1 /* mpq_cmp_ui(u,vn,vd) -- Compare U with Vn/Vd. Return positive, zero, or 2 negative based on if U > V, U == V, or U < V. Vn and Vd may have 3 common factors. 4 5 Copyright 1993, 1994, 1996, 2000-2003, 2005, 2014, 2018 Free Software 6 Foundation, Inc. 7 8 This file is part of the GNU MP Library. 9 10 The GNU MP Library is free software; you can redistribute it and/or modify 11 it under the terms of either: 12 13 * the GNU Lesser General Public License as published by the Free 14 Software Foundation; either version 3 of the License, or (at your 15 option) any later version. 16 17 or 18 19 * the GNU General Public License as published by the Free Software 20 Foundation; either version 2 of the License, or (at your option) any 21 later version. 22 23 or both in parallel, as here. 24 25 The GNU MP Library is distributed in the hope that it will be useful, but 26 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 27 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 28 for more details. 29 30 You should have received copies of the GNU General Public License and the 31 GNU Lesser General Public License along with the GNU MP Library. If not, 32 see https://www.gnu.org/licenses/. */ 33 34 #include "gmp-impl.h" 35 36 int 37 _mpq_cmp_ui (mpq_srcptr op1, unsigned long int num2, unsigned long int den2) 38 { 39 mp_size_t num1_size = SIZ(NUM(op1)); 40 mp_size_t den1_size = SIZ(DEN(op1)); 41 mp_size_t tmp1_size, tmp2_size; 42 mp_ptr tmp1_ptr, tmp2_ptr; 43 mp_limb_t cy_limb; 44 int cc; 45 TMP_DECL; 46 47 #if GMP_NAIL_BITS != 0 48 if ((num2 | den2) > GMP_NUMB_MAX) 49 { 50 mpq_t op2; 51 mpq_init (op2); 52 mpz_set_ui (mpq_numref (op2), num2); 53 mpz_set_ui (mpq_denref (op2), den2); 54 cc = mpq_cmp (op1, op2); 55 mpq_clear (op2); 56 return cc; 57 } 58 #endif 59 60 /* need canonical sign to get right result */ 61 ASSERT (den1_size > 0); 62 63 if (UNLIKELY (den2 == 0)) 64 DIVIDE_BY_ZERO; 65 66 if (num2 == 0) 67 return num1_size; 68 if (num1_size <= 0) 69 return -1; 70 71 /* NUM1 x DEN2 is either TMP1_SIZE limbs or TMP1_SIZE-1 limbs. 72 Same for NUM2 x DEN1 with respect to TMP2_SIZE. */ 73 /* If frac2 <= 1 (i.e. num2 <= den2), shortcut with a simpler 74 condition: num1 > den1. Here we only test sizes. */ 75 if (num1_size > den1_size + (num2 > den2)) 76 /* NUM1 x DEN2 is surely larger in magnitude than NUM2 x DEN1. */ 77 return num1_size; 78 if (den1_size > num1_size + (den2 > num2)) 79 /* NUM1 x DEN2 is surely smaller in magnitude than NUM2 x DEN1. */ 80 return -num1_size; 81 82 TMP_MARK; 83 TMP_ALLOC_LIMBS_2 (tmp1_ptr, num1_size + 1, tmp2_ptr, den1_size + 1); 84 85 cy_limb = mpn_mul_1 (tmp1_ptr, PTR(NUM(op1)), num1_size, 86 (mp_limb_t) den2); 87 tmp1_ptr[num1_size] = cy_limb; 88 tmp1_size = num1_size + (cy_limb != 0); 89 90 cy_limb = mpn_mul_1 (tmp2_ptr, PTR(DEN(op1)), den1_size, 91 (mp_limb_t) num2); 92 tmp2_ptr[den1_size] = cy_limb; 93 tmp2_size = den1_size + (cy_limb != 0); 94 95 cc = tmp1_size - tmp2_size; 96 cc = cc != 0 ? cc : mpn_cmp (tmp1_ptr, tmp2_ptr, tmp1_size); 97 TMP_FREE; 98 return cc; 99 } 100