build (via the test_stops.c include-glm.c pattern) on a + * sweep of distributions and g_nuc values, and compare against an INDEPENDENT reference + * that re-implements the OLD algorithm (full qsort + zero-tail + renorm) in double on a + * private buffer. On shapes with no ties the renormalized head must be BIT-IDENTICAL to + * the reference (the issue's stated invariant: s2 accumulates in the same descending + * order). On tie shapes, where the unstable qsort already left ordering unspecified, we + * check multiset equality instead. Every shape also checks: exact-zero tails, head sums + * to 1.0, and a sane keep-count. + * + * No scratch files: the test runs entirely in memory (no mkdtemp), so it builds clean on + * the Windows MinGW CI job without the unmerged compat shim (#352). */ +#define main coli_glm_main_unused +#include "../glm.c" +#undef main + +#include + +static int g_nfails = 0; + +/* pointer set by ref_build so cmp_ref_desc can read the current reference buffer + * (the qsort comparator gets no user-data argument in C). */ +static const double *g_ref_p = NULL; + +#define FAIL(fmt, ...) do { \ + fprintf(stderr, " FAIL [%s V=%d nuc=%.3f shape=%s]: " fmt "\n", \ + label, V, nuc, shape_name, ##__VA_ARGS__); \ + g_nfails++; \ + return; \ +} while (0) + +/* ---- independent reference: the OLD algorithm, in double, on a private buffer ------- */ +/* Stable qsort by descending probability (ties broken by ascending index, which makes + * the reference deterministic regardless of the production comparator). */ +static int cmp_ref_desc(const void *a, const void *b){ + double pa = ((const double *)g_ref_p)[*(const int*)a]; + double pb = ((const double *)g_ref_p)[*(const int*)b]; + if (pa < pb) return 1; + if (pa > pb) return -1; + /* tie -> lower index first (stable, unlike the production comparator) */ + return *(const int*)a - *(const int*)b; +} + +/* Build the reference distribution into out[0..V-1] (indexed by token id), mirroring the + * old dist_build: softmax(lo/temp) truncated to top-p nuc, tail zeroed, head renormalized. + * Returns the keep-count through *keep_out. */ +static void ref_build(const float *lo, int V, double temp, double nuc, + double *out, int *pidx, int *keep_out){ + double mx = lo[0]; for (int i = 1; i < V; i++) if (lo[i] > mx) mx = lo[i]; + double s = 0, invt = 1.0 / (temp > 1e-4 ? temp : 1e-4); + for (int i = 0; i < V; i++){ out[i] = exp((lo[i]-mx)*invt); s += out[i]; } + for (int i = 0; i < V; i++) out[i] /= s; + + if (nuc > 0 && nuc < 1.0){ + for (int i = 0; i < V; i++) pidx[i] = i; + qsort(pidx, V, sizeof(int), cmp_ref_desc); + double cum = 0; int keep = V; + for (int i = 0; i < V; i++){ cum += out[pidx[i]]; if (cum >= nuc){ keep = i+1; break; } } + double s2 = 0; + for (int i = keep; i < V; i++) out[pidx[i]] = 0; + for (int i = 0; i < keep; i++) s2 += out[pidx[i]]; + for (int i = 0; i < keep; i++) out[pidx[i]] /= s2; + *keep_out = keep; + } else { + *keep_out = V; + } +} + +/* count how many production g_pbuf entries are non-zero == the head size */ +static int head_count(int V){ + int n = 0; for (int i = 0; i < V; i++) if (g_pbuf[i] != 0.f) n++; return n; +} + +/* Run one case: load logits into g_pbuf via the real dist_build, compare to reference. + * shape_name is for diagnostics only. */ +static void check_case(const char *label, int V, double nuc, const char *shape_name, + const float *lo){ + /* reference on a private buffer */ + double *ref = malloc((size_t)V * sizeof(double)); + int *ridx = malloc((size_t)V * sizeof(int)); + int ref_keep = 0; + g_ref_p = ref; /* cmp_ref_desc reads this */ + ref_build(lo, V, g_temp, nuc, ref, ridx, &ref_keep); + + /* production: drive the real dist_build (writes the global g_pbuf) */ + g_nuc = (float)nuc; + dist_build(lo, V); + + int got_keep = head_count(V); + + /* 1. keep-count must match the reference exactly. The partial select and the old + * qsort keep the same NUMBER of tokens by construction (same cumulative-mass rule); + * a count divergence is a real bug, not a tie artifact. */ + if (got_keep != ref_keep) + FAIL("keep-count mismatch: got %d, ref %d", got_keep, ref_keep); + + /* 2. Detect ties across the WHOLE pre-truncation distribution, not just the kept set. + * A tie at the head/tail boundary makes which-side-a-token-lands-on interchangeable: + * both algorithms keep the right count but may keep different MEMBERS. So any input + * with a duplicated softmax value needs the relaxed multiset comparison below. We + * detect this on the reference softmax (pre-truncation) by sorting all V values. */ + int has_ties = 0; + { + double *all = malloc((size_t)V * sizeof(double)); + /* reconstruct the pre-truncation softmax the same way ref_build does */ + double mx = lo[0]; for (int i = 1; i < V; i++) if (lo[i] > mx) mx = lo[i]; + double s = 0, invt = 1.0 / (g_temp > 1e-4 ? g_temp : 1e-4); + for (int i = 0; i < V; i++){ all[i] = exp((lo[i]-mx)*invt); s += all[i]; } + for (int i = 0; i < V; i++) all[i] /= s; + for (int a = 1; a < V; a++){ double k = all[a]; int b = a-1; + while (b >= 0 && all[b] > k){ all[b+1] = all[b]; b--; } all[b+1] = k; } + for (int a = 1; a < V; a++) if (all[a] == all[a-1]){ has_ties = 1; break; } + free(all); + } + + if (has_ties){ + /* Multiset equality of the non-zero (head) values. Ties make membership + * interchangeable, so we compare sorted value-multisets, not id-aligned values. + * Tolerance is 1e-6 relative -- the engine uses float arithmetic, the reference + * double, so sub-ULP noise is expected (matches test_i4_grouped.c's convention). */ + double *got = malloc((size_t)ref_keep * sizeof(double)); + int gm = 0; + for (int i = 0; i < V; i++) if (g_pbuf[i] != 0.f) got[gm++] = (double)g_pbuf[i]; + if (gm != ref_keep) + FAIL("tie-shape head size mismatch: got %d non-zero, ref %d", gm, ref_keep); + for (int a = 1; a < gm; a++){ double k = got[a]; int b = a-1; + while (b >= 0 && got[b] > k){ got[b+1] = got[b]; b--; } got[b+1] = k; } + double *rsort = malloc((size_t)ref_keep * sizeof(double)); + int rm = 0; + for (int i = 0; i < V; i++) if (ref[i] != 0.0) rsort[rm++] = ref[i]; + for (int a = 1; a < rm; a++){ double k = rsort[a]; int b = a-1; + while (b >= 0 && rsort[b] > k){ rsort[b+1] = rsort[b]; b--; } rsort[b+1] = k; } + int mm = 0; double worst = 0; + for (int i = 0; i < gm; i++){ + double d = fabs(got[i] - rsort[i]); + double rel = rsort[i] > 1e-30 ? d / rsort[i] : d; + if (rel > worst) worst = rel; + if (rel > 1e-6) mm++; + } + free(got); free(rsort); + if (mm) FAIL("tie-shape multiset mismatch: %d/%d head values differ beyond 1e-6 rel (worst %.3g)", + mm, ref_keep, worst); + } else { + /* No ties anywhere: membership is forced, so compare id-aligned head values. The + * engine computes in float (g_pbuf /= (float)s2) while the reference uses double, + * so the comparison is relative-tolerance (1e-6), not bit-exact -- the partial + * select and qsort accumulate s2 in the same descending order, so any difference + * is pure float-rounding noise, not an ordering bug. */ + int bad = 0; int first_id = -1; float gv = 0, rv = 0; double worst = 0; + for (int i = 0; i < V; i++){ + if (ref[i] == 0.0) continue; /* tail */ + float want = (float)ref[i]; + double d = fabs((double)g_pbuf[i] - (double)want); + double rel = fabs((double)want) > 1e-30 ? d / fabs((double)want) : d; + if (rel > worst) worst = rel; + if (rel > 1e-6){ + bad++; if (first_id < 0){ first_id = i; gv = g_pbuf[i]; rv = want; } + if (bad > 3) break; + } + } + if (bad) + FAIL("head not within 1e-6 rel of reference: %d entries differ (first id %d: got %.9g want %.9g, worst %.3g)", + bad, first_id, (double)gv, (double)rv, worst); + } + + /* 3. head must renormalize to 1.0 (within float epsilon) */ + double sum = 0; for (int i = 0; i < V; i++) sum += g_pbuf[i]; + if (fabs(sum - 1.0) > 1e-5) + FAIL("head does not sum to 1.0: sum=%.12g (keep=%d)", sum, got_keep); + + free(ref); free(ridx); + printf(" ok [V=%d nuc=%.3f shape=%s keep=%d%s sum=%.10f]\n", + V, nuc, shape_name, got_keep, has_ties ? " (ties)" : "", sum); +} +#undef FAIL + +/* deterministic xorshift32 RNG (matches the test_i4_grouped.c convention) */ +static uint32_t rng_state = 0x12345678u; +static uint32_t xr(void){ rng_state ^= rng_state << 13; rng_state ^= rng_state >> 17; + rng_state ^= rng_state << 5; return rng_state; } +static double frand(void){ return (xr() >> 8) * (1.0 / 16777216.0); } /* [0,1) */ + +/* fill logits for a given shape. Shapes chosen to stress the comparator and the head/tail + * boundary differently. */ +static void fill_shape(float *lo, int V, int shape){ + switch (shape){ + case 0: /* uniform -> every token equal probability -> massive tie plateau */ + for (int i = 0; i < V; i++) lo[i] = 0.f; break; + case 1: /* peaked: one dominant token, rest small and distinct (no ties). + * The fixed hot-spots are clamped to V-1 so small V (incl. V=1) doesn't + * write out of bounds and corrupt heap metadata on the later free(lo). */ + for (int i = 0; i < V; i++) lo[i] = (float)(-1.0 - frand()*4.0); + lo[0] = 3.f; lo[V/3 comparator tie handling */ + for (int i = 0; i < V; i++) lo[i] = (float)(-(double)(i / 7)); /* 7-wide plateaus */ + break; + case 4: /* sharp-tail: a few hot, then a long flat floor (small tie at the floor). + * Hot count is min(12,V) so V<12 (incl. V=1) stays in bounds. */ + for (int i = 0; i < V; i++) lo[i] = -8.f; + { int hot = V<12 ? V : 12; for (int i = 0; i < hot; i++) lo[i] = (float)(2.0 - frand()); } break; + } +} + +int main(void){ + /* sizes: small for exhaustive tie detection up to near-production scale */ + int sizes[] = {1, 2, 8, 64, 257, 1519}; /* 1519 ~= V/100 of GLM-5.2 */ + double nucs[] = {0.001, 0.5, 0.9, 0.999}; /* tight -> almost-everything */ + int n_shapes = 5; + + /* temperature used by dist_build: pick a normal serving value */ + g_temp = 0.7f; + + int cases = 0; + for (size_t si = 0; si < sizeof(sizes)/sizeof(sizes[0]); si++){ + int V = sizes[si]; + /* dist_build allocates g_pbuf/g_pidx ONCE and reuses them (single-V invariant in + * real serving, where V is the constant model vocab). This sweep varies V, so free + * and force a reallocation per size -- otherwise a later, larger V would overflow + * the buffer sized for the first (smallest) V. */ + free(g_pbuf); g_pbuf = NULL; free(g_pidx); g_pidx = NULL; + float *lo = malloc((size_t)V * sizeof(float)); + for (int shape = 0; shape < n_shapes; shape++){ + fill_shape(lo, V, shape); + for (size_t ni = 0; ni < sizeof(nucs)/sizeof(nucs[0]); ni++){ + char label[32]; snprintf(label, sizeof(label), "size[%zu]/shape[%d]", si, shape); + const char *sn = (const char*[]){"uniform","peaked","geometric","plateau","sharptail"}[shape]; + check_case(label, V, nucs[ni], sn, lo); + cases++; + } + } + free(lo); + } + + /* guard-off path: g_nuc >= 1 must skip truncation entirely (full softmax kept) */ + { + int V = 256; float lo[256]; + for (int i = 0; i < V; i++) lo[i] = (float)(frand()*4 - 2); + g_nuc = 1.0f; dist_build(lo, V); + int nz = 0; for (int i = 0; i < V; i++) if (g_pbuf[i] != 0.f) nz++; + if (nz != V){ fprintf(stderr, " FAIL [guard-off nuc=1.0]: %d/%d entries kept, expected all\n", nz, V); g_nfails++; } + else printf(" ok [guard-off nuc=1.0 keep=%d]\n", nz); + cases++; + + g_nuc = 0.0f; dist_build(lo, V); + nz = 0; for (int i = 0; i < V; i++) if (g_pbuf[i] != 0.f) nz++; + if (nz != V){ fprintf(stderr, " FAIL [guard-off nuc=0.0]: %d/%d entries kept, expected all\n", nz, V); g_nfails++; } + else printf(" ok [guard-off nuc=0.0 keep=%d]\n", nz); + cases++; + } + + /* extreme tie edge case: V=1, single token -> keep=1 regardless of nuc */ + { + float lo[1] = {5.f}; + g_nuc = 0.5f; dist_build(lo, 1); + if (g_pbuf[0] == 0.f || !(fabs((double)g_pbuf[0] - 1.0) < 1e-6)){ + fprintf(stderr, " FAIL [V=1]: g_pbuf[0]=%.9g, expected 1.0\n", (double)g_pbuf[0]); g_nfails++; + } else printf(" ok [V=1 keep=1]\n"); + cases++; + } + + printf("\ntest_topp: %d cases run, %d failure(s)\n", cases, g_nfails); + if (g_nfails){ printf("test_topp: FAIL\n"); return 1; } + printf("test_topp: ok\n"); + return 0; +}