void fmpr_divappr_abs_ubound(fmpr_t z, const fmpr_t x, const fmpr_t y, slong prec) { if (fmpr_is_special(x) || fmpr_is_special(y) || fmpz_is_pm1(fmpr_manref(y))) { fmpr_div(z, x, y, prec, FMPR_RND_UP); fmpr_abs(z, z); } else { fmpz_t t, u; slong xbits, ybits, tbits, ubits, shift; xbits = fmpz_bits(fmpr_manref(x)); ybits = fmpz_bits(fmpr_manref(y)); fmpz_init(t); fmpz_init(u); ubits = FLINT_MIN(ybits, prec); tbits = prec + ubits + 1; /* upper bound for |x|, shifted */ if (xbits <= tbits) { fmpz_mul_2exp(t, fmpr_manref(x), tbits - xbits); fmpz_abs(t, t); } else if (fmpz_sgn(fmpr_manref(x)) > 0) { fmpz_cdiv_q_2exp(t, fmpr_manref(x), xbits - tbits); } else { fmpz_fdiv_q_2exp(t, fmpr_manref(x), xbits - tbits); fmpz_neg(t, t); } /* lower bound for |y|, shifted */ if (ybits <= ubits) fmpz_mul_2exp(u, fmpr_manref(y), ubits - ybits); else fmpz_tdiv_q_2exp(u, fmpr_manref(y), ybits - ubits); fmpz_abs(u, u); fmpz_cdiv_q(fmpr_manref(z), t, u); shift = (ubits - ybits) - (tbits - xbits); fmpz_sub(fmpr_expref(z), fmpr_expref(x), fmpr_expref(y)); if (shift >= 0) fmpz_add_ui(fmpr_expref(z), fmpr_expref(z), shift); else fmpz_sub_ui(fmpr_expref(z), fmpr_expref(z), -shift); _fmpr_normalise(fmpr_manref(z), fmpr_expref(z), prec, FMPR_RND_UP); fmpz_clear(t); fmpz_clear(u); } }
/* quotient of absolute value, rounded up */ static __inline__ void fmpz_cdiv_abs_q(fmpz_t q, const fmpz_t x, const fmpz_t y) { if (fmpz_sgn(x) == fmpz_sgn(y)) { fmpz_cdiv_q(q, x, y); } else { fmpz_fdiv_q(q, x, y); fmpz_neg(q, q); } }
int main(void) { int i, result; FLINT_TEST_INIT(state); flint_printf("cdiv_q...."); fflush(stdout); for (i = 0; i < 10000 * flint_test_multiplier(); i++) { fmpz_t a, b, c; mpz_t d, e, f, g; fmpz_init(a); fmpz_init(b); fmpz_init(c); mpz_init(d); mpz_init(e); mpz_init(f); mpz_init(g); fmpz_randtest(a, state, 200); fmpz_randtest_not_zero(b, state, 200); fmpz_get_mpz(d, a); fmpz_get_mpz(e, b); fmpz_cdiv_q(c, a, b); mpz_cdiv_q(f, d, e); fmpz_get_mpz(g, c); result = (mpz_cmp(f, g) == 0); if (!result) { flint_printf("FAIL\n"); gmp_printf("d = %Zd, e = %Zd, f = %Zd, g = %Zd\n", d, e, f, g); abort(); } fmpz_clear(a); fmpz_clear(b); fmpz_clear(c); mpz_clear(d); mpz_clear(e); mpz_clear(f); mpz_clear(g); } /* Check aliasing of a and b */ for (i = 0; i < 10000 * flint_test_multiplier(); i++) { fmpz_t a, c; mpz_t d, f, g; fmpz_init(a); fmpz_init(c); mpz_init(d); mpz_init(f); mpz_init(g); fmpz_randtest_not_zero(a, state, 200); fmpz_get_mpz(d, a); fmpz_cdiv_q(c, a, a); mpz_cdiv_q(f, d, d); fmpz_get_mpz(g, c); result = (mpz_cmp(f, g) == 0); if (!result) { flint_printf("FAIL\n"); gmp_printf("d = %Zd, f = %Zd, g = %Zd\n", d, f, g); abort(); } fmpz_clear(a); fmpz_clear(c); mpz_clear(d); mpz_clear(f); mpz_clear(g); } /* Test aliasing of a and c */ for (i = 0; i < 10000 * flint_test_multiplier(); i++) { fmpz_t a, b; mpz_t d, e, f, g; fmpz_init(a); fmpz_init(b); mpz_init(d); mpz_init(e); mpz_init(f); mpz_init(g); fmpz_randtest(a, state, 200); fmpz_randtest_not_zero(b, state, 200); fmpz_get_mpz(d, a); fmpz_get_mpz(e, b); fmpz_cdiv_q(a, a, b); mpz_cdiv_q(f, d, e); fmpz_get_mpz(g, a); result = (mpz_cmp(f, g) == 0); if (!result) { flint_printf("FAIL\n"); gmp_printf("d = %Zd, e = %Zd, f = %Zd, g = %Zd\n", d, e, f, g); abort(); } fmpz_clear(a); fmpz_clear(b); mpz_clear(d); mpz_clear(e); mpz_clear(f); mpz_clear(g); } /* Test aliasing of b and c */ for (i = 0; i < 10000 * flint_test_multiplier(); i++) { fmpz_t a, b; mpz_t d, e, f, g; fmpz_init(a); fmpz_init(b); mpz_init(d); mpz_init(e); mpz_init(f); mpz_init(g); fmpz_randtest(a, state, 200); fmpz_randtest_not_zero(b, state, 200); fmpz_get_mpz(d, a); fmpz_get_mpz(e, b); fmpz_cdiv_q(b, a, b); mpz_cdiv_q(f, d, e); fmpz_get_mpz(g, b); result = (mpz_cmp(f, g) == 0); if (!result) { flint_printf("FAIL\n"); gmp_printf("d = %Zd, e = %Zd, f = %Zd, g = %Zd\n", d, e, f, g); abort(); } fmpz_clear(a); fmpz_clear(b); mpz_clear(d); mpz_clear(e); mpz_clear(f); mpz_clear(g); } FLINT_TEST_CLEANUP(state); flint_printf("PASS\n"); return 0; }