1 /* Truncate argument to nearest integral value not larger than the argument.
2 Copyright (C) 1997, 1999 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997 and
5 Jakub Jelinek <jj@ultra.linux.cz>, 1999.
7 The GNU C Library is free software; you can redistribute it and/or
8 modify it under the terms of the GNU Lesser General Public
9 License as published by the Free Software Foundation; either
10 version 2.1 of the License, or (at your option) any later version.
12 The GNU C Library is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 Lesser General Public License for more details.
17 You should have received a copy of the GNU Lesser General Public
18 License along with the GNU C Library; if not, write to the Free
19 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
24 /* On Cygwin it should be little endian. */
25 #define __FLOAT_WORD_ORDER LITTLE_ENDIAN
27 /* A union which permits us to convert between a long double and
28 four 32 bit ints or two 64 bit ints. */
30 #if __FLOAT_WORD_ORDER == BIG_ENDIAN
42 u_int32_t w0, w1, w2, w3;
44 } ieee854_long_double_shape_type;
48 #if __FLOAT_WORD_ORDER == LITTLE_ENDIAN
60 u_int32_t w3, w2, w1, w0;
62 } ieee854_long_double_shape_type;
66 /* Get two 64 bit ints from a long double. */
68 #define GET_LDOUBLE_WORDS64(ix0,ix1,d) \
70 ieee854_long_double_shape_type qw_u; \
72 (ix0) = qw_u.parts64.msw; \
73 (ix1) = qw_u.parts64.lsw; \
76 /* Set a long double from two 64 bit ints. */
78 #define SET_LDOUBLE_WORDS64(d,ix0,ix1) \
80 ieee854_long_double_shape_type qw_u; \
81 qw_u.parts64.msw = (ix0); \
82 qw_u.parts64.lsw = (ix1); \
87 static long double truncl(long double x)
92 GET_LDOUBLE_WORDS64 (i0, i1, x);
93 sx = i0 & 0x8000000000000000ULL;
94 j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
98 /* The magnitude of the number is < 1 so the result is +-0. */
99 SET_LDOUBLE_WORDS64 (x, sx, 0);
101 SET_LDOUBLE_WORDS64 (x, i0 & ~(0x0000ffffffffffffLL >> j0), 0);
106 /* x is inf or NaN. */
111 SET_LDOUBLE_WORDS64 (x, i0, i1 & ~(0xffffffffffffffffULL >> (j0 - 48)));