1 /* IEEE754 floating point arithmetic 2 * single precision 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 ieee754sp ieee754sp_nan_fdp(int xs, u64 xm) 26 { 27 return buildsp(xs, SP_EMAX + 1 + SP_EBIAS, 28 xm >> (DP_FBITS - SP_FBITS)); 29 } 30 31 union ieee754sp ieee754sp_fdp(union ieee754dp x) 32 { 33 union ieee754sp y; 34 u32 rm; 35 36 COMPXDP; 37 COMPYSP; 38 39 EXPLODEXDP; 40 41 ieee754_clearcx(); 42 43 FLUSHXDP; 44 45 switch (xc) { 46 case IEEE754_CLASS_SNAN: 47 x = ieee754dp_nanxcpt(x); 48 EXPLODEXDP; 49 /* fall through */ 50 51 case IEEE754_CLASS_QNAN: 52 y = ieee754sp_nan_fdp(xs, xm); 53 if (!ieee754_csr.nan2008) { 54 EXPLODEYSP; 55 if (!ieee754_class_nan(yc)) 56 y = ieee754sp_indef(); 57 } 58 return y; 59 60 case IEEE754_CLASS_INF: 61 return ieee754sp_inf(xs); 62 63 case IEEE754_CLASS_ZERO: 64 return ieee754sp_zero(xs); 65 66 case IEEE754_CLASS_DNORM: 67 /* can't possibly be sp representable */ 68 ieee754_setcx(IEEE754_UNDERFLOW); 69 ieee754_setcx(IEEE754_INEXACT); 70 if ((ieee754_csr.rm == FPU_CSR_RU && !xs) || 71 (ieee754_csr.rm == FPU_CSR_RD && xs)) 72 return ieee754sp_mind(xs); 73 return ieee754sp_zero(xs); 74 75 case IEEE754_CLASS_NORM: 76 break; 77 } 78 79 /* 80 * Convert from DP_FBITS to SP_FBITS+3 with sticky right shift. 81 */ 82 rm = (xm >> (DP_FBITS - (SP_FBITS + 3))) | 83 ((xm << (64 - (DP_FBITS - (SP_FBITS + 3)))) != 0); 84 85 return ieee754sp_format(xs, xe, rm); 86 } 87