1 /* mpz_ior -- Logical inclusive or. 2 3 Copyright 1991, 1993, 1994, 1996, 1997, 2000, 2001, 2005, 2012, 2013 Free 4 Software Foundation, Inc. 5 6 This file is part of the GNU MP Library. 7 8 The GNU MP Library is free software; you can redistribute it and/or modify 9 it under the terms of the GNU Lesser General Public License as published by 10 the Free Software Foundation; either version 3 of the License, or (at your 11 option) any later version. 12 13 The GNU MP Library is distributed in the hope that it will be useful, but 14 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 15 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 16 License for more details. 17 18 You should have received a copy of the GNU Lesser General Public License 19 along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. */ 20 21 #include "gmp.h" 22 #include "gmp-impl.h" 23 24 void 25 mpz_ior (mpz_ptr res, mpz_srcptr op1, mpz_srcptr op2) 26 { 27 mp_srcptr op1_ptr, op2_ptr; 28 mp_size_t op1_size, op2_size; 29 mp_ptr res_ptr; 30 mp_size_t res_size; 31 mp_size_t i; 32 TMP_DECL; 33 34 TMP_MARK; 35 op1_size = SIZ(op1); 36 op2_size = SIZ(op2); 37 38 op1_ptr = PTR(op1); 39 op2_ptr = PTR(op2); 40 res_ptr = PTR(res); 41 42 if (op1_size >= 0) 43 { 44 if (op2_size >= 0) 45 { 46 if (op1_size >= op2_size) 47 { 48 if (ALLOC(res) < op1_size) 49 { 50 _mpz_realloc (res, op1_size); 51 /* No overlapping possible: op1_ptr = PTR(op1); */ 52 op2_ptr = PTR(op2); 53 res_ptr = PTR(res); 54 } 55 56 if (res_ptr != op1_ptr) 57 MPN_COPY (res_ptr + op2_size, op1_ptr + op2_size, 58 op1_size - op2_size); 59 if (LIKELY (op2_size != 0)) 60 mpn_ior_n (res_ptr, op1_ptr, op2_ptr, op2_size); 61 res_size = op1_size; 62 } 63 else 64 { 65 if (ALLOC(res) < op2_size) 66 { 67 _mpz_realloc (res, op2_size); 68 op1_ptr = PTR(op1); 69 /* No overlapping possible: op2_ptr = PTR(op2); */ 70 res_ptr = PTR(res); 71 } 72 73 if (res_ptr != op2_ptr) 74 MPN_COPY (res_ptr + op1_size, op2_ptr + op1_size, 75 op2_size - op1_size); 76 if (LIKELY (op1_size != 0)) 77 mpn_ior_n (res_ptr, op1_ptr, op2_ptr, op1_size); 78 res_size = op2_size; 79 } 80 81 SIZ(res) = res_size; 82 return; 83 } 84 else /* op2_size < 0 */ 85 { 86 /* Fall through to the code at the end of the function. */ 87 } 88 } 89 else 90 { 91 if (op2_size < 0) 92 { 93 mp_ptr opx, opy; 94 mp_limb_t cy; 95 96 /* Both operands are negative, so will be the result. 97 -((-OP1) | (-OP2)) = -(~(OP1 - 1) | ~(OP2 - 1)) = 98 = ~(~(OP1 - 1) | ~(OP2 - 1)) + 1 = 99 = ((OP1 - 1) & (OP2 - 1)) + 1 */ 100 101 op1_size = -op1_size; 102 op2_size = -op2_size; 103 104 res_size = MIN (op1_size, op2_size); 105 106 /* Possible optimization: Decrease mpn_sub precision, 107 as we won't use the entire res of both. */ 108 TMP_ALLOC_LIMBS_2 (opx, res_size, opy, res_size); 109 mpn_sub_1 (opx, op1_ptr, res_size, (mp_limb_t) 1); 110 op1_ptr = opx; 111 112 mpn_sub_1 (opy, op2_ptr, res_size, (mp_limb_t) 1); 113 op2_ptr = opy; 114 115 /* First loop finds the size of the result. */ 116 for (i = res_size - 1; i >= 0; i--) 117 if ((op1_ptr[i] & op2_ptr[i]) != 0) 118 break; 119 res_size = i + 1; 120 121 if (res_size != 0) 122 { 123 res_ptr = MPZ_REALLOC (res, res_size + 1); 124 125 /* Second loop computes the real result. */ 126 mpn_and_n (res_ptr, op1_ptr, op2_ptr, res_size); 127 128 cy = mpn_add_1 (res_ptr, res_ptr, res_size, (mp_limb_t) 1); 129 if (cy) 130 { 131 res_ptr[res_size] = cy; 132 res_size++; 133 } 134 } 135 else 136 { 137 res_ptr[0] = 1; 138 res_size = 1; 139 } 140 141 SIZ(res) = -res_size; 142 TMP_FREE; 143 return; 144 } 145 else 146 { 147 /* We should compute -OP1 | OP2. Swap OP1 and OP2 and fall 148 through to the code that handles OP1 | -OP2. */ 149 MPZ_SRCPTR_SWAP (op1, op2); 150 MPN_SRCPTR_SWAP (op1_ptr,op1_size, op2_ptr,op2_size); 151 } 152 } 153 154 { 155 mp_ptr opx; 156 mp_limb_t cy; 157 mp_size_t res_alloc; 158 mp_size_t count; 159 160 /* Operand 2 negative, so will be the result. 161 -(OP1 | (-OP2)) = -(OP1 | ~(OP2 - 1)) = 162 = ~(OP1 | ~(OP2 - 1)) + 1 = 163 = (~OP1 & (OP2 - 1)) + 1 */ 164 165 op2_size = -op2_size; 166 167 res_alloc = op2_size; 168 169 opx = TMP_ALLOC_LIMBS (op2_size); 170 mpn_sub_1 (opx, op2_ptr, op2_size, (mp_limb_t) 1); 171 op2_ptr = opx; 172 op2_size -= op2_ptr[op2_size - 1] == 0; 173 174 if (ALLOC(res) < res_alloc) 175 { 176 _mpz_realloc (res, res_alloc); 177 op1_ptr = PTR(op1); 178 /* op2_ptr points to temporary space. */ 179 res_ptr = PTR(res); 180 } 181 182 if (op1_size >= op2_size) 183 { 184 /* We can just ignore the part of OP1 that stretches above OP2, 185 because the result limbs are zero there. */ 186 187 /* First loop finds the size of the result. */ 188 for (i = op2_size - 1; i >= 0; i--) 189 if ((~op1_ptr[i] & op2_ptr[i]) != 0) 190 break; 191 res_size = i + 1; 192 count = res_size; 193 } 194 else 195 { 196 res_size = op2_size; 197 198 /* Copy the part of OP2 that stretches above OP1, to RES. */ 199 MPN_COPY (res_ptr + op1_size, op2_ptr + op1_size, op2_size - op1_size); 200 count = op1_size; 201 } 202 203 if (res_size != 0) 204 { 205 /* Second loop computes the real result. */ 206 if (LIKELY (count != 0)) 207 mpn_andn_n (res_ptr, op2_ptr, op1_ptr, count); 208 209 cy = mpn_add_1 (res_ptr, res_ptr, res_size, (mp_limb_t) 1); 210 if (cy) 211 { 212 res_ptr[res_size] = cy; 213 res_size++; 214 } 215 } 216 else 217 { 218 res_ptr[0] = 1; 219 res_size = 1; 220 } 221 222 SIZ(res) = -res_size; 223 } 224 TMP_FREE; 225 } 226