1 /* mpz_mul_ui/si (product, multiplier, small_multiplicand) -- Set PRODUCT to 2 MULTIPLICATOR times SMALL_MULTIPLICAND. 3 4 Copyright 1991, 1993, 1994, 1996, 2000-2002, 2005, 2008, 2012 Free Software 5 Foundation, Inc. 6 7 This file is part of the GNU MP Library. 8 9 The GNU MP Library is free software; you can redistribute it and/or modify 10 it under the terms of either: 11 12 * the GNU Lesser General Public License as published by the Free 13 Software Foundation; either version 3 of the License, or (at your 14 option) any later version. 15 16 or 17 18 * the GNU General Public License as published by the Free Software 19 Foundation; either version 2 of the License, or (at your option) any 20 later version. 21 22 or both in parallel, as here. 23 24 The GNU MP Library is distributed in the hope that it will be useful, but 25 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 26 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 27 for more details. 28 29 You should have received copies of the GNU General Public License and the 30 GNU Lesser General Public License along with the GNU MP Library. If not, 31 see https://www.gnu.org/licenses/. */ 32 33 #include "gmp-impl.h" 34 35 36 #ifdef OPERATION_mul_si 37 #define FUNCTION mpz_mul_si 38 #define MULTIPLICAND_UNSIGNED 39 #define MULTIPLICAND_ABS(x) ABS_CAST(unsigned long, (x)) 40 #endif 41 42 #ifdef OPERATION_mul_ui 43 #define FUNCTION mpz_mul_ui 44 #define MULTIPLICAND_UNSIGNED unsigned 45 #define MULTIPLICAND_ABS(x) x 46 #endif 47 48 #ifndef FUNCTION 49 Error, error, unrecognised OPERATION 50 #endif 51 52 53 void 54 FUNCTION (mpz_ptr prod, mpz_srcptr mult, 55 MULTIPLICAND_UNSIGNED long int small_mult) 56 { 57 mp_size_t size; 58 mp_size_t sign_product; 59 mp_limb_t sml; 60 mp_limb_t cy; 61 mp_ptr pp; 62 63 sign_product = SIZ(mult); 64 if (sign_product == 0 || small_mult == 0) 65 { 66 SIZ(prod) = 0; 67 return; 68 } 69 70 size = ABS (sign_product); 71 72 sml = MULTIPLICAND_ABS (small_mult); 73 74 if (sml <= GMP_NUMB_MAX) 75 { 76 pp = MPZ_REALLOC (prod, size + 1); 77 cy = mpn_mul_1 (pp, PTR(mult), size, sml); 78 pp[size] = cy; 79 size += cy != 0; 80 } 81 #if GMP_NAIL_BITS != 0 82 else 83 { 84 /* Operand too large for the current nails size. Use temporary for 85 intermediate products, to allow prod and mult being identical. */ 86 mp_ptr tp; 87 TMP_DECL; 88 TMP_MARK; 89 90 tp = TMP_ALLOC_LIMBS (size + 2); 91 92 /* Use, maybe, mpn_mul_2? */ 93 cy = mpn_mul_1 (tp, PTR(mult), size, sml & GMP_NUMB_MASK); 94 tp[size] = cy; 95 cy = mpn_addmul_1 (tp + 1, PTR(mult), size, sml >> GMP_NUMB_BITS); 96 tp[size + 1] = cy; 97 size += 2; 98 MPN_NORMALIZE_NOT_ZERO (tp, size); /* too general, need to trim one or two limb */ 99 pp = MPZ_NEWALLOC (prod, size); 100 MPN_COPY (pp, tp, size); 101 TMP_FREE; 102 } 103 #endif 104 105 SIZ(prod) = ((sign_product < 0) ^ (small_mult < 0)) ? -size : size; 106 } 107