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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 | /* IEEE754 floating point arithmetic * double precision: common utilities */ /* * MIPS floating point support * Copyright (C) 1994-2000 Algorithmics Ltd. All rights reserved. * http://www.algor.co.uk * * ######################################################################## * * This program is free software; you can distribute it and/or modify it * under the terms of the GNU General Public License (Version 2) as * published by the Free Software Foundation. * * This program is distributed in the hope it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA. * * ######################################################################## */ #include "ieee754dp.h" long long ieee754dp_tlong(ieee754dp x) { COMPXDP; CLEARCX; EXPLODEXDP; switch (xc) { case IEEE754_CLASS_SNAN: case IEEE754_CLASS_QNAN: SETCX(IEEE754_INVALID_OPERATION); return ieee754di_xcpt(ieee754di_indef(), "dp_tlong", x); case IEEE754_CLASS_INF: SETCX(IEEE754_OVERFLOW); return ieee754di_xcpt(ieee754di_indef(), "dp_tlong", x); case IEEE754_CLASS_ZERO: return 0; case IEEE754_CLASS_DNORM: /* much too small */ SETCX(IEEE754_UNDERFLOW); return ieee754di_xcpt(0, "dp_tlong", x); case IEEE754_CLASS_NORM: break; } if (xe >= 63) { SETCX(IEEE754_OVERFLOW); return ieee754di_xcpt(ieee754di_indef(), "dp_tlong", x); } if (xe < 0) { if (ieee754_csr.rm == IEEE754_RU) { if (xs) { /* Negative */ return 0x0000000000000000LL; } else { /* Positive */ return 0x0000000000000001LL; } } else if (ieee754_csr.rm == IEEE754_RD) { if (xs) { /* Negative , return -1 */ return 0xffffffffffffffffLL; } else { /* Positive */ return 0x0000000000000000LL; } } else { SETCX(IEEE754_UNDERFLOW); return ieee754di_xcpt(0, "dp_tlong", x); } } /* oh gawd */ if (xe > DP_MBITS) { xm <<= xe - DP_MBITS; } else if (xe < DP_MBITS) { unsigned long long residue; unsigned long long mask = 0; int i; int round; int sticky; int odd; /* compute mask */ for (i = 0; i < DP_MBITS - xe; i++) { mask = mask << 1; mask = mask | 0x1; } residue = (xm & mask) << (64 - (DP_MBITS - xe)); round = ((0x8000000000000000LL & residue) != 0x0000000000000000LL); sticky = ((0x7fffffffffffffffLL & residue) != 0x0000000000000000LL); xm >>= DP_MBITS - xe; odd = ((xm & 0x1) != 0x0000000000000000LL); /* Do the rounding */ if (!round && sticky) { if ((ieee754_csr.rm == IEEE754_RU && !xs) || (ieee754_csr.rm == IEEE754_RD && xs)) { xm++; } } else if (round && !sticky) { if ((ieee754_csr.rm == IEEE754_RU && !xs) || (ieee754_csr.rm == IEEE754_RD && xs) || (ieee754_csr.rm == IEEE754_RN && odd)) { xm++; } } else if (round && sticky) { if ((ieee754_csr.rm == IEEE754_RU && !xs) || (ieee754_csr.rm == IEEE754_RD && xs) || (ieee754_csr.rm == IEEE754_RN)) { xm++; } } } if (xs) return -xm; else return xm; } unsigned long long ieee754dp_tulong(ieee754dp x) { ieee754dp hb = ieee754dp_1e63(); /* what if x < 0 ?? */ if (ieee754dp_lt(x, hb)) return (unsigned long long) ieee754dp_tlong(x); return (unsigned long long) ieee754dp_tlong(ieee754dp_sub(x, hb)) | (1ULL << 63); } |