diff options
Diffstat (limited to 'kernel/arch/mips/math-emu/dp_flong.c')
-rw-r--r-- | kernel/arch/mips/math-emu/dp_flong.c | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/kernel/arch/mips/math-emu/dp_flong.c b/kernel/arch/mips/math-emu/dp_flong.c new file mode 100644 index 000000000..a267c2e39 --- /dev/null +++ b/kernel/arch/mips/math-emu/dp_flong.c @@ -0,0 +1,65 @@ +/* IEEE754 floating point arithmetic + * double precision: common utilities + */ +/* + * 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 "ieee754dp.h" + +union ieee754dp ieee754dp_flong(s64 x) +{ + u64 xm; + int xe; + int xs; + + ieee754_clearcx(); + + if (x == 0) + return ieee754dp_zero(0); + if (x == 1 || x == -1) + return ieee754dp_one(x < 0); + if (x == 10 || x == -10) + return ieee754dp_ten(x < 0); + + xs = (x < 0); + if (xs) { + if (x == (1ULL << 63)) + xm = (1ULL << 63); /* max neg can't be safely negated */ + else + xm = -x; + } else { + xm = x; + } + + /* normalize */ + xe = DP_FBITS + 3; + if (xm >> (DP_FBITS + 1 + 3)) { + /* shunt out overflow bits */ + while (xm >> (DP_FBITS + 1 + 3)) { + XDPSRSX1(); + } + } else { + /* normalize in grs extended double precision */ + while ((xm >> (DP_FBITS + 3)) == 0) { + xm <<= 1; + xe--; + } + } + + return ieee754dp_format(xs, xe, xm); +} |