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Diffstat (limited to 'sysdeps/libm-ieee754/s_lrint.c')
| -rw-r--r-- | sysdeps/libm-ieee754/s_lrint.c | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/sysdeps/libm-ieee754/s_lrint.c b/sysdeps/libm-ieee754/s_lrint.c new file mode 100644 index 0000000000..6779f974bd --- /dev/null +++ b/sysdeps/libm-ieee754/s_lrint.c @@ -0,0 +1,242 @@ +/* Round argument to nearest integral value according to current rounding + direction. + 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. */ +static long double two52[2] = +{ + 4.50359962737049600000e+15, /* 0x43300000, 0x00000000 */ + -4.50359962737049600000e+15, /* 0xC3300000, 0x00000000 */ +}; + + +long int +__lrint (long double x) +{ + int32_t j0,sx; + u_int32_t i0,i1,i; + long double t, w; + long int result; + + EXTRACT_WORDS (i0, i1, x); + + sx = i0 >> 31; + j0 = ((i0 >> 20) & 0x7ff) - 0x3ff; + + if (j0 < 20) + { + if (j0 < 0) + { + if (((i0 & 0x7fffffff) | i1) == 0) + /* The number is 0. */ + result = 0; + else + { + i1 |= i0; + i0 &= 0xfffe0000; + i0 |= ((i1 | -i1) >> 12) & 0x80000; + SET_HIGH_WORD (x, i0); + w = two52[sx] + x; + t = w - two52[sx]; + GET_HIGH_WORD (i0, t); + if ((i0 & 0x7fffffff) >= 0x3fff0000) + result = sx ? -1 : 1; + else + result = 0; + } + } + else + { + u_int32_t i = 0x000fffff >> j0; + if (((i0 & i) | i1) == 0) + { + /* X is not integral. */ + i >>= 1; + if (((i0 & i) | i1) != 0) + { + if (j0 == 19) + i1 = 0x40000000; + else + i0 = (i0 & (~i)) | (0x20000 >> j0); + + INSERT_WORDS (x, i0, i1); + w = two52[sx] + x; + x = w - two52[sx]; + EXTRACT_WORDS (i0, i1, x); + + j0 = ((i0 >> 20) & 0x7ff) - 0x3ff; + } + } + + result = ((i0 >> (20 - j0)) & 0xfffff) | (0x00100000 >> (20 - j0)); + if (sx) + result = -result; + } + } + else if ((unsigned int) j0 < sizeof (long int) * 8 && j0 < 53) + { + i = ((u_int32_t) (0xffffffff)) >> (j0 - 20); + if ((i1 & i) != 0) + { + /* x is not integral. */ + i >>= 1; + if ((i1 & i) != 0) + i1 = (i1 & (~i)) | (0x40000000 >> (j0 - 20)); + } + + INSERT_WORDS (x, i0, i1); + w = two52[sx] + x; + x = w - two52[sx]; + EXTRACT_WORDS (i0, i1, x); + + j0 = ((i0 >> 20) & 0x7ff) - 0x3ff; + + result = i0 | 0x00100000; + if (j0 > 20) + { + result <<= j0 - 20; + result |= i1 >> (52 - j0); + } + if (sx) + result = -result; + } + else + /* Too large. The number is either +-inf or NaN or it is too + large to be effected by rounding. The standard leaves it + undefined what to return when the number is too large to fit in + a `long int'. */ + result = (long int) x; + + return result; +} + +#else +static long double two63[2] = +{ + 9.223372036854775808000000e+18, /* 0x403E, 0x00000000, 0x00000000 */ + -9.223372036854775808000000e+18 /* 0xC03E, 0x00000000, 0x00000000 */ +}; + + +long int +__lrint (long double x) +{ + int32_t se,j0,sx; + u_int32_t i0,i1,i; + long int result; + long double w, t; + + GET_LDOUBLE_WORDS (se, i0, i1, x); + + sx = (se >> 15) & 1; + j0 = (se & 0x7fff) - 0x3fff; + + if (j0 < 31) + { + if (j0 < 0) + { + if (((se & 0x7fff) | i0 | i1) == 0) + /* The number is 0. */ + result = 0; + else + { + i1 |= i0; + i0 &= 0xe0000000; + i0 |= (i1 | -i1) & 0x80000000; + SET_LDOUBLE_MSW (x, i0); + w = two63[sx] + x; + t = w - two63[sx]; + GET_LDOUBLE_EXP (i0, t); + if ((i0 & 0x7fff) >= 0x3fff) + result = sx ? -1 : 1; + else + result = 0; + } + } + else + { + u_int32_t i = 0x7fffffff >> j0; + if (((i0 & i) | i1) == 0) + { + /* X is not integral. */ + i >>= 1; + if (((i0 & i) | i1) != 0) + { + if (j0 == 31) + i1 = 0x40000000; + else + i0 = (i0 & (~i)) | (0x20000000 >> j0); + + SET_LDOUBLE_WORDS (x, se, i0, i1); + w = two63[sx] + x; + x = w - two63[sx]; + GET_LDOUBLE_WORDS (se, i0, i1, x); + + sx = (se >> 15) & 1; + j0 = (se & 0x7fff) - 0x3fff; + } + } + + + result = i0 >> (31 - j0); + } + } + else if ((unsigned int) j0 < sizeof (long int) * 8 && j0 < 64) + { + i = ((u_int32_t) (0xffffffff)) >> (j0 - 31); + if ((i1 & i) != 0) + { + /* x is not integral. */ + i >>= 1; + if ((i1 & i) != 0) + i1 = (i1 & (~i)) | (0x40000000 >> (j0 - 31)); + } + + SET_LDOUBLE_WORDS (x, se, i0, i1); + w = two63[sx] + x; + x = w - two63[sx]; + GET_LDOUBLE_WORDS (se, i0, i1, x); + + j0 = (se & 0x7fff) - 0x3fff; + + result = i0; + if (j0 > 31) + { + result <<= j0 - 31; + result |= i1 >> (63 - j0); + } + } + else + /* Too large. The number is either +-inf or NaN or it is too + large to be effected by rounding. The standard leaves it + undefined what to return when the number is too large to fit in + a `long int'. */ + result = (long int) x; + + return result; +} +#endif + +weak_alias (__lrint, lrint) |