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 union ieee754sp ieee754sp_fdp(union ieee754dp x) 26 { 27 u32 rm; 28 29 COMPXDP; 30 union ieee754sp nan; 31 32 EXPLODEXDP; 33 34 ieee754_clearcx(); 35 36 FLUSHXDP; 37 38 switch (xc) { 39 case IEEE754_CLASS_SNAN: 40 ieee754_setcx(IEEE754_INVALID_OPERATION); 41 return ieee754sp_nanxcpt(ieee754sp_indef()); 42 43 case IEEE754_CLASS_QNAN: 44 nan = buildsp(xs, SP_EMAX + 1 + SP_EBIAS, (u32) 45 (xm >> (DP_FBITS - SP_FBITS))); 46 if (!ieee754sp_isnan(nan)) 47 nan = ieee754sp_indef(); 48 return ieee754sp_nanxcpt(nan); 49 50 case IEEE754_CLASS_INF: 51 return ieee754sp_inf(xs); 52 53 case IEEE754_CLASS_ZERO: 54 return ieee754sp_zero(xs); 55 56 case IEEE754_CLASS_DNORM: 57 /* can't possibly be sp representable */ 58 ieee754_setcx(IEEE754_UNDERFLOW); 59 ieee754_setcx(IEEE754_INEXACT); 60 if ((ieee754_csr.rm == FPU_CSR_RU && !xs) || 61 (ieee754_csr.rm == FPU_CSR_RD && xs)) 62 return ieee754sp_mind(xs); 63 return ieee754sp_zero(xs); 64 65 case IEEE754_CLASS_NORM: 66 break; 67 } 68 69 /* 70 * Convert from DP_FBITS to SP_FBITS+3 with sticky right shift. 71 */ 72 rm = (xm >> (DP_FBITS - (SP_FBITS + 3))) | 73 ((xm << (64 - (DP_FBITS - (SP_FBITS + 3)))) != 0); 74 75 return ieee754sp_format(xs, xe, rm); 76 } 77