int m_apm_is_even_mt(M_APM m) { int i; m_apm_enter(); i=m_apm_is_even(m); m_apm_leave(); return(i); }
static int Biseven(lua_State *L) /** iseven(x) */ { M_APM a=Bget(L,1); lua_pushboolean(L,m_apm_is_integer(a) && m_apm_is_even(a)); return 1; }
int MAPM::is_even(void) const { return m_apm_is_even(cval()); }
/* * From Knuth, The Art of Computer Programming: * * This is the binary GCD algorithm as described * in the book (Algorithm B) */ void m_apm_gcd(M_APM r, M_APM u, M_APM v) { M_APM tmpM, tmpN, tmpT, tmpU, tmpV; int kk, kr, mm; long pow_2; /* 'is_integer' will return 0 || 1 */ if ((m_apm_is_integer(u) + m_apm_is_integer(v)) != 2) { M_apm_log_error_msg(M_APM_RETURN, "Warning! \'m_apm_gcd\', Non-integer input"); M_set_to_zero(r); return; } if (u->m_apm_sign == 0) { m_apm_absolute_value(r, v); return; } if (v->m_apm_sign == 0) { m_apm_absolute_value(r, u); return; } tmpM = M_get_stack_var(); tmpN = M_get_stack_var(); tmpT = M_get_stack_var(); tmpU = M_get_stack_var(); tmpV = M_get_stack_var(); m_apm_absolute_value(tmpU, u); m_apm_absolute_value(tmpV, v); /* Step B1 */ kk = 0; while (TRUE) { mm = 1; if (m_apm_is_odd(tmpU)) break; mm = 0; if (m_apm_is_odd(tmpV)) break; m_apm_multiply(tmpN, MM_0_5, tmpU); m_apm_copy(tmpU, tmpN); m_apm_multiply(tmpN, MM_0_5, tmpV); m_apm_copy(tmpV, tmpN); kk++; } /* Step B2 */ if (mm) { m_apm_negate(tmpT, tmpV); goto B4; } m_apm_copy(tmpT, tmpU); /* Step: */ B3: m_apm_multiply(tmpN, MM_0_5, tmpT); m_apm_copy(tmpT, tmpN); /* Step: */ B4: if (m_apm_is_even(tmpT)) goto B3; /* Step B5 */ if (tmpT->m_apm_sign == 1) m_apm_copy(tmpU, tmpT); else m_apm_negate(tmpV, tmpT); /* Step B6 */ m_apm_subtract(tmpT, tmpU, tmpV); if (tmpT->m_apm_sign != 0) goto B3; /* * result = U * 2 ^ kk */ if (kk == 0) m_apm_copy(r, tmpU); else { if (kk == 1) m_apm_multiply(r, tmpU, MM_Two); if (kk == 2) m_apm_multiply(r, tmpU, MM_Four); if (kk >= 3) { mm = kk / 28; kr = kk % 28; pow_2 = 1L << kr; if (mm == 0) { m_apm_set_long(tmpN, pow_2); m_apm_multiply(r, tmpU, tmpN); } else { m_apm_copy(tmpN, MM_One); m_apm_set_long(tmpM, 0x10000000L); /* 2 ^ 28 */ while (TRUE) { m_apm_multiply(tmpT, tmpN, tmpM); m_apm_copy(tmpN, tmpT); if (--mm == 0) break; } if (kr == 0) { m_apm_multiply(r, tmpU, tmpN); } else { m_apm_set_long(tmpM, pow_2); m_apm_multiply(tmpT, tmpN, tmpM); m_apm_multiply(r, tmpU, tmpT); } } } } M_restore_stack(5); }