github.com/aergoio/aergo@v1.3.1/libtool/src/gmp-6.1.2/mpz/aors.h (about) 1 /* mpz_add, mpz_sub -- add or subtract integers. 2 3 Copyright 1991, 1993, 1994, 1996, 2000, 2001, 2011, 2012 Free Software 4 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 either: 10 11 * the GNU Lesser General Public License as published by the Free 12 Software Foundation; either version 3 of the License, or (at your 13 option) any later version. 14 15 or 16 17 * the GNU General Public License as published by the Free Software 18 Foundation; either version 2 of the License, or (at your option) any 19 later version. 20 21 or both in parallel, as here. 22 23 The GNU MP Library is distributed in the hope that it will be useful, but 24 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 25 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 26 for more details. 27 28 You should have received copies of the GNU General Public License and the 29 GNU Lesser General Public License along with the GNU MP Library. If not, 30 see https://www.gnu.org/licenses/. */ 31 32 #include "gmp.h" 33 #include "gmp-impl.h" 34 35 36 #ifdef OPERATION_add 37 #define FUNCTION mpz_add 38 #define VARIATION 39 #endif 40 #ifdef OPERATION_sub 41 #define FUNCTION mpz_sub 42 #define VARIATION - 43 #endif 44 45 #ifndef FUNCTION 46 Error, need OPERATION_add or OPERATION_sub 47 #endif 48 49 50 void 51 FUNCTION (mpz_ptr w, mpz_srcptr u, mpz_srcptr v) 52 { 53 mp_srcptr up, vp; 54 mp_ptr wp; 55 mp_size_t usize, vsize, wsize; 56 mp_size_t abs_usize; 57 mp_size_t abs_vsize; 58 59 usize = SIZ(u); 60 vsize = VARIATION SIZ(v); 61 abs_usize = ABS (usize); 62 abs_vsize = ABS (vsize); 63 64 if (abs_usize < abs_vsize) 65 { 66 /* Swap U and V. */ 67 MPZ_SRCPTR_SWAP (u, v); 68 MP_SIZE_T_SWAP (usize, vsize); 69 MP_SIZE_T_SWAP (abs_usize, abs_vsize); 70 } 71 72 /* True: ABS_USIZE >= ABS_VSIZE. */ 73 74 /* If not space for w (and possible carry), increase space. */ 75 wsize = abs_usize + 1; 76 wp = MPZ_REALLOC (w, wsize); 77 78 /* These must be after realloc (u or v may be the same as w). */ 79 up = PTR(u); 80 vp = PTR(v); 81 82 if ((usize ^ vsize) < 0) 83 { 84 /* U and V have different sign. Need to compare them to determine 85 which operand to subtract from which. */ 86 87 /* This test is right since ABS_USIZE >= ABS_VSIZE. */ 88 if (abs_usize != abs_vsize) 89 { 90 mpn_sub (wp, up, abs_usize, vp, abs_vsize); 91 wsize = abs_usize; 92 MPN_NORMALIZE (wp, wsize); 93 if (usize < 0) 94 wsize = -wsize; 95 } 96 else if (mpn_cmp (up, vp, abs_usize) < 0) 97 { 98 mpn_sub_n (wp, vp, up, abs_usize); 99 wsize = abs_usize; 100 MPN_NORMALIZE (wp, wsize); 101 if (usize >= 0) 102 wsize = -wsize; 103 } 104 else 105 { 106 mpn_sub_n (wp, up, vp, abs_usize); 107 wsize = abs_usize; 108 MPN_NORMALIZE (wp, wsize); 109 if (usize < 0) 110 wsize = -wsize; 111 } 112 } 113 else 114 { 115 /* U and V have same sign. Add them. */ 116 mp_limb_t cy_limb = mpn_add (wp, up, abs_usize, vp, abs_vsize); 117 wp[abs_usize] = cy_limb; 118 wsize = abs_usize + cy_limb; 119 if (usize < 0) 120 wsize = -wsize; 121 } 122 123 SIZ(w) = wsize; 124 }