1 /* mpf_cmp -- Compare two floats. 2 3 Copyright 1993, 1994, 1996, 2001 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 "gmp.h" 21 #include "gmp-impl.h" 22 23 int 24 mpf_cmp (mpf_srcptr u, mpf_srcptr v) __GMP_NOTHROW 25 { 26 mp_srcptr up, vp; 27 mp_size_t usize, vsize; 28 mp_exp_t uexp, vexp; 29 int cmp; 30 int usign; 31 32 uexp = u->_mp_exp; 33 vexp = v->_mp_exp; 34 35 usize = u->_mp_size; 36 vsize = v->_mp_size; 37 38 /* 1. Are the signs different? */ 39 if ((usize ^ vsize) >= 0) 40 { 41 /* U and V are both non-negative or both negative. */ 42 if (usize == 0) 43 /* vsize >= 0 */ 44 return -(vsize != 0); 45 if (vsize == 0) 46 /* usize >= 0 */ 47 return usize != 0; 48 /* Fall out. */ 49 } 50 else 51 { 52 /* Either U or V is negative, but not both. */ 53 return usize >= 0 ? 1 : -1; 54 } 55 56 /* U and V have the same sign and are both non-zero. */ 57 58 usign = usize >= 0 ? 1 : -1; 59 60 /* 2. Are the exponents different? */ 61 if (uexp > vexp) 62 return usign; 63 if (uexp < vexp) 64 return -usign; 65 66 usize = ABS (usize); 67 vsize = ABS (vsize); 68 69 up = u->_mp_d; 70 vp = v->_mp_d; 71 72 #define STRICT_MPF_NORMALIZATION 0 73 #if ! STRICT_MPF_NORMALIZATION 74 /* Ignore zeroes at the low end of U and V. */ 75 while (up[0] == 0) 76 { 77 up++; 78 usize--; 79 } 80 while (vp[0] == 0) 81 { 82 vp++; 83 vsize--; 84 } 85 #endif 86 87 if (usize > vsize) 88 { 89 cmp = mpn_cmp (up + usize - vsize, vp, vsize); 90 if (cmp == 0) 91 return usign; 92 } 93 else if (vsize > usize) 94 { 95 cmp = mpn_cmp (up, vp + vsize - usize, usize); 96 if (cmp == 0) 97 return -usign; 98 } 99 else 100 { 101 cmp = mpn_cmp (up, vp, usize); 102 if (cmp == 0) 103 return 0; 104 } 105 return cmp > 0 ? usign : -usign; 106 } 107