/* IEEE754 floating point arithmetic * single precision */ /* * MIPS floating point support * Copyright (C) 1994-2000 Algorithmics Ltd. * 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 <linux/kernel.h> #include "ieee754sp.h" int ieee754sp_tint(ieee754sp x) { COMPXSP; CLEARCX; EXPLODEXSP; FLUSHXSP; switch (xc) { case IEEE754_CLASS_SNAN: case IEEE754_CLASS_QNAN: case IEEE754_CLASS_INF: SETCX(IEEE754_INVALID_OPERATION); return ieee754si_xcpt(ieee754si_indef(), "sp_tint", x); case IEEE754_CLASS_ZERO: return 0; case IEEE754_CLASS_DNORM: case IEEE754_CLASS_NORM: break; } if (xe >= 31) { /* look for valid corner case */ if (xe == 31 && xs && xm == SP_HIDDEN_BIT) return -0x80000000; /* Set invalid. We will only use overflow for floating point overflow */ SETCX(IEEE754_INVALID_OPERATION); return ieee754si_xcpt(ieee754si_indef(), "sp_tint", x); } /* oh gawd */ if (xe > SP_MBITS) { xm <<= xe - SP_MBITS; } else { u32 residue; int round; int sticky; int odd; if (xe < -1) { residue = xm; round = 0; sticky = residue != 0; xm = 0; } else { /* Shifting a u32 32 times does not work, * so we do it in two steps. Be aware that xe * may be -1 */ residue = xm << (xe + 1); residue <<= 31 - SP_MBITS; round = (residue >> 31) != 0; sticky = (residue << 1) != 0; xm >>= SP_MBITS - xe; } odd = (xm & 0x1) != 0x0; switch (ieee754_csr.rm) { case IEEE754_RN: if (round && (sticky || odd)) xm++; break; case IEEE754_RZ: break; case IEEE754_RU: /* toward +Infinity */ if ((round || sticky) && !xs) xm++; break; case IEEE754_RD: /* toward -Infinity */ if ((round || sticky) && xs) xm++; break; } if ((xm >> 31) != 0) { /* This can happen after rounding */ SETCX(IEEE754_INVALID_OPERATION); return ieee754si_xcpt(ieee754si_indef(), "sp_tint", x); } if (round || sticky) SETCX(IEEE754_INEXACT); } if (xs) return -xm; else return xm; } unsigned int ieee754sp_tuns(ieee754sp x) { ieee754sp hb = ieee754sp_1e31(); /* what if x < 0 ?? */ if (ieee754sp_lt(x, hb)) return (unsigned) ieee754sp_tint(x); return (unsigned) ieee754sp_tint(ieee754sp_sub(x, hb)) | ((unsigned) 1 << 31); }