diff options
Diffstat (limited to 'arch/mips/math-emu/dp_tlong.c')
| -rw-r--r-- | arch/mips/math-emu/dp_tlong.c | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/arch/mips/math-emu/dp_tlong.c b/arch/mips/math-emu/dp_tlong.c new file mode 100644 index 000000000..f941c4dd4 --- /dev/null +++ b/arch/mips/math-emu/dp_tlong.c @@ -0,0 +1,148 @@ +/* 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 <limits.h> +#ifdef __KERNEL__ +#define assert(expr) ((void)0) +#else +#include <assert.h> +#endif +#include <stdarg.h> +#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); +} |