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 "ieee754sp.h" 23 #include "ieee754dp.h" 24 25 static inline union ieee754dp ieee754dp_nan_fsp(int xs, u64 xm) 26 { 27 return builddp(xs, DP_EMAX + 1 + DP_EBIAS, 28 xm << (DP_FBITS - SP_FBITS)); 29 } 30 31 union ieee754dp ieee754dp_fsp(union ieee754sp x) 32 { 33 COMPXSP; 34 35 EXPLODEXSP; 36 37 ieee754_clearcx(); 38 39 FLUSHXSP; 40 41 switch (xc) { 42 case IEEE754_CLASS_SNAN: 43 return ieee754dp_nanxcpt(ieee754dp_nan_fsp(xs, xm)); 44 45 case IEEE754_CLASS_QNAN: 46 return ieee754dp_nan_fsp(xs, xm); 47 48 case IEEE754_CLASS_INF: 49 return ieee754dp_inf(xs); 50 51 case IEEE754_CLASS_ZERO: 52 return ieee754dp_zero(xs); 53 54 case IEEE754_CLASS_DNORM: 55 /* normalize */ 56 while ((xm >> SP_FBITS) == 0) { 57 xm <<= 1; 58 xe--; 59 } 60 break; 61 62 case IEEE754_CLASS_NORM: 63 break; 64 } 65 66 /* 67 * Can't possibly overflow,underflow, or need rounding 68 */ 69 70 /* drop the hidden bit */ 71 xm &= ~SP_HIDDEN_BIT; 72 73 return builddp(xs, xe + DP_EBIAS, 74 (u64) xm << (DP_FBITS - SP_FBITS)); 75 } 76