dfcmp.c revision 1.1.2.2
1 1.1.2.2 jdolecek /* $NetBSD: dfcmp.c,v 1.1.2.2 2002/06/23 17:37:12 jdolecek Exp $ */ 2 1.1.2.2 jdolecek 3 1.1.2.2 jdolecek /* $OpenBSD: dfcmp.c,v 1.4 2001/03/29 03:58:17 mickey Exp $ */ 4 1.1.2.2 jdolecek 5 1.1.2.2 jdolecek /* 6 1.1.2.2 jdolecek * Copyright 1996 1995 by Open Software Foundation, Inc. 7 1.1.2.2 jdolecek * All Rights Reserved 8 1.1.2.2 jdolecek * 9 1.1.2.2 jdolecek * Permission to use, copy, modify, and distribute this software and 10 1.1.2.2 jdolecek * its documentation for any purpose and without fee is hereby granted, 11 1.1.2.2 jdolecek * provided that the above copyright notice appears in all copies and 12 1.1.2.2 jdolecek * that both the copyright notice and this permission notice appear in 13 1.1.2.2 jdolecek * supporting documentation. 14 1.1.2.2 jdolecek * 15 1.1.2.2 jdolecek * OSF DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE 16 1.1.2.2 jdolecek * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 17 1.1.2.2 jdolecek * FOR A PARTICULAR PURPOSE. 18 1.1.2.2 jdolecek * 19 1.1.2.2 jdolecek * IN NO EVENT SHALL OSF BE LIABLE FOR ANY SPECIAL, INDIRECT, OR 20 1.1.2.2 jdolecek * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 21 1.1.2.2 jdolecek * LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT, 22 1.1.2.2 jdolecek * NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION 23 1.1.2.2 jdolecek * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 24 1.1.2.2 jdolecek */ 25 1.1.2.2 jdolecek /* 26 1.1.2.2 jdolecek * pmk1.1 27 1.1.2.2 jdolecek */ 28 1.1.2.2 jdolecek /* 29 1.1.2.2 jdolecek * (c) Copyright 1986 HEWLETT-PACKARD COMPANY 30 1.1.2.2 jdolecek * 31 1.1.2.2 jdolecek * To anyone who acknowledges that this file is provided "AS IS" 32 1.1.2.2 jdolecek * without any express or implied warranty: 33 1.1.2.2 jdolecek * permission to use, copy, modify, and distribute this file 34 1.1.2.2 jdolecek * for any purpose is hereby granted without fee, provided that 35 1.1.2.2 jdolecek * the above copyright notice and this notice appears in all 36 1.1.2.2 jdolecek * copies, and that the name of Hewlett-Packard Company not be 37 1.1.2.2 jdolecek * used in advertising or publicity pertaining to distribution 38 1.1.2.2 jdolecek * of the software without specific, written prior permission. 39 1.1.2.2 jdolecek * Hewlett-Packard Company makes no representations about the 40 1.1.2.2 jdolecek * suitability of this software for any purpose. 41 1.1.2.2 jdolecek */ 42 1.1.2.2 jdolecek 43 1.1.2.2 jdolecek 44 1.1.2.2 jdolecek #include "../spmath/float.h" 45 1.1.2.2 jdolecek #include "../spmath/dbl_float.h" 46 1.1.2.2 jdolecek 47 1.1.2.2 jdolecek /* 48 1.1.2.2 jdolecek * dbl_cmp: compare two values 49 1.1.2.2 jdolecek */ 50 1.1.2.2 jdolecek int 51 1.1.2.2 jdolecek dbl_fcmp(leftptr, rightptr, cond, status) 52 1.1.2.2 jdolecek dbl_floating_point *leftptr, *rightptr; 53 1.1.2.2 jdolecek unsigned int cond; /* The predicate to be tested */ 54 1.1.2.2 jdolecek unsigned int *status; 55 1.1.2.2 jdolecek { 56 1.1.2.2 jdolecek register unsigned int leftp1, leftp2, rightp1, rightp2; 57 1.1.2.2 jdolecek register int xorresult; 58 1.1.2.2 jdolecek 59 1.1.2.2 jdolecek /* Create local copies of the numbers */ 60 1.1.2.2 jdolecek Dbl_copyfromptr(leftptr,leftp1,leftp2); 61 1.1.2.2 jdolecek Dbl_copyfromptr(rightptr,rightp1,rightp2); 62 1.1.2.2 jdolecek /* 63 1.1.2.2 jdolecek * Test for NaN 64 1.1.2.2 jdolecek */ 65 1.1.2.2 jdolecek if( (Dbl_exponent(leftp1) == DBL_INFINITY_EXPONENT) 66 1.1.2.2 jdolecek || (Dbl_exponent(rightp1) == DBL_INFINITY_EXPONENT) ) 67 1.1.2.2 jdolecek { 68 1.1.2.2 jdolecek /* Check if a NaN is involved. Signal an invalid exception when 69 1.1.2.2 jdolecek * comparing a signaling NaN or when comparing quiet NaNs and the 70 1.1.2.2 jdolecek * low bit of the condition is set */ 71 1.1.2.2 jdolecek if( ((Dbl_exponent(leftp1) == DBL_INFINITY_EXPONENT) 72 1.1.2.2 jdolecek && Dbl_isnotzero_mantissa(leftp1,leftp2) 73 1.1.2.2 jdolecek && (Exception(cond) || Dbl_isone_signaling(leftp1))) 74 1.1.2.2 jdolecek || 75 1.1.2.2 jdolecek ((Dbl_exponent(rightp1) == DBL_INFINITY_EXPONENT) 76 1.1.2.2 jdolecek && Dbl_isnotzero_mantissa(rightp1,rightp2) 77 1.1.2.2 jdolecek && (Exception(cond) || Dbl_isone_signaling(rightp1))) ) 78 1.1.2.2 jdolecek { 79 1.1.2.2 jdolecek if( Is_invalidtrap_enabled() ) { 80 1.1.2.2 jdolecek Set_status_cbit(Unordered(cond)); 81 1.1.2.2 jdolecek return(INVALIDEXCEPTION); 82 1.1.2.2 jdolecek } 83 1.1.2.2 jdolecek else Set_invalidflag(); 84 1.1.2.2 jdolecek Set_status_cbit(Unordered(cond)); 85 1.1.2.2 jdolecek return(NOEXCEPTION); 86 1.1.2.2 jdolecek } 87 1.1.2.2 jdolecek /* All the exceptional conditions are handled, now special case 88 1.1.2.2 jdolecek NaN compares */ 89 1.1.2.2 jdolecek else if( ((Dbl_exponent(leftp1) == DBL_INFINITY_EXPONENT) 90 1.1.2.2 jdolecek && Dbl_isnotzero_mantissa(leftp1,leftp2)) 91 1.1.2.2 jdolecek || 92 1.1.2.2 jdolecek ((Dbl_exponent(rightp1) == DBL_INFINITY_EXPONENT) 93 1.1.2.2 jdolecek && Dbl_isnotzero_mantissa(rightp1,rightp2)) ) 94 1.1.2.2 jdolecek { 95 1.1.2.2 jdolecek /* NaNs always compare unordered. */ 96 1.1.2.2 jdolecek Set_status_cbit(Unordered(cond)); 97 1.1.2.2 jdolecek return(NOEXCEPTION); 98 1.1.2.2 jdolecek } 99 1.1.2.2 jdolecek /* infinities will drop down to the normal compare mechanisms */ 100 1.1.2.2 jdolecek } 101 1.1.2.2 jdolecek /* First compare for unequal signs => less or greater or 102 1.1.2.2 jdolecek * special equal case */ 103 1.1.2.2 jdolecek Dbl_xortointp1(leftp1,rightp1,xorresult); 104 1.1.2.2 jdolecek if( xorresult < 0 ) 105 1.1.2.2 jdolecek { 106 1.1.2.2 jdolecek /* left negative => less, left positive => greater. 107 1.1.2.2 jdolecek * equal is possible if both operands are zeros. */ 108 1.1.2.2 jdolecek if( Dbl_iszero_exponentmantissa(leftp1,leftp2) 109 1.1.2.2 jdolecek && Dbl_iszero_exponentmantissa(rightp1,rightp2) ) 110 1.1.2.2 jdolecek { 111 1.1.2.2 jdolecek Set_status_cbit(Equal(cond)); 112 1.1.2.2 jdolecek } 113 1.1.2.2 jdolecek else if( Dbl_isone_sign(leftp1) ) 114 1.1.2.2 jdolecek { 115 1.1.2.2 jdolecek Set_status_cbit(Lessthan(cond)); 116 1.1.2.2 jdolecek } 117 1.1.2.2 jdolecek else 118 1.1.2.2 jdolecek { 119 1.1.2.2 jdolecek Set_status_cbit(Greaterthan(cond)); 120 1.1.2.2 jdolecek } 121 1.1.2.2 jdolecek } 122 1.1.2.2 jdolecek /* Signs are the same. Treat negative numbers separately 123 1.1.2.2 jdolecek * from the positives because of the reversed sense. */ 124 1.1.2.2 jdolecek else if(Dbl_isequal(leftp1,leftp2,rightp1,rightp2)) 125 1.1.2.2 jdolecek { 126 1.1.2.2 jdolecek Set_status_cbit(Equal(cond)); 127 1.1.2.2 jdolecek } 128 1.1.2.2 jdolecek else if( Dbl_iszero_sign(leftp1) ) 129 1.1.2.2 jdolecek { 130 1.1.2.2 jdolecek /* Positive compare */ 131 1.1.2.2 jdolecek if( Dbl_allp1(leftp1) < Dbl_allp1(rightp1) ) 132 1.1.2.2 jdolecek { 133 1.1.2.2 jdolecek Set_status_cbit(Lessthan(cond)); 134 1.1.2.2 jdolecek } 135 1.1.2.2 jdolecek else if( Dbl_allp1(leftp1) > Dbl_allp1(rightp1) ) 136 1.1.2.2 jdolecek { 137 1.1.2.2 jdolecek Set_status_cbit(Greaterthan(cond)); 138 1.1.2.2 jdolecek } 139 1.1.2.2 jdolecek else 140 1.1.2.2 jdolecek { 141 1.1.2.2 jdolecek /* Equal first parts. Now we must use unsigned compares to 142 1.1.2.2 jdolecek * resolve the two possibilities. */ 143 1.1.2.2 jdolecek if( Dbl_allp2(leftp2) < Dbl_allp2(rightp2) ) 144 1.1.2.2 jdolecek { 145 1.1.2.2 jdolecek Set_status_cbit(Lessthan(cond)); 146 1.1.2.2 jdolecek } 147 1.1.2.2 jdolecek else 148 1.1.2.2 jdolecek { 149 1.1.2.2 jdolecek Set_status_cbit(Greaterthan(cond)); 150 1.1.2.2 jdolecek } 151 1.1.2.2 jdolecek } 152 1.1.2.2 jdolecek } 153 1.1.2.2 jdolecek else 154 1.1.2.2 jdolecek { 155 1.1.2.2 jdolecek /* Negative compare. Signed or unsigned compares 156 1.1.2.2 jdolecek * both work the same. That distinction is only 157 1.1.2.2 jdolecek * important when the sign bits differ. */ 158 1.1.2.2 jdolecek if( Dbl_allp1(leftp1) > Dbl_allp1(rightp1) ) 159 1.1.2.2 jdolecek { 160 1.1.2.2 jdolecek Set_status_cbit(Lessthan(cond)); 161 1.1.2.2 jdolecek } 162 1.1.2.2 jdolecek else if( Dbl_allp1(leftp1) < Dbl_allp1(rightp1) ) 163 1.1.2.2 jdolecek { 164 1.1.2.2 jdolecek Set_status_cbit(Greaterthan(cond)); 165 1.1.2.2 jdolecek } 166 1.1.2.2 jdolecek else 167 1.1.2.2 jdolecek { 168 1.1.2.2 jdolecek /* Equal first parts. Now we must use unsigned compares to 169 1.1.2.2 jdolecek * resolve the two possibilities. */ 170 1.1.2.2 jdolecek if( Dbl_allp2(leftp2) > Dbl_allp2(rightp2) ) 171 1.1.2.2 jdolecek { 172 1.1.2.2 jdolecek Set_status_cbit(Lessthan(cond)); 173 1.1.2.2 jdolecek } 174 1.1.2.2 jdolecek else 175 1.1.2.2 jdolecek { 176 1.1.2.2 jdolecek Set_status_cbit(Greaterthan(cond)); 177 1.1.2.2 jdolecek } 178 1.1.2.2 jdolecek } 179 1.1.2.2 jdolecek } 180 1.1.2.2 jdolecek return(NOEXCEPTION); 181 1.1.2.2 jdolecek } 182
Indexes created Sun Oct 12 09:09:55 GMT 2025