diff options
Diffstat (limited to 'arch/mips/math-emu/dp_tint.c')
| -rw-r--r-- | arch/mips/math-emu/dp_tint.c | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/arch/mips/math-emu/dp_tint.c b/arch/mips/math-emu/dp_tint.c new file mode 100644 index 000000000000..77b2b7ccf28a --- /dev/null +++ b/arch/mips/math-emu/dp_tint.c @@ -0,0 +1,124 @@ +/* IEEE754 floating point arithmetic + * double precision: common utilities + */ +/* + * 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 "ieee754dp.h" + +int ieee754dp_tint(ieee754dp x) +{ + COMPXDP; + + CLEARCX; + + EXPLODEXDP; + FLUSHXDP; + + switch (xc) { + case IEEE754_CLASS_SNAN: + case IEEE754_CLASS_QNAN: + case IEEE754_CLASS_INF: + SETCX(IEEE754_INVALID_OPERATION); + return ieee754si_xcpt(ieee754si_indef(), "dp_tint", x); + case IEEE754_CLASS_ZERO: + return 0; + case IEEE754_CLASS_DNORM: + case IEEE754_CLASS_NORM: + break; + } + if (xe > 31) { + /* Set invalid. We will only use overflow for floating + point overflow */ + SETCX(IEEE754_INVALID_OPERATION); + return ieee754si_xcpt(ieee754si_indef(), "dp_tint", x); + } + /* oh gawd */ + if (xe > DP_MBITS) { + xm <<= xe - DP_MBITS; + } else if (xe < DP_MBITS) { + u64 residue; + int round; + int sticky; + int odd; + + if (xe < -1) { + residue = xm; + round = 0; + sticky = residue != 0; + xm = 0; + } + else { + residue = xm << (64 - DP_MBITS + xe); + round = (residue >> 63) != 0; + sticky = (residue << 1) != 0; + xm >>= DP_MBITS - xe; + } + /* Note: At this point upper 32 bits of xm are guaranteed + to be zero */ + 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; + } + /* look for valid corner case 0x80000000 */ + if ((xm >> 31) != 0 && (xs == 0 || xm != 0x80000000)) { + /* This can happen after rounding */ + SETCX(IEEE754_INVALID_OPERATION); + return ieee754si_xcpt(ieee754si_indef(), "dp_tint", x); + } + if (round || sticky) + SETCX(IEEE754_INEXACT); + } + if (xs) + return -xm; + else + return xm; +} + + +unsigned int ieee754dp_tuns(ieee754dp x) +{ + ieee754dp hb = ieee754dp_1e31(); + + /* what if x < 0 ?? */ + if (ieee754dp_lt(x, hb)) + return (unsigned) ieee754dp_tint(x); + + return (unsigned) ieee754dp_tint(ieee754dp_sub(x, hb)) | + ((unsigned) 1 << 31); +} |