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 * 8 * This program is free software; you can distribute it and/or modify it 9 * under the terms of the GNU General Public License (Version 2) as 10 * published by the Free Software Foundation. 11 * 12 * This program is distributed in the hope it will be useful, but WITHOUT 13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15 * for more details. 16 * 17 * You should have received a copy of the GNU General Public License along 18 * with this program; if not, write to the Free Software Foundation, Inc., 19 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 */ 21 22 #include "ieee754dp.h" 23 24 union ieee754dp ieee754dp_flong(s64 x) 25 { 26 u64 xm; 27 int xe; 28 int xs; 29 30 ieee754_clearcx(); 31 32 if (x == 0) 33 return ieee754dp_zero(0); 34 if (x == 1 || x == -1) 35 return ieee754dp_one(x < 0); 36 if (x == 10 || x == -10) 37 return ieee754dp_ten(x < 0); 38 39 xs = (x < 0); 40 if (xs) { 41 if (x == (1ULL << 63)) 42 xm = (1ULL << 63); /* max neg can't be safely negated */ 43 else 44 xm = -x; 45 } else { 46 xm = x; 47 } 48 49 /* normalize */ 50 xe = DP_FBITS + 3; 51 if (xm >> (DP_FBITS + 1 + 3)) { 52 /* shunt out overflow bits */ 53 while (xm >> (DP_FBITS + 1 + 3)) { 54 XDPSRSX1(); 55 } 56 } else { 57 /* normalize in grs extended double precision */ 58 while ((xm >> (DP_FBITS + 3)) == 0) { 59 xm <<= 1; 60 xe--; 61 } 62 } 63 64 return ieee754dp_format(xs, xe, xm); 65 } 66