1 /* IEEE754 floating point arithmetic 2 * double precision: common utilities 3 */ 4 /* 5 * MIPS floating point support 6 * Copyright (C) 1994-2000 Algorithmics Ltd. 7 * http://www.algor.co.uk 8 * 9 * ######################################################################## 10 * 11 * This program is free software; you can distribute it and/or modify it 12 * under the terms of the GNU General Public License (Version 2) as 13 * published by the Free Software Foundation. 14 * 15 * This program is distributed in the hope it will be useful, but WITHOUT 16 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 17 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 18 * for more details. 19 * 20 * You should have received a copy of the GNU General Public License along 21 * with this program; if not, write to the Free Software Foundation, Inc., 22 * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA. 23 * 24 * ######################################################################## 25 */ 26 27 28 #include "ieee754dp.h" 29 30 ieee754dp ieee754dp_fint(int x) 31 { 32 COMPXDP; 33 34 CLEARCX; 35 36 if (x == 0) 37 return ieee754dp_zero(0); 38 if (x == 1 || x == -1) 39 return ieee754dp_one(x < 0); 40 if (x == 10 || x == -10) 41 return ieee754dp_ten(x < 0); 42 43 xs = (x < 0); 44 if (xs) { 45 if (x == (1 << 31)) 46 xm = ((unsigned) 1 << 31); /* max neg can't be safely negated */ 47 else 48 xm = -x; 49 } else { 50 xm = x; 51 } 52 53 #if 1 54 /* normalize - result can never be inexact or overflow */ 55 xe = DP_MBITS; 56 while ((xm >> DP_MBITS) == 0) { 57 xm <<= 1; 58 xe--; 59 } 60 return builddp(xs, xe + DP_EBIAS, xm & ~DP_HIDDEN_BIT); 61 #else 62 /* normalize */ 63 xe = DP_MBITS + 3; 64 while ((xm >> (DP_MBITS + 3)) == 0) { 65 xm <<= 1; 66 xe--; 67 } 68 DPNORMRET1(xs, xe, xm, "fint", x); 69 #endif 70 } 71 72 ieee754dp ieee754dp_funs(unsigned int u) 73 { 74 if ((int) u < 0) 75 return ieee754dp_add(ieee754dp_1e31(), 76 ieee754dp_fint(u & ~(1 << 31))); 77 return ieee754dp_fint(u); 78 } 79