1 /* mpz_set_d(integer, val) -- Assign INTEGER with a double value VAL. 2 3 Copyright 1995, 1996, 2000, 2001, 2002, 2003, 2006 Free Software Foundation, 4 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 "config.h" 22 23 #if HAVE_FLOAT_H 24 #include <float.h> /* for DBL_MAX */ 25 #endif 26 27 #include "gmp.h" 28 #include "gmp-impl.h" 29 30 31 /* We used to have a special case for d < MP_BASE_AS_DOUBLE, just casting 32 double -> limb. Unfortunately gcc 3.3 on powerpc970-apple-darwin6.8.5 33 got this wrong. (It assumed __fixunsdfdi returned its result in a single 34 64-bit register, where instead that function followed the calling 35 conventions and gave the result in two parts r3 and r4.) Hence the use 36 of __gmp_extract_double in all cases. */ 37 38 void 39 mpz_set_d (mpz_ptr r, double d) 40 { 41 int negative; 42 mp_limb_t tp[LIMBS_PER_DOUBLE]; 43 mp_ptr rp; 44 mp_size_t rn; 45 46 DOUBLE_NAN_INF_ACTION (d, 47 __gmp_invalid_operation (), 48 __gmp_invalid_operation ()); 49 50 negative = d < 0; 51 d = ABS (d); 52 53 rn = __gmp_extract_double (tp, d); 54 55 if (ALLOC(r) < rn) 56 _mpz_realloc (r, rn); 57 58 if (rn <= 0) 59 rn = 0; 60 61 rp = PTR (r); 62 63 switch (rn) 64 { 65 default: 66 MPN_ZERO (rp, rn - LIMBS_PER_DOUBLE); 67 rp += rn - LIMBS_PER_DOUBLE; 68 /* fall through */ 69 #if LIMBS_PER_DOUBLE == 2 70 case 2: 71 rp[1] = tp[1], rp[0] = tp[0]; 72 break; 73 case 1: 74 rp[0] = tp[1]; 75 break; 76 #endif 77 #if LIMBS_PER_DOUBLE == 3 78 case 3: 79 rp[2] = tp[2], rp[1] = tp[1], rp[0] = tp[0]; 80 break; 81 case 2: 82 rp[1] = tp[2], rp[0] = tp[1]; 83 break; 84 case 1: 85 rp[0] = tp[2]; 86 break; 87 #endif 88 #if LIMBS_PER_DOUBLE == 4 89 case 4: 90 rp[3] = tp[3], rp[2] = tp[2], rp[1] = tp[1], rp[0] = tp[0]; 91 break; 92 case 3: 93 rp[2] = tp[3], rp[1] = tp[2], rp[0] = tp[1]; 94 break; 95 case 2: 96 rp[1] = tp[3], rp[0] = tp[2]; 97 break; 98 case 1: 99 rp[0] = tp[3]; 100 break; 101 #endif 102 case 0: 103 break; 104 } 105 106 SIZ(r) = negative ? -rn : rn; 107 } 108