1 /* Reference mpz functions. 2 3 Copyright 1997, 1999, 2000, 2001, 2002 Free Software Foundation, Inc. 4 5 This file is part of the GNU MP Library. 6 7 The GNU MP Library is free software; you can redistribute it and/or modify 8 it under the terms of the GNU Lesser General Public License as published by 9 the Free Software Foundation; either version 3 of the License, or (at your 10 option) any later version. 11 12 The GNU MP Library is distributed in the hope that it will be useful, but 13 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 14 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 15 License for more details. 16 17 You should have received a copy of the GNU Lesser General Public License 18 along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. */ 19 20 /* always do assertion checking */ 21 #define WANT_ASSERT 1 22 23 #include <stdio.h> 24 #include <stdlib.h> /* for free */ 25 #include "gmp.h" 26 #include "gmp-impl.h" 27 #include "longlong.h" 28 #include "tests.h" 29 30 31 /* Change this to "#define TRACE(x) x" for some traces. */ 32 #define TRACE(x) 33 34 35 /* FIXME: Shouldn't use plain mpz functions in a reference routine. */ 36 void 37 refmpz_combit (mpz_ptr r, unsigned long bit) 38 { 39 if (mpz_tstbit (r, bit)) 40 mpz_clrbit (r, bit); 41 else 42 mpz_setbit (r, bit); 43 } 44 45 46 unsigned long 47 refmpz_hamdist (mpz_srcptr x, mpz_srcptr y) 48 { 49 mp_size_t xsize, ysize, tsize; 50 mp_ptr xp, yp; 51 unsigned long ret; 52 53 if ((SIZ(x) < 0 && SIZ(y) >= 0) 54 || (SIZ(y) < 0 && SIZ(x) >= 0)) 55 return ULONG_MAX; 56 57 xsize = ABSIZ(x); 58 ysize = ABSIZ(y); 59 tsize = MAX (xsize, ysize); 60 61 xp = refmpn_malloc_limbs (tsize); 62 refmpn_zero (xp, tsize); 63 refmpn_copy (xp, PTR(x), xsize); 64 65 yp = refmpn_malloc_limbs (tsize); 66 refmpn_zero (yp, tsize); 67 refmpn_copy (yp, PTR(y), ysize); 68 69 if (SIZ(x) < 0) 70 refmpn_neg (xp, xp, tsize); 71 72 if (SIZ(x) < 0) 73 refmpn_neg (yp, yp, tsize); 74 75 ret = refmpn_hamdist (xp, yp, tsize); 76 77 free (xp); 78 free (yp); 79 return ret; 80 } 81 82 83 /* (0/b), with mpz b; is 1 if b=+/-1, 0 otherwise */ 84 #define JACOBI_0Z(b) JACOBI_0LS (PTR(b)[0], SIZ(b)) 85 86 /* (a/b) effect due to sign of b: mpz/mpz */ 87 #define JACOBI_BSGN_ZZ_BIT1(a, b) JACOBI_BSGN_SS_BIT1 (SIZ(a), SIZ(b)) 88 89 /* (a/b) effect due to sign of a: mpz/unsigned-mpz, b odd; 90 is (-1/b) if a<0, or +1 if a>=0 */ 91 #define JACOBI_ASGN_ZZU_BIT1(a, b) JACOBI_ASGN_SU_BIT1 (SIZ(a), PTR(b)[0]) 92 93 int 94 refmpz_kronecker (mpz_srcptr a_orig, mpz_srcptr b_orig) 95 { 96 unsigned long twos; 97 mpz_t a, b; 98 int result_bit1 = 0; 99 100 if (mpz_sgn (b_orig) == 0) 101 return JACOBI_Z0 (a_orig); /* (a/0) */ 102 103 if (mpz_sgn (a_orig) == 0) 104 return JACOBI_0Z (b_orig); /* (0/b) */ 105 106 if (mpz_even_p (a_orig) && mpz_even_p (b_orig)) 107 return 0; 108 109 if (mpz_cmp_ui (b_orig, 1) == 0) 110 return 1; 111 112 mpz_init_set (a, a_orig); 113 mpz_init_set (b, b_orig); 114 115 if (mpz_sgn (b) < 0) 116 { 117 result_bit1 ^= JACOBI_BSGN_ZZ_BIT1 (a, b); 118 mpz_neg (b, b); 119 } 120 if (mpz_even_p (b)) 121 { 122 twos = mpz_scan1 (b, 0L); 123 mpz_tdiv_q_2exp (b, b, twos); 124 result_bit1 ^= JACOBI_TWOS_U_BIT1 (twos, PTR(a)[0]); 125 } 126 127 if (mpz_sgn (a) < 0) 128 { 129 result_bit1 ^= JACOBI_N1B_BIT1 (PTR(b)[0]); 130 mpz_neg (a, a); 131 } 132 if (mpz_even_p (a)) 133 { 134 twos = mpz_scan1 (a, 0L); 135 mpz_tdiv_q_2exp (a, a, twos); 136 result_bit1 ^= JACOBI_TWOS_U_BIT1 (twos, PTR(b)[0]); 137 } 138 139 for (;;) 140 { 141 ASSERT (mpz_odd_p (a)); 142 ASSERT (mpz_odd_p (b)); 143 ASSERT (mpz_sgn (a) > 0); 144 ASSERT (mpz_sgn (b) > 0); 145 146 TRACE (printf ("top\n"); 147 mpz_trace (" a", a); 148 mpz_trace (" b", b)); 149 150 if (mpz_cmp (a, b) < 0) 151 { 152 TRACE (printf ("swap\n")); 153 mpz_swap (a, b); 154 result_bit1 ^= JACOBI_RECIP_UU_BIT1 (PTR(a)[0], PTR(b)[0]); 155 } 156 157 if (mpz_cmp_ui (b, 1) == 0) 158 break; 159 160 mpz_sub (a, a, b); 161 TRACE (printf ("sub\n"); 162 mpz_trace (" a", a)); 163 if (mpz_sgn (a) == 0) 164 goto zero; 165 166 twos = mpz_scan1 (a, 0L); 167 mpz_fdiv_q_2exp (a, a, twos); 168 TRACE (printf ("twos %lu\n", twos); 169 mpz_trace (" a", a)); 170 result_bit1 ^= JACOBI_TWOS_U_BIT1 (twos, PTR(b)[0]); 171 } 172 173 mpz_clear (a); 174 mpz_clear (b); 175 return JACOBI_BIT1_TO_PN (result_bit1); 176 177 zero: 178 mpz_clear (a); 179 mpz_clear (b); 180 return 0; 181 } 182 183 /* Same as mpz_kronecker, but ignoring factors of 2 on b */ 184 int 185 refmpz_jacobi (mpz_srcptr a, mpz_srcptr b) 186 { 187 mpz_t b_odd; 188 mpz_init_set (b_odd, b); 189 if (mpz_sgn (b_odd) != 0) 190 mpz_fdiv_q_2exp (b_odd, b_odd, mpz_scan1 (b_odd, 0L)); 191 return refmpz_kronecker (a, b_odd); 192 } 193 194 int 195 refmpz_legendre (mpz_srcptr a, mpz_srcptr b) 196 { 197 return refmpz_jacobi (a, b); 198 } 199 200 201 int 202 refmpz_kronecker_ui (mpz_srcptr a, unsigned long b) 203 { 204 mpz_t bz; 205 int ret; 206 mpz_init_set_ui (bz, b); 207 ret = refmpz_kronecker (a, bz); 208 mpz_clear (bz); 209 return ret; 210 } 211 212 int 213 refmpz_kronecker_si (mpz_srcptr a, long b) 214 { 215 mpz_t bz; 216 int ret; 217 mpz_init_set_si (bz, b); 218 ret = refmpz_kronecker (a, bz); 219 mpz_clear (bz); 220 return ret; 221 } 222 223 int 224 refmpz_ui_kronecker (unsigned long a, mpz_srcptr b) 225 { 226 mpz_t az; 227 int ret; 228 mpz_init_set_ui (az, a); 229 ret = refmpz_kronecker (az, b); 230 mpz_clear (az); 231 return ret; 232 } 233 234 int 235 refmpz_si_kronecker (long a, mpz_srcptr b) 236 { 237 mpz_t az; 238 int ret; 239 mpz_init_set_si (az, a); 240 ret = refmpz_kronecker (az, b); 241 mpz_clear (az); 242 return ret; 243 } 244 245 246 void 247 refmpz_pow_ui (mpz_ptr w, mpz_srcptr b, unsigned long e) 248 { 249 mpz_t s, t; 250 unsigned long i; 251 252 mpz_init_set_ui (t, 1L); 253 mpz_init_set (s, b); 254 255 if ((e & 1) != 0) 256 mpz_mul (t, t, s); 257 258 for (i = 2; i <= e; i <<= 1) 259 { 260 mpz_mul (s, s, s); 261 if ((i & e) != 0) 262 mpz_mul (t, t, s); 263 } 264 265 mpz_set (w, t); 266 267 mpz_clear (s); 268 mpz_clear (t); 269 } 270