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 u64 xm; 33 int xe; 34 int xs; 35 36 CLEARCX; 37 38 if (x == 0) 39 return ieee754dp_zero(0); 40 if (x == 1 || x == -1) 41 return ieee754dp_one(x < 0); 42 if (x == 10 || x == -10) 43 return ieee754dp_ten(x < 0); 44 45 xs = (x < 0); 46 if (xs) { 47 if (x == (1 << 31)) 48 xm = ((unsigned) 1 << 31); /* max neg can't be safely negated */ 49 else 50 xm = -x; 51 } else { 52 xm = x; 53 } 54 55 #if 1 56 /* normalize - result can never be inexact or overflow */ 57 xe = DP_MBITS; 58 while ((xm >> DP_MBITS) == 0) { 59 xm <<= 1; 60 xe--; 61 } 62 return builddp(xs, xe + DP_EBIAS, xm & ~DP_HIDDEN_BIT); 63 #else 64 /* normalize */ 65 xe = DP_MBITS + 3; 66 while ((xm >> (DP_MBITS + 3)) == 0) { 67 xm <<= 1; 68 xe--; 69 } 70 DPNORMRET1(xs, xe, xm, "fint", x); 71 #endif 72 } 73 74 ieee754dp ieee754dp_funs(unsigned int u) 75 { 76 if ((int) u < 0) 77 return ieee754dp_add(ieee754dp_1e31(), 78 ieee754dp_fint(u & ~(1 << 31))); 79 return ieee754dp_fint(u); 80 } 81