/* Copyright (C) 2013 Mike Hansen This file is part of FLINT. FLINT is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License (LGPL) as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. See . */ #ifdef T #include "templates.h" void _TEMPLATE(T, poly_powmod_fmpz_sliding_preinv) ( TEMPLATE(T, struct) * res, const TEMPLATE(T, struct) * poly, const fmpz_t e, ulong k, const TEMPLATE(T, struct) * f, slong lenf, const TEMPLATE(T, struct) * finv, slong lenfinv, const TEMPLATE(T, ctx_t) ctx) { TEMPLATE(T, struct) * T, *Q; TEMPLATE(T, poly_struct) * precomp; TEMPLATE(T, poly_t) poly_squared; ulong twokm1; slong lenT, lenQ; slong i, l, j; int index; if (lenf == 2) { TEMPLATE(T, pow) (res, poly, e, ctx); return; } lenT = 2 * lenf - 3; lenQ = lenT - lenf + 1; T = _TEMPLATE(T, vec_init) (lenT + lenQ, ctx); Q = T + lenT; /* Precomputation */ twokm1 = n_pow(2, k - 1); precomp = flint_malloc(twokm1 * sizeof(TEMPLATE(T, poly_struct))); TEMPLATE(T, poly_init) (precomp, ctx); TEMPLATE(T, poly_fit_length) (precomp, lenf - 1, ctx); _TEMPLATE(T, vec_set) (precomp->coeffs, poly, lenf - 1, ctx); TEMPLATE(T, poly_init) (poly_squared, ctx); if (k > 1) { TEMPLATE(T, poly_fit_length) (poly_squared, lenf - 1, ctx); _TEMPLATE(T, poly_mul) (T, poly, lenf - 1, poly, lenf - 1, ctx); _TEMPLATE(T, poly_divrem_newton_n_preinv) (Q, poly_squared->coeffs, T, 2 * lenf - 3, f, lenf, finv, lenfinv, ctx); } for (i = 1; i < twokm1; i++) { TEMPLATE(T, poly_init) (precomp + i, ctx); TEMPLATE(T, poly_fit_length) (precomp + i, lenf - 1, ctx); _TEMPLATE(T, poly_mul) (T, (precomp + i - 1)->coeffs, lenf - 1, poly_squared->coeffs, lenf - 1, ctx); _TEMPLATE(T, poly_divrem_newton_n_preinv) (Q, (precomp + i)->coeffs, T, 2 * lenf - 3, f, lenf, finv, lenfinv, ctx); } _TEMPLATE(T, vec_set) (res, poly, lenf - 1, ctx); i = fmpz_sizeinbase(e, 2) - 2; while (i >= 0) { if (fmpz_tstbit(e, i) == 0) { _TEMPLATE(T, poly_sqr) (T, res, lenf - 1, ctx); _TEMPLATE(T, poly_divrem_newton_n_preinv) (Q, res, T, 2 * lenf - 3, f, lenf, finv, lenfinv, ctx); i -= 1; } else { l = FLINT_MAX(i - k + 1, 0); while (fmpz_tstbit(e, l) == 0) { l += 1; } for (j = 0; j < i - l + 1; j++) { _TEMPLATE(T, poly_sqr) (T, res, lenf - 1, ctx); _TEMPLATE(T, poly_divrem_newton_n_preinv) (Q, res, T, 2 * lenf - 3, f, lenf, finv, lenfinv, ctx); } index = fmpz_tstbit(e, i); for (j = i - 1; j >= l; j--) { index = index << 1; index += fmpz_tstbit(e, j); } index = (index - 1) / 2; _TEMPLATE(T, poly_mul) (T, res, lenf - 1, (precomp + index)->coeffs, lenf - 1, ctx); _TEMPLATE(T, poly_divrem_newton_n_preinv) (Q, res, T, 2 * lenf - 3, f, lenf, finv, lenfinv, ctx); i = l - 1; } } for (j = 0; j < twokm1; j++) { TEMPLATE(T, poly_clear) (precomp + j, ctx); } flint_free(precomp); TEMPLATE(T, poly_clear) (poly_squared, ctx); _TEMPLATE(T, vec_clear) (T, lenT + lenQ, ctx); } void TEMPLATE(T, poly_powmod_fmpz_sliding_preinv) (TEMPLATE(T, poly_t) res, const TEMPLATE(T, poly_t) poly, const fmpz_t e, ulong k, const TEMPLATE(T, poly_t) f, const TEMPLATE(T, poly_t) finv, const TEMPLATE(T, ctx_t) ctx) { TEMPLATE(T, struct) * q; slong len = poly->length; slong lenf = f->length; slong trunc = lenf - 1; int qcopy = 0; flint_bitcnt_t bits; if (lenf == 0) { TEMPLATE_PRINTF("Exception: %s_poly_powmod_fmpz_sliding_preinv", T); flint_printf(": divide by zero\n"); flint_abort(); } if (fmpz_sgn(e) < 0) { TEMPLATE_PRINTF("Exception: %s_poly_powmod_fmpz_sliding_preinv:", T); flint_printf(" negative exp not implemented\n"); flint_abort(); } if (len >= lenf) { TEMPLATE(T, poly_t) t, r; TEMPLATE(T, poly_init) (t, ctx); TEMPLATE(T, poly_init) (r, ctx); TEMPLATE(T, poly_divrem) (t, r, poly, f, ctx); TEMPLATE(T, poly_powmod_fmpz_sliding_preinv) (res, r, e, k, f, finv, ctx); TEMPLATE(T, poly_clear) (t, ctx); TEMPLATE(T, poly_clear) (r, ctx); return; } if (fmpz_abs_fits_ui(e)) { ulong exp = fmpz_get_ui(e); if (exp <= 2) { if (exp == UWORD(0)) { TEMPLATE(T, poly_fit_length) (res, 1, ctx); TEMPLATE(T, one) (res->coeffs, ctx); _TEMPLATE(T, poly_set_length) (res, 1, ctx); } else if (exp == UWORD(1)) { TEMPLATE(T, poly_set) (res, poly, ctx); } else TEMPLATE(T, poly_mulmod_preinv) (res, poly, poly, f, finv, ctx); return; } } if (lenf == 1 || len == 0) { TEMPLATE(T, poly_zero) (res, ctx); return; } if (poly->length < trunc) { q = _TEMPLATE(T, vec_init) (trunc, ctx); _TEMPLATE(T, vec_set) (q, poly->coeffs, len, ctx); _TEMPLATE(T, vec_zero) (q + len, trunc - len, ctx); qcopy = 1; } else { q = poly->coeffs; } /* Determine "optimum" sliding window size */ if (k == 0) { bits = fmpz_bits(e); if (bits < 9) k = 1; else if (bits < 15) k = 2; else if (bits < 62) k = 3; else if (bits < 203) k = 4; else if (bits < 587) k = 5; else if (bits < 1560) k = 6; else k = 7; } if ((res == poly && !qcopy) || (res == f)) { TEMPLATE(T, poly_t) t; TEMPLATE(T, poly_init2) (t, 2 * lenf - 3, ctx); _TEMPLATE(T, poly_powmod_fmpz_sliding_preinv) (t->coeffs, q, e, k, f->coeffs, lenf, finv->coeffs, finv->length, ctx); TEMPLATE(T, poly_swap) (res, t, ctx); TEMPLATE(T, poly_clear) (t, ctx); } else { TEMPLATE(T, poly_fit_length) (res, 2 * lenf - 3, ctx); _TEMPLATE(T, poly_powmod_fmpz_sliding_preinv) (res->coeffs, q, e, k, f->coeffs, lenf, finv->coeffs, finv->length, ctx); } if (qcopy) _TEMPLATE(T, vec_clear) (q, trunc, ctx); _TEMPLATE(T, poly_set_length) (res, trunc, ctx); _TEMPLATE(T, poly_normalise) (res, ctx); } #endif