int bn_cmp_words(const BN_ULONG *a, const BN_ULONG *b, int n)
{
    int i;
    BN_ULONG aa, bb;
    aa = a[n - 1];
    bb = b[n - 1];
    if (aa != bb)
        return ((aa > bb) ? 1 : -1);
    for (i = n - 2; i >= 0; i--) {
        aa = a[i];
        bb = b[i];
        if (aa != bb)
            return ((aa > bb) ? 1 : -1);
    }
    return (0);
}
['static int test_negzero()\n{\n    BIGNUM *a = NULL, *b = NULL, *c = NULL, *d = NULL;\n    BIGNUM *numerator = NULL, *denominator = NULL;\n    int consttime, st = 0;\n    if (!TEST_ptr(a = BN_new())\n            || !TEST_ptr(b = BN_new())\n            || !TEST_ptr(c = BN_new())\n            || !TEST_ptr(d = BN_new()))\n        goto err;\n    if (!TEST_true(BN_set_word(a, 1)))\n        goto err;\n    BN_set_negative(a, 1);\n    BN_zero(b);\n    if (!TEST_true(BN_mul(c, a, b, ctx)))\n        goto err;\n    if (!TEST_BN_eq_zero(c)\n            || !TEST_BN_ge_zero(c))\n        goto err;\n    for (consttime = 0; consttime < 2; consttime++) {\n        if (!TEST_ptr(numerator = BN_new())\n                || !TEST_ptr(denominator = BN_new()))\n            goto err;\n        if (consttime) {\n            BN_set_flags(numerator, BN_FLG_CONSTTIME);\n            BN_set_flags(denominator, BN_FLG_CONSTTIME);\n        }\n        if (!TEST_true(BN_set_word(numerator, 1))\n                || !TEST_true(BN_set_word(denominator, 2)))\n            goto err;\n        BN_set_negative(numerator, 1);\n        if (!TEST_true(BN_div(a, b, numerator, denominator, ctx))\n                || !TEST_BN_eq_zero(a)\n                || !TEST_BN_ge_zero(a))\n            goto err;\n        if (!TEST_true(BN_set_word(denominator, 1))\n                || !TEST_true(BN_div(a, b, numerator, denominator, ctx))\n                || !TEST_BN_eq_zero(b)\n                || !TEST_BN_ge_zero(b))\n            goto err;\n        BN_free(numerator);\n        BN_free(denominator);\n        numerator = denominator = NULL;\n    }\n    BN_zero(a);\n    BN_set_negative(a, 1);\n    if (BN_is_negative(a))\n        goto err;\n    st = 1;\nerr:\n    BN_free(a);\n    BN_free(b);\n    BN_free(c);\n    BN_free(d);\n    BN_free(numerator);\n    BN_free(denominator);\n    return st;\n}', 'int BN_set_word(BIGNUM *a, BN_ULONG w)\n{\n    bn_check_top(a);\n    if (bn_expand(a, (int)sizeof(BN_ULONG) * 8) == NULL)\n        return (0);\n    a->neg = 0;\n    a->d[0] = w;\n    a->top = (w ? 1 : 0);\n    bn_check_top(a);\n    return (1);\n}', 'static ossl_inline BIGNUM *bn_expand(BIGNUM *a, int bits)\n{\n    if (bits > (INT_MAX - BN_BITS2 + 1))\n        return NULL;\n    if (((bits+BN_BITS2-1)/BN_BITS2) <= (a)->dmax)\n        return a;\n    return bn_expand2((a),(bits+BN_BITS2-1)/BN_BITS2);\n}', 'int BN_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)\n{\n    int ret = 0;\n    int top, al, bl;\n    BIGNUM *rr;\n#if defined(BN_MUL_COMBA) || defined(BN_RECURSION)\n    int i;\n#endif\n#ifdef BN_RECURSION\n    BIGNUM *t = NULL;\n    int j = 0, k;\n#endif\n    bn_check_top(a);\n    bn_check_top(b);\n    bn_check_top(r);\n    al = a->top;\n    bl = b->top;\n    if ((al == 0) || (bl == 0)) {\n        BN_zero(r);\n        return (1);\n    }\n    top = al + bl;\n    BN_CTX_start(ctx);\n    if ((r == a) || (r == b)) {\n        if ((rr = BN_CTX_get(ctx)) == NULL)\n            goto err;\n    } else\n        rr = r;\n#if defined(BN_MUL_COMBA) || defined(BN_RECURSION)\n    i = al - bl;\n#endif\n#ifdef BN_MUL_COMBA\n    if (i == 0) {\n# if 0\n        if (al == 4) {\n            if (bn_wexpand(rr, 8) == NULL)\n                goto err;\n            rr->top = 8;\n            bn_mul_comba4(rr->d, a->d, b->d);\n            goto end;\n        }\n# endif\n        if (al == 8) {\n            if (bn_wexpand(rr, 16) == NULL)\n                goto err;\n            rr->top = 16;\n            bn_mul_comba8(rr->d, a->d, b->d);\n            goto end;\n        }\n    }\n#endif\n#ifdef BN_RECURSION\n    if ((al >= BN_MULL_SIZE_NORMAL) && (bl >= BN_MULL_SIZE_NORMAL)) {\n        if (i >= -1 && i <= 1) {\n            if (i >= 0) {\n                j = BN_num_bits_word((BN_ULONG)al);\n            }\n            if (i == -1) {\n                j = BN_num_bits_word((BN_ULONG)bl);\n            }\n            j = 1 << (j - 1);\n            assert(j <= al || j <= bl);\n            k = j + j;\n            t = BN_CTX_get(ctx);\n            if (t == NULL)\n                goto err;\n            if (al > j || bl > j) {\n                if (bn_wexpand(t, k * 4) == NULL)\n                    goto err;\n                if (bn_wexpand(rr, k * 4) == NULL)\n                    goto err;\n                bn_mul_part_recursive(rr->d, a->d, b->d,\n                                      j, al - j, bl - j, t->d);\n            } else {\n                if (bn_wexpand(t, k * 2) == NULL)\n                    goto err;\n                if (bn_wexpand(rr, k * 2) == NULL)\n                    goto err;\n                bn_mul_recursive(rr->d, a->d, b->d, j, al - j, bl - j, t->d);\n            }\n            rr->top = top;\n            goto end;\n        }\n# if 0\n        if (i == 1 && !BN_get_flags(b, BN_FLG_STATIC_DATA)) {\n            BIGNUM *tmp_bn = (BIGNUM *)b;\n            if (bn_wexpand(tmp_bn, al) == NULL)\n                goto err;\n            tmp_bn->d[bl] = 0;\n            bl++;\n            i--;\n        } else if (i == -1 && !BN_get_flags(a, BN_FLG_STATIC_DATA)) {\n            BIGNUM *tmp_bn = (BIGNUM *)a;\n            if (bn_wexpand(tmp_bn, bl) == NULL)\n                goto err;\n            tmp_bn->d[al] = 0;\n            al++;\n            i++;\n        }\n        if (i == 0) {\n            j = BN_num_bits_word((BN_ULONG)al);\n            j = 1 << (j - 1);\n            k = j + j;\n            t = BN_CTX_get(ctx);\n            if (al == j) {\n                if (bn_wexpand(t, k * 2) == NULL)\n                    goto err;\n                if (bn_wexpand(rr, k * 2) == NULL)\n                    goto err;\n                bn_mul_recursive(rr->d, a->d, b->d, al, t->d);\n            } else {\n                if (bn_wexpand(t, k * 4) == NULL)\n                    goto err;\n                if (bn_wexpand(rr, k * 4) == NULL)\n                    goto err;\n                bn_mul_part_recursive(rr->d, a->d, b->d, al - j, j, t->d);\n            }\n            rr->top = top;\n            goto end;\n        }\n# endif\n    }\n#endif\n    if (bn_wexpand(rr, top) == NULL)\n        goto err;\n    rr->top = top;\n    bn_mul_normal(rr->d, a->d, al, b->d, bl);\n#if defined(BN_MUL_COMBA) || defined(BN_RECURSION)\n end:\n#endif\n    rr->neg = a->neg ^ b->neg;\n    bn_correct_top(rr);\n    if (r != rr && BN_copy(r, rr) == NULL)\n        goto err;\n    ret = 1;\n err:\n    bn_check_top(r);\n    BN_CTX_end(ctx);\n    return (ret);\n}', 'void bn_mul_part_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n,\n                           int tna, int tnb, BN_ULONG *t)\n{\n    int i, j, n2 = n * 2;\n    int c1, c2, neg;\n    BN_ULONG ln, lo, *p;\n    if (n < 8) {\n        bn_mul_normal(r, a, n + tna, b, n + tnb);\n        return;\n    }\n    c1 = bn_cmp_part_words(a, &(a[n]), tna, n - tna);\n    c2 = bn_cmp_part_words(&(b[n]), b, tnb, tnb - n);\n    neg = 0;\n    switch (c1 * 3 + c2) {\n    case -4:\n        bn_sub_part_words(t, &(a[n]), a, tna, tna - n);\n        bn_sub_part_words(&(t[n]), b, &(b[n]), tnb, n - tnb);\n        break;\n    case -3:\n    case -2:\n        bn_sub_part_words(t, &(a[n]), a, tna, tna - n);\n        bn_sub_part_words(&(t[n]), &(b[n]), b, tnb, tnb - n);\n        neg = 1;\n        break;\n    case -1:\n    case 0:\n    case 1:\n    case 2:\n        bn_sub_part_words(t, a, &(a[n]), tna, n - tna);\n        bn_sub_part_words(&(t[n]), b, &(b[n]), tnb, n - tnb);\n        neg = 1;\n        break;\n    case 3:\n    case 4:\n        bn_sub_part_words(t, a, &(a[n]), tna, n - tna);\n        bn_sub_part_words(&(t[n]), &(b[n]), b, tnb, tnb - n);\n        break;\n    }\n# if 0\n    if (n == 4) {\n        bn_mul_comba4(&(t[n2]), t, &(t[n]));\n        bn_mul_comba4(r, a, b);\n        bn_mul_normal(&(r[n2]), &(a[n]), tn, &(b[n]), tn);\n        memset(&r[n2 + tn * 2], 0, sizeof(*r) * (n2 - tn * 2));\n    } else\n# endif\n    if (n == 8) {\n        bn_mul_comba8(&(t[n2]), t, &(t[n]));\n        bn_mul_comba8(r, a, b);\n        bn_mul_normal(&(r[n2]), &(a[n]), tna, &(b[n]), tnb);\n        memset(&r[n2 + tna + tnb], 0, sizeof(*r) * (n2 - tna - tnb));\n    } else {\n        p = &(t[n2 * 2]);\n        bn_mul_recursive(&(t[n2]), t, &(t[n]), n, 0, 0, p);\n        bn_mul_recursive(r, a, b, n, 0, 0, p);\n        i = n / 2;\n        if (tna > tnb)\n            j = tna - i;\n        else\n            j = tnb - i;\n        if (j == 0) {\n            bn_mul_recursive(&(r[n2]), &(a[n]), &(b[n]),\n                             i, tna - i, tnb - i, p);\n            memset(&r[n2 + i * 2], 0, sizeof(*r) * (n2 - i * 2));\n        } else if (j > 0) {\n            bn_mul_part_recursive(&(r[n2]), &(a[n]), &(b[n]),\n                                  i, tna - i, tnb - i, p);\n            memset(&(r[n2 + tna + tnb]), 0,\n                   sizeof(BN_ULONG) * (n2 - tna - tnb));\n        } else {\n            memset(&r[n2], 0, sizeof(*r) * n2);\n            if (tna < BN_MUL_RECURSIVE_SIZE_NORMAL\n                && tnb < BN_MUL_RECURSIVE_SIZE_NORMAL) {\n                bn_mul_normal(&(r[n2]), &(a[n]), tna, &(b[n]), tnb);\n            } else {\n                for (;;) {\n                    i /= 2;\n                    if (i < tna || i < tnb) {\n                        bn_mul_part_recursive(&(r[n2]),\n                                              &(a[n]), &(b[n]),\n                                              i, tna - i, tnb - i, p);\n                        break;\n                    } else if (i == tna || i == tnb) {\n                        bn_mul_recursive(&(r[n2]),\n                                         &(a[n]), &(b[n]),\n                                         i, tna - i, tnb - i, p);\n                        break;\n                    }\n                }\n            }\n        }\n    }\n    c1 = (int)(bn_add_words(t, r, &(r[n2]), n2));\n    if (neg) {\n        c1 -= (int)(bn_sub_words(&(t[n2]), t, &(t[n2]), n2));\n    } else {\n        c1 += (int)(bn_add_words(&(t[n2]), &(t[n2]), t, n2));\n    }\n    c1 += (int)(bn_add_words(&(r[n]), &(r[n]), &(t[n2]), n2));\n    if (c1) {\n        p = &(r[n + n2]);\n        lo = *p;\n        ln = (lo + c1) & BN_MASK2;\n        *p = ln;\n        if (ln < (BN_ULONG)c1) {\n            do {\n                p++;\n                lo = *p;\n                ln = (lo + 1) & BN_MASK2;\n                *p = ln;\n            } while (ln == 0);\n        }\n    }\n}', 'int bn_cmp_part_words(const BN_ULONG *a, const BN_ULONG *b, int cl, int dl)\n{\n    int n, i;\n    n = cl - 1;\n    if (dl < 0) {\n        for (i = dl; i < 0; i++) {\n            if (b[n - i] != 0)\n                return -1;\n        }\n    }\n    if (dl > 0) {\n        for (i = dl; i > 0; i--) {\n            if (a[n + i] != 0)\n                return 1;\n        }\n    }\n    return bn_cmp_words(a, b, cl);\n}', 'int bn_cmp_words(const BN_ULONG *a, const BN_ULONG *b, int n)\n{\n    int i;\n    BN_ULONG aa, bb;\n    aa = a[n - 1];\n    bb = b[n - 1];\n    if (aa != bb)\n        return ((aa > bb) ? 1 : -1);\n    for (i = n - 2; i >= 0; i--) {\n        aa = a[i];\n        bb = b[i];\n        if (aa != bb)\n            return ((aa > bb) ? 1 : -1);\n    }\n    return (0);\n}']