1/* IEEE754 floating point arithmetic 2 * single precision 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 "ieee754sp.h" 29 30ieee754sp ieee754sp_fdp(ieee754dp x) 31{ 32 COMPXDP; 33 ieee754sp nan; 34 35 EXPLODEXDP; 36 37 CLEARCX; 38 39 FLUSHXDP; 40 41 switch (xc) { 42 case IEEE754_CLASS_SNAN: 43 SETCX(IEEE754_INVALID_OPERATION); 44 return ieee754sp_nanxcpt(ieee754sp_indef(), "fdp"); 45 case IEEE754_CLASS_QNAN: 46 nan = buildsp(xs, SP_EMAX + 1 + SP_EBIAS, (u32) 47 (xm >> (DP_MBITS - SP_MBITS))); 48 if (!ieee754sp_isnan(nan)) 49 nan = ieee754sp_indef(); 50 return ieee754sp_nanxcpt(nan, "fdp", x); 51 case IEEE754_CLASS_INF: 52 return ieee754sp_inf(xs); 53 case IEEE754_CLASS_ZERO: 54 return ieee754sp_zero(xs); 55 case IEEE754_CLASS_DNORM: 56 /* can't possibly be sp representable */ 57 SETCX(IEEE754_UNDERFLOW); 58 SETCX(IEEE754_INEXACT); 59 if ((ieee754_csr.rm == IEEE754_RU && !xs) || 60 (ieee754_csr.rm == IEEE754_RD && xs)) 61 return ieee754sp_xcpt(ieee754sp_mind(xs), "fdp", x); 62 return ieee754sp_xcpt(ieee754sp_zero(xs), "fdp", x); 63 case IEEE754_CLASS_NORM: 64 break; 65 } 66 67 { 68 u32 rm; 69 70 /* convert from DP_MBITS to SP_MBITS+3 with sticky right shift 71 */ 72 rm = (xm >> (DP_MBITS - (SP_MBITS + 3))) | 73 ((xm << (64 - (DP_MBITS - (SP_MBITS + 3)))) != 0); 74 75 SPNORMRET1(xs, xe, rm, "fdp", x); 76 } 77} 78