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 | /* IEEE754 floating point arithmetic * single precision */ /* * MIPS floating point support * Copyright (C) 1994-2000 Algorithmics Ltd. * * 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., * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. */ #include "ieee754sp.h" #include "ieee754dp.h" s64 ieee754sp_tlong(union ieee754sp x) { u32 residue; int round; int sticky; int odd; COMPXDP; /* <-- need 64-bit mantissa tmp */ ieee754_clearcx(); EXPLODEXSP; FLUSHXSP; switch (xc) { case IEEE754_CLASS_SNAN: case IEEE754_CLASS_QNAN: ieee754_setcx(IEEE754_INVALID_OPERATION); return ieee754di_indef(); case IEEE754_CLASS_INF: ieee754_setcx(IEEE754_INVALID_OPERATION); return ieee754di_overflow(xs); case IEEE754_CLASS_ZERO: return 0; case IEEE754_CLASS_DNORM: case IEEE754_CLASS_NORM: break; } if (xe >= 63) { /* look for valid corner case */ if (xe == 63 && xs && xm == SP_HIDDEN_BIT) return -0x8000000000000000LL; /* Set invalid. We will only use overflow for floating point overflow */ ieee754_setcx(IEEE754_INVALID_OPERATION); return ieee754di_overflow(xs); } /* oh gawd */ if (xe > SP_FBITS) { xm <<= xe - SP_FBITS; } else if (xe < SP_FBITS) { if (xe < -1) { residue = xm; round = 0; sticky = residue != 0; xm = 0; } else { residue = xm << (32 - SP_FBITS + xe); round = (residue >> 31) != 0; sticky = (residue << 1) != 0; xm >>= SP_FBITS - xe; } odd = (xm & 0x1) != 0x0; switch (ieee754_csr.rm) { case FPU_CSR_RN: if (round && (sticky || odd)) xm++; break; case FPU_CSR_RZ: break; case FPU_CSR_RU: /* toward +Infinity */ if ((round || sticky) && !xs) xm++; break; case FPU_CSR_RD: /* toward -Infinity */ if ((round || sticky) && xs) xm++; break; } if ((xm >> 63) != 0) { /* This can happen after rounding */ ieee754_setcx(IEEE754_INVALID_OPERATION); return ieee754di_overflow(xs); } if (round || sticky) ieee754_setcx(IEEE754_INEXACT); } if (xs) return -xm; else return xm; } |