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 30s64 ieee754sp_tlong(ieee754sp x) 31{ 32 COMPXDP; /* <-- need 64-bit mantissa tmp */ 33 34 CLEARCX; 35 36 EXPLODEXSP; 37 FLUSHXSP; 38 39 switch (xc) { 40 case IEEE754_CLASS_SNAN: 41 case IEEE754_CLASS_QNAN: 42 case IEEE754_CLASS_INF: 43 SETCX(IEEE754_INVALID_OPERATION); 44 return ieee754di_xcpt(ieee754di_indef(), "sp_tlong", x); 45 case IEEE754_CLASS_ZERO: 46 return 0; 47 case IEEE754_CLASS_DNORM: 48 case IEEE754_CLASS_NORM: 49 break; 50 } 51 if (xe >= 63) { 52 /* look for valid corner case */ 53 if (xe == 63 && xs && xm == SP_HIDDEN_BIT) 54 return -0x8000000000000000LL; 55 /* Set invalid. We will only use overflow for floating 56 point overflow */ 57 SETCX(IEEE754_INVALID_OPERATION); 58 return ieee754di_xcpt(ieee754di_indef(), "sp_tlong", x); 59 } 60 /* oh gawd */ 61 if (xe > SP_MBITS) { 62 xm <<= xe - SP_MBITS; 63 } else if (xe < SP_MBITS) { 64 u32 residue; 65 int round; 66 int sticky; 67 int odd; 68 69 if (xe < -1) { 70 residue = xm; 71 round = 0; 72 sticky = residue != 0; 73 xm = 0; 74 } else { 75 residue = xm << (32 - SP_MBITS + xe); 76 round = (residue >> 31) != 0; 77 sticky = (residue << 1) != 0; 78 xm >>= SP_MBITS - xe; 79 } 80 odd = (xm & 0x1) != 0x0; 81 switch (ieee754_csr.rm) { 82 case IEEE754_RN: 83 if (round && (sticky || odd)) 84 xm++; 85 break; 86 case IEEE754_RZ: 87 break; 88 case IEEE754_RU: /* toward +Infinity */ 89 if ((round || sticky) && !xs) 90 xm++; 91 break; 92 case IEEE754_RD: /* toward -Infinity */ 93 if ((round || sticky) && xs) 94 xm++; 95 break; 96 } 97 if ((xm >> 63) != 0) { 98 /* This can happen after rounding */ 99 SETCX(IEEE754_INVALID_OPERATION); 100 return ieee754di_xcpt(ieee754di_indef(), "sp_tlong", x); 101 } 102 if (round || sticky) 103 SETCX(IEEE754_INEXACT); 104 } 105 if (xs) 106 return -xm; 107 else 108 return xm; 109} 110 111 112u64 ieee754sp_tulong(ieee754sp x) 113{ 114 ieee754sp hb = ieee754sp_1e63(); 115 116 /* what if x < 0 ?? */ 117 if (ieee754sp_lt(x, hb)) 118 return (u64) ieee754sp_tlong(x); 119 120 return (u64) ieee754sp_tlong(ieee754sp_sub(x, hb)) | 121 (1ULL << 63); 122} 123