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Diffstat (limited to 'sysdeps/libm-ieee754/s_lround.c')
| -rw-r--r-- | sysdeps/libm-ieee754/s_lround.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/sysdeps/libm-ieee754/s_lround.c b/sysdeps/libm-ieee754/s_lround.c new file mode 100644 index 0000000000..0f91280a79 --- /dev/null +++ b/sysdeps/libm-ieee754/s_lround.c @@ -0,0 +1,177 @@ +/* Round long double value to long int. + Copyright (C) 1997 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include <math.h> + +#include "math_private.h" + + +#ifdef NO_LONG_DOUBLE +/* The `long double' is in fact the IEEE `double' type. */ + +long int +__lround (long double x) +{ + int32_t j0; + u_int32_t i1, i0; + long int result; + + EXTRACT_WORDS (i0, i1, x); + j0 = ((i0 >> 20) & 0x7ff) - 0x3ff; + if (j0 < 20) + { + if (j0 < 0) + result = j0 < -1 ? 0 : ((i0 & 0x80000000) ? -1 : 1); + else + { + u_int32_t i = 0xfffff >> j0; + if (((i0 & i) | i1) == 0) + result = (long int) ((i0 & 0xfffff) | 0x100000) >> j0; + else + { + /* X is not integral. */ + u_int32_t j = i0 + (0x80000 >> j0); + if (j < i0) + result = (long int) 0x80000 >> (20 - j0); + else + result = (j | 0x100000) >> (20 - j0); + } + } + } + else if (j0 >= 8 * sizeof (long int) || j0 > 51) + { + /* The number is too large. It is left implementation defined + what happens. */ + result = (long int) x; + } + else + { + u_int32_t i = ((u_int32_t) (0xffffffff)) >> (j0 - 20); + if ((i1 & i) != 0) + { + /* x is not integral. */ + u_int32_t j = i1 + (0x80000000 >> (j0 - 20)); + if (j < i1) + { + j = i0 + 1; + if ((j & 0xfffff) == 0) + { + if (sizeof (long int) <= 4) + /* Overflow. */ + result = (long int) x; + else + result = 1l << (j0 + 1); + } + else + result = (long int) ((i0 & 0xfffff) | 0x100000) << (j0 - 31); + } + else + { + result = (long int) ((i0 & 0xfffff) | 0x100000) << (j0 - 31); + if (sizeof (long int) > 4 && j0 > 31) + result |= j >> (63 - j0); + } + } + else + { + result = (long int) ((i0 & 0xfffff) | 0x100000) << (j0 - 31); + if (sizeof (long int) > 4 && j0 > 31) + result |= i1 >> (63 - j0); + } + } + + return i0 & 0x80000000 ? -result : result; +} +#else +long int +__lround (long double x) +{ + int32_t j0; + u_int32_t se, i1, i0; + long int result; + + GET_LDOUBLE_WORDS (se, i0, i1, x); + j0 = (se & 0x7fff) - 0x3fff; + if (j0 < 31) + { + if (j0 < 0) + result = j0 < -1 ? 0 : 1; + else + { + u_int32_t i = 0x7fffffff >> j0; + if (((i0 & i) | i1) == 0) + result = (long int) i0 >> j0; + else + { + /* X is not integral. */ + u_int32_t j = i0 + (0x40000000 >> j0); + if (j < i0) + result = 0x80000000l >> (30 - j0); + else + result = j >> (31 - j0); + } + } + } + else if ((unsigned int) j0 >= 8 * sizeof (long int) || j0 > 62) + { + /* The number is too large. It is left implementation defined + what happens. */ + result = (long int) x; + } + else + { + u_int32_t i = ((u_int32_t) (0xffffffff)) >> (j0 - 31); + if ((i1 & i) != 0) + { + /* x is not integral. */ + u_int32_t j = i1 + (0x80000000 >> (j0 - 31)); + if (j < i1) + { + j = i0 + 1; + if (j == 0) + { + if (sizeof (long int) <= 4) + /* Overflow. */ + result = (long int) x; + else + result = 1l << (j0 + 1); + } + else + result = (long int) i0 << (j0 - 31); + } + else + { + result = (long int) i0 << (j0 - 31); + if (sizeof (long int) > 4 && j0 > 31) + result |= j >> (63 - j0); + } + } + else + { + result = (long int) i0 << (j0 - 31); + if (sizeof (long int) > 4 && j0 > 31) + result |= i1 >> (63 - j0); + } + } + + return se & 0x8000 ? -result : result; +} +#endif +weak_alias (__lround, lround) |