1 /* mpz_cmpabs_d -- compare absolute values of mpz and double. 2 3 Copyright 2001, 2002, 2003 Free Software Foundation, Inc. 4 5 This file is part of the GNU MP Library. 6 7 The GNU MP Library is free software; you can redistribute it and/or modify 8 it under the terms of the GNU Lesser General Public License as published by 9 the Free Software Foundation; either version 3 of the License, or (at your 10 option) any later version. 11 12 The GNU MP Library is distributed in the hope that it will be useful, but 13 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 14 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 15 License for more details. 16 17 You should have received a copy of the GNU Lesser General Public License 18 along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. */ 19 20 #include "config.h" 21 22 #if HAVE_FLOAT_H 23 #include <float.h> /* for DBL_MAX */ 24 #endif 25 26 #include "gmp.h" 27 #include "gmp-impl.h" 28 29 30 #define RETURN_CMP(zl, dl) \ 31 do { \ 32 zlimb = (zl); \ 33 dlimb = (dl); \ 34 if (zlimb != dlimb) \ 35 return (zlimb >= dlimb ? 1 : -1); \ 36 } while (0) 37 38 #define RETURN_NONZERO(ptr, size, val) \ 39 do { \ 40 mp_size_t __i; \ 41 for (__i = (size)-1; __i >= 0; __i--) \ 42 if ((ptr)[__i] != 0) \ 43 return val; \ 44 return 0; \ 45 } while (0) 46 47 48 int 49 mpz_cmpabs_d (mpz_srcptr z, double d) 50 { 51 mp_limb_t darray[LIMBS_PER_DOUBLE], zlimb, dlimb; 52 mp_srcptr zp; 53 mp_size_t zsize; 54 int dexp; 55 56 /* d=NaN is an invalid operation, there's no sensible return value. 57 d=Inf or -Inf is always bigger than z. */ 58 DOUBLE_NAN_INF_ACTION (d, __gmp_invalid_operation (), return -1); 59 60 /* 1. Check for either operand zero. */ 61 zsize = SIZ(z); 62 if (d == 0.0) 63 return (zsize != 0); 64 if (zsize == 0) 65 return (d != 0 ? -1 : 0); 66 67 /* 2. Ignore signs. */ 68 zsize = ABS(zsize); 69 d = ABS(d); 70 71 /* 3. Small d, knowing abs(z) >= 1. */ 72 if (d < 1.0) 73 return 1; 74 75 dexp = __gmp_extract_double (darray, d); 76 ASSERT (dexp >= 1); 77 78 /* 4. Check for different high limb positions. */ 79 if (zsize != dexp) 80 return (zsize >= dexp ? 1 : -1); 81 82 /* 5. Limb data. */ 83 zp = PTR(z); 84 85 #if LIMBS_PER_DOUBLE == 2 86 RETURN_CMP (zp[zsize-1], darray[1]); 87 if (zsize == 1) 88 return (darray[0] != 0 ? -1 : 0); 89 90 RETURN_CMP (zp[zsize-2], darray[0]); 91 RETURN_NONZERO (zp, zsize-2, 1); 92 #endif 93 94 #if LIMBS_PER_DOUBLE == 3 95 RETURN_CMP (zp[zsize-1], darray[2]); 96 if (zsize == 1) 97 return ((darray[0] | darray[1]) != 0 ? -1 : 0); 98 99 RETURN_CMP (zp[zsize-2], darray[1]); 100 if (zsize == 2) 101 return (darray[0] != 0 ? -1 : 0); 102 103 RETURN_CMP (zp[zsize-3], darray[0]); 104 RETURN_NONZERO (zp, zsize-3, 1); 105 #endif 106 107 #if LIMBS_PER_DOUBLE >= 4 108 { 109 int i; 110 for (i = 1; i <= LIMBS_PER_DOUBLE; i++) 111 { 112 RETURN_CMP (zp[zsize-i], darray[LIMBS_PER_DOUBLE-i]); 113 if (i >= zsize) 114 RETURN_NONZERO (darray, LIMBS_PER_DOUBLE-i, -1); 115 } 116 RETURN_NONZERO (zp, zsize-LIMBS_PER_DOUBLE, 1); 117 } 118 #endif 119 } 120